/*******************************************************************************
 * Copyright (C) 2007 The University of Manchester
 *
 *  Modifications to the initial code base are copyright of their
 *  respective authors, or their employers as appropriate.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2.1 of
 *  the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 ******************************************************************************/
package net.sf.taverna.t2.workbench.file.impl;

import static org.apache.commons.collections.map.LazyMap.decorate;
import static org.apache.commons.lang.ClassUtils.getAllInterfaces;
import static org.apache.commons.lang.ClassUtils.getAllSuperclasses;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.taverna.workbench.file.DataflowPersistenceHandler;
import org.apache.taverna.workbench.file.FileType;

import org.apache.commons.collections.Factory;

// TODO: Cache lookups / build one massive structure
public class DataflowPersistenceHandlerRegistry {
	private static final MapFactory MAP_FACTORY = new MapFactory();
	private static final SetFactory SET_FACTORY = new SetFactory();

	@SuppressWarnings("unchecked")
	protected static List<Class<?>> findAllParentClasses(
			final Class<?> sourceClass) {
		List<Class<?>> superClasses = new ArrayList<>();
		superClasses.add(sourceClass);
		superClasses.addAll(getAllSuperclasses(sourceClass));
		superClasses.addAll(getAllInterfaces(sourceClass));
		return superClasses;
	}

	private Map<Class<?>, Set<DataflowPersistenceHandler>> openClassToHandlers;
	private Map<Class<?>, Set<FileType>> openClassToTypes;
	private Map<FileType, Map<Class<?>, Set<DataflowPersistenceHandler>>> openFileClassToHandler;
	private Map<FileType, Set<DataflowPersistenceHandler>> openFileToHandler;
	private Map<Class<?>, Set<DataflowPersistenceHandler>> saveClassToHandlers;
	private Map<Class<?>, Set<FileType>> saveClassToTypes;
	private Map<FileType, Map<Class<?>, Set<DataflowPersistenceHandler>>> saveFileClassToHandler;
	private Map<FileType, Set<DataflowPersistenceHandler>> saveFileToHandler;

	private List<DataflowPersistenceHandler> dataflowPersistenceHandlers;

	public DataflowPersistenceHandlerRegistry() {
	}

	public Set<FileType> getOpenFileTypes() {
		return getOpenFileClassToHandler().keySet();
	}

	public Set<FileType> getOpenFileTypesFor(Class<?> sourceClass) {
		Set<FileType> fileTypes = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(sourceClass))
			fileTypes.addAll(getOpenClassToTypes().get(candidateClass));
		return fileTypes;
	}

	public Set<DataflowPersistenceHandler> getOpenHandlersFor(
			Class<? extends Object> sourceClass) {
		Set<DataflowPersistenceHandler> handlers = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(sourceClass))
			handlers.addAll(getOpenClassToHandlers().get(candidateClass));
		return handlers;
	}

	public Set<DataflowPersistenceHandler> getOpenHandlersFor(
			FileType fileType, Class<? extends Object> sourceClass) {
		Set<DataflowPersistenceHandler> handlers = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(sourceClass))
			handlers.addAll(getOpenFileClassToHandler().get(fileType).get(
					candidateClass));
		return handlers;
	}

	public Set<DataflowPersistenceHandler> getOpenHandlersForType(
			FileType fileType) {
		return getOpenFileToHandler().get(fileType);
	}

	public synchronized Set<DataflowPersistenceHandler> getOpenHandlersForType(
			FileType fileType, Class<?> sourceClass) {
		Set<DataflowPersistenceHandler> handlers = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(sourceClass))
			handlers.addAll(getOpenFileClassToHandler().get(fileType).get(
					candidateClass));
		return handlers;
	}

	public Set<FileType> getSaveFileTypes() {
		return getSaveFileClassToHandler().keySet();
	}

	public Set<FileType> getSaveFileTypesFor(Class<?> destinationClass) {
		Set<FileType> fileTypes = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(destinationClass))
			fileTypes.addAll(getSaveClassToTypes().get(candidateClass));
		return fileTypes;
	}

	public Set<DataflowPersistenceHandler> getSaveHandlersFor(
			Class<? extends Object> destinationClass) {
		Set<DataflowPersistenceHandler> handlers = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(destinationClass))
			handlers.addAll(getSaveClassToHandlers().get(candidateClass));
		return handlers;
	}

	public Set<DataflowPersistenceHandler> getSaveHandlersForType(
			FileType fileType, Class<?> destinationClass) {
		Set<DataflowPersistenceHandler> handlers = new LinkedHashSet<>();
		for (Class<?> candidateClass : findAllParentClasses(destinationClass))
			handlers.addAll(getSaveFileClassToHandler().get(fileType).get(
					candidateClass));
		return handlers;
	}

	@SuppressWarnings({ "unchecked", "rawtypes" })
	private synchronized void createCollections() {
		openFileClassToHandler = decorate(new HashMap(), MAP_FACTORY);
		openFileToHandler = decorate(new HashMap(), SET_FACTORY);
		openClassToTypes = decorate(new HashMap(), SET_FACTORY);
		openClassToHandlers = decorate(new HashMap(), SET_FACTORY);

		saveFileClassToHandler = decorate(new HashMap(), MAP_FACTORY);
		saveFileToHandler = decorate(new HashMap(), SET_FACTORY);
		saveClassToTypes = decorate(new HashMap(), SET_FACTORY);
		saveClassToHandlers = decorate(new HashMap(), SET_FACTORY);
	}

	private Map<Class<?>, Set<DataflowPersistenceHandler>> getOpenClassToHandlers() {
		return openClassToHandlers;
	}

	private synchronized Map<Class<?>, Set<FileType>> getOpenClassToTypes() {
		return openClassToTypes;
	}

	private synchronized Map<FileType, Map<Class<?>, Set<DataflowPersistenceHandler>>> getOpenFileClassToHandler() {
		return openFileClassToHandler;
	}

	private Map<FileType, Set<DataflowPersistenceHandler>> getOpenFileToHandler() {
		return openFileToHandler;
	}

	private Map<Class<?>, Set<DataflowPersistenceHandler>> getSaveClassToHandlers() {
		return saveClassToHandlers;
	}

	private synchronized Map<Class<?>, Set<FileType>> getSaveClassToTypes() {
		return saveClassToTypes;
	}

	private synchronized Map<FileType, Map<Class<?>, Set<DataflowPersistenceHandler>>> getSaveFileClassToHandler() {
		return saveFileClassToHandler;
	}

	/**
	 * Bind method for SpringDM.
	 * 
	 * @param service
	 * @param properties
	 */
	public void update(Object service, Map<?, ?> properties) {
		if (dataflowPersistenceHandlers != null)
			updateColletions();
	}

	public synchronized void updateColletions() {
		createCollections();
		for (DataflowPersistenceHandler handler : dataflowPersistenceHandlers) {
			for (FileType openFileType : handler.getOpenFileTypes()) {
				Set<DataflowPersistenceHandler> set = openFileToHandler
						.get(openFileType);
				set.add(handler);
				for (Class<?> openClass : handler.getOpenSourceTypes()) {
					openFileClassToHandler.get(openFileType).get(openClass)
							.add(handler);
					openClassToTypes.get(openClass).add(openFileType);
				}
			}
			for (Class<?> openClass : handler.getOpenSourceTypes())
				openClassToHandlers.get(openClass).add(handler);

			for (FileType saveFileType : handler.getSaveFileTypes()) {
				saveFileToHandler.get(saveFileType).add(handler);
				for (Class<?> saveClass : handler.getSaveDestinationTypes()) {
					saveFileClassToHandler.get(saveFileType).get(saveClass)
							.add(handler);
					saveClassToTypes.get(saveClass).add(saveFileType);
				}
			}
			for (Class<?> openClass : handler.getSaveDestinationTypes())
				saveClassToHandlers.get(openClass).add(handler);
		}
	}

	public void setDataflowPersistenceHandlers(
			List<DataflowPersistenceHandler> dataflowPersistenceHandlers) {
		this.dataflowPersistenceHandlers = dataflowPersistenceHandlers;
	}

	private static class MapFactory implements Factory {
		@Override
		@SuppressWarnings("rawtypes")
		public Object create() {
			return decorate(new HashMap(), SET_FACTORY);
		}
	}

	private static class SetFactory implements Factory {
		@Override
		public Object create() {
			return new LinkedHashSet<Object>();
		}
	}
}