/*******************************************************************************
 * Copyright (c) 2007, 2010 BMW Car IT, Technische Universitaet Muenchen, and others.
 * 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:
 *     BMW Car IT - Initial API and implementation
 *     Technische Universitaet Muenchen - Major refactoring and extension
 *******************************************************************************/
package org.eclipse.emf.edapt.migration.test;

import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.Set;

import junit.framework.TestCase;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.edapt.common.ResourceUtils;
import org.eclipse.emf.edapt.history.reconstruction.ModelAssert;
import org.eclipse.emf.edapt.history.util.HistoryUtils;
import org.eclipse.emf.edapt.internal.migration.BackupUtils;
import org.eclipse.emf.edapt.internal.migration.Persistency;
import org.eclipse.emf.edapt.internal.migration.PrintStreamProgressMonitor;
import org.eclipse.emf.edapt.internal.migration.execution.IClassLoader;
import org.eclipse.emf.edapt.migration.MigrationException;
import org.eclipse.emf.edapt.migration.ReleaseUtils;
import org.eclipse.emf.edapt.migration.execution.Migrator;
import org.eclipse.emf.edapt.migration.execution.MigratorRegistry;
import org.eclipse.emf.edapt.spi.history.Release;
import org.eclipse.emf.edapt.spi.migration.Metamodel;

/**
 * A class for test cases to validate a model migration.
 * 
 * @author herrmama
 * @author $Author$
 * @version $Rev$
 * @levd.rating YELLOW Hash: 028BD5369E87644723FF537FB5E55E4D
 */
public abstract class MigrationTestBase extends TestCase {

	/**
	 * Test a model migration.
	 * 
	 * @param migratorURI
	 *            URI of the migrator
	 * @param modelURI
	 *            URI of the model to be migrated
	 * @param expectedTargetModelURI
	 *            URI of the expected result of the migration
	 * @param expectedTargetMetamodelURI
	 *            URI of the target metamodel of the migration
	 */
	public void testMigration(URI migratorURI, URI modelURI,
			URI expectedTargetModelURI, URI expectedTargetMetamodelURI,
			IClassLoader loader) throws MigrationException, IOException {

		Migrator migrator = new Migrator(migratorURI, loader);
		testMigration(migrator, modelURI, expectedTargetModelURI,
				expectedTargetMetamodelURI);
	}

	/**
	 * Test a model migration.
	 * 
	 * @param migrator
	 *            Migrator
	 * @param modelURI
	 *            URI of the model to be migrated
	 * @param expectedTargetModelURI
	 *            URI of the expected result of the migration
	 * @param expectedTargetMetamodelURI
	 *            URI of the target metamodel of the migration
	 */
	public void testMigration(Migrator migrator, URI modelURI,
			URI expectedTargetModelURI, URI expectedTargetMetamodelURI)
			throws MigrationException, IOException {
		testMigration(migrator, modelURI, expectedTargetModelURI,
				expectedTargetMetamodelURI, 0);
	}

	/**
	 * Test a model migration.
	 * 
	 * @param migrator
	 *            Migrator
	 * @param modelURI
	 *            URI of the model to be migrated
	 * @param expectedTargetModelURI
	 *            URI of the expected result of the migration
	 * @param expectedTargetMetamodelURI
	 *            URI of the target metamodel of the migration
	 * @param expectedNumber
	 *            Expected number of differences
	 */
	public void testMigration(Migrator migrator, URI modelURI,
			URI expectedTargetModelURI, URI expectedTargetMetamodelURI,
			int expectedNumber) throws MigrationException, IOException {

		Set<Release> releases = migrator.getRelease(modelURI);
		assertTrue(releases.size() >= 1);
		Release release = HistoryUtils.getMinimumRelease(releases);
		URI targetModelURI = rename(migrator, modelURI, release);

		migrator.migrateAndSave(Collections.singletonList(targetModelURI), release,
				null, new PrintStreamProgressMonitor(System.out));

		Metamodel expectedMetamodel = Persistency
				.loadMetamodel(expectedTargetMetamodelURI);

		EObject actualModel = ResourceUtils.loadResourceSet(targetModelURI,
				expectedMetamodel.getEPackages()).getResources().get(0)
				.getContents().get(0);
		EObject expectedModel = ResourceUtils.loadResourceSet(
				expectedTargetModelURI, expectedMetamodel.getEPackages())
				.getResources().get(0).getContents().get(0);

		ModelAssert
				.assertDifference(expectedModel, actualModel, expectedNumber);
	}

	/**
	 * Rename a model.
	 * 
	 * @param migrator
	 *            Migrator (required to be able to open the model)
	 * @param modelURI
	 *            URI of the model to be renamed
	 * @return URI of the renamed model
	 */
	private URI rename(Migrator migrator, URI modelURI, Release release)
			throws IOException {

		Metamodel metamodel = migrator.getMetamodel(release);
		List<URI> modelURIs = Collections.singletonList(modelURI);
		List<URI> backupURIs = rename(modelURIs, metamodel);
		return backupURIs.get(0);
	}

	/**
	 * Rename a model.
	 */
	protected List<URI> rename(List<URI> modelURIs, Metamodel metamodel)
			throws IOException {
		List<URI> backupURIs = BackupUtils.copy(modelURIs, metamodel,
				new BackupUtils.URIMapper() {

					public URI map(URI uri) {
						String name = uri.lastSegment().replace(".",
								"_migrated.");
						return uri.trimSegments(1).appendSegment(name);
					}

				});
		return backupURIs;
	}

	/**
	 * Test a model migration.
	 * 
	 * @param modelURI
	 *            URI of the model to be migrated
	 * @param expectedTargetModelURI
	 *            URI of the expected result of the migration
	 * @param expectedTargetMetamodelURI
	 *            URI of the target metamodel of the migration
	 */
	public void testMigration(URI modelURI, URI expectedTargetModelURI,
			URI expectedTargetMetamodelURI, int expectedDifferences)
			throws MigrationException, IOException {

		String nsURI = ReleaseUtils.getNamespaceURI(modelURI);

		Migrator migrator = MigratorRegistry.getInstance().getMigrator(nsURI);
		assertNotNull(migrator);
		testMigration(migrator, modelURI, expectedTargetModelURI,
				expectedTargetMetamodelURI, expectedDifferences);
	}
}