/*
 * Copyright (c) 2008 NoMagic, Inc. All Rights Reserved.
 */
package com.nomagic.magicdraw.examples.merge;

import com.nomagic.magicdraw.core.Application;
import com.nomagic.magicdraw.core.Project;
import com.nomagic.magicdraw.core.project.ProjectDescriptor;
import com.nomagic.magicdraw.core.project.ProjectDescriptorsFactory;
import com.nomagic.magicdraw.core.project.ProjectsManager;
import com.nomagic.magicdraw.diff.*;
import com.nomagic.magicdraw.diff.macro.MacroDifference;
import com.nomagic.magicdraw.merge.Change;
import com.nomagic.magicdraw.merge.ChangeState;
import com.nomagic.magicdraw.merge.MergeUtil;
import com.nomagic.magicdraw.merge.ProjectDifference;
import com.nomagic.magicdraw.merge.macro.MacroChange;
import com.nomagic.magicdraw.teamwork.application.TeamworkUtils;
import com.nomagic.magicdraw.uml.BaseElement;
import com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Operation;
import com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Property;
import com.nomagic.uml2.impl.PropertyNames;
import com.nomagic.utils.ErrorHandler;

import javax.annotation.CheckForNull;
import java.io.File;
import java.rmi.RemoteException;
import java.util.Iterator;
import java.util.Set;

/**
 * Project merge API usage sample.
 *
 * @author Martynas Lelevicius
 */
@SuppressWarnings({"UnusedDeclaration"})
public class MergeSample
{
	/**
	 * 2-way merge - merge source changes to target project.
	 *
	 * @param targetProject target project.
	 * @param sourceFile    source project file.
	 * @return merged project.
	 */
	@CheckForNull
	public static Project standard2wayMerge(Project targetProject, File sourceFile)
	{
		final ProjectDescriptor source = getProjectDescriptor(sourceFile);
		if (source == null)
		{
			return null;
		}
		if (MergeUtil.merge(targetProject, source, null, null, new SimpleErrorHandler(), MergeUtil.Optimization.PERFORMANCE))
		{
			// merged
			return Application.getInstance().getProjectsManager().getActiveProject();
		}
		// project not merged
		return null;
	}

	/**
	 * 3-way merge - merge branch changes to trunk.
	 *
	 * @param projectName remote project name.
	 * @param branchName  branch name.
	 * @return merged project.
	 * @throws java.rmi.RemoteException remote exception.
	 */
	@CheckForNull
	public static Project standard3wayMerge(String projectName, String branchName) throws RemoteException
	{
		final ProjectDescriptor trunkDescriptor = TeamworkUtils.getRemoteProjectDescriptorByQualifiedName(projectName);
		if (trunkDescriptor == null)
		{
			return null;
		}
		// load target project (trunk head)
		final ProjectsManager projectsManager = Application.getInstance().getProjectsManager();
		projectsManager.loadProject(trunkDescriptor, true);
		final Project targetProject = projectsManager.getActiveProject();
		if (targetProject == null)
		{
			return null;
		}

		// ancestor is 1st version from trunk
		final ProjectDescriptor ancestor = createProjectDescriptor(projectName, trunkDescriptor, 1);

		// source is 2nd version from branch
		final String branchedProjectName = TeamworkUtils.generateProjectQualifiedName(projectName, new String[]{branchName});
		final ProjectDescriptor branchDescriptor = TeamworkUtils.getRemoteProjectDescriptorByQualifiedName(branchedProjectName);
		if (branchDescriptor == null)
		{
			return null;
		}
		final ProjectDescriptor source = createProjectDescriptor(branchedProjectName, branchDescriptor, 2);
		if (source == null)
		{
			return null;
		}

		// merge project (prefer low memory usage to performance)
		if (MergeUtil.merge(targetProject, source, ancestor, MergeUtil.ConflictResolution.TARGET_PREFERRED, new SimpleErrorHandler(), MergeUtil.Optimization.MEMORY))
		{
			// merged
			// NOTE that merged project is not the same as targetProject after 3 way merge
			return projectsManager.getActiveProject();
		}
		// not merged
		return null;
	}

	/**
	 * Advanced 3-way merge - merge all changes except deletion of property "myProperty" and addition of operation "myOperation".
	 *
	 * @param targetProject target project.
	 * @param sourceFile,   source project file.
	 * @param ancestorFile  ancestor project file.
	 * @return merged project.
	 */
	@CheckForNull
	public static Project advanced3wayMerge(Project targetProject, File sourceFile, File ancestorFile)
	{
		final ProjectDescriptor source = getProjectDescriptor(sourceFile);
		if (source == null)
		{
			return null;
		}
		final ProjectDescriptor ancestor = getProjectDescriptor(ancestorFile);
		if (ancestor == null)
		{
			return null;
		}

		// NOTE! MagicDraw loads ancestor (in a 3-way merge) and source projects (if they are not loaded yet),
		// also changes active projects during merge. Your code must not load any additional projects on merge.

		// if you are going access the target or source projects after diff - use MergeUtil.Optimization.PERFORMANCE,
		// when using MergeUtil.Optimization.MEMORY - source and target projects are closed to reduce memory usage.
		final MergeUtil.Optimization optimization = MergeUtil.Optimization.PERFORMANCE;

		// get differences
		final ProjectDifference projectDifference = MergeUtil.getDifference(targetProject, source, ancestor, new SimpleErrorHandler(), optimization);

		if (projectDifference != null)
		{
			final ProjectsManager projectsManager = Application.getInstance().getProjectsManager();

			final Set<Change> sourceChanges = projectDifference.getSourceChanges();
			final Set<Change> targetChanges = projectDifference.getTargetChanges();

			if (!targetChanges.isEmpty() || !sourceChanges.isEmpty())
			{
				// standard change acceptance - accept all target changes and non conflicting source changes
				// swap passed parameters to accept all source changes and non conflicting target changes
				MergeUtil.acceptChanges(targetChanges, sourceChanges);

				Change deletion = null;
				Change addition = null;
				for (Iterator<Change> changeIterator = targetChanges.iterator(); changeIterator.hasNext() && (deletion == null || addition == null); )
				{
					final Change change = changeIterator.next();
					if (change.getState().equals(ChangeState.ACCEPTED))
					{
						for (Iterator<Difference> diffIterator = ((MacroChange) change).getDifference().getDifferences().iterator();
							 diffIterator.hasNext() && (deletion == null || addition == null); )
						{
							final Difference difference = diffIterator.next();
							if (deletion == null && difference instanceof ElementDeletion)
							{
								final ElementDeletion elementDeletion = (ElementDeletion) difference;
								// get ancestor project so we can search for "deleted" element
								final Project ancestorProject = projectsManager.findProject(ancestor);
								if (ancestorProject != null)
								{
									final String elementID = elementDeletion.getElementID();
									final BaseElement elementByID = ancestorProject.getElementByID(elementID);
									if (elementByID instanceof Property && "myProperty".equals(((Property) elementByID).getName()))
									{
										// deleted Property "myProperty"
										deletion = change;
									}
								}
							}
							else if (addition == null && difference instanceof ElementAddition)
							{
								final ElementAddition elementAddition = (ElementAddition) difference;
								// use MergeUtil.Optimization.PERFORMANCE option when getting differences to make sure the target project is not closed
								final String elementID = elementAddition.getElementID();
								final BaseElement elementByID = targetProject.getElementByID(elementID);
								if (elementByID instanceof Operation && "myOperation".equals(((Operation) elementByID).getName()))
								{
									// added(created) Operation "myOperation"
									addition = change;
								}
							}
						}
					}
				}
				if (deletion != null)
				{
					// reject element deletion
					MergeUtil.setChangeState(deletion, ChangeState.REJECTED);
				}
				if (addition != null)
				{
					// reject element addition
					MergeUtil.setChangeState(addition, ChangeState.REJECTED);
				}

				if (MergeUtil.getConflictingChanges(projectDifference.getTargetChanges()).isEmpty() || MergeUtil.showMergeGUI(projectDifference))
				{
					// if there are no conflicts or we resolved them via GUI
					// apply changes
					MergeUtil.applyChanges(projectDifference, new SimpleErrorHandler());

					// merged
					// NOTE that merged project is not the same as targetProject after 3 way merge
					return projectsManager.getActiveProject();
				}
			}
			else
			{
				// on diff MagicDraw may load projects, lock teamwork elements so need to restore previous state after diff
				MergeUtil.restore(projectDifference);
			}
		}
		return null;
	}

	/**
	 * Find elements that changed name.
	 *
	 * @param project         project.
	 * @param baseProjectFile base project file.
	 */
	public static void findElementsWithChangedName(Project project, File baseProjectFile)
	{
		final ProjectDescriptor baseProjectDescriptor = getProjectDescriptor(baseProjectFile);
		if (baseProjectDescriptor == null)
		{
			return;
		}

		// if you are going access the target or source projects after diff - use MergeUtil.Optimization.PERFORMANCE,
		// when using MergeUtil.Optimization.MEMORY - source project is closed to reduce memory usage.
		final MergeUtil.Optimization optimization = MergeUtil.Optimization.PERFORMANCE;
		// compare projects
		final ProjectDifference projectDifference = MergeUtil.compareProjects(project, baseProjectDescriptor, new SimpleErrorHandler(), optimization);
		if (projectDifference != null)
		{
			for (Change change : projectDifference.getChanges())
			{
				final MacroDifference macroDifference = ((MacroChange) change).getDifference();
				for (Difference difference : macroDifference.getDifferences())
				{
					// analyze difference
					if (difference instanceof ElementModification)
					{
						final ElementModification elementModification = (ElementModification) difference;
						if (PropertyNames.NAME.equals(elementModification.getChangedPropertyName()))
						{
							final BaseElement elementByID = project.getElementByID(elementModification.getElementID());
							if (elementByID != null)
							{
								// name changed for element
								final ModificationInfo modificationInfo = elementModification.getModificationInfo();
								System.out.println("Name for " + elementByID.getHumanName() + " changed to \"" +
												   ((PrimitiveValueModificationInfo) modificationInfo).getValue() + "\"");
							}
						}
					}
				}
			}

			// on diff MagicDraw may load projects, so need to restore previous state after diff
			MergeUtil.restore(projectDifference);
		}
	}

	/**
	 * Compare projects and display project difference GUI.
	 *
	 * @param project         project to compare.
	 * @param baseProjectFile base project file.
	 */
	public static void compareProjects(Project project, File baseProjectFile)
	{
		final ProjectDescriptor baseProjectDescriptor = getProjectDescriptor(baseProjectFile);
		if (baseProjectDescriptor != null)
		{
			final ProjectDifference difference = MergeUtil.compareProjects(project, baseProjectDescriptor, new SimpleErrorHandler(), MergeUtil.Optimization.MEMORY);
			if (difference != null)
			{
				if (difference.getChanges().isEmpty())
				{
					// on diff MagicDraw may load projects, so need to restore previous state after diff
					MergeUtil.restore(difference);
				}
				else
				{
					MergeUtil.showDifferenceGUI(difference);
				}
			}
		}
	}

	@CheckForNull
	private static ProjectDescriptor getProjectDescriptor(File sourceFile)
	{
		return ProjectDescriptorsFactory.createProjectDescriptor(sourceFile.toURI());
	}

	@CheckForNull
	private static ProjectDescriptor createProjectDescriptor(String projectName, ProjectDescriptor projectDescriptor, int version)
	{
		final String remoteID = ProjectDescriptorsFactory.getRemoteID(projectDescriptor.getURI());
		return remoteID != null ? ProjectDescriptorsFactory.createRemoteProjectDescriptor(remoteID, projectName, version) : null;
	}

	private static class SimpleErrorHandler implements ErrorHandler<Exception>
	{
		@Override
		public void error(Exception ex) throws Exception
		{
			// just print stack trace
			ex.printStackTrace();
		}
	}
}