/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.util.tester;

import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.fail;

import java.io.IOException;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.nio.charset.Charset;
import java.text.ParseException;
import java.time.Duration;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.UUID;
import java.util.regex.Pattern;

import org.apache.wicket.Application;
import org.apache.wicket.Component;
import org.apache.wicket.IPageManagerProvider;
import org.apache.wicket.IPageRendererProvider;
import org.apache.wicket.IRequestCycleProvider;
import org.apache.wicket.IRequestListener;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.Page;
import org.apache.wicket.Session;
import org.apache.wicket.ThreadContext;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.ajax.AbstractAjaxTimerBehavior;
import org.apache.wicket.ajax.AbstractDefaultAjaxBehavior;
import org.apache.wicket.ajax.AjaxEventBehavior;
import org.apache.wicket.ajax.form.AjaxFormSubmitBehavior;
import org.apache.wicket.ajax.markup.html.AjaxFallbackLink;
import org.apache.wicket.ajax.markup.html.AjaxLink;
import org.apache.wicket.ajax.markup.html.IAjaxLink;
import org.apache.wicket.ajax.markup.html.form.AjaxSubmitLink;
import org.apache.wicket.behavior.AbstractAjaxBehavior;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.core.request.handler.BookmarkableListenerRequestHandler;
import org.apache.wicket.core.request.handler.BookmarkablePageRequestHandler;
import org.apache.wicket.core.request.handler.IPageProvider;
import org.apache.wicket.core.request.handler.ListenerRequestHandler;
import org.apache.wicket.core.request.handler.PageAndComponentProvider;
import org.apache.wicket.core.request.handler.PageProvider;
import org.apache.wicket.core.request.handler.RenderPageRequestHandler;
import org.apache.wicket.feedback.ExactLevelFeedbackMessageFilter;
import org.apache.wicket.feedback.FeedbackCollector;
import org.apache.wicket.feedback.FeedbackMessage;
import org.apache.wicket.feedback.IFeedbackMessageFilter;
import org.apache.wicket.markup.ContainerInfo;
import org.apache.wicket.markup.IMarkupFragment;
import org.apache.wicket.markup.Markup;
import org.apache.wicket.markup.MarkupParser;
import org.apache.wicket.markup.MarkupResourceStream;
import org.apache.wicket.markup.html.WebPage;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.markup.html.form.FormComponent;
import org.apache.wicket.markup.html.form.SubmitLink;
import org.apache.wicket.markup.html.internal.Enclosure;
import org.apache.wicket.markup.html.link.AbstractLink;
import org.apache.wicket.markup.html.link.BookmarkablePageLink;
import org.apache.wicket.markup.html.link.ExternalLink;
import org.apache.wicket.markup.html.link.Link;
import org.apache.wicket.markup.html.link.ResourceLink;
import org.apache.wicket.markup.parser.XmlPullParser;
import org.apache.wicket.markup.parser.XmlTag;
import org.apache.wicket.mock.MockApplication;
import org.apache.wicket.mock.MockPageManager;
import org.apache.wicket.mock.MockRequestParameters;
import org.apache.wicket.model.PropertyModel;
import org.apache.wicket.page.IPageManager;
import org.apache.wicket.protocol.http.AjaxEnclosureListener;
import org.apache.wicket.protocol.http.IMetaDataBufferingWebResponse;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.protocol.http.WicketFilter;
import org.apache.wicket.protocol.http.mock.CookieCollection;
import org.apache.wicket.protocol.http.mock.MockHttpServletRequest;
import org.apache.wicket.protocol.http.mock.MockHttpServletResponse;
import org.apache.wicket.protocol.http.mock.MockHttpSession;
import org.apache.wicket.protocol.http.mock.MockServletContext;
import org.apache.wicket.protocol.http.servlet.ServletWebRequest;
import org.apache.wicket.protocol.http.servlet.ServletWebResponse;
import org.apache.wicket.request.IExceptionMapper;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.IRequestMapper;
import org.apache.wicket.request.Request;
import org.apache.wicket.request.Response;
import org.apache.wicket.request.Url;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.cycle.RequestCycleContext;
import org.apache.wicket.request.handler.render.PageRenderer;
import org.apache.wicket.request.handler.resource.ResourceReferenceRequestHandler;
import org.apache.wicket.request.http.WebRequest;
import org.apache.wicket.request.http.WebResponse;
import org.apache.wicket.request.mapper.IRequestMapperDelegate;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.apache.wicket.request.resource.IResource;
import org.apache.wicket.request.resource.ResourceReference;
import org.apache.wicket.settings.RequestCycleSettings.RenderStrategy;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.lang.Classes;
import org.apache.wicket.util.lang.Generics;
import org.apache.wicket.util.resource.StringResourceStream;
import org.apache.wicket.util.string.Strings;
import org.apache.wicket.util.visit.IVisit;
import org.apache.wicket.util.visit.IVisitor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jakarta.servlet.FilterConfig;
import jakarta.servlet.ServletContext;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpSession;

/**
 * A helper class to ease unit testing of Wicket applications without the need for a servlet
 * container. See javadoc of <code>WicketTester</code> for example usage. This class can be used as
 * is, but JUnit users should use derived class <code>WicketTester</code>.
 *
 * @see WicketTester
 *
 * @author Ingram Chen
 * @author Juergen Donnerstag
 * @author Frank Bille
 * @author Igor Vaynberg
 *
 * @since 1.2.6
 */
@SuppressWarnings("serial")
public class BaseWicketTester
{
        /** log. */
        private static final Logger log = LoggerFactory.getLogger(BaseWicketTester.class);

        private final ServletContext servletContext;
        private final WebApplication application;
        private final List<MockHttpServletRequest> previousRequests = Generics.newArrayList();
        private final List<MockHttpServletResponse> previousResponses = Generics.newArrayList();
        private MockHttpSession httpSession;
        private boolean followRedirects = true;
        private int redirectCount;
        private MockHttpServletRequest lastRequest;
        private MockHttpServletResponse lastResponse;
        /** current request and response */
        private MockHttpServletRequest request;
        private MockHttpServletResponse response;

        /** current session */
        private Session session;

        /** current request cycle */
        private RequestCycle requestCycle;

        private Page lastRenderedPage;

        private boolean exposeExceptions = true;

        private boolean useRequestUrlAsBase = true;

        private IRequestHandler forcedHandler;

        private IFeedbackMessageFilter originalFeedbackMessageCleanupFilter;

        private ComponentInPage componentInPage;

        // User may provide request header value any time. They get applied (and reset) upon next
        // invocation of processRequest()
        private Map<String, String> preHeader;

        /**
         * Creates <code>WicketTester</code> and automatically create a <code>WebApplication</code>, but
         * the tester will have no home page.
         */
        public BaseWicketTester()
        {
                this(new MockApplication());
        }

        /**
         * Creates <code>WicketTester</code> and automatically creates a <code>WebApplication</code>.
         *
         * @param <C>
         * @param homePage
         *            a home page <code>Class</code>
         */
        public <C extends Page> BaseWicketTester(final Class<C> homePage)
        {
                this(new MockApplication()
                {
                        @Override
                        public Class<? extends Page> getHomePage()
                        {
                                return homePage;
                        }
                });
        }

        /**
         * Creates a <code>WicketTester</code>.
         *
         * @param application
         *            a <code>WicketTester</code> <code>WebApplication</code> object
         */
        public BaseWicketTester(final WebApplication application)
        {
                this(application, (MockServletContext)null);
        }

        /**
         * Creates a <code>WicketTester</code>.
         *
         * @param application
         *            a <code>WicketTester</code> <code>WebApplication</code> object
         * @param servletContextBasePath
         *            the absolute path on disk to the web application's contents (e.g. war root) - may
         *            be <code>null</code>
         */
        public BaseWicketTester(final WebApplication application, String servletContextBasePath)
        {
                this(application, new MockServletContext(application, servletContextBasePath));
        }

        /**
         * Creates a <code>WicketTester</code>.
         *
         * @param application
         *            a <code>WicketTester</code> <code>WebApplication</code> object
         * @param servletCtx
         *            the servlet context used as backend
         */
        public BaseWicketTester(final WebApplication application, final ServletContext servletCtx)
        {
                this(application, servletCtx, true);
        }

        /**
         * Creates a <code>WicketTester</code>.
         *
         * @param application
         *            a <code>WicketTester</code> <code>WebApplication</code> object
         * @param init
         *            force the application to be initialized (default = true)
         */
        public BaseWicketTester(final WebApplication application, boolean init)
        {
                this(application, null, init);
        }

        /**
         * Creates a <code>WicketTester</code>.
         *
         * @param application
         *            a <code>WicketTester</code> <code>WebApplication</code> object
         * @param servletCtx
         *            the servlet context used as backend
         * @param init
         *            force the application to be initialized (default = true)
         */
        public BaseWicketTester(final WebApplication application, final ServletContext servletCtx,
                boolean init)
        {
                if (!init)
                {
                        Args.notNull(application, "application");
                }

                servletContext = servletCtx != null
                        ? servletCtx
                        // If it's provided from the container it's not necessary to mock.
                        : !init && application.getServletContext() != null
                                ? application.getServletContext()
                                : new MockServletContext(application, null);

                // If using Arquillian and it's configured in a web.xml it'll be provided. If not, mock it.
                if (application.getWicketFilter() == null)
                {
                        final FilterConfig filterConfig = new TestFilterConfig();
                        WicketFilter filter = new WicketFilter()
                        {
                                @Override
                                public FilterConfig getFilterConfig()
                                {
                                        return filterConfig;
                                }
                        };
                        application.setWicketFilter(filter);
                }

                httpSession = new MockHttpSession(servletContext);

                ThreadContext.detach();

                this.application = application;

                ThreadContext.setApplication(application);

                if (init)
                {
                        if (application.getName() == null)
                        {
                                application.setName("WicketTesterApplication-" + UUID.randomUUID());
                        }

                        application.setServletContext(servletContext);
                        // initialize the application
                        application.initApplication();
                }

                // We don't expect any changes during testing. In addition we avoid creating
                // ModificationWatcher threads tests.
                application.getResourceSettings().setResourcePollFrequency(getResourcePollFrequency());

                // reconfigure application for the test environment
                application.setPageRendererProvider(
                        new LastPageRecordingPageRendererProvider(application.getPageRendererProvider()));
                application.setRequestCycleProvider(
                        new TestRequestCycleProvider(application.getRequestCycleProvider()));

                // set a feedback message filter that will not remove any messages
                originalFeedbackMessageCleanupFilter = application.getApplicationSettings()
                        .getFeedbackMessageCleanupFilter();
                application.getApplicationSettings()
                        .setFeedbackMessageCleanupFilter(IFeedbackMessageFilter.NONE);
                IPageManagerProvider pageManagerProvider = newTestPageManagerProvider();
                if (pageManagerProvider != null)
                {
                        application.setPageManagerProvider(pageManagerProvider);
                }

                // create a new session when the old one is invalidated
                application.getSessionStore().registerUnboundListener(sessionId -> newSession());

                // prepare session
                setupNextRequestCycle();
        }

        /**
         * By default Modification Watcher is disabled by default for the tests.
         *
         * @return the duration between two checks for changes in the resources
         */
        protected Duration getResourcePollFrequency()
        {
                return null;
        }

        /**
         *
         * @return page manager provider
         */
        protected IPageManagerProvider newTestPageManagerProvider()
        {
                return new TestPageManagerProvider();
        }

        /**
         * @return last rendered page
         */
        public Page getLastRenderedPage()
        {
                return lastRenderedPage;
        }

        private void setupNextRequestCycle()
        {
                request = new MockHttpServletRequest(application, httpSession, servletContext,
                        servletRequestLocale());
                request.setURL(request.getContextPath() + request.getServletPath() + "/");

                // assign protocol://host:port to next request unless the last request was ajax
                final boolean assignBaseLocation = lastRequest != null
                        && lastRequest.getHeader("Wicket-Ajax") == null;

                // resume request processing with scheme://host:port from last request
                if (assignBaseLocation)
                {
                        request.setScheme(lastRequest.getScheme());
                        request.setSecure(lastRequest.isSecure());
                        request.setServerName(lastRequest.getServerName());
                        request.setServerPort(lastRequest.getServerPort());
                }

                response = new MockHttpServletResponse(request);

                // Preserve response cookies in redirects
                // XXX: is this really needed ? Browsers wont do that, but some
                // Wicket tests assert that a cookie is in the response,
                // even after redirects (see
                // org.apache.wicket.util.cookies.SetCookieAndRedirectTest.statefulPage())
                // They should assert that the cookie is in the next *request*
                if (lastResponse != null)
                {
                        List<Cookie> lastResponseCookies = lastResponse.getCookies();
                        if (lastResponse.isRedirect())
                        {
                                CookieCollection responseCookies = new CookieCollection();

                                // if the last request is a redirect, all cookies from last response should appear
                                // in current response
                                // this call will filter duplicates
                                responseCookies.addAll(lastResponseCookies);
                                for (Cookie cookie : responseCookies.allAsList())
                                {
                                        response.addCookie(cookie);
                                }

                                // copy all request cookies from last request to the new request because of redirect
                                // handling this way, the cookie will be send to the next requested page
                                if (lastRequest != null)
                                {
                                        CookieCollection requestCookies = new CookieCollection();
                                        // this call will filter duplicates
                                        requestCookies.addAll(lastRequest.getCookies());
                                        request.addCookies(requestCookies.asList());
                                }
                        }
                        else
                        {
                                // if the last response is not a redirect
                                // - copy last request cookies to collection
                                // - copy last response cookies to collection
                                // - set only the not expired cookies to the next request
                                CookieCollection cookies = new CookieCollection();
                                if (lastRequest != null)
                                {
                                        // this call will filter duplicates
                                        cookies.addAll(lastRequest.getCookies());
                                }
                                // this call will filter duplicates
                                cookies.addAll(lastResponseCookies);
                                request.addCookies(cookies.asList());
                        }
                }

                ServletWebRequest servletWebRequest = newServletWebRequest();
                requestCycle = application.createRequestCycle(servletWebRequest,
                        newServletWebResponse(servletWebRequest));
                ThreadContext.setRequestCycle(requestCycle);

                if (session == null)
                {
                        newSession();
                }
        }

        protected Locale servletRequestLocale()
        {
                return Locale.getDefault();
        }

        /**
         * Cleans up feedback messages. This usually happens on detach, but is disabled in unit testing
         * so feedback messages can be examined.
         */
        public void cleanupFeedbackMessages()
        {
                cleanupFeedbackMessages(originalFeedbackMessageCleanupFilter);
        }

        /**
         * Removes all feedback messages
         */
        public void clearFeedbackMessages()
        {
                cleanupFeedbackMessages(IFeedbackMessageFilter.ALL);
        }

        /**
         * Cleans up feedback messages given the specified filter.
         *
         * @param filter
         *            filter used to cleanup messages, accepted messages will be removed
         */
        protected void cleanupFeedbackMessages(IFeedbackMessageFilter filter)
        {

                IVisitor<Component, Void> clearer = new IVisitor<Component, Void>()
                {
                        @Override
                        public void component(Component component, IVisit<Void> visit)
                        {
                                if (component.hasFeedbackMessage())
                                {
                                        component.getFeedbackMessages().clear(filter);
                                }
                        }
                };
                clearer.component(getLastRenderedPage(), null);
                getLastRenderedPage().visitChildren(clearer);

                getSession().getFeedbackMessages().clear(filter);
        }

        /**
         * @param servletWebRequest
         * @return servlet web response
         */
        protected Response newServletWebResponse(final ServletWebRequest servletWebRequest)
        {
                return new WicketTesterServletWebResponse(servletWebRequest, response);
        }

        /**
         * @return the configured in the user's application web request
         */
        private ServletWebRequest newServletWebRequest()
        {
                return (ServletWebRequest)application.newWebRequest(request, request.getFilterPrefix());
        }

        /**
         *
         */
        private void newSession()
        {
                ThreadContext.setSession(null);

                // the following will create a new session and put it in the thread context
                session = Session.get();
        }

        /**
         * @return request object
         */
        public MockHttpServletRequest getRequest()
        {
                return request;
        }

        /**
         * @param request
         */
        public void setRequest(final MockHttpServletRequest request)
        {
                this.request = request;
                applyRequest();
        }

        /**
         * @param response
         */
        public void setLastResponse(final MockHttpServletResponse response)
        {
                this.lastResponse = response;
        }

        /**
         * @return session
         */
        public Session getSession()
        {
                return session;
        }

        /**
         * Returns {@link HttpSession} for this environment
         *
         * @return session
         */
        public MockHttpSession getHttpSession()
        {
                return httpSession;
        }

        /**
         * Returns the {@link Application} for this environment.
         *
         * @return application
         */
        public WebApplication getApplication()
        {
                return application;
        }

        /**
         * Returns the {@link ServletContext} for this environment
         *
         * @return servlet context
         */
        public ServletContext getServletContext()
        {
                return servletContext;
        }

        /**
         * Destroys the tester. Restores {@link ThreadContext} to state before instance of
         * {@link WicketTester} was created.
         */
        public void destroy()
        {
                try
                {
                        ThreadContext.setApplication(application);
                        application.internalDestroy();
                }
                finally
                {
                        ThreadContext.detach();
                }
        }

        /**
         * @return true, if process was executed successfully
         */
        public boolean processRequest()
        {
                return processRequest(null, null);
        }

        /**
         * Processes the request in mocked Wicket environment.
         *
         * @param request
         *            request to process
         * @return true, if process was executed successfully
         */
        public boolean processRequest(final MockHttpServletRequest request)
        {
                return processRequest(request, null);
        }

        /**
         * Processes the request in mocked Wicket environment.
         *
         * @param request
         *            request to process
         * @param forcedRequestHandler
         *            optional parameter to override parsing the request URL and force
         *            {@link IRequestHandler}
         * @return true, if process was executed successfully
         */
        public boolean processRequest(final MockHttpServletRequest request,
                final IRequestHandler forcedRequestHandler)
        {
                return processRequest(request, forcedRequestHandler, false);
        }

        /**
         * @param forcedRequestHandler
         * @return true, if process was executed successfully
         */
        public boolean processRequest(final IRequestHandler forcedRequestHandler)
        {
                return processRequest(null, forcedRequestHandler, false);
        }

        /**
         * Process the request. This is a fairly central function and is almost always invoked for
         * executing the request.
         * <p>
         * You may subclass processRequest it, to monitor or change any pre-configured value. Request
         * headers can be configured more easily by calling {@link #addRequestHeader(String, String)}.
         *
         * @param forcedRequest
         *            Can be null.
         * @param forcedRequestHandler
         *            Can be null.
         * @param redirect
         * @return true, if process was executed successfully
         */
        protected boolean processRequest(final MockHttpServletRequest forcedRequest,
                final IRequestHandler forcedRequestHandler, final boolean redirect)
        {
                if (forcedRequest != null)
                {
                        request = forcedRequest;
                }

                forcedHandler = forcedRequestHandler;

                if (!redirect && getRequest().getHeader("Wicket-Ajax") == null)
                {
                        lastRenderedPage = null;
                }

                // Add or replace any system provided header entry with the user provided.
                if ((request != null) && (preHeader != null))
                {
                        for (Map.Entry<String, String> entry : preHeader.entrySet())
                        {
                                if (Strings.isEmpty(entry.getKey()) == false)
                                {
                                        request.setHeader(entry.getKey(), entry.getValue());
                                }
                        }

                        // Reset the user provided headers
                        preHeader = null;
                }

                applyRequest();
                requestCycle.scheduleRequestHandlerAfterCurrent(null);

                try
                {
                        if (!requestCycle.processRequestAndDetach())
                        {
                                return false;
                        }
                }
                finally
                {
                        recordRequestResponse();
                        setupNextRequestCycle();
                }

                try
                {
                        if (isFollowRedirects() && lastResponse.isRedirect())
                        {
                                if (redirectCount++ >= 100)
                                {
                                        throw new AssertionError("Possible infinite redirect detected. Bailing out.");
                                }

                                Url newUrl = Url.parse(lastResponse.getRedirectLocation(),
                                        Charset.forName(request.getCharacterEncoding()));

                                if (isExternalRedirect(lastRequest.getUrl(), newUrl))
                                {
                                        // we can't handle external redirects here
                                        // just bail out here and let the user's test code
                                        // check #assertRedirectUrl
                                        return true;
                                }

                                if (newUrl.isFull() || newUrl.isContextAbsolute())
                                {
                                        request.setUrl(newUrl);

                                        final String protocol = newUrl.getProtocol();

                                        if (protocol != null)
                                        {
                                                request.setScheme(protocol);
                                        }

                                        request.setSecure("https".equals(protocol));

                                        if (newUrl.getHost() != null)
                                        {
                                                request.setServerName(newUrl.getHost());
                                        }
                                        if (newUrl.getPort() != null)
                                        {
                                                request.setServerPort(newUrl.getPort());
                                        }
                                }
                                else
                                {
                                        // append redirect URL to current URL (what browser would do)
                                        Url mergedURL = new Url(lastRequest.getUrl().getSegments(),
                                                newUrl.getQueryParameters());
                                        mergedURL.concatSegments(newUrl.getSegments());

                                        request.setUrl(mergedURL);
                                }

                                processRequest(null, null, true);

                                --redirectCount;
                        }

                        return true;
                }
                finally
                {
                        redirectCount = 0;
                }
        }

        /**
         * Determine whether a given response contains a redirect leading to an external site (which
         * cannot be replicated in WicketTester). This is done by comparing the previous request's
         * hostname with the hostname given in the redirect.
         *
         * @param requestUrl
         *            request...
         * @param newUrl
         *            ...and the redirect generated in its response
         * @return true if there is a redirect and it is external, false otherwise
         */
        private boolean isExternalRedirect(Url requestUrl, Url newUrl)
        {
                String originalHost = requestUrl.getHost();
                String redirectHost = newUrl.getHost();
                Integer originalPort = requestUrl.getPort();
                Integer newPort = newUrl.getPort();

                if (originalHost.equals(redirectHost))
                {
                        return false; // identical or both null
                }
                else if (redirectHost == null)
                {
                        return false; // no new host
                }
                else if (originalPort.equals(newPort) == false)
                {
                        return true;
                }
                else
                {
                        return !(redirectHost.equals(originalHost));
                }
        }

        /**
         * Allows to set Request header value any time. They'll be applied (add/modify) on process
         * execution {@link #processRequest(MockHttpServletRequest, IRequestHandler, boolean)}. They are
         * reset immediately after and thus are not re-used for a sequence of requests.
         * <p>
         * Deletion (not replace) of pre-configured header value can be achieved by subclassing
         * {@link #processRequest(MockHttpServletRequest, IRequestHandler, boolean)} and modifying the
         * request header directly.
         *
         * @param key
         * @param value
         */
        public final void addRequestHeader(final String key, final String value)
        {
                Args.notEmpty(key, "key");

                if (preHeader == null)
                {
                        preHeader = Generics.newHashMap();
                }

                preHeader.put(key, value);
        }

        private void recordRequestResponse()
        {
                lastRequest = request;
                setLastResponse(response);

                previousRequests.add(request);
                previousResponses.add(response);
        }

        /**
         * Renders the page specified by given {@link IPageProvider}. After render the page instance can
         * be retrieved using {@link #getLastRenderedPage()} and the rendered document will be available
         * in {@link #getLastResponse()}.
         *
         * Depending on {@link RenderStrategy} invoking this method can mean that a redirect will happen
         * before the actual render.
         *
         * @param pageProvider
         * @return last rendered page
         */
        public Page startPage(final IPageProvider pageProvider)
        {
                // should be null for Pages
                componentInPage = null;

                // prepare request
                request.setURL(request.getContextPath() + request.getServletPath() + "/");
                IRequestHandler handler = new RenderPageRequestHandler(pageProvider);

                // process request
                processRequest(request, handler);

                // The page rendered
                return getLastRenderedPage();
        }

        /**
         * Renders the page.
         *
         * @see #startPage(IPageProvider)
         *
         * @param page
         * @return Page
         */
        @SuppressWarnings("unchecked")
        public <T extends Page> T startPage(final T page)
        {
                return (T)startPage(new PageProvider(page));
        }

        /**
         * Simulates a request to a mounted {@link IResource}
         *
         * @param resource
         *            the resource to test
         * @return the used {@link ResourceReference} for the simulation
         */
        public ResourceReference startResource(final IResource resource)
        {
                return startResourceReference(new ResourceReference("testResourceReference")
                {
                        private static final long serialVersionUID = 1L;

                        @Override
                        public IResource getResource()
                        {
                                return resource;
                        }
                });
        }

        /**
         * Simulates a request to a mounted {@link ResourceReference}
         *
         * @param reference
         *            the resource reference to test
         * @return the tested resource reference
         */
        public ResourceReference startResourceReference(final ResourceReference reference)
        {
                return startResourceReference(reference, null);
        }

        /**
         * Simulates a request to a mounted {@link ResourceReference}
         *
         * @param reference
         *            the resource reference to test
         * @param pageParameters
         *            the parameters passed to the resource reference
         * @return the tested resource reference
         */
        public ResourceReference startResourceReference(final ResourceReference reference,
                final PageParameters pageParameters)
        {
                // prepare request
                request.setURL(request.getContextPath() + request.getServletPath() + "/");
                IRequestHandler handler = new ResourceReferenceRequestHandler(reference, pageParameters);

                // execute request
                processRequest(request, handler);

                // the reference processed
                return reference;
        }

        /**
         * @return last response or <code>null</code> if no response has been produced yet.
         */
        public MockHttpServletResponse getLastResponse()
        {
                return lastResponse;
        }

        /**
         * The last response as a string when a page is tested via {@code startPage()} methods.
         * <p>
         * In case the processed component was not a {@link Page} then the automatically created page
         * markup gets removed. If you need the whole returned markup in this case use
         * {@link #getLastResponse()}{@link MockHttpServletResponse#getDocument() .getDocument()}
         * </p>
         *
         * @return last response as String.
         */
        public String getLastResponseAsString()
        {
                String response = lastResponse.getDocument();

                // null, if a Page was rendered last
                if (componentInPage == null)
                {
                        return response;
                }

                // remove the markup for the auto-generated page. leave just component's markup
                int end = response.lastIndexOf("</body>");
                if (end > -1)
                {
                        int start = response.indexOf("<body>") + "<body>".length();
                        response = response.substring(start, end);
                }

                return response;
        }

        /**
         * This method tries to parse the last response to return the encoded base URL and will throw an
         * exception if there none was encoded.
         *
         * @return Wicket-Ajax-BaseURL set on last response by {@link AbstractDefaultAjaxBehavior}
         * @throws IOException
         * @throws ParseException
         */
        public String getWicketAjaxBaseUrlEncodedInLastResponse() throws IOException, ParseException
        {
                XmlPullParser parser = new XmlPullParser();
                parser.parse(getLastResponseAsString());
                XmlTag tag;
                while ((tag = parser.nextTag()) != null)
                {
                        if (tag.isOpen() && tag.getName().equals("script")
                                && "wicket-ajax-base-url".equals(tag.getAttribute("id")))
                        {
                                parser.next();
                                return parser.getString().toString().split("\\\"")[1];
                        }
                }

                fail("Last response has no AJAX base URL set by AbstractDefaultAjaxBehavior.");
                return null;
        }

        /**
         * @return list of prior requests
         */
        public List<MockHttpServletRequest> getPreviousRequests()
        {
                return previousRequests;
        }

        /**
         * @return list of prior responses
         */
        public List<MockHttpServletResponse> getPreviousResponses()
        {
                return previousResponses;
        }

        /**
         * Sets whether responses with redirects will be followed automatically.
         *
         * @param followRedirects
         */
        public void setFollowRedirects(boolean followRedirects)
        {
                this.followRedirects = followRedirects;
        }

        /**
         * @return <code>true</code> if redirect responses will be followed automatically,
         *         <code>false</code> otherwise.
         */
        public boolean isFollowRedirects()
        {
                return followRedirects;
        }

        /**
         * Encodes the {@link IRequestHandler} to {@link Url}. It should be safe to call this method
         * outside request thread as log as no registered {@link IRequestMapper} requires a
         * {@link RequestCycle}.
         *
         * @param handler
         * @return {@link Url} for handler.
         */
        public Url urlFor(final IRequestHandler handler)
        {
                Url url = application.getRootRequestMapper().mapHandler(handler);
                return transform(url);
        }

        /**
         * @param link
         * @return url for Link
         */
        public String urlFor(Link<?> link)
        {
                Args.notNull(link, "link");

                Url url = Url.parse(link.urlForListener(new PageParameters()).toString());
                return transform(url).toString();
        }

        /**
         * Simulates processing URL that invokes an {@link IRequestListener} on a component.
         *
         * After the listener is invoked the page containing the component will be rendered (with an
         * optional redirect - depending on {@link RenderStrategy}).
         *
         * @param component
         */
        public void executeListener(final Component component)
        {
                Args.notNull(component, "component");

                // there are two ways to do this. RequestCycle could be forced to call the handler
                // directly but constructing and parsing the URL increases the chance of triggering bugs
                Page page = component.getPage();
                PageAndComponentProvider pageAndComponentProvider = new PageAndComponentProvider(page,
                        component);

                IRequestHandler handler = null;
                if (page.isPageStateless() || (page.isBookmarkable() && page.wasCreatedBookmarkable()))
                {
                        handler = new BookmarkableListenerRequestHandler(pageAndComponentProvider);
                }
                else
                {
                        handler = new ListenerRequestHandler(pageAndComponentProvider);
                }

                Url url = urlFor(handler);
                request.setUrl(url);

                // Process the request
                processRequest(request, null);
        }

        /**
         * Simulates invoking an {@link IRequestListener} on a component. As opposed to the
         * {@link #executeListener(Component)} method, current request/response objects will be used
         *
         * After the listener is invoked the page containing the component will be rendered (with an
         * optional redirect - depending on {@link RenderStrategy}).
         *
         * @param component
         */
        public void invokeListener(final Component component)
        {
                Args.notNull(component, "component");

                // there are two ways to do this. RequestCycle could be forced to call the handler
                // directly but constructing and parsing the URL increases the chance of triggering bugs
                IRequestHandler handler = new ListenerRequestHandler(
                        new PageAndComponentProvider(component.getPage(), component));

                processRequest(handler);
        }

        /**
         * Simulates invoking an {@link IRequestListener} on a component. As opposed to the
         * {@link #executeListener(Component)} method, current request/response objects will be used
         *
         * After the listener is invoked the page containing the component will be rendered (with an
         * optional redirect - depending on {@link RenderStrategy}).
         *
         * @param component
         * @param behavior
         */
        public void invokeListener(Component component, final Behavior behavior)
        {
                Args.notNull(component, "component");
                Args.notNull(behavior, "behavior");

                // there are two ways to do this. RequestCycle could be forced to call the handler
                // directly but constructing and parsing the URL increases the chance of triggering bugs
                IRequestHandler handler = new ListenerRequestHandler(
                        new PageAndComponentProvider(component.getPage(), component),
                        component.getBehaviorId(behavior));

                processRequest(handler);
        }

        /**
         * Builds and processes a request suitable for executing an <code>AbstractAjaxBehavior</code>.
         *
         * @param behavior
         *            an <code>AbstractAjaxBehavior</code> to execute
         */
        public void executeBehavior(final AbstractAjaxBehavior behavior)
        {
                Args.notNull(behavior, "behavior");

                Url url = Url.parse(behavior.getCallbackUrl().toString(),
                        Charset.forName(request.getCharacterEncoding()));
                transform(url);
                request.setUrl(url);
                request.addHeader(WebRequest.HEADER_ORIGIN, createOriginHeader());
                request.addHeader(WebRequest.HEADER_AJAX_BASE_URL, url.toString());
                request.addHeader(WebRequest.HEADER_AJAX, "true");

                if (behavior instanceof AjaxFormSubmitBehavior)
                {
                        AjaxFormSubmitBehavior formSubmitBehavior = (AjaxFormSubmitBehavior)behavior;
                        Form<?> form = formSubmitBehavior.getForm();
                        getRequest().setUseMultiPartContentType(form.isMultiPart());
                        serializeFormToRequest(form);

                        // mark behavior's component as the form submitter,
                        String name = Form.getRootFormRelativeId(
                                new PropertyModel<Component>(behavior, "component").getObject());
                        if (!request.getPostParameters().getParameterNames().contains(name))
                        {
                                request.getPostParameters().setParameterValue(name, "marked");
                        }
                }

                processRequest();
        }

        /**
         * Build value to Origin header based on RequestCycle Url
         *
         * @return Origin header
         */
        protected String createOriginHeader()
        {
                Url url = RequestCycle.get().getRequest().getUrl();
                return url.getProtocol() + "://" + url.getHost() + ":" + url.getPort();
        }

        /**
         *
         * @param link
         * @return Url
         */
        public Url urlFor(final AjaxLink<?> link)
        {
                AbstractAjaxBehavior behavior = WicketTesterHelper.findAjaxEventBehavior(link, "click");
                Url url = Url.parse(behavior.getCallbackUrl().toString(),
                        Charset.forName(request.getCharacterEncoding()));
                return transform(url);
        }

        /**
         *
         * @param url
         */
        public void executeAjaxUrl(final Url url)
        {
                Args.notNull(url, "url");

                transform(url);
                request.setUrl(url);
                request.addHeader("Wicket-Ajax-BaseURL", url.toString());
                request.addHeader("Wicket-Ajax", "true");

                processRequest();
        }

        /**
         * Renders a <code>Page</code> from its default constructor.
         *
         * @param <C>
         * @param pageClass
         *            a test <code>Page</code> class with default constructor
         * @return the rendered <code>Page</code>
         */
        public final <C extends Page> C startPage(final Class<C> pageClass)
        {
                return startPage(pageClass, null);
        }

        /**
         * Renders a <code>Page</code> from its default constructor.
         *
         * @param <C>
         * @param pageClass
         *            a test <code>Page</code> class with default constructor
         * @param parameters
         *            the parameters to use for the class.
         * @return the rendered <code>Page</code>
         */
        @SuppressWarnings("unchecked")
        public final <C extends Page> C startPage(final Class<C> pageClass,
                final PageParameters parameters)
        {
                Args.notNull(pageClass, "pageClass");

                // must be null for Pages
                componentInPage = null;

                // prepare the request
                request.setUrl(application.getRootRequestMapper().mapHandler(
                        new BookmarkablePageRequestHandler(new PageProvider(pageClass, parameters))));

                // process the request
                processRequest();

                // The last rendered page
                return (C)getLastRenderedPage();
        }

        /**
         * Creates a {@link FormTester} for the <code>Form</code> at a given path, and fills all child
         * {@link org.apache.wicket.markup.html.form.FormComponent}s with blank <code>String</code>s.
         *
         * @param path
         *            path to <code>FormComponent</code>
         * @return a <code>FormTester</code> instance for testing the <code>Form</code>
         * @see #newFormTester(String, boolean)
         */
        public FormTester newFormTester(final String path)
        {
                return newFormTester(path, true);
        }

        /**
         * Creates a {@link FormTester} for the <code>Form</code> at a given path.
         *
         * @param path
         *            path to <code>FormComponent</code>
         * @param fillBlankString
         *            specifies whether to fill all child <code>FormComponent</code>s with blank
         *            <code>String</code>s
         * @return a <code>FormTester</code> instance for testing the <code>Form</code>
         * @see FormTester
         */
        public FormTester newFormTester(final String path, final boolean fillBlankString)
        {
                return new FormTester(path, (Form<?>)getComponentFromLastRenderedPage(path), this,
                        fillBlankString);
        }

        /**
         * Process a component. A web page will be automatically created with the markup created in
         * {@link #createPageMarkup(String)}.
         * <p>
         * <strong>Note</strong>: the instantiated component will have an auto-generated id. To reach
         * any of its children use their relative path to the component itself. For example if the
         * started component has a child a Link component with id "link" then after starting the
         * component you can click it with: <code>tester.clickLink("link")</code>
         * </p>
         *
         * @param <C>
         *            the type of the component
         * @param componentClass
         *            the class of the component to be tested
         * @return The component processed
         * @see #startComponentInPage(org.apache.wicket.Component)
         */
        public final <C extends Component> C startComponentInPage(final Class<C> componentClass)
        {
                return startComponentInPage(componentClass, null);
        }

        /**
         * Process a component. A web page will be automatically created with the {@code pageMarkup}
         * provided. In case pageMarkup is null, the markup will be automatically created with
         * {@link #createPageMarkup(String)}.
         * <p>
         * <strong>Note</strong>: the instantiated component will have an auto-generated id. To reach
         * any of its children use their relative path to the component itself. For example if the
         * started component has a child a Link component with id "link" then after starting the
         * component you can click it with: <code>tester.clickLink("link")</code>
         * </p>
         *
         * @param <C>
         *            the type of the component
         *
         * @param componentClass
         *            the class of the component to be tested
         * @param pageMarkup
         *            the markup for the Page that will be automatically created. May be {@code null}.
         * @return The component processed
         */
        public final <C extends Component> C startComponentInPage(final Class<C> componentClass,
                final IMarkupFragment pageMarkup)
        {
                Args.notNull(componentClass, "componentClass");

                // Create the component instance from the class
                C comp = null;
                try
                {
                        Constructor<C> c = componentClass.getConstructor(String.class);
                        comp = c.newInstance(ComponentInPage.ID);
                }
                catch (Exception e)
                {
                        log.error(e.getMessage(), e);
                        fail(String.format("Cannot instantiate component with type '%s' because of '%s'",
                                componentClass.getName(), e.getMessage()));
                }

                // process the component
                C started = startComponentInPage(comp, pageMarkup);

                componentInPage.isInstantiated = true;

                return started;
        }

        /**
         * Process a component. A web page will be automatically created with markup created by the
         * {@link #createPageMarkup(String)}.
         * <p>
         * <strong>Note</strong>: the component id is set by the user. To reach any of its children use
         * this id + their relative path to the component itself. For example if the started component
         * has id <em>compId</em> and a Link child component component with id "link" then after
         * starting the component you can click it with: <code>tester.clickLink("compId:link")</code>
         * </p>
         *
         * @param <C>
         *            the type of the component
         * @param component
         *            the component to be tested
         * @return The component processed
         * @see #startComponentInPage(Class)
         */
        public final <C extends Component> C startComponentInPage(final C component)
        {
                return startComponentInPage(component, null);
        }

        /**
         * Process a component. A web page will be automatically created with the {@code pageMarkup}
         * provided. In case {@code pageMarkup} is null, the markup will be automatically created with
         * {@link #createPageMarkup(String)}.
         * <p>
         * <strong>Note</strong>: the component id is set by the user. To reach any of its children use
         * this id + their relative path to the component itself. For example if the started component
         * has id <em>compId</em> and a Link child component component with id "link" then after
         * starting the component you can click it with: <code>tester.clickLink("compId:link")</code>
         * </p>
         *
         * @param <C>
         *            the type of the component
         * @param component
         *            the component to be tested
         * @param pageMarkup
         *            the markup for the Page that will be automatically created. May be {@code null}.
         * @return The component processed
         */
        public final <C extends Component> C startComponentInPage(final C component,
                IMarkupFragment pageMarkup)
        {
                Args.notNull(component, "component");

                // Create a page object and assign the markup
                Page page = createPage();
                if (page == null)
                {
                        fail("The automatically created page should not be null.");
                }

                // Automatically create the page markup if not provided
                if (pageMarkup == null)
                {
                        String markup = createPageMarkup(component.getId());
                        if (markup == null)
                        {
                                fail("The markup for the automatically created page should not be null.");
                        }

                        try
                        {
                                // set a ContainerInfo to be able to use HtmlHeaderContainer so header contribution
                                // still work. WICKET-3700
                                ContainerInfo containerInfo = new ContainerInfo(page);
                                MarkupResourceStream markupResourceStream = new MarkupResourceStream(
                                        new StringResourceStream(markup), containerInfo, page.getClass());

                                MarkupParser markupParser = getApplication().getMarkupSettings().getMarkupFactory()
                                        .newMarkupParser(markupResourceStream);
                                pageMarkup = markupParser.parse();
                        }
                        catch (Exception e)
                        {
                                String errorMessage = "Error while parsing the markup for the autogenerated page: "
                                        + e.getMessage();
                                log.error(errorMessage, e);
                                fail(errorMessage);
                        }
                }

                if (page instanceof StartComponentInPage)
                {
                        ((StartComponentInPage)page).setPageMarkup(pageMarkup);
                }
                else
                {
                        page.setMarkup(pageMarkup);
                }

                // Add the child component
                page.add(component);

                // Process the page
                startPage(page);

                componentInPage = new ComponentInPage();
                componentInPage.component = component;

                return component;
        }

        /**
         * Creates the markup that will be used for the automatically created {@link Page} that will be
         * used to test a component with {@link #startComponentInPage(Class, IMarkupFragment)}
         *
         * @param componentId
         *            the id of the component to be tested
         * @return the markup for the {@link Page} as {@link String}. Cannot be {@code null}.
         */
        protected String createPageMarkup(final String componentId)
        {
                return "<html><head></head><body><span wicket:id='" + componentId
                        + "'></span></body></html>";
        }

        /**
         * Creates a {@link Page} to test a component with
         * {@link #startComponentInPage(Component, IMarkupFragment)}
         *
         * @return a {@link Page} which will contain the component under test as a single child
         */
        protected Page createPage()
        {
                return new StartComponentInPage();
        }

        public Component getComponentFromLastRenderedPage(String path, boolean wantVisibleInHierarchy)
        {
                return getComponentFromLastRenderedPage(path, wantVisibleInHierarchy, true);
        }

        /**
         * Gets the component with the given path from last rendered page. This method fails in case the
         * component couldn't be found.
         *
         * @param path
         *            Path to component
         * @param wantVisibleInHierarchy
         *            if true component needs to be visible in hierarchy else {@code null} is returned
         * @return The component at the path
         * @see org.apache.wicket.MarkupContainer#get(String)
         */
        public Component getComponentFromLastRenderedPage(String path, boolean wantVisibleInHierarchy,
                boolean failOnAbsent)
        {
                if (componentInPage != null && componentInPage.isInstantiated)
                {
                        String componentIdPageId = componentInPage.component.getId() + ':';
                        if (path.startsWith(componentIdPageId) == false)
                        {
                                path = componentIdPageId + path;
                        }
                }

                Component component = getLastRenderedPage().get(path);
                if (component == null)
                {
                        if (failOnAbsent)
                        {
                                fail("path: '" + path + "' does not exist for page: "
                                        + Classes.simpleName(getLastRenderedPage().getClass()));
                        }
                        return null;
                }

                if (!wantVisibleInHierarchy || component.isVisibleInHierarchy())
                {
                        return component;
                }

                // Not found or not visible
                return null;
        }

        /**
         * Gets the component with the given path from last rendered page. This method fails in case the
         * component couldn't be found, and it will return null if the component was found, but is not
         * visible.
         *
         * @param path
         *            Path to component
         * @return The component at the path
         * @see org.apache.wicket.MarkupContainer#get(String)
         */
        public Component getComponentFromLastRenderedPage(String path)
        {
                return getComponentFromLastRenderedPage(path, true);
        }

        /**
         * Returns the first {@link Component} (breadth-first search) matching the given Wicket-ID. If
         * no such {@link Component} exists it returns {@link Optional#empty()}
         *
         * @param wicketId
         *            the Wicket-ID of the {@link Component} to be found
         * @return Optional of the component, {@link Optional#empty()} if no matching component can be
         *         found or wicketId is null or blank.
         */
        public Optional<Component> getFirstComponentByWicketId(String wicketId)
        {
                if (wicketId == null || wicketId.isBlank())
                {
                        return Optional.empty();
                }

                if (getLastRenderedPage() != null && componentInPage != null)
                {
                        Component component = getLastRenderedPage().visitChildren((c, visit) -> {
                                if (c.getId().equals(wicketId))
                                {
                                        visit.stop(c);
                                }
                        });

                        return Optional.ofNullable(component);
                }

                return Optional.empty();
        }

        /**
         * Returns a {@link List} of all {@link Component}s matching the given Wicket-ID. Returns an
         * empty list if no such component can be found or the Wicket-ID is null.
         *
         * @param wicketId
         *            the Wicket-ID of the components to be found
         * @return A list of all {@link Component}s that have the given Wicket-ID, an empty List if no
         *         such component can be found. Returns an empty List of wicketId is null or blank.
         */
        public List<Component> getAllComponentsByWicketId(String wicketId)
        {
                var result = new ArrayList<Component>();

                if (wicketId == null || wicketId.isBlank())
                {
                        return result;
                }

                if (getLastRenderedPage() != null && componentInPage != null)
                {
                        getLastRenderedPage().visitChildren((c, visit) -> {
                                if (c.getId().equals(wicketId))
                                {
                                        result.add(c);
                                }
                        });
                }

                log.debug("Found {} Components with ID '{}'", result.size(), wicketId);

                return result;
        }

        /**
         * assert the text of <code>Label</code> component.
         *
         * @param path
         *            path to <code>Label</code> component
         * @param expectedLabelText
         *            expected label text
         * @return a <code>Result</code>
         */
        public Result hasLabel(String path, String expectedLabelText)
        {
                Label label = (Label)getComponentFromLastRenderedPage(path);
                return isEqual(expectedLabelText, label.getDefaultModelObjectAsString());
        }

        /**
         * assert component class
         *
         * @param <C>
         *
         * @param path
         *            path to component
         * @param expectedComponentClass
         *            expected component class
         * @return a <code>Result</code>
         */
        public <C extends Component> Result isComponent(String path, Class<C> expectedComponentClass)
        {
                Component component = assertExists(path);

                return isTrue(
                        "component '" + Classes.name(component.getClass()) + "' is not of type: "
                                + Classes.name(expectedComponentClass),
                        expectedComponentClass.isAssignableFrom(component.getClass()));
        }

        /**
         * assert component visible.
         *
         * @param path
         *            path to component
         * @return a <code>Result</code>
         */
        public Result isVisible(final String path)
        {
                final Result result;

                Component component = getComponentFromLastRenderedPage(path, false);
                if (component == null)
                {
                        result = Result.fail("path: '" + path + "' does not exist for page: "
                                + Classes.simpleName(getLastRenderedPage().getClass()));
                }
                else
                {
                        result = isTrue("component '" + path + "' is not visible",
                                component.isVisibleInHierarchy());
                }

                return result;
        }

        /**
         * assert component invisible.
         *
         * @param path
         *            path to component
         * @return a <code>Result</code>
         */
        public Result isInvisible(final String path)
        {
                final Result result;

                Component component = getComponentFromLastRenderedPage(path, false);
                if (component == null)
                {
                        result = Result.fail("path: '" + path + "' does not exist for page: "
                                + Classes.simpleName(getLastRenderedPage().getClass()));
                }
                else
                {
                        result = isFalse("component '" + path + "' is visible",
                                component.isVisibleInHierarchy());
                }

                return result;
        }

        /**
         * assert component enabled.
         *
         * @param path
         *            path to component
         * @return a <code>Result</code>
         */
        public Result isEnabled(final String path)
        {
                Component component = assertExists(path);

                return isTrue("component '" + path + "' is disabled", component.isEnabledInHierarchy());
        }

        /**
         * assert component disabled.
         *
         * @param path
         *            path to component
         * @return a <code>Result</code>
         */
        public Result isDisabled(final String path)
        {
                Component component = assertExists(path);

                return isFalse("component '" + path + "' is enabled", component.isEnabledInHierarchy());
        }

        public Component assertExists(final String path)
        {
                Component component = getComponentFromLastRenderedPage(path);
                if (component == null)
                {
                        fail("path: '" + path + "' does not exist for page: "
                                + Classes.simpleName(getLastRenderedPage().getClass()));
                        return null;
                }
                return component;
        }

        public void assertNotExists(final String path)
        {
                Component component = getComponentFromLastRenderedPage(path, true, false);
                if (component != null)
                {
                        fail("path: '" + path + "' does exists for page: "
                                + Classes.simpleName(getLastRenderedPage().getClass()));
                }
        }

        private FormComponent<?> assertFormComponent(final String path)
        {
                Component component = assertExists(path);

                if (component instanceof FormComponent<?> == false)
                {
                        fail("path: '" + path + "' is not a form component");
                        return null;
                }
                return (FormComponent<?>)component;
        }

        /**
         * assert component required.
         *
         * @param path
         *            path to component
         * @return a <code>Result</code>
         */
        public Result isRequired(String path)
        {
                FormComponent<?> formComponent = assertFormComponent(path);

                return isRequired(formComponent);
        }

        /**
         * assert component required.
         *
         * @param component
         *            a form component
         * @return a <code>Result</code>
         */
        public Result isRequired(FormComponent<?> component)
        {
                return isTrue("component '" + component + "' is not required", component.isRequired());
        }

        /**
         * Asserts that a component is not required.
         *
         * @param path
         *            path to component
         * @return a <code>Result</code>
         */
        public Result isNotRequired(String path)
        {
                FormComponent<?> formComponent = assertFormComponent(path);

                return isNotRequired(formComponent);
        }

        /**
         * Asserts that a component is not required.
         *
         * @param component
         *            a form component
         * @return a <code>Result</code>
         */
        public Result isNotRequired(FormComponent<?> component)
        {
                return isFalse("component '" + component + "' is required", component.isRequired());
        }

        /**
         * assert the content of last rendered page contains(matches) regex pattern.
         *
         * @param pattern
         *            reqex pattern to match
         * @return a <code>Result</code>
         */
        public Result ifContains(String pattern)
        {
                return isTrue("pattern '" + pattern + "' not found in:\n" + getLastResponseAsString(),
                        getLastResponseAsString().matches("(?s).*" + pattern + ".*"));
        }

        /**
         * assert the content of last rendered page contains(matches) regex pattern.
         *
         * @param pattern
         *            reqex pattern to match
         * @return a <code>Result</code>
         */
        public Result ifContainsNot(String pattern)
        {
                return isFalse("pattern '" + pattern + "' found",
                        getLastResponseAsString().matches("(?s).*" + pattern + ".*"));
        }

        /**
         * Click the {@link Link} in the last rendered Page.
         * <p>
         * Simulate that AJAX is enabled.
         *
         * @see WicketTester#clickLink(String, boolean)
         * @param path
         *            Click the <code>Link</code> in the last rendered Page.
         */
        public void clickLink(String path)
        {
                clickLink(path, true);
        }

        /**
         * Click the {@link Link} in the last rendered Page.
         * <p>
         * This method also works for {@link AjaxLink}, {@link AjaxFallbackLink} and
         * {@link AjaxSubmitLink}.
         * <p>
         * On AjaxLinks and AjaxFallbackLinks the onClick method is invoked with a valid
         * AjaxRequestTarget. In that way you can test the flow of your application when using AJAX.
         * <p>
         * When clicking an AjaxSubmitLink the form, which the AjaxSubmitLink is attached to is first
         * submitted, and then the onSubmit method on AjaxSubmitLink is invoked. If you have changed
         * some values in the form during your test, these will also be submitted. This should not be
         * used as a replacement for the {@link FormTester} to test your forms. It should be used to
         * test that the code in your onSubmit method in AjaxSubmitLink actually works.
         * <p>
         * This method is also able to simulate that AJAX (javascript) is disabled on the client. This
         * is done by setting the isAjax parameter to false. If you have an AjaxFallbackLink you can
         * then check that it doesn't fail when invoked as a normal link.
         *
         * @param path
         *            path to <code>Link</code> component
         * @param isAjax
         *            Whether to simulate that AJAX (javascript) is enabled or not. If it's false then
         *            AjaxLink and AjaxSubmitLink will fail, since it wouldn't work in real life.
         *            AjaxFallbackLink will be invoked with null as the AjaxRequestTarget parameter.
         */
        public void clickLink(String path, boolean isAjax)
        {
                Component linkComponent = getComponentFromLastRenderedPage(path);

                checkUsability(linkComponent, true);

                // if the link is an AjaxLink, we process it differently
                // than a normal link
                if (linkComponent instanceof AjaxLink)
                {
                        // If it's not ajax we fail
                        if (isAjax == false)
                        {
                                fail("Link " + path + "is an AjaxLink and will "
                                        + "not be invoked when AJAX (javascript) is disabled.");
                        }

                        List<AjaxEventBehavior> behaviors = WicketTesterHelper
                                .findAjaxEventBehaviors(linkComponent, "click");
                        for (AjaxEventBehavior behavior : behaviors)
                        {
                                executeBehavior(behavior);
                        }
                }
                // if the link is an AjaxSubmitLink, we need to find the form
                // from it using reflection so we know what to submit.
                else if (linkComponent instanceof AjaxSubmitLink)
                {
                        // If it's not ajax we fail
                        if (isAjax == false)
                        {
                                fail("Link " + path + " is an AjaxSubmitLink and "
                                        + "will not be invoked when AJAX (javascript) is disabled.");
                        }

                        AjaxSubmitLink link = (AjaxSubmitLink)linkComponent;

                        String pageRelativePath = link.getInputName();
                        request.getPostParameters().setParameterValue(pageRelativePath, "x");

                        submitAjaxFormSubmitBehavior(link,
                                (AjaxFormSubmitBehavior)WicketTesterHelper.findAjaxEventBehavior(link, "click"));
                }
                // if the link is an IAjaxLink, use it (do check if AJAX is expected)
                else if (isAjax
                        && (linkComponent instanceof IAjaxLink || linkComponent instanceof AjaxFallbackLink))
                {
                        List<AjaxEventBehavior> behaviors = WicketTesterHelper
                                .findAjaxEventBehaviors(linkComponent, "click");
                        for (AjaxEventBehavior behavior : behaviors)
                        {
                                executeBehavior(behavior);
                        }
                }
                /*
                 * If the link is a submitlink then we pretend to have clicked it
                 */
                else if (linkComponent instanceof SubmitLink)
                {
                        SubmitLink submitLink = (SubmitLink)linkComponent;

                        String pageRelativePath = submitLink.getInputName();
                        request.getPostParameters().setParameterValue(pageRelativePath, "x");

                        serializeFormToRequest(submitLink.getForm());
                        submitForm(submitLink.getForm().getPageRelativePath());
                }
                else if (linkComponent instanceof ExternalLink)
                {
                        ExternalLink externalLink = (ExternalLink)linkComponent;
                        String href = externalLink.getDefaultModelObjectAsString();
                        try
                        {
                                getResponse().sendRedirect(href);
                                recordRequestResponse();
                                setupNextRequestCycle();
                        }
                        catch (IOException iox)
                        {
                                throw new WicketRuntimeException("An error occurred while redirecting to: " + href,
                                        iox);
                        }
                }
                // if the link is a normal link (or ResourceLink)
                else if (linkComponent instanceof AbstractLink)
                {
                        AbstractLink link = (AbstractLink)linkComponent;

                        /*
                         * If the link is a bookmarkable link, then we need to transfer the parameters to the
                         * next request.
                         */
                        if (link instanceof BookmarkablePageLink)
                        {
                                BookmarkablePageLink<?> bookmarkablePageLink = (BookmarkablePageLink<?>)link;
                                try
                                {
                                        Method getParametersMethod = BookmarkablePageLink.class
                                                .getDeclaredMethod("getPageParameters", (Class<?>[])null);
                                        getParametersMethod.setAccessible(true);

                                        PageParameters parameters = (PageParameters)getParametersMethod
                                                .invoke(bookmarkablePageLink, (Object[])null);

                                        startPage(bookmarkablePageLink.getPageClass(), parameters);
                                }
                                catch (Exception e)
                                {
                                        throw new WicketRuntimeException("Internal error in WicketTester. "
                                                + "Please report this in Wicket's Issue Tracker.", e);
                                }
                        }
                        else if (link instanceof ResourceLink)
                        {
                                try
                                {
                                        Method getURL = ResourceLink.class.getDeclaredMethod("getURL");
                                        getURL.setAccessible(true);
                                        CharSequence url = (CharSequence)getURL.invoke(link);
                                        executeUrl(url.toString());
                                }
                                catch (Exception x)
                                {
                                        throw new RuntimeException("An error occurred while clicking on a ResourceLink",
                                                x);
                                }
                        }
                        else
                        {
                                executeListener(link);
                        }
                }
                // The link requires AJAX
                else if (linkComponent instanceof IAjaxLink && isAjax == false)
                {
                        fail("Link " + path + "is an IAjaxLink and will "
                                + "not be invoked when AJAX (javascript) is disabled.");
                }
                else
                {
                        fail("Link " + path + " is not an instance of AbstractLink or IAjaxLink");
                }
        }

        /**
         * Submit the given form in the last rendered {@link Page}
         * <p>
         * <strong>Note</strong>: Form request parameters have to be set explicitly.
         *
         * @param form
         *            path to component
         */
        public void submitForm(Form<?> form)
        {
                submitForm(form.getPageRelativePath());
        }

        /**
         * Submits the {@link Form} in the last rendered {@link Page}.
         * <p>
         * <strong>Note</strong>: Form request parameters have to be set explicitely.
         *
         * @param path
         *            path to component
         */
        public void submitForm(String path)
        {
                Form<?> form = (Form<?>)getComponentFromLastRenderedPage(path);
                Url url = Url.parse(form.getRootForm().urlForListener(new PageParameters()).toString(),
                        Charset.forName(request.getCharacterEncoding()));

                // make url absolute
                transform(url);

                request.setUrl(url);
                processRequest();
        }

        /**
         * make url suitable for wicket tester use. usually this involves stripping any leading ..
         * segments to make the url absolute
         *
         * @param url
         * @return Url
         */
        private Url transform(final Url url)
        {
                while (url.getSegments().size() > 0
                        && (url.getSegments().get(0).equals("..") || url.getSegments().get(0).equals(".")))
                {
                        url.getSegments().remove(0);
                }
                return url;
        }

        /**
         * Asserts the last rendered <code>Page</code> class.
         *
         * @param <C>
         * @param expectedRenderedPageClass
         *            expected class of last rendered page
         * @return a <code>Result</code>
         */
        public <C extends Page> Result isRenderedPage(Class<C> expectedRenderedPageClass)
        {
                Args.notNull(expectedRenderedPageClass, "expectedRenderedPageClass");

                Page page = getLastRenderedPage();
                if (page == null)
                {
                        return Result.fail("page was null");
                }
                if (!expectedRenderedPageClass.isAssignableFrom(page.getClass()))
                {
                        return Result.fail(String.format("classes not the same, expected '%s', current '%s'",
                                expectedRenderedPageClass, page.getClass()));
                }
                return Result.pass();
        }

        /**
         * Asserts last rendered <code>Page</code> against an expected HTML document.
         * <p>
         * Use <code>-Dwicket.replace.expected.results=true</code> to automatically replace the expected
         * output file.
         * </p>
         *
         * @param pageClass
         *            used to load the <code>File</code> (relative to <code>clazz</code> package)
         * @param filename
         *            expected output <code>File</code> name
         * @throws Exception
         */
        public void assertResultPage(final Class<?> pageClass, final String filename) throws Exception
        {
                // Validate the document
                String document = getLastResponseAsString();
                DiffUtil.validatePage(document, pageClass, filename, true);
        }

        /**
         * Asserts last rendered <code>Page</code> against an expected HTML document as a
         * <code>String</code>.
         *
         * @param expectedDocument
         *            expected output
         * @return a <code>Result</code>
         */
        public Result isResultPage(final String expectedDocument)
        {
                // Validate the document
                String document = getLastResponseAsString();
                return isTrue("expected rendered page equals", document.equals(expectedDocument));
        }

        /**
         * Asserts no error-level feedback messages.
         *
         * @return a <code>Result</code>
         * @see #hasNoFeedbackMessage(int)
         */
        public Result hasNoErrorMessage()
        {
                return hasNoFeedbackMessage(FeedbackMessage.ERROR);
        }

        /**
         * Asserts no info-level feedback messages.
         *
         * @return a <code>Result</code>
         * @see #hasNoFeedbackMessage(int)
         */
        public Result hasNoInfoMessage()
        {
                return hasNoFeedbackMessage(FeedbackMessage.INFO);
        }

        /**
         * Asserts there are no feedback messages with the given level.
         *
         * @param level
         *            the level of the feedback message
         * @return a <code>Result</code>
         */
        public Result hasNoFeedbackMessage(int level)
        {
                List<Serializable> messages = getMessages(level);
                return isTrue(String.format("expected no %s message, but contains\n%s",
                        new FeedbackMessage(null, "", level).getLevelAsString().toLowerCase(Locale.ROOT),
                        WicketTesterHelper.asLined(messages)), messages.isEmpty());
        }

        /**
         * Retrieves <code>FeedbackMessages</code>.
         *
         * @param level
         *            level of feedback message, for example:
         *            <code>FeedbackMessage.DEBUG or FeedbackMessage.INFO.. etc</code>
         * @return <code>List</code> of messages (as <code>String</code>s)
         * @see FeedbackMessage
         */
        public List<Serializable> getMessages(final int level)
        {
                List<FeedbackMessage> messages = getFeedbackMessages(
                        new ExactLevelFeedbackMessageFilter(level));

                List<Serializable> actualMessages = Generics.newArrayList();
                for (FeedbackMessage message : messages)
                {
                        actualMessages.add(message.getMessage());
                }
                return actualMessages;
        }

        /**
         * Retrieves <code>FeedbackMessages</code>.
         *
         * @param filter
         *            A filter that decides which messages to collect
         * @return <code>List</code> of messages (as <code>String</code>s)
         * @see FeedbackMessage
         */
        public List<FeedbackMessage> getFeedbackMessages(final IFeedbackMessageFilter filter)
        {
                return new FeedbackCollector(getLastRenderedPage(), true).collect(filter);
        }

        /**
         * Dumps the source of last rendered <code>Page</code>.
         */
        public void dumpPage()
        {
                log.info(getLastResponseAsString());
        }

        /**
         * Dumps the <code>Component</code> trees.
         */
        public void debugComponentTrees()
        {
                debugComponentTrees("");
        }

        /**
         * Dumps the <code>Component</code> trees to log. Show only the <code>Component</code>s whose
         * paths contain the filter <code>String</code>.
         *
         * @param filter
         *            a filter <code>String</code>
         */
        public void debugComponentTrees(String filter)
        {
                log.info("debugging ----------------------------------------------");
                for (WicketTesterHelper.ComponentData obj : WicketTesterHelper
                        .getComponentData(getLastRenderedPage()))
                {
                        if (obj.path.matches(".*" + filter + ".*"))
                        {
                                var enabled = obj.isEnabled ? "E" : "-";
                                var visible = obj.isVisible ? "V" : "-";
                                log.info("[{}{}] path\t{} \t{} \t[{}]", enabled, visible, obj.path, obj.type,
                                        obj.value);
                        }
                }
        }

        /**
         * Tests that a <code>Component</code> has been added to a <code>AjaxRequestTarget</code>, using
         * {@link org.apache.wicket.ajax.AjaxRequestTarget#add(org.apache.wicket.Component...)}. This
         * method actually tests that a <code>Component</code> is on the Ajax response sent back to the
         * client.
         * <p>
         * PLEASE NOTE! This method doesn't actually insert the <code>Component</code> in the client DOM
         * tree, using JavaScript. But it shouldn't be needed because you have to trust that the Wicket
         * Ajax JavaScript just works.
         *
         * @param component
         *            the <code>Component</code> to test
         * @return a <code>Result</code>
         */
        public Result isComponentOnAjaxResponse(final Component component)
        {
                String failMessage = "A component which is null could not have been added to the AJAX response";
                notNull(failMessage, component);

                Result result;

                // test that the component renders the placeholder tag if it's not visible
                String componentInfo = component.toString();
                if (!component.isVisible())
                {
                        failMessage = "A component which is invisible and doesn't render a placeholder tag"
                                + " will not be rendered at all and thus won't be accessible for subsequent AJAX interaction. "
                                + componentInfo;
                        result = isTrue(failMessage, component.getOutputMarkupPlaceholderTag());
                        if (result.wasFailed())
                        {
                                return result;
                        }
                }

                // Get the AJAX response
                String ajaxResponse = getLastResponseAsString();

                // Test that the previous response was actually a AJAX response
                failMessage = "The previous response was not an AJAX response. "
                        + "You need to execute an AJAX event, using #clickLink() or "
                        + "#executeAjaxEvent(), before using this assertion method";
                boolean isAjaxResponse = Pattern
                        .compile("^<\\?xml version=\"1.0\" encoding=\".*?\"\\?><ajax-response>")
                        .matcher(ajaxResponse).find();
                result = isTrue(failMessage, isAjaxResponse);
                if (result.wasFailed())
                {
                        return result;
                }

                // See if the component has a markup id
                String markupId = component.getMarkupId();

                failMessage = "The component doesn't have a markup id, "
                        + "which means that it can't have been added to the AJAX response. " + componentInfo;
                result = isTrue(failMessage, !Strings.isEmpty(markupId));
                if (result.wasFailed())
                {
                        return result;
                }

                // Look for that the component is on the response, using the markup id
                boolean isComponentInAjaxResponse = ajaxResponse
                        .matches("(?s).*<component id=\"" + markupId + "\"[^>]*?>.*");
                failMessage = "Component wasn't found in the AJAX response. " + componentInfo;
                result = isTrue(failMessage, isComponentInAjaxResponse);

                if (!result.wasFailed())
                {
                        return result;
                }

                // Check if the component has been included as part of an enclosure render
                Enclosure enclosure = getLastRenderedPage().visitChildren(Enclosure.class,
                        (Enclosure enc, IVisit<Enclosure> visit) -> {
                                if (AjaxEnclosureListener.isControllerOfEnclosure(component, enc))
                                {
                                        visit.stop(enc);
                                }
                        });

                if (enclosure == null)
                {
                        return result;
                }

                failMessage = "Component's enclosure was not found in the AJAX response. " + enclosure;
                boolean isEnclosureInAjaxResponse = !isComponentOnAjaxResponse(enclosure).wasFailed();
                return isTrue(failMessage, isEnclosureInAjaxResponse);

        }

        /**
         * Simulates the firing of an Ajax event.
         *
         * @see #executeAjaxEvent(Component, String)
         *
         * @since 1.2.3
         * @param componentPath
         *            the <code>Component</code> path
         * @param event
         *            the event which we simulate being fired. If <code>event</code> is
         *            <code>null</code>, the test will fail.
         */
        public void executeAjaxEvent(final String componentPath, final String event)
        {
                Component component = getComponentFromLastRenderedPage(componentPath);
                executeAjaxEvent(component, event);
        }

        /**
         * Simulates the firing of all ajax timer behaviors on the page
         *
         * @param page
         *            the page which timers will be executed
         */
        public void executeAllTimerBehaviors(final MarkupContainer page)
        {
                // execute all timer behaviors for the page itself
                internalExecuteAllTimerBehaviors(page);

                // and for all its children
                page.visitChildren(Component.class, new IVisitor<Component, Void>()
                {
                        @Override
                        public void component(final Component component, final IVisit<Void> visit)
                        {
                                internalExecuteAllTimerBehaviors(component);
                        }
                });
        }

        private void internalExecuteAllTimerBehaviors(final Component component)
        {
                List<AbstractAjaxTimerBehavior> behaviors = component
                        .getBehaviors(AbstractAjaxTimerBehavior.class);
                for (AbstractAjaxTimerBehavior timer : behaviors)
                {
                        checkUsability(component, true);

                        if (!timer.isStopped())
                        {
                                if (log.isDebugEnabled())
                                {
                                        log.debug("Triggering AjaxSelfUpdatingTimerBehavior: {}",
                                                component.getClassRelativePath());
                                }

                                executeBehavior(timer);
                        }
                }
        }

        /**
         * Simulates the firing of an Ajax event. You add an Ajax event to a <code>Component</code> by
         * using:
         *
         * <pre>
         *     ...
         *     component.add(new AjaxEventBehavior(&quot;ondblclick&quot;) {
         *         public void onEvent(AjaxRequestTarget) {}
         *     });
         *     ...
         * </pre>
         *
         * You can then test that the code inside <code>onEvent</code> actually does what it's supposed
         * to, using the <code>WicketTester</code>:
         *
         * <pre>
         *     ...
         *     tester.executeAjaxEvent(component, &quot;ondblclick&quot;);
         *     // Test that the code inside onEvent is correct.
         *     ...
         * </pre>
         *
         * This also works with <code>AjaxFormSubmitBehavior</code>, where it will "submit" the
         * <code>Form</code> before executing the command.
         * <p>
         * PLEASE NOTE! This method doesn't actually insert the <code>Component</code> in the client DOM
         * tree, using JavaScript.
         *
         * @param component
         *            the <code>Component</code> that has the <code>AjaxEventBehavior</code> we want to
         *            test. If the <code>Component</code> is <code>null</code>, the test will fail.
         * @param event
         *            the event to simulate being fired. If <code>event</code> is <code>null</code>, the
         *            test will fail.
         */
        public void executeAjaxEvent(final Component component, final String event)
        {
                Args.notNull(component, "component");
                Args.notNull(event, "event");

                checkUsability(component, true);

                List<AjaxEventBehavior> ajaxEventBehaviors = WicketTesterHelper
                        .findAjaxEventBehaviors(component, event);
                for (AjaxEventBehavior ajaxEventBehavior : ajaxEventBehaviors)
                {
                        executeBehavior(ajaxEventBehavior);
                }
        }

        /**
         * Retrieves a <code>TagTester</code> based on a <code>wicket:id</code>. If more
         * <code>Component</code>s exist with the same <code>wicket:id</code> in the markup, only the
         * first one is returned.
         *
         * @param wicketId
         *            the <code>wicket:id</code> to search for
         * @return the <code>TagTester</code> for the tag which has the given <code>wicket:id</code>
         */
        public TagTester getTagByWicketId(String wicketId)
        {
                return TagTester.createTagByAttribute(getLastResponseAsString(), "wicket:id", wicketId);
        }

        /**
         * Modified version of BaseWicketTester#getTagByWicketId(String) that returns all matching tags
         * instead of just the first.
         *
         * @param wicketId
         * @return List of Tags
         */
        public List<TagTester> getTagsByWicketId(String wicketId)
        {
                return TagTester.createTagsByAttribute(getLastResponseAsString(), "wicket:id", wicketId,
                        false);
        }

        /**
         * Retrieves a <code>TagTester</code> based on an DOM id. If more <code>Component</code>s exist
         * with the same id in the markup, only the first one is returned.
         *
         * @param id
         *            the DOM id to search for.
         * @return the <code>TagTester</code> for the tag which has the given DOM id
         */
        public TagTester getTagById(String id)
        {
                return TagTester.createTagByAttribute(getLastResponseAsString(), "id", id);
        }

        /**
         * Helper method for all the places where an Ajax call should submit an associated
         * <code>Form</code>.
         *
         * @param component
         *            The component the behavior is attached to
         * @param behavior
         *            The <code>AjaxFormSubmitBehavior</code> with the <code>Form</code> to "submit"
         */
        private void submitAjaxFormSubmitBehavior(final Component component,
                AjaxFormSubmitBehavior behavior)
        {
                // The form that needs to be "submitted".
                Form<?> form = behavior.getForm();
                assertNotNull(form, "No form attached to the submitlink.");

                checkUsability(form, true);
                serializeFormToRequest(form);
                executeBehavior(behavior);
        }

        /**
         * Puts all not already scheduled (e.g. via {@link FormTester#setValue(String, String)}) form
         * component values in the post parameters for the next form submit
         *
         * @param form
         *            the {@link Form} which components should be submitted
         */
        private void serializeFormToRequest(final Form<?> form)
        {
                final MockRequestParameters postParameters = request.getPostParameters();
                final Set<String> currentParameterNamesSet = postParameters.getParameterNames();

                form.visitFormComponents(new IVisitor<FormComponent<?>, Void>()
                {
                        @Override
                        public void component(final FormComponent<?> formComponent, final IVisit<Void> visit)
                        {
                                final String inputName = formComponent.getInputName();
                                if (!currentParameterNamesSet.contains(inputName))
                                {
                                        String[] values = FormTester.getInputValue(formComponent);
                                        for (String value : values)
                                        {
                                                postParameters.addParameterValue(inputName, value);
                                        }
                                }
                        }
                });
        }

        /**
         * Retrieves the content type from the response header.
         *
         * @return the content type from the response header
         */
        public String getContentTypeFromResponseHeader()
        {
                String contentType = getLastResponse().getContentType();
                assertNotNull("No Content-Type header found", contentType);
                return contentType;
        }

        /**
         * Retrieves the content length from the response header.
         *
         * @return the content length from the response header
         */
        public int getContentLengthFromResponseHeader()
        {
                String contentLength = getLastResponse().getHeader("Content-Length");
                assertNotNull("No Content-Length header found", contentLength);
                return Integer.parseInt(contentLength);
        }

        /**
         * Retrieves the last-modified value from the response header.
         *
         * @return the last-modified value from the response header
         */
        public String getLastModifiedFromResponseHeader()
        {
                return getLastResponse().getHeader("Last-Modified");
        }

        /**
         * Retrieves the content disposition from the response header.
         *
         * @return the content disposition from the response header
         */
        public String getContentDispositionFromResponseHeader()
        {
                return getLastResponse().getHeader("Content-Disposition");
        }

        /**
         * Rebuilds {@link ServletWebRequest} used by wicket from the mock request used to build
         * requests. Sometimes this method is useful when changes need to be checked without processing
         * a request.
         */
        public void applyRequest()
        {
                Request req = newServletWebRequest();
                requestCycle.setRequest(req);
                if (useRequestUrlAsBase)
                {
                        requestCycle.getUrlRenderer().setBaseUrl(req.getUrl());
                }
        }

        /**
         *
         * @param message
         * @param condition
         * @return fail with message if false
         */
        private Result isTrue(String message, boolean condition)
        {
                if (condition)
                {
                        return Result.pass();
                }
                return Result.fail(message);
        }

        /**
         *
         * @param message
         * @param condition
         * @return fail with message if true
         */
        private Result isFalse(String message, boolean condition)
        {
                if (!condition)
                {
                        return Result.pass();
                }
                return Result.fail(message);
        }

        /**
         *
         * @param expected
         * @param actual
         * @return fail with message if not equal
         */
        protected final Result isEqual(Object expected, Object actual)
        {
                if (expected == null && actual == null)
                {
                        return Result.pass();
                }
                if (expected != null && expected.equals(actual))
                {
                        return Result.pass();
                }
                String message = "expected:<" + expected + "> but was:<" + actual + ">";
                return Result.fail(message);
        }

        /**
         *
         * @param message
         * @param object
         */
        private void notNull(String message, Object object)
        {
                if (object == null)
                {
                        fail(message);
                }
        }

        /**
         * Checks whether a component is visible and/or enabled before usage
         *
         * @param component
         * @param throwException
         * @return result
         */
        protected Result checkUsability(final Component component, boolean throwException)
        {
                Result res = Result.pass();

                if (component.isVisibleInHierarchy() == false)
                {
                        res = Result.fail(
                                "The component is currently not visible in the hierarchy and thus you can not be used."
                                        + " Component: " + component);
                }

                if (component.isEnabledInHierarchy() == false)
                {
                        res = Result.fail(
                                "The component is currently not enabled in the hierarchy and thus you can not be used."
                                        + " Component: " + component);
                }

                if (throwException && res.wasFailed())
                {
                        throw new AssertionError(res.getMessage());
                }
                return res;
        }

        /**
         * @return request cycle
         */
        public RequestCycle getRequestCycle()
        {
                return requestCycle;
        }

        /**
         * @return servlet response
         */
        public MockHttpServletResponse getResponse()
        {
                return response;
        }

        /**
         * @return last request
         */
        public MockHttpServletRequest getLastRequest()
        {
                return lastRequest;
        }

        /**
         * @return true, if exceptions are exposed
         */
        public boolean isExposeExceptions()
        {
                return exposeExceptions;
        }

        /**
         * @param exposeExceptions
         */
        public void setExposeExceptions(boolean exposeExceptions)
        {
                this.exposeExceptions = exposeExceptions;
        }

        /**
         * @return useRequestUrlAsBase
         */
        public boolean isUseRequestUrlAsBase()
        {
                return useRequestUrlAsBase;
        }

        /**
         * @param setBaseUrl
         */
        public void setUseRequestUrlAsBase(boolean setBaseUrl)
        {
                useRequestUrlAsBase = setBaseUrl;
        }

        /**
         * Starts a page, a shared resource or a {@link IRequestListener} depending on what the
         * {@link IRequestMapper}s resolve for the passed url.
         *
         * @param _url
         *            the url to resolve and execute
         */
        public void executeUrl(final String _url)
        {
                Url url = Url.parse(_url, Charset.forName(request.getCharacterEncoding()));
                transform(url);
                getRequest().setUrl(url);
                processRequest();
        }

        /**
         * A page that is used as the automatically created page for
         * {@link BaseWicketTester#startComponentInPage(Class)} and the other variations.
         * <p>
         * This page caches the generated markup so that it is available even after
         * {@link Component#detach()} where the {@link Component#markup component's markup cache} is
         * cleared.
         */
        public static class StartComponentInPage extends WebPage
        {
                private transient IMarkupFragment pageMarkup = null;

                /**
                 * Construct.
                 */
                public StartComponentInPage()
                {
                        setStatelessHint(false);
                }

                @Override
                public IMarkupFragment getMarkup()
                {
                        IMarkupFragment calculatedMarkup = null;
                        if (pageMarkup == null)
                        {
                                IMarkupFragment markup = super.getMarkup();
                                if (markup != null && markup != Markup.NO_MARKUP)
                                {
                                        calculatedMarkup = markup;
                                        pageMarkup = markup;
                                }
                        }
                        else
                        {
                                calculatedMarkup = pageMarkup;
                        }

                        return calculatedMarkup;
                }

                /**
                 * @param markup
                 */
                public void setPageMarkup(IMarkupFragment markup)
                {
                        setMarkup(markup);
                        pageMarkup = markup;
                }
        }

        private static class TestPageManagerProvider implements IPageManagerProvider
        {
                @Override
                public IPageManager get()
                {
                        return new MockPageManager();
                }
        }

        private static class WicketTesterServletWebResponse extends ServletWebResponse
                implements
                        IMetaDataBufferingWebResponse
        {
                private List<Cookie> cookies = new ArrayList<Cookie>();

                private WicketTesterServletWebResponse(ServletWebRequest request,
                        MockHttpServletResponse response)
                {
                        super(request, response);
                }

                @Override
                public void addCookie(Cookie cookie)
                {
                        super.addCookie(cookie);
                        cookies.add(cookie);
                }

                @Override
                public void writeMetaData(WebResponse webResponse)
                {
                        for (Cookie cookie : cookies)
                        {
                                webResponse.addCookie(cookie);
                        }
                }

                @Override
                public void sendRedirect(String url)
                {
                        super.sendRedirect(url);
                        try
                        {
                                getContainerResponse().sendRedirect(url);
                        }
                        catch (IOException e)
                        {
                                throw new RuntimeException(e);
                        }
                }
        }

        private class LastPageRecordingPageRendererProvider implements IPageRendererProvider
        {
                private final IPageRendererProvider delegate;

                private Page lastPage;

                private LastPageRecordingPageRendererProvider(IPageRendererProvider delegate)
                {
                        this.delegate = delegate;
                }

                @Override
                public PageRenderer apply(final RenderPageRequestHandler handler)
                {
                        return new PageRenderer(handler)
                        {
                                @Override
                                public void respond(RequestCycle requestCycle)
                                {
                                        delegate.apply(handler).respond(requestCycle);

                                        // WICKET-5424 record page after wrapped renderer has responded
                                        if (handler.getPageProvider().hasPageInstance())
                                        {
                                                Page renderedPage = (Page)handler.getPageProvider().getPageInstance();
                                                if (componentInPage != null && lastPage != null && renderedPage != null
                                                        && lastPage.getPageClass() != renderedPage.getPageClass())
                                                {
                                                        // WICKET-3913: reset startComponent if a new page
                                                        // type is rendered
                                                        componentInPage = null;
                                                }
                                                lastRenderedPage = lastPage = renderedPage;
                                        }
                                        else
                                        {
                                                lastRenderedPage = null;
                                        }
                                }
                        };
                }
        }

        private class TestExceptionMapper implements IExceptionMapper
        {
                private final IExceptionMapper delegate;

                private TestExceptionMapper(IExceptionMapper delegate)
                {
                        this.delegate = delegate;
                }

                @Override
                public IRequestHandler map(Exception e)
                {
                        if (exposeExceptions)
                        {
                                if (e instanceof RuntimeException)
                                {
                                        throw (RuntimeException)e;
                                }
                                else
                                {
                                        throw new WicketRuntimeException(e);
                                }
                        }
                        else
                        {
                                return delegate.map(e);
                        }
                }
        }

        private class TestRequestCycleProvider implements IRequestCycleProvider
        {
                private final IRequestCycleProvider delegate;

                private TestRequestCycleProvider(IRequestCycleProvider delegate)
                {
                        this.delegate = delegate;
                }

                @Override
                public RequestCycle apply(RequestCycleContext context)
                {
                        context.setRequestMapper(new TestRequestMapper(context.getRequestMapper()));
                        forcedHandler = null;
                        context.setExceptionMapper(new TestExceptionMapper(context.getExceptionMapper()));
                        return delegate.apply(context);
                }
        }

        private class TestRequestMapper implements IRequestMapperDelegate
        {
                private final IRequestMapper delegate;

                private TestRequestMapper(IRequestMapper delegate)
                {
                        this.delegate = delegate;
                }

                @Override
                public IRequestMapper getDelegateMapper()
                {
                        return delegate;
                }

                @Override
                public int getCompatibilityScore(Request request)
                {
                        return delegate.getCompatibilityScore(request);
                }

                @Override
                public Url mapHandler(IRequestHandler requestHandler)
                {
                        return delegate.mapHandler(requestHandler);
                }

                @Override
                public IRequestHandler mapRequest(Request request)
                {
                        if (forcedHandler != null)
                        {
                                IRequestHandler handler = forcedHandler;
                                forcedHandler = null;
                                return handler;
                        }
                        else
                        {
                                return delegate.mapRequest(request);
                        }
                }
        }

        public class TestFilterConfig implements FilterConfig
        {
                private final Map<String, String> initParameters = new HashMap<String, String>();

                private TestFilterConfig()
                {
                        initParameters.put(WicketFilter.FILTER_MAPPING_PARAM, "/servlet/*");
                }

                @Override
                public String getFilterName()
                {
                        return getClass().getName();
                }

                @Override
                public ServletContext getServletContext()
                {
                        return servletContext;
                }

                @Override
                public String getInitParameter(String s)
                {
                        return initParameters.get(s);
                }

                @Override
                public Enumeration<String> getInitParameterNames()
                {
                        throw new UnsupportedOperationException("Not implemented");
                }
        }
}