/*
 * 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.protocol.http.servlet;

import java.io.IOException;
import java.time.Instant;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.request.Url;
import org.apache.wicket.request.UrlRenderer;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.http.WebResponse;
import org.apache.wicket.util.lang.Args;

/**
 * WebResponse that wraps a {@link ServletWebResponse}.
 * 
 * @author Matej Knopp
 */
public class ServletWebResponse extends WebResponse
{
        private final HttpServletResponse httpServletResponse;
        private final ServletWebRequest webRequest;

        private boolean redirect = false;

        /**
         * Construct.
         * 
         * @param webRequest
         * @param httpServletResponse
         */
        public ServletWebResponse(ServletWebRequest webRequest, HttpServletResponse httpServletResponse)
        {
                Args.notNull(webRequest, "webRequest");
                Args.notNull(httpServletResponse, "httpServletResponse");

                this.httpServletResponse = httpServletResponse;
                this.webRequest = webRequest;
        }

        @Override
        public void addCookie(Cookie cookie)
        {
                httpServletResponse.addCookie(cookie);
        }

        @Override
        public void clearCookie(Cookie cookie)
        {
                cookie.setMaxAge(0);
                cookie.setValue(null);
                addCookie(cookie);
        }

        @Override
        public void setContentLength(long length)
        {
                httpServletResponse.addHeader("Content-Length", Long.toString(length));
        }

        @Override
        public void setContentType(String mimeType)
        {
                httpServletResponse.setContentType(mimeType);
        }

        @Override
        public void setDateHeader(String name, Instant date)
        {
                Args.notNull(date, "date");
                httpServletResponse.setDateHeader(name, date.toEpochMilli());
        }

        @Override
        public boolean isHeaderSupported()
        {
                return !httpServletResponse.isCommitted();
        }
        
        @Override
        public void setHeader(String name, String value)
        {
                httpServletResponse.setHeader(name, value);
        }

        @Override
        public void addHeader(String name, String value)
        {
                httpServletResponse.addHeader(name, value);
        }

        @Override
        public void write(CharSequence sequence)
        {
                try
                {
                        httpServletResponse.getWriter().append(sequence);
                }
                catch (IOException e)
                {
                        throw new ResponseIOException(e);
                }
        }

        @Override
        public void write(byte[] array)
        {
                try
                {
                        httpServletResponse.getOutputStream().write(array);
                }
                catch (IOException e)
                {
                        throw new ResponseIOException(e);
                }
        }

        @Override
        public void write(byte[] array, int offset, int length)
        {
                try
                {
                        httpServletResponse.getOutputStream().write(array, offset, length);
                }
                catch (IOException e)
                {
                        throw new ResponseIOException(e);
                }
        }


        @Override
        public void setStatus(int sc)
        {
                httpServletResponse.setStatus(sc);
        }

        @Override
        public void sendError(int sc, String msg)
        {
                try
                {
                        if (msg == null)
                        {
                                httpServletResponse.sendError(sc);
                        }
                        else
                        {
                                httpServletResponse.sendError(sc, msg);
                        }
                }
                catch (IOException e)
                {
                        throw new WicketRuntimeException(e);
                }
        }

        @Override
        public String encodeURL(CharSequence url)
        {
                Args.notNull(url, "url");

                UrlRenderer urlRenderer = getUrlRenderer();

                Url originalUrl = Url.parse(url);

                /*
                  WICKET-4645 - always pass absolute url to the web container for encoding
                  because when REDIRECT_TO_BUFFER is in use Wicket may render PageB when
                  PageA is actually the requested one and the web container cannot resolve
                  the base url properly
                 */
                String fullUrl = urlRenderer.renderFullUrl(originalUrl);
                String encodedFullUrl = httpServletResponse.encodeURL(fullUrl);

                final String encodedUrl;
                if (originalUrl.isFull())
                {
                        encodedUrl = encodedFullUrl;
                }
                else
                {
                        if (fullUrl.equals(encodedFullUrl))
                        {
                                // no encoding happened so just reuse the original url
                                encodedUrl = url.toString();
                        }
                        else
                        {
                                // get the relative url with the jsessionid encoded in it
                                Url _encoded = Url.parse(encodedFullUrl);
                                encodedUrl = urlRenderer.renderRelativeUrl(_encoded);
                        }
                }
                return encodedUrl;
        }

        private UrlRenderer getUrlRenderer()
        {
                RequestCycle requestCycle = RequestCycle.get();
                if (requestCycle == null)
                {
                        return new UrlRenderer(webRequest);
                }
                return requestCycle.getUrlRenderer();
        }

        @Override
        public String encodeRedirectURL(CharSequence url)
        {
                Args.notNull(url, "url");

                UrlRenderer urlRenderer = getUrlRenderer();

                Url originalUrl = Url.parse(url);

                /*
                 * WICKET-4645 - always pass absolute url to the web container for encoding because when
                 * REDIRECT_TO_BUFFER is in use Wicket may render PageB when PageA is actually the requested
                 * one and the web container cannot resolve the base url properly
                 */
                String fullUrl = urlRenderer.renderFullUrl(originalUrl);
                String encodedFullUrl = httpServletResponse.encodeRedirectURL(fullUrl);

                final String encodedUrl;
                if (originalUrl.isFull())
                {
                        encodedUrl = encodedFullUrl;
                }
                else
                {
                        if (fullUrl.equals(encodedFullUrl))
                        {
                                // no encoding happened so just reuse the original url
                                encodedUrl = url.toString();
                        }
                        else
                        {
                                // get the relative url with the jsessionid encoded in it
                                Url _encoded = Url.parse(encodedFullUrl);
                                encodedUrl = urlRenderer.renderRelativeUrl(_encoded);
                        }
                }
                return encodedUrl;
        }

        @Override
        public void sendRedirect(String url)
        {
                try
                {
                        redirect = true;
                        url = encodeRedirectURL(url);

                        // wicket redirects should never be cached
                        disableCaching();

                        if (webRequest.isAjax())
                        {
                                setHeader("Ajax-Location", url);
                                setContentType("text/xml;charset=" +
                                        webRequest.getContainerRequest().getCharacterEncoding());

                                /*
                                 * usually the Ajax-Location header is enough and we do not need to the redirect url
                                 * into the response, but sometimes the response is processed via an iframe (eg
                                 * using multipart ajax handling) and the headers are not available because XHR is
                                 * not used and that is the only way javascript has access to response headers.
                                 */
                                httpServletResponse.getWriter().write(
                                        "<ajax-response><redirect><![CDATA[" + url + "]]></redirect></ajax-response>");
                        }
                        else
                        {
                                httpServletResponse.sendRedirect(url);
                        }
                }
                catch (IOException e)
                {
                        throw new WicketRuntimeException(e);
                }
        }

        @Override
        public boolean isRedirect()
        {
                return redirect;
        }

        @Override
        public void flush()
        {
                try
                {
                        HttpServletRequest httpServletRequest = webRequest.getContainerRequest();
                        if (httpServletRequest.isAsyncStarted() == false)
                        {
                                httpServletResponse.flushBuffer();
                        }
                }
                catch (IOException e)
                {
                        throw new ResponseIOException(e);
                }
        }

        @Override
        public void reset()
        {
                super.reset();
                httpServletResponse.reset();
                redirect = false;
        }

        @Override
        public HttpServletResponse getContainerResponse()
        {
                return httpServletResponse;
        }

}