/*******************************************************************************
 * Copyright (c) 2006-2012
 * Software Technology Group, Dresden University of Technology
 * DevBoost GmbH, Berlin, Amtsgericht Charlottenburg, HRB 140026
 * 
 * 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:
 *   Software Technology Group - TU Dresden, Germany;
 *   DevBoost GmbH - Berlin, Germany
 *      - initial API and implementation
 ******************************************************************************/
package org.reuseware.coconut.reuseextension.resource.rex.mopp;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.reuseware.coconut.resource.ReuseResources;
import org.reuseware.coconut.reuseextension.ReuseExtension;
import org.reuseware.coconut.reuseextension.resource.rex.IRexBuilder;
import org.reuseware.coconut.reuseextension.resource.rex.RexEProblemType;

/**
 * Builder for REX files that synchronizes the ID inside the REX file
 * with the ID in the repository, which is determined by the position
 * of the file in a store.
 */
public class RexBuilder implements IRexBuilder {
	
	/**
	 * @param uri of the REX file
	 * 
	 * @return true for all files
	 */
	public boolean isBuildingNeeded(URI uri) {
		return true;
	}
	
	/**
	 * @param resource the REX file that is synchronized
	 * @param monitor not used
	 * 
	 * @return org.eclipse.core.runtime.Status.OK_STATUS
	 */
	public IStatus build(RexResource resource, IProgressMonitor monitor) {
		String warning = validateAndCorrect(resource);
		if (warning != null) {
			resource.addWarning(warning, RexEProblemType.BUILDER_ERROR, resource.getContents().get(0));
		}
		return org.eclipse.core.runtime.Status.OK_STATUS;
	}
	
	private String validateAndCorrect(Resource resource) {
		if (resource.getContents().isEmpty()) {
			return null;
		}
		EObject root = resource.getContents().get(0);
		if (!(root instanceof ReuseExtension)) {
			return null;
		}
		ReuseExtension element = (ReuseExtension) root;

		List<String> idOutsideModel = ReuseResources.INSTANCE.getID(resource.getURI());
		if (idOutsideModel == null) {	
			return "Place this specification into a fragment store to activate it";
		}
		
		String warningMessage = null;
		
		List<String> idInsideModel = new ArrayList<String>(element.getRexNamespace());
		idInsideModel.add(element.getRexName());
		
		if (!idOutsideModel.equals(idInsideModel)) {
			//correct!
			String name = idOutsideModel.remove(idOutsideModel.size() - 1);
			
			element.setRexName(name);
			element.getRexNamespace().clear();
			element.getRexNamespace().addAll(idOutsideModel);
			
			try {
				ResourceSet rs = resource.getResourceSet();
				Map<Object, Object> options = null;
				if (rs != null) {
					options = rs.getLoadOptions();
				}
				resource.save(options);
			} catch (IOException e) {
				RexPlugin.logError("Error during ID correction", e);
			}
			
		}

		return warningMessage;
	}

	public IStatus handleDeletion(URI uri, IProgressMonitor monitor) {
		return Status.OK_STATUS;
	}
}