/* 
 * Copyright (c) 2005 FlexDock Development Team. All rights reserved. 
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of 
 * this software and associated documentation files (the "Software"), to deal in the 
 * Software without restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
 * to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all 
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE.
 */
package org.flexdock.perspective;

import java.awt.Component;
import java.awt.Dialog;
import java.awt.EventQueue;
import java.awt.Window;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

import javax.swing.SwingUtilities;

import org.flexdock.docking.Dockable;
import org.flexdock.docking.DockingConstants;
import org.flexdock.docking.DockingManager;
import org.flexdock.docking.DockingPort;
import org.flexdock.docking.event.hierarchy.DockingPortTracker;
import org.flexdock.docking.state.DockingState;
import org.flexdock.docking.state.FloatManager;
import org.flexdock.docking.state.LayoutManager;
import org.flexdock.docking.state.LayoutNode;
import org.flexdock.docking.state.PersistenceException;
import org.flexdock.event.EventManager;
import org.flexdock.event.RegistrationEvent;
import org.flexdock.perspective.event.LayoutEventHandler;
import org.flexdock.perspective.event.PerspectiveEvent;
import org.flexdock.perspective.event.PerspectiveEventHandler;
import org.flexdock.perspective.event.PerspectiveListener;
import org.flexdock.perspective.event.RegistrationHandler;
import org.flexdock.perspective.persist.FilePersistenceHandler;
import org.flexdock.perspective.persist.PersistenceHandler;
import org.flexdock.perspective.persist.PerspectiveModel;
import org.flexdock.util.RootWindow;
import org.flexdock.util.Utilities;

/**
 * @author Mateusz Szczap
 */
public class PerspectiveManager implements LayoutManager {

    public static final String EMPTY_PERSPECTIVE = "PerspectiveManager.EMPTY_PERSPECTIVE";
    public static final String DEFAULT_PERSISTENCE_KEY_VALUE = "perspectiveFile.data";
	private static PerspectiveManager SINGLETON = new PerspectiveManager();
	private static DockingStateListener UPDATE_LISTENER = new DockingStateListener();
	
	private HashMap m_perspectives = new HashMap();
	private PerspectiveFactory perspectiveFactory;
	private String m_defaultPerspective;
	private String m_currentPerspective;
	private PersistenceHandler m_persistHandler;
	private boolean restoreFloatingOnLoad;
	private String m_defaultPersistenceKey;
	
	static {
		initialize();
	}
	
	private static void initialize() {
		// TODO: Add logic to add and remove event handlers based on whether
		// the perspective manager is currently installed.  Right now, we're 
		// just referencing DockingManager.class to ensure the class is properly
		// initialized before we add our event handlers.  This should be 
		// called indirectly form within DockingManager, and we should have
		// uninstall capability as well.
		Class c = DockingManager.class;
		
		EventManager.addHandler(new RegistrationHandler());
		EventManager.addHandler(PerspectiveEventHandler.getInstance());
		EventManager.addHandler(new LayoutEventHandler());

		EventManager.addListener(UPDATE_LISTENER);
		
		String pKey = System.getProperty(DockingConstants.DEFAULT_PERSISTENCE_KEY);
		setPersistenceHandler(FilePersistenceHandler.createDefault(DEFAULT_PERSISTENCE_KEY_VALUE));
		getInstance().setDefaultPersistenceKey(pKey);
	}
	
	public static PerspectiveManager getInstance() {
		return SINGLETON;
	}
	
	public static void setFactory(PerspectiveFactory factory) {
		getInstance().perspectiveFactory = factory;
	}
	
	public static void setPersistenceHandler(PersistenceHandler handler) {
		getInstance().m_persistHandler = handler;
	}
	
	public static PersistenceHandler getPersistenceHandler() {
		return getInstance().m_persistHandler;
	}

	
	private PerspectiveManager() {
		setDefaultPerspective(EMPTY_PERSPECTIVE);
		loadPerspective(m_defaultPerspective, (DockingPort)null);
	}
	
	public void add(Perspective perspective) {
		add(perspective, false);
	}

	public void add(Perspective perspective, boolean isDefault) {
		if (perspective == null) throw new NullPointerException("perspective cannot be null");
		
		m_perspectives.put(perspective.getPersistentId(), perspective);
		if(isDefault)
			setDefaultPerspective(perspective.getPersistentId());
		
		EventManager.dispatch(new RegistrationEvent(perspective, this, true));
	}
	
	public void remove(String perspectiveId) {
		if (perspectiveId == null) throw new NullPointerException("perspectiveId cannot be null");
		
		Perspective perspective = getPerspective(perspectiveId);
		if (perspective == null)
			return;
		
		m_perspectives.remove(perspectiveId);

		//set defaultPerspective
		if(m_defaultPerspective.equals(perspectiveId))
			setDefaultPerspective(EMPTY_PERSPECTIVE);

		EventManager.dispatch(new RegistrationEvent(perspective, this, false));
	}
	
	public Perspective getPerspective(String perspectiveId) {
		if (perspectiveId == null)
			return null;
		
		Perspective perspective = (Perspective) m_perspectives.get(perspectiveId);
		if(perspective==null) {
			perspective = createPerspective(perspectiveId);
			if(perspective!=null) {
				add(perspective);
			}
		}
		return perspective;
	}
	
	public Perspective createPerspective(String perspectiveId) {
		if(EMPTY_PERSPECTIVE.equals(perspectiveId))
			return new Perspective(EMPTY_PERSPECTIVE, EMPTY_PERSPECTIVE) {
				public void load(DockingPort port, boolean defaultSetting) {
					// noop
				}
		};
		
        Perspective p = null;
        
        if (perspectiveFactory != null) {
            p = perspectiveFactory.getPerspective(perspectiveId);
            
            //this code ensures that perspective factory create perspectives that return the correct id
            //otherwise a NPE appears extremely far away in the code during the first docking operation
            if (!p.getPersistentId().equals(perspectiveId)) {
                //TODO create a good exception for this
                throw new IllegalStateException("Factory created perspective does not match intended ID: " + perspectiveId);
            }
        }
        
		return p;
	}
	
	public Perspective[] getPerspectives() {
		synchronized(m_perspectives) {
			ArrayList list = new ArrayList(m_perspectives.values());
			return (Perspective[])list.toArray(new Perspective[0]);
		}
		
	}
	
	public void addListener(PerspectiveListener perspectiveListener) {
		EventManager.addListener(perspectiveListener);
	}
	
	public void removeListener(PerspectiveListener perspectiveListener) {
		EventManager.removeListener(perspectiveListener);
	}
	
	public PerspectiveListener[] getPerspectiveListeners() {
		return PerspectiveEventHandler.getInstance().getListeners();
	}
	
	public void setDefaultPerspective(String perspectiveId) {
		m_defaultPerspective = perspectiveId;
	}
	
	public void setCurrentPerspective(String perspectiveId) {
		setCurrentPerspective(perspectiveId, false);
	}
	
	public String getCurrentPerspectiveName() {
		return m_currentPerspective;
	}
	
	private void setCurrentPerspectiveName(String name) {
		m_currentPerspective = "".equals(name)? null: name;
	}
	
	public void setCurrentPerspective(String perspectiveId, boolean asDefault) {
		perspectiveId = perspectiveId==null? m_defaultPerspective: perspectiveId;
		setCurrentPerspectiveName(perspectiveId);
		if(asDefault)
			setDefaultPerspective(perspectiveId);
	}
	
	public Perspective getDefaultPerspective() {
		return getPerspective(m_defaultPerspective);
	}

	public Perspective getCurrentPerspective() {
		return getPerspective(getCurrentPerspectiveName());
	}
	
	
	public DockingState getDockingState(Dockable dockable) {
		return getCurrentPerspective().getDockingState(dockable);
	}
	
	public DockingState getDockingState(String dockable) {
		return getCurrentPerspective().getDockingState(dockable);
	}
	
	public DockingState getDockingState(Dockable dockable, boolean load) {
		return getCurrentPerspective().getDockingState(dockable, load);
	}
	
	public DockingState getDockingState(String dockable, boolean load) {
		return getCurrentPerspective().getDockingState(dockable, load);
	}
	
	
	public FloatManager getFloatManager() {
		return getCurrentPerspective().getLayout();
	}

	public void reset() {
		RootWindow[] windows = DockingManager.getDockingWindows();
		if(windows.length!=0)
			reset(windows[0].getRootContainer());
	}
	
	public void reset(Component window) {
		if(window==null) {
			reset();
		}
		else {
			DockingPort port = DockingManager.getRootDockingPort(window);
			reset(port);
		}
	}
	
	public void reset(DockingPort rootPort) {
		loadPerspectiveImpl(getCurrentPerspectiveName(), rootPort, true);
	}
    
    /**
     * PerspectiveManager#getMainApplicationWindow returns the first
     * window where #getOwner == null. This is especially a problem for apps with
     * multiple frames. To display a perspective for a specified window
     * it is highly recommended to use #reload(Window w) instead of #reload()
     * which is the same as DockingManager#restoreLayout().
     * You can use #restoreLayout when the application does not need multiple
     * independent docking windows. 
     */    
    public void reload(Window w) {
      reload(w, true);
    }
    
    // use to load parentless frames 
    public void reload(Window w, boolean reset) {
        String current = getCurrentPerspectiveName();
        // if the current perspective is null, use the default value
        String key = current == null ? m_defaultPerspective : current;

        // null-out the current perspective name to force a reload
        // otherwise, the loadPerspective() call will short-circuit since 
        // it'll detect that the requested perspective is already loaded.
        setCurrentPerspectiveName(null);

        DockingPort port = DockingManager.getRootDockingPort(w);
        Perspective[] perspectives = getPerspectives();
        for (int i = 0; i < perspectives.length; i++)
        {  
          String id = perspectives[i].getPersistentId();
          if (!id.equals(EMPTY_PERSPECTIVE))
          {  
            //TODO reset layout, maybe there is a better way
            if (reset)
              perspectives[i].getLayout().setRestorationLayout(null);
            //p.unload();
            //p.reset(port);
          }  
        } 
        loadPerspectiveImpl(key, port, reset);
        
        // if perspective load fails, then rollback the perspective name
        // to its previous value (instead of null)
        if(!Utilities.isEqual(getCurrentPerspectiveName(), key))
          setCurrentPerspectiveName(current);
    }
    
    public void restore(Window w) throws IOException, PersistenceException {
        reload(w, true);
        load();
        reload(w, false);
        /*DockingPort port = DockingManager.getRootDockingPort(w);
        String current = getCurrentPerspectiveName();
        String key = current == null ? m_defaultPerspective : current;
        setCurrentPerspectiveName(null);
        loadPerspectiveImpl(key, port, false);
        if(!Utilities.isEqual(getCurrentPerspectiveName(), key))
          setCurrentPerspectiveName(current);*/
    }
        	
	public void reload() {
		String current = getCurrentPerspectiveName();
		// if the current perspective is null, the use the default value
		String key = current==null? m_defaultPerspective: current;
		// null-out the current perspective name to force a reload.
		// otherwise, the loadPerspective() call will short-circuit since 
		// it'll detect that the requested perspective is already loaded.
		setCurrentPerspectiveName(null);
		// load the perspective
		loadPerspective(key);
		// if the perspective load failed, then rollback the perspective name
		// to its previous value (instead of null)
		if(!Utilities.isEqual(getCurrentPerspectiveName(), key))
			setCurrentPerspectiveName(current);
	}

	public void loadPerspective() {
		loadPerspective(m_defaultPerspective);
	}
	
	public void loadPerspectiveAsDefault(String perspectiveId) {
		loadPerspectiveAsDefault(perspectiveId, false);
	}
	
	public void loadPerspectiveAsDefault(String perspectiveId, boolean reset) {
		if(perspectiveId!=null)
			setDefaultPerspective(perspectiveId);
		loadPerspective(perspectiveId, reset);
	}
	
	public void loadPerspective(String perspectiveId) {
		loadPerspective(perspectiveId, false);
	}
	
	public void loadPerspective(String perspectiveId, boolean reset) {
		RootWindow window = getMainApplicationWindow();
		if(window!=null) {
			loadPerspective(perspectiveId, window.getRootContainer(), reset);
			return;
		}
		
		DockingPort rootPort = findMainDockingPort();
		if(rootPort!=null)
			loadPerspective(perspectiveId, rootPort, reset);
	}
	
	public void loadPerspective(String perspectiveId, Component window) {
		loadPerspective(perspectiveId, window, false);
	}
	
	public void loadPerspective(String perspectiveId, Component window, boolean reset) {
		if(window==null) {
			loadPerspective(perspectiveId, reset);
			return;
		}
		
		DockingPort port = DockingManager.getRootDockingPort(window);
		loadPerspective(perspectiveId, port, reset);		
	}
	
	public void loadPerspective(String perspectiveId, DockingPort rootPort) {
		loadPerspective(perspectiveId, rootPort, false);
	}
	
	public void loadPerspective(String perspectiveId, DockingPort rootPort, boolean reset) {
		if(perspectiveId==null || perspectiveId.equals(getCurrentPerspectiveName()))
			return;
		loadPerspectiveImpl(perspectiveId, rootPort, reset);
	}
	
	private void loadPerspectiveImpl(String perspectiveId, final DockingPort rootPort, boolean reset) {
		if(perspectiveId==null)
			return;

		Perspective current = getCurrentPerspective();
		final Perspective perspective = getPerspective(perspectiveId);

		// remember the current layout state so we'll be able to
		// restore when we switch back
		if(current!=null) {
			cacheLayoutState(current, rootPort);
			current.unload();
		}
		
		// if the new perspective isn't available, then we're done
		if(perspective==null)
			return;
		
		synchronized(this) {
			setCurrentPerspectiveName(perspectiveId);
			if(reset) {
				perspective.reset(rootPort);
                EventManager.dispatch(new PerspectiveEvent(perspective, current,
                        PerspectiveEvent.RESET));
            } else {
				perspective.load(rootPort);
                EventManager.dispatch(new PerspectiveEvent(perspective, current,
                        PerspectiveEvent.CHANGED));
            }
		}
		
		EventQueue.invokeLater(new Runnable() {
			public void run() {
			    cacheLayoutState(perspective, rootPort);
			}
		});
	}
	
	private void cacheLayoutState(Perspective p, DockingPort port) {
		if(p!=null)
			p.cacheLayoutState(port);
	}
	
	
	
	public LayoutNode createLayout(DockingPort port) {
		return LayoutBuilder.getInstance().createLayout(port);
	}
	
	public boolean display(Dockable dockable) {
		return RestorationManager.getInstance().restore(dockable);
	}

	static void setDockingStateListening(boolean enabled) {
		UPDATE_LISTENER.setEnabled(enabled);
	}
	
	static boolean isDockingStateListening() {
		return UPDATE_LISTENER.isEnabled();
	}
	
	static void clear(DockingPort port) {
		if(port!=null) {
			boolean currState = isDockingStateListening();
			setDockingStateListening(false);
			port.clear();
			setDockingStateListening(currState);
		}
	}
	
	static void updateDockingStates(final Dockable[] dockables) {
		if(dockables==null)
			return;
			
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				for(int i=0; i<dockables.length; i++) {
					UPDATE_LISTENER.updateState(dockables[i]);
				}
			}
		});
	}
	
	public synchronized boolean store() throws IOException, PersistenceException {
		return store(null);
	}
	
	public synchronized boolean store(String persistenceKey) throws IOException, PersistenceException {
		if(m_persistHandler==null)
			return false;

		DockingPort rootPort = findMainDockingPort();
		cacheLayoutState(getCurrentPerspective(), rootPort);
		
		Perspective[] items = getPerspectives();
		for(int i=0; i<items.length; i++) {
			items[i] = (Perspective)items[i].clone();
		}
		
		PerspectiveModel info = new PerspectiveModel(m_defaultPerspective, getCurrentPerspectiveName(), items);
		String pKey = persistenceKey==null? m_defaultPersistenceKey: persistenceKey;
		return m_persistHandler.store(pKey, info);
	}
	
	public synchronized boolean load() throws IOException, PersistenceException {
		return load(null);
	}
	
	public synchronized boolean load(String persistenceKey) throws IOException, PersistenceException {
		if(m_persistHandler==null)
			return false;
		
		String pKey = persistenceKey==null? m_defaultPersistenceKey: persistenceKey;
		PerspectiveModel info = m_persistHandler.load(pKey);
		if(info==null)
			return false;

		Perspective[] perspectives = info.getPerspectives();
		
		m_perspectives.clear();
		for(int i=0; i<perspectives.length; i++) {
			add(perspectives[i]);
		}
		setDefaultPerspective(info.getDefaultPerspective());
		setCurrentPerspectiveName(info.getCurrentPerspective());
		return true;
	}
	
	public static boolean isRestoreFloatingOnLoad() {
		return getInstance().restoreFloatingOnLoad;
	}
	
	public static void setRestoreFloatingOnLoad(boolean restoreFloatingOnLoad) {
		getInstance().restoreFloatingOnLoad = restoreFloatingOnLoad;
	}
		
    //FIXME returns wrong window (first found) for multiple frames
    public static RootWindow getMainApplicationWindow() {
		RootWindow[] windows = DockingManager.getDockingWindows();
		// if the DockingManager couldn't resolve any windows using the 
		// standard mechanism, we can try our own custom search
		if(windows.length==0)
			windows = resolveDockingWindows();

		// TODO: fix this code to keep track of the proper dialog owner
		RootWindow window = null;
		for(int i=0; i<windows.length; i++) {
			window = windows[i];
			if(window.getOwner()==null)
				break;
		}
		return window;
	}
	
	private static RootWindow[] resolveDockingWindows() {
		// locate all the root dockingports
		Set rootPorts = DockingPortTracker.getRootDockingPorts();
		ArrayList windows = new ArrayList(rootPorts.size());
		// for each dockingPort, resolve its root window
		for(Iterator it=rootPorts.iterator(); it.hasNext();) {
			DockingPort port = (DockingPort)it.next();
			RootWindow window = RootWindow.getRootContainer((Component)port);
			if(window!=null)
				windows.add(window);
		}
		return (RootWindow[])windows.toArray(new RootWindow[0]);
	}
	
	public static DockingPort getMainDockingPort() {
		RootWindow window = getMainApplicationWindow();
		return window==null? null: DockingManager.getRootDockingPort(window.getRootContainer());
	}
	
	public boolean restore(boolean loadFromStorage) throws IOException, PersistenceException {
		boolean loaded = loadFromStorage? load(): true;
		reload();
		return loaded;
	}
	
	public String getDefaultPersistenceKey() {
		return m_defaultPersistenceKey;
	}
	
	public void setDefaultPersistenceKey(String key) {
		m_defaultPersistenceKey = key;
	}
	
	private DockingPort findMainDockingPort() {
		Set rootPorts = DockingPortTracker.getRootDockingPorts();
		DockingPort rootPort = null;
		for(Iterator it=rootPorts.iterator(); it.hasNext();) {
			DockingPort port = (DockingPort)it.next();
			Window win = SwingUtilities.getWindowAncestor((Component)port);
			if(win instanceof Dialog)
				continue;
			
			rootPort = port;
			break;
		}
		return rootPort;
	}
}
