/*******************************************************************************
 * Copyright (c) 2007, 2011 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.charts.editor;

import java.util.concurrent.atomic.AtomicInteger;

import org.simantics.databoard.annotations.Optional;
import org.simantics.db.Resource;
import org.simantics.history.Collector;
import org.simantics.history.HistoryManager;
import org.simantics.simulation.data.Datasource;
import org.simantics.simulation.experiment.IExperiment;

/**
 * @author Tuukka Lehtonen
 */
public final class ChartData {

    /**
     * The model for which this ChartData is valid, i.e. the model that contains
     * {@link #run} if {@link #run} is non<code>non-null</code>
     */
    @Optional
    public Resource       model;

    /**
     * If just reading data from file system, not the database, this may be
     * <code>null</code>.
     */
    @Optional
    public Resource       run;

    /**
     * Used for giving the chart access to the active experiment state.
     */
    @Optional
    public IExperiment    experiment;

    /**
     * May be null if the chart data is not connected to a running experiment.
     */
    @Optional
    public Datasource     datasource;

    @Optional
    public HistoryManager history;

    /**
     * Optional collector, Chart uses this to flush data right before drawing it
     */
    @Optional
    public Collector      collector;

    /**
     * This (shared instance) is used to track the amount of users of this ChartData
     * instance. The same instance may end up in many ChartData instances through
     * {@link #readFrom(ChartData)}.
     */
    public AtomicInteger  refCount = new AtomicInteger();

    public ChartData(Resource model, Resource run, IExperiment experiment, Datasource datasource, HistoryManager history, Collector collector) {
        this.model = model;
        this.run = run;
        this.experiment = experiment;
        this.datasource = datasource;
        this.history = history;
        this.collector = collector;
    }
    
    public void readFrom(ChartData other) {
    	if (other==null) {
    		this.model = null;
    		this.run = null;
    		this.experiment = null;
    		this.datasource = null;
    		this.history = null;
    		this.collector = null;
    		this.refCount = null;
    	} else {
	    	this.model = other.model;
	    	this.run = other.run;
	    	this.experiment = other.experiment;
	    	this.datasource = other.datasource;
	    	this.history = other.history;
	    	this.collector = other.collector;
	    	this.refCount = other.refCount;
    	}
    }

    /**
     * Dispose by closing history
     */
    public void dispose() {
        model = null;
    	run = null;
    	experiment = null;
    	datasource = null;
    	if (history != null) {
    		history.close();
    		history = null;
    	}
    }

    public int reference() {
        AtomicInteger i = refCount;
        if (i == null)
            return 0;
        int result = i.incrementAndGet();
        //System.out.println(this + ": reference: " + (result-1) + " -> " + result + " (" + System.identityHashCode(refCount) + ")");
        return result;
    }

    public int dereference() {
        AtomicInteger i = refCount;
        if (i == null)
            return 0;
        int result = i.decrementAndGet();
        //System.out.println(this + ": dereference: " + (result+1) + " -> " + result + " (" + System.identityHashCode(refCount) + ")");
        if (result <= 0) {
            synchronized (i) {
                i.notifyAll();
            }
        }
        return result;
    }

    public void waitUntilNotReferenced() throws InterruptedException {
        AtomicInteger i = refCount;
        if (i == null)
            return;
        synchronized (i) {
            while (i.get() > 0) {
                i.wait();
            }
        }
    }

}