/*******************************************************************************
 * Copyright (c) 2007, 2018 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.diagram.participant;

import java.awt.Color;
import java.awt.Font;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;

import org.simantics.Simantics;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.request.PossibleIndexRoot;
import org.simantics.db.common.request.UnaryRead;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.adapter.Instances;
import org.simantics.db.layer0.request.IsActive;
import org.simantics.db.layer0.util.Layer0Utils;
import org.simantics.db.procedure.Listener;
import org.simantics.diagram.elements.TextNode;
import org.simantics.diagram.stubs.DiagramResource;
import org.simantics.g2d.canvas.Hints;
import org.simantics.g2d.canvas.ICanvasContext;
import org.simantics.g2d.canvas.SGDesignation;
import org.simantics.g2d.canvas.impl.AbstractCanvasParticipant;
import org.simantics.g2d.canvas.impl.HintReflection.HintListener;
import org.simantics.g2d.canvas.impl.SGNodeReflection.SGCleanup;
import org.simantics.g2d.canvas.impl.SGNodeReflection.SGInit;
import org.simantics.g2d.participant.RulerPainter;
import org.simantics.g2d.utils.Alignment;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.ModelingResources;
import org.simantics.scenegraph.g2d.G2DParentNode;
import org.simantics.scenegraph.utils.DPIUtil;
import org.simantics.structural.stubs.StructuralResource2;
import org.simantics.utils.datastructures.hints.IHintContext;
import org.simantics.utils.datastructures.hints.IHintContext.Key;
import org.simantics.utils.datastructures.hints.IHintContext.KeyOf;
import org.simantics.utils.datastructures.hints.IHintObservable;
import org.simantics.utils.ui.ErrorLogger;

/**
 * DiagramModelActivityTracker tracks whether or not the specified input
 * resource is part of the diagram model or not and modifies the canvas
 * background color accordingly. If the diagram is not in an active model, an
 * <b>INACTIVE MODEL</b> banner is also shown in the background using
 * {@link TextNode}.
 * 
 * @author Tuukka Lehtonen
 */
public class DiagramModelActivityTracker extends AbstractCanvasParticipant {

    public static final Key    KEY_IN_ACTIVE_MODEL         = new KeyOf(String.class, "IN_ACTIVE_MODEL");
    public static final Key    KEY_ACTIVE_BACKGROUND       = new KeyOf(Color.class, "ACTIVE_BACKGROUND");
    public static final Key    KEY_INACTIVE_BACKGROUND     = new KeyOf(Color.class, "INACTIVE_BACKGROUND");

    private static final Color DEFAULT_ACTIVE_BACKGROUND   = Color.WHITE;
    private static final Color DEFAULT_INACTIVE_BACKGROUND = new Color(242, 242, 242);

    Resource                   input;
    IsInActiveModelListener    listener;
    TextNode                   bannerNode;
    Rectangle2D                bounds;
    boolean                    rulerVisible = false;
    double                     rulerSize = 0;

    public DiagramModelActivityTracker(Resource input) {
        if (input == null)
            throw new NullPointerException("null input");
        this.input = input;
    }

    @HintListener(Class=Hints.class, Field="KEY_CONTROL_BOUNDS")
    public void controlBoundsChanged(IHintObservable sender, Key key, Object oldValue, Object newValue) {
        bounds = (Rectangle2D) newValue;
        resetBannerNode(bounds, rulerVisible, rulerSize);
    }

    @HintListener(Class=RulerPainter.class, Field="KEY_RULER_ENABLED")
    public void rulerToggled(IHintObservable sender, Key key, Object oldValue, Object newValue) {
        rulerVisible = Boolean.TRUE.equals(newValue);
        resetBannerNode(bounds, rulerVisible, rulerSize);
    }

    @HintListener(Class=RulerPainter.class, Field="KEY_RULER_SIZE")
    public void rulerSizeChanged(IHintObservable sender, Key key, Object oldValue, Object newValue) {
        rulerSize = newValue != null ? (Double) newValue : 0.0;
        resetBannerNode(bounds, rulerVisible, rulerSize);
    }

    private void resetBannerNode(Rectangle2D bounds, boolean rulerVisible, double rulerSize) {
        if (bannerNode == null)
            return;
        if (bounds != null) {
            AffineTransform at = new AffineTransform();
            at.translate(5,5);
            if (rulerVisible) {
                double s = DPIUtil.upscale(rulerSize);
                at.translate(s, s);
            }
            bannerNode.setTransform(at);
            bannerNode.setColor(Color.BLACK);
        } else {
            // Disable rendering
            bannerNode.setColor(null);
        }
    }

    @HintListener(Class=DiagramModelActivityTracker.class, Field="KEY_IN_ACTIVE_MODEL")
    public void containingModelActivityChanged(IHintObservable sender, Key key, Object oldValue, Object _newValue) {
    	String newValue = (String)_newValue;
        if (bannerNode == null)
            return;
        if (newValue == null) {
        	bannerNode.setText("");
        } else {
        	bannerNode.setText(newValue);
            //bannerNode.setColor(new Color(192, 32, 32, 128));
            //bannerNode.setColor(new Color(192, 32, 32, 32));
        }
    }

    @Override
    public void addedToContext(ICanvasContext ctx) {
        super.addedToContext(ctx);

        rulerVisible = Boolean.TRUE.equals(getHint(RulerPainter.KEY_RULER_ENABLED));
        Double rs = getHint(RulerPainter.KEY_RULER_SIZE);
        rulerSize = rs != null ? rs : 0;

        listener = new IsInActiveModelListener(ctx);
        Simantics.getSession().async(new IsActiveDiagram(input), listener);

        if (!ctx.getHintStack().containsHint(KEY_ACTIVE_BACKGROUND))
            ctx.getDefaultHintContext().setHint(KEY_ACTIVE_BACKGROUND, DEFAULT_ACTIVE_BACKGROUND);
        if (!ctx.getHintStack().containsHint(KEY_INACTIVE_BACKGROUND))
            ctx.getDefaultHintContext().setHint(KEY_INACTIVE_BACKGROUND, DEFAULT_INACTIVE_BACKGROUND);
    }

    @Override
    public void removedFromContext(ICanvasContext ctx) {
        if (listener != null) {
            listener.dispose();
            listener = null;
        }
        super.removedFromContext(ctx);
    }

    @SGInit(designation = SGDesignation.CONTROL)
    public void initSG(G2DParentNode parent) {
        bannerNode = parent.addNode("inactivity-banner", TextNode.class);
        bannerNode.setZIndex(Integer.MIN_VALUE / 4);
        //bannerNode.setZIndex(Integer.MAX_VALUE / 4);
        bannerNode.setHorizontalAlignment((byte) Alignment.LEADING.ordinal());
        bannerNode.setVerticalAlignment((byte) Alignment.LEADING.ordinal());
        //bannerNode.setText("Model is not active.");
        bannerNode.setText("");
        int fontSize = DPIUtil.upscale(16);
        bannerNode.setFont(new Font("Tahoma", Font.PLAIN, fontSize));
        //bannerNode.setBackgroundColor(new Color(192, 192, 192, 128));
        bannerNode.setPadding(10, 10);
        bannerNode.setBorderColor(Color.GRAY);
        bannerNode.setBorderWidth(0);
        bannerNode.setEditable(false);
        bannerNode.setColor(Color.BLACK);
    }

    @SGCleanup
    public void cleanupSG() {
        if (bannerNode != null) {
            bannerNode.remove();
            bannerNode = null;
        }
    }

    static class IsActiveDiagram extends UnaryRead<Resource, String> {
        public IsActiveDiagram(Resource parameter) {
            super(parameter);
        }
        @Override
        public String perform(ReadGraph graph) throws DatabaseException {
        	
            Resource indexRoot = graph.syncRequest( new PossibleIndexRoot(parameter) );
            if (indexRoot == null) {
                return "This diagram is not part of any model or shared library";
            }
        	Layer0 L0 = Layer0.getInstance(graph);
        	StructuralResource2 STR = StructuralResource2.getInstance(graph);
        	ModelingResources MOD = ModelingResources.getInstance(graph);
        	Resource composite = graph.getPossibleObject(parameter, MOD.DiagramToComposite);
        	if(composite == null)
                return "This diagram does not have a corresponding configuration";
        	
        	Resource componentType = graph.getPossibleObject(composite, STR.Defines);
        	if(componentType != null) {
        		// This is a component type
        		boolean published = Layer0Utils.isPublished(graph, componentType);
        		if(published)
                    return "This diagram defines a published (read-only) user component";
        	}
        	
        	if(graph.isInstanceOf(indexRoot, L0.SharedOntology)) {
        		return "";
        	}
        	
        	boolean activeModel = graph.syncRequest( new IsActive(indexRoot) );
        	if(!activeModel)
                return "The model of this diagram is not active";
        	
        	DiagramResource DIA = DiagramResource.getInstance(graph);
        	Instances query = graph.adapt(DIA.DiagramActivityCondition, Instances.class);

        	for(Resource condition : query.find(graph, indexRoot)) {
                String value = Simantics.tryInvokeSCL(graph, condition, DIA.DiagramActivityCondition_test, parameter);
                if(value != null && !value.isEmpty()) return value;
        	}
        	
            return "";
            
        }
    }

    static class IsInActiveModelListener implements Listener<String> {
        ICanvasContext context;
        public IsInActiveModelListener(ICanvasContext context) {
            this.context = context;
        }
        @Override
        public void execute(final String result) {
            final Color color = (result.isEmpty())
                    ? context.getHintStack().<Color>getHint(KEY_ACTIVE_BACKGROUND)
                    : context.getHintStack().<Color>getHint(KEY_INACTIVE_BACKGROUND);

            context.getThreadAccess().asyncExec(new Runnable() {
                @Override
                public void run() {
                    ICanvasContext ctx = context;
                    if (ctx == null)
                        return;
                    if (ctx.isDisposed())
                        return;
                    IHintContext hints = ctx.getDefaultHintContext();
                    if (color != null)
                        hints.setHint(Hints.KEY_BACKGROUND_COLOR, color);
                    hints.setHint(KEY_IN_ACTIVE_MODEL, result);
                }
            });
        }
        public void dispose() {
            context = null;
        }
        @Override
        public boolean isDisposed() {
            ICanvasContext context = this.context;
            return context == null || context.isDisposed();
        }
        @Override
        public void exception(Throwable t) {
            ErrorLogger.defaultLogError(t);
        }
    }

}