/*
 * 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;

import java.io.File;

import org.apache.wicket.page.IPageManager;
import org.apache.wicket.page.IPageManagerContext;
import org.apache.wicket.page.PageStoreManager;
import org.apache.wicket.pageStore.AsynchronousDataStore;
import org.apache.wicket.pageStore.AsynchronousPageStore;
import org.apache.wicket.pageStore.DefaultPageStore;
import org.apache.wicket.pageStore.DiskDataStore;
import org.apache.wicket.pageStore.IDataStore;
import org.apache.wicket.pageStore.IPageStore;
import org.apache.wicket.serialize.ISerializer;
import org.apache.wicket.settings.StoreSettings;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.lang.Bytes;

/**
 * {@link IPageManagerProvider} implementation that creates new instance of {@link IPageManager}
 * that persists the pages in {@link DiskDataStore}
 */
public class DefaultPageManagerProvider implements IPageManagerProvider
{
	protected final Application application;

	/**
	 * Constructor.
	 * 
	 * @param application
	 *          The application instance
	 */
	public DefaultPageManagerProvider(Application application)
	{
		this.application = Args.notNull(application, "application");
	}

	@Override
	public IPageManager apply(IPageManagerContext pageManagerContext)
	{
		IDataStore dataStore = newDataStore();

		StoreSettings storeSettings = getStoreSettings();

		IPageStore pageStore;

		if (dataStore.canBeAsynchronous())
		{
			int capacity = storeSettings.getAsynchronousQueueCapacity();
			dataStore = new AsynchronousDataStore(dataStore, capacity);

			pageStore = newPageStore(dataStore);

			if (pageStore.canBeAsynchronous())
			{
				pageStore = new AsynchronousPageStore(pageStore, capacity);
			}
		}
		else
		{
			pageStore = newPageStore(dataStore);
		}

		return new PageStoreManager(application.getName(), pageStore, pageManagerContext);

	}

	protected IPageStore newPageStore(IDataStore dataStore)
	{
		int inmemoryCacheSize = getStoreSettings().getInmemoryCacheSize();
		ISerializer pageSerializer = application.getFrameworkSettings().getSerializer();
		return new DefaultPageStore(pageSerializer, dataStore, inmemoryCacheSize);
	}

	protected IDataStore newDataStore()
	{
		StoreSettings storeSettings = getStoreSettings();
		Bytes maxSizePerSession = storeSettings.getMaxSizePerSession();
		File fileStoreFolder = storeSettings.getFileStoreFolder();

		return new DiskDataStore(application.getName(), fileStoreFolder, maxSizePerSession);
	}

	StoreSettings getStoreSettings()
	{
		return application.getStoreSettings();
	}
}