/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.scenegraph.g2d;

import java.awt.Component;
import java.awt.Container;
import java.awt.Graphics2D;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.swing.JComponent;
import javax.swing.RepaintManager;

import org.simantics.scenegraph.ILookupService;
import org.simantics.scenegraph.INode;
import org.simantics.scenegraph.LookupService;
import org.simantics.scenegraph.ParentNode;
import org.simantics.scenegraph.g2d.events.EventDelegator;
import org.simantics.scenegraph.g2d.events.INodeEventHandlerProvider;
import org.simantics.scenegraph.g2d.events.NodeEventHandler;

/**
 * The root node of a 2D scene graph.
 * 
 * Implements {@link ILookupService} according to the reference implementation
 * {@link LookupService}.
 * 
 * @author J-P Laine
 */
@SuppressWarnings("deprecation")
public class G2DSceneGraph extends G2DParentNode implements ILookupService, INodeEventHandlerProvider {

    private static final long          serialVersionUID = -7066146333849901429L;
    
    public static final String        IGNORE_FOCUS = "ignoreFocus";

    protected transient Container     rootPane         = null;
    // TODO: swing dependency in here might not be a good idea

    // This variable is actually used in remote use, when rendering is not performed locally
    private transient final Object     treeLock         = new Object();

    private HashMap<Object, Integer>   pending          = new HashMap<Object, Integer>();
    private HashMap<String, Object>    globalProperties = new HashMap<String, Object>();

    /**
     * For preventing duplicates on the nodesToRemove queue.
     */
    protected transient Set<INode>     nodesToRemoveSet = new HashSet<INode>();
    protected Deque<INode>             nodesToRemove    = new ArrayDeque<INode>();

    private transient EventDelegator   eventDelegator   = new EventDelegator(this);
    private transient NodeEventHandler eventHandler     = new NodeEventHandler(this);

    /**
     * The node that has input focus in the scene graph. The input node will
     * receive key and command events.
     */
    private transient IG2DNode         focusNode;

    /**
     * The custom repaint manager of this scene graph.
     */
    private transient G2DRepaintManager repaintManager;

    /**
     * Returns the event delegator, that is responsible for delegating events to nodes in the sg tree
     * 
     * @return EventDelegator instance, always not null
     */
    public EventDelegator getEventDelegator() {
        return eventDelegator;
    }

    /**
     * Returns the node event handler, that is responsible for delegating events
     * to nodes in the sg tree.
     * 
     * @return NodeEventHandler instance for this scene graph, always non-null
     */
    public NodeEventHandler getEventHandler() {
        return eventHandler;
    }

    public void setFocusNode(IG2DNode focusNode) {
        this.focusNode = focusNode;
    }

    public IG2DNode getFocusNode() {
        return focusNode;
    }

    @Override    
    public void render(Graphics2D g2d) {
        refresh();
        Component rootPane = getRootPane();
        if (rootPane != null)
            g2d.setRenderingHint(G2DRenderingHints.KEY_COMPONENT, rootPane);
        synchronized(treeLock) {
            super.render(g2d);
        }
    }

    @Override
    public void refresh() {
        performCleanup();
        super.refresh();
    }

    /**
     * Util method for executing updates to scenegraph tree
     * NOTE: You should really consider performance issues when using this
     * 
     * @param r  Runnable to be executed while rendering is not performed
     */
    public void syncExec(Runnable r) {
        synchronized(treeLock) {
            r.run();
        }
    }

    /**
     * Set rootpane for swing components. This is used as parent for the components created by ComponentNode.
     * 
     * @param rootPane Component that is used as a parent for the swing component (This shouldn't be visible)
     */
    public void setRootPane(JComponent rootPane) {
        synchronized (RepaintManager.class) {
            RepaintManager old = RepaintManager.currentManager(rootPane);
            old = findProperRepaintManager(old);
            this.repaintManager = new G2DRepaintManager(rootPane.getClass(), old);
            RepaintManager.setCurrentManager(repaintManager);
        }
        this.rootPane = rootPane;
    }

    /**
     * Set rootpane for swing components. This is used as parent for the components created by ComponentNode.
     * Supports separate component that is responsible for repainting the scenegraph.
     * 
     * @param rootPane     Component that is used as a parent for the swing component (This shouldn't be visible)
     * @param paintContext Component that is responsible for repainting the scenegraph
     */
    public void setRootPane(Container rootPane, Component paintContext) {
        synchronized (RepaintManager.class) {
            RepaintManager old = RepaintManager.currentManager(paintContext);
            old = findProperRepaintManager(old);
            this.repaintManager = new G2DRepaintManager(paintContext.getClass(), old);
            RepaintManager.setCurrentManager(repaintManager);
        }
        this.rootPane = rootPane;
    }

    private RepaintManager findProperRepaintManager(RepaintManager old) {
        while (old instanceof G2DRepaintManager) {
            G2DRepaintManager g2drm = (G2DRepaintManager) old;
            old = g2drm.getDelegate();
        }
        return old;
    }

    public G2DRepaintManager getRepaintManager() {
        return repaintManager;
    }

    /**
     * Put the node to the remove queue
     */
    @Override
    public void asyncRemoveNode(INode node) {
        synchronized(nodesToRemove) {
            // Prevent nodes from winding up twice on the nodesToRemove queue
            if (nodesToRemoveSet.add(node)) {
                nodesToRemove.add(node); // This is performed when called inside the render
            }
        }
    }

    /**
     * Perform the actual removal of the nodes in the nodesToRemove list
     */
    public void performCleanup() {
        synchronized(nodesToRemove) {
            while(nodesToRemove.size() > 0) {
                INode node = nodesToRemove.removeFirst();
                ParentNode<?> parent = node.getParent();
                // This works around issue #2071
                if (parent != null)
                    parent.removeNode(node);
            }
            if (!nodesToRemoveSet.isEmpty())
                nodesToRemoveSet.clear();
        }
    }

    @Override
    public void cleanup() {
        super.cleanup();
        nodesToRemove.clear();
        nodesToRemove = null;
        nodesToRemoveSet.clear();
        nodesToRemoveSet = null;
        eventHandler.dispose();
        eventHandler = null;
        eventDelegator.dispose();
        eventDelegator = null;
    }

    public Container getRootPane() {
        return (Container) this.rootPane;
    }

    @Override
    public String toString() {
        return super.toString() + " [root pane=" + rootPane + "]";
    }

    @Override
    public ParentNode<?> getRootNode() {
        // This is a root node!
        return this;
    }

    // ILookupService implementation

    private final Object             lookupLock = new Object();
    private final Map<String, INode> toNode     = new HashMap<String, INode>();
    private final Map<INode, String> toId       = new HashMap<INode, String>();

    transient Logger                 logger     = Logger.getLogger(getClass().getName());

    @Override
    public INode map(String id, INode node) {
        if (id == null)
            throw new NullPointerException("null id");
        if (node == null)
            throw new NullPointerException("null node");

        INode oldNode;
        String oldId;
        synchronized (lookupLock) {
            oldNode = toNode.put(id, node);
            oldId = toId.put(node, id);

            // Keep the mapping a consistent bijection:
            // If ID => INode mapping is removed, the INode => ID mappings must
            // removed also.

            if (oldNode != null && !oldNode.equals(node)) {
                String removedId = toId.remove(oldNode);
                if (!id.equals(removedId))
                    toNode.remove(removedId);
            }
            if (oldId != null && !oldId.equals(id)) {
                INode removedNode = toNode.remove(oldId);
                if (removedNode != node)
                    toId.remove(removedNode);
            }
        }
        if (logger.isLoggable(Level.FINER))
            logger.fine("map(" + id + ", " + node + ")");
        if (oldNode != null || oldId != null) {
            if (logger.isLoggable(Level.FINE)) {
                logger.info("replaced mappings for ID " + oldId + " and node " + oldNode);
            }
        }
        return oldNode;
    }

    @Override
    public INode unmap(String id) {
        INode node;
        String mappedId;
        synchronized (lookupLock) {
            node = toNode.remove(id);
            if (node == null)
                return null;
            mappedId = toId.remove(node);
        }
        if (logger.isLoggable(Level.FINER))
            logger.fine("unmap(" + id + "): " + node);
        if (mappedId != null && !mappedId.equals(id)) {
            if (logger.isLoggable(Level.WARNING))
                logger.log(Level.WARNING, "mapping was out-of-sync: " + id + " => " + node + " & " + mappedId + " => " + node, new Exception("trace"));
        }
        return node;
    }

    @Override
    public String unmap(INode node) {
        String id;
        INode mappedNode;
        synchronized (lookupLock) {
            id = toId.remove(node);
            if (node == null)
                return null;
            mappedNode = toNode.remove(id);
        }
        if (logger.isLoggable(Level.FINER))
            logger.fine("unmap(" + node + "): " + id);
        if (mappedNode != null && node != mappedNode) {
            if (logger.isLoggable(Level.WARNING))
                logger.log(Level.WARNING, "mapping was out-of-sync: " + node + " => " + id + " & " + id + " => " + mappedNode, new Exception("trace"));
        }
        return id;
    }

    @Override
    public INode lookupNode(String id) {
        synchronized (lookupLock) {
            return toNode.get(id);
        }
    }

    @Override
    public String lookupId(INode node) {
        synchronized (lookupLock) {
            return toId.get(node);
        }
    }

    public boolean isPending() {
        return !pending.isEmpty();
    }

    synchronized public void increasePending(Object object) {
        Integer ref = pending.get(object);
        if (ref == null) pending.put(object, 1);
        else pending.put(object, ref+1);
    }

    synchronized public void setPending(Object object) {
        pending.put(object, 1);
    }

    synchronized public void clearPending(Object object) {
        pending.remove(object);
    }

    synchronized public void decreasePending(Object object) {
        Integer ref = pending.get(object);
        if (ref == null) {
            return;
            //throw new IllegalStateException("Ref count in unregister was 0 for " + object);
        }
        if (ref > 1) pending.put(object, ref-1);
        else if (ref==1) pending.remove(object);
        else {
            return;
            //throw new IllegalStateException("Ref count in unregister was 0 for " + object);
        }
    }
    
    synchronized public void setGlobalProperty(String key, Object value) {
    	globalProperties.put(key, value);
    }
    
    @SuppressWarnings("unchecked")
	synchronized public <T> T getGlobalProperty(String key, T defaultValue) {
    	T t = (T)globalProperties.get(key);
    	if(t == null) return defaultValue;
    	return t;
    }

}