package org.simantics.interop.issues;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.swt.widgets.Display;

/**
 * IssueReporter is singleton class that handles collecting issues.
 * 
 * TODO: how to store issues when the application is closed? Memento-based?
 * 
 * @author Marko Luukkainen <marko.luukkainen@vtt.fi>
 *
 */
public class IssueReporter implements IssueListener{
	
	private static IssueReporter INSTANCE;
	
	private List<Issue> issues = new ArrayList<Issue>();
	private List<IssueReporterListener> listeners = new ArrayList<IssueReporterListener>();
	
	
	private IssueReporter() {
		
	}
	
	public static IssueReporter getInstance() {
		if (INSTANCE == null)
			INSTANCE = new IssueReporter();
		return INSTANCE;
	}
	
	/**
	 * Retuns list of issues.
	 * @return
	 */
	public List<Issue> getIssues() {
		return Collections.unmodifiableList(issues);
	}
	
	public void addIssue(Issue issue) {
		issues.add(issue);
		issue.addListener(this);
		fireAdded(issue);
	}
	
	public void removeIssue(Issue issue) {
		issue.removeListener(this);
		issues.remove(issue);
		fireRemoved(issue);
	}
	
	@Override
	public void updated(Issue issue) {
		fireUpdated(issue);
	}
	
	@Override
	public void disposed(Issue issue) {
		issue.removeListener(this);
		issues.remove(issue);
		fireRemoved(issue);
	}
	
	
	public void addListener(IssueReporterListener listener) {
		listeners.add(listener);
	}
	
	public void removeListener(IssueReporterListener listener) {
		listeners.remove(listener);
	}
	
	protected void fireAdded(final Issue issue) {
		Display.getDefault().asyncExec(new Runnable() {
			@Override
			public void run() {
				for (IssueReporterListener l : listeners)
					l.added(issue);
			}
		});
	}
	
	protected void fireRemoved(final Issue issue) {
		Display.getDefault().asyncExec(new Runnable() {
			@Override
			public void run() {
				for (IssueReporterListener l : listeners)
					l.removed(issue);
			}
		});
	}
	
	protected void fireUpdated(final Issue issue) {
		Display.getDefault().asyncExec(new Runnable() {
			@Override
			public void run() {
				for (IssueReporterListener l : listeners)
					l.updated(issue);
			}
		});
	}
	

}