/*******************************************************************************
 * Copyright (c) 2011 xored software, Inc.
 *
 * 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:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.compiler.problem;

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

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.dltk.compiler.util.Util;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.IScriptModelMarker;
import org.eclipse.dltk.internal.core.InternalDLTKLanguageManager;
import org.eclipse.dltk.utils.NatureExtensionManager;

public enum DefaultProblemIdentifier implements IProblemIdentifier {
	TASK;

	public String contributor() {
		return DLTKCore.PLUGIN_ID;
	}

	private static class Manager extends
			NatureExtensionManager<IProblemIdentifierFactory> {

		public Manager() {
			super(InternalDLTKLanguageManager.PROBLEM_FACTORY_EXTPOINT,
					IProblemIdentifierFactory.class);
		}

		@Override
		protected boolean isValidElement(IConfigurationElement element) {
			return "problemIdentifierFactory".equals(element.getName());
		}

		@Override
		protected String getCategoryAttributeName() {
			return "namespace";
		}

	}

	private static synchronized Manager getManager() {
		if (manager == null) {
			manager = new Manager();
		}
		return manager;
	}

	public static IProblemIdentifier decode(int id) {
		if (id == 0 || id == -1) {
			return null;
		}
		return new ProblemIdentifierInt(id);
	}

	public static IProblemIdentifier decode(String id) {
		if (id != null && id.length() != 0) {
			final int pos = id.indexOf(SEPARATOR);
			if (pos >= 0) {
				IProblemIdentifierFactory[] factories = getManager()
						.getInstances(id.substring(0, pos));
				if (factories != null) {
					final String localName = id.substring(pos + 1);
					for (IProblemIdentifierFactory factory : factories) {
						try {
							final IProblemIdentifier value = factory
									.valueOf(localName);
							if (value != null) {
								return value;
							}
						} catch (IllegalArgumentException e) {
							// ignore
						}
					}
				}
			}
			synchronized (reportedProblemIds) {
				if (reportedProblemIds.size() < 100
						&& reportedProblemIds.add(id)) {
					DLTKCore.warn("Error decoding problem idenfier \"" + id
							+ "\"");
				}
			}
			try {
				return new ProblemIdentifierInt(Integer.parseInt(id));
			} catch (NumberFormatException e) {
				// ignore
			}
			return new ProblemIdentifierString(id);
		} else {
			return null;
		}
	}

	public static IProblemIdentifier[] values(String namespace) {
		final IProblemIdentifierFactory[] factories = getManager()
				.getInstances(namespace);
		final List<IProblemIdentifier> result = new ArrayList<IProblemIdentifier>();
		if (factories != null) {
			for (IProblemIdentifierFactory factory : factories) {
				Collections.addAll(result, factory.values());
			}
		}
		return result.toArray(new IProblemIdentifier[result.size()]);
	}

	private static final Set<String> reportedProblemIds = new HashSet<String>();

	public static IProblemIdentifier getProblemId(IMarker marker) {
		return decode(marker.getAttribute(IScriptModelMarker.ID, null));
	}

	private static final char SEPARATOR = '#';

	private static Manager manager = null;

	public static String encode(IProblemIdentifier identifier) {
		if (identifier == null) {
			return Util.EMPTY_STRING;
		} else if (identifier instanceof Enum<?>) {
			return identifier.getClass().getName() + SEPARATOR
					+ identifier.name();
		} else {
			return identifier.name();
		}
	}

}