/*******************************************************************************
 * Copyright (c) 2008, 2016 xored software, Inc. and others.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.core.builder;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExecutableExtension;
import org.eclipse.dltk.ast.parser.IModuleDeclaration;
import org.eclipse.dltk.ast.parser.ISourceParser;
import org.eclipse.dltk.compiler.env.IModuleSource;
import org.eclipse.dltk.compiler.problem.ProblemCollector;
import org.eclipse.dltk.core.DLTKLanguageManager;
import org.eclipse.dltk.core.IScriptProject;
import org.eclipse.dltk.core.ISourceModuleInfoCache.ISourceModuleInfo;
import org.eclipse.dltk.core.SourceParserUtil;
import org.eclipse.dltk.internal.core.ModelManager;

public class ParserBuildParticipantFactory extends AbstractBuildParticipantType
		implements IExecutableExtension {

	@Override
	public IBuildParticipant createBuildParticipant(IScriptProject project)
			throws CoreException {
		if (natureId != null) {
			final ISourceParser parser = DLTKLanguageManager.getSourceParser(
					project.getProject(), natureId);
			if (parser != null) {
				return new ParserBuildParticipant(parser);
			}
		}
		return null;
	}

	private String natureId = null;

	@Override
	public void setInitializationData(IConfigurationElement config,
			String propertyName, Object data) throws CoreException {
		natureId = config.getAttribute("nature"); //$NON-NLS-1$
	}

	private static class ParserBuildParticipant implements IBuildParticipant {

		private final ISourceParser parser;

		public ParserBuildParticipant(ISourceParser parser) {
			this.parser = parser;
		}

		@Override
		public void build(IBuildContext context) throws CoreException {
			IModuleDeclaration moduleDeclaration = (IModuleDeclaration) context
					.get(IBuildContext.ATTR_MODULE_DECLARATION);
			if (moduleDeclaration != null) {
				// do nothing if already have AST - optimization for reconcile
				return;
			}
			// get cache entry
			final ISourceModuleInfo cacheEntry = ModelManager.getModelManager()
					.getSourceModuleInfoCache().get(context.getSourceModule());
			// check if there is cached AST
			moduleDeclaration = SourceParserUtil.getModuleFromCache(cacheEntry,
					context.getProblemReporter());
			if (moduleDeclaration != null) {
				// use AST from cache
				context.set(IBuildContext.ATTR_MODULE_DECLARATION,
						moduleDeclaration);
				return;
			}
			// create problem collector
			final ProblemCollector problemCollector = new ProblemCollector();
			// parse
			moduleDeclaration = parser
					.parse((IModuleSource) context.getSourceModule(),
							problemCollector);
			// put result to the cache
			SourceParserUtil.putModuleToCache(cacheEntry, moduleDeclaration,
					problemCollector);
			context.set(IBuildContext.ATTR_MODULE_DECLARATION,
					moduleDeclaration);
			// report errors to the build context
			problemCollector.copyTo(context.getProblemReporter());
		}
	}

}