/*
 * 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.extensions.markup.html.repeater.data.grid;

import java.util.List;

import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.markup.repeater.Item;
import org.apache.wicket.markup.repeater.RefreshingView;
import org.apache.wicket.markup.repeater.RepeatingView;
import org.apache.wicket.markup.repeater.data.DataViewBase;
import org.apache.wicket.markup.repeater.data.IDataProvider;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.Model;


/**
 * Acts as a base for data-grid views. Unlike a data view a data-grid view populates both rows and
 * columns. The columns are populated by an array of provided ICellPopulator objects.
 * 
 * @see DataGridView
 * 
 * @author Igor Vaynberg (ivaynberg)
 * 
 * @param <T>
 *            Model object type
 */
public abstract class AbstractDataGridView<T> extends DataViewBase<T>
{
        private static final long serialVersionUID = 1L;

        private static final String CELL_REPEATER_ID = "cells";
        private static final String CELL_ITEM_ID = "cell";

        private final List<? extends ICellPopulator<T>> populators;

        /**
         * Constructor
         * 
         * @param id
         *            component id
         * @param populators
         *            array of ICellPopulator objects that will be used to populate cell items
         * @param dataProvider
         *            data provider
         */
        public AbstractDataGridView(final String id,
                final List<? extends ICellPopulator<T>> populators, final IDataProvider<T> dataProvider)
        {
                super(id, dataProvider);

                this.populators = populators;
        }

        protected final List<? extends ICellPopulator<T>> internalGetPopulators()
        {
                return populators;
        }


        /**
         * Factory method for Item container that represents a cell.
         * 
         * @see Item
         * @see RefreshingView#newItem(String, int, IModel)
         * 
         * @param id
         *            component id for the new data item
         * @param index
         *            the index of the new data item
         * @param model
         *            the model for the new data item
         * 
         * @return DataItem created DataItem
         */
        protected Item<ICellPopulator<T>> newCellItem(final String id, final int index,
                final IModel<ICellPopulator<T>> model)
        {
                return new Item<>(id, index, model);
        }

        @Override
        protected final Item<T> newItem(final String id, final int index, final IModel<T> model)
        {
                return newRowItem(id, index, model);
        }

        /**
         * Factory method for Item container that represents a row.
         * 
         * @see Item
         * @see RefreshingView#newItem(String, int, IModel)
         * 
         * @param id
         *            component id for the new data item
         * @param index
         *            the index of the new data item
         * @param model
         *            the model for the new data item.
         * 
         * @return DataItem created DataItem
         */
        protected Item<T> newRowItem(final String id, final int index, final IModel<T> model)
        {
                return new Item<>(id, index, model);
        }


        /**
         * @see org.apache.wicket.markup.repeater.data.DataViewBase#onDetach()
         */
        @Override
        protected void onDetach()
        {
                super.onDetach();
                if (populators != null)
                {
                        for (ICellPopulator<T> populator : populators)
                        {
                                populator.detach();
                        }
                }
        }

        /**
         * @see org.apache.wicket.markup.repeater.RefreshingView#populateItem(org.apache.wicket.markup.repeater.Item)
         */
        @Override
        protected final void populateItem(final Item<T> item)
        {
                RepeatingView cells = new RepeatingView(CELL_REPEATER_ID);
                item.add(cells);

                int populatorsNumber = populators.size();
                for (int i = 0; i < populatorsNumber; i++)
                {
                        ICellPopulator<T> populator = populators.get(i);
                        IModel<ICellPopulator<T>> populatorModel = new Model<>(populator);
                        Item<ICellPopulator<T>> cellItem = newCellItem(cells.newChildId(), i, populatorModel);
                        cells.add(cellItem);

                        populator.populateItem(cellItem, CELL_ITEM_ID, item.getModel());

                        if (cellItem.get("cell") == null)
                        {
                                throw new WicketRuntimeException(
                                        populator.getClass().getName() +
                                                ".populateItem() failed to add a component with id [" +
                                                CELL_ITEM_ID +
                                                "] to the provided [cellItem] object. Make sure you call add() on cellItem and make sure you gave the added component passed in 'componentId' id. ( *cellItem*.add(new MyComponent(*componentId*, rowModel) )");
                        }
                }

        }
}