/*******************************************************************************
 * Copyright (c) 2000, 2018 IBM Corporation 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
 *
 *******************************************************************************/
package org.eclipse.dltk.internal.corext.refactoring.changes;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.core.IScriptFolder;
import org.eclipse.dltk.core.ISourceModule;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.internal.corext.refactoring.AbstractModelElementRenameChange;
import org.eclipse.dltk.internal.corext.refactoring.RefactoringCoreMessages;
import org.eclipse.dltk.internal.corext.refactoring.util.ModelElementUtil;
import org.eclipse.dltk.internal.corext.util.Messages;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.NullChange;
import org.eclipse.ltk.core.refactoring.RefactoringDescriptor;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;

public class RenameScriptFolderChange extends AbstractModelElementRenameChange {

	private Map fSourceModuleStamps;
	private final boolean fRenameSubpackages;

	public RenameScriptFolderChange(RefactoringDescriptor descriptor, IScriptFolder pack, String newName,
			String comment, boolean renameSubpackages) {
		this(descriptor, pack.getPath(), pack.getElementName(), newName, comment, IResource.NULL_STAMP, null,
				renameSubpackages);
		Assert.isTrue(!pack.isReadOnly(), "package must not be read only"); //$NON-NLS-1$
	}

	private RenameScriptFolderChange(RefactoringDescriptor descriptor, IPath resourcePath, String oldName,
			String newName, String comment, long stampToRestore, Map compilationUnitStamps, boolean renameSubpackages) {
		super(descriptor, resourcePath, oldName, newName, comment, stampToRestore);
		fSourceModuleStamps = compilationUnitStamps;
		fRenameSubpackages = renameSubpackages;
	}

	@Override
	public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException {
		RefactoringStatus result = new RefactoringStatus();
		IModelElement element = (IModelElement) getModifiedElement();
		// don't check for read-only since we don't go through
		// validate edit.
		result.merge(isValid(DIRTY));
		if (result.hasFatalError())
			return result;
		if (element != null && element.exists() && element instanceof IScriptFolder) {
			IScriptFolder pack = (IScriptFolder) element;
			if (fRenameSubpackages) {
				IScriptFolder[] allPackages = ModelElementUtil.getPackageAndSubpackages(pack);
				pm.beginTask("", allPackages.length); //$NON-NLS-1$
				for (int i = 0; i < allPackages.length; i++) {
					// don't check for read-only since we don't go through
					// validate edit.
					checkIfModifiable(result, allPackages[i], DIRTY);
					if (result.hasFatalError())
						return result;
					isValid(result, allPackages[i], new SubProgressMonitor(pm, 1));
				}
				pm.done();
			} else {
				isValid(result, pack, pm);
			}
		}
		return result;
	}

	private void isValid(RefactoringStatus result, IScriptFolder pack, IProgressMonitor pm) throws ModelException {
		ISourceModule[] units = pack.getSourceModules();
		pm.beginTask("", units.length); //$NON-NLS-1$
		for (int i = 0; i < units.length; i++) {
			pm.subTask(Messages.format(RefactoringCoreMessages.RenamePackageChange_checking_change,
					pack.getElementName()));
			checkIfModifiable(result, units[i], READ_ONLY | DIRTY);
			pm.worked(1);
		}
		pm.done();
	}

	@Override
	protected IPath createNewPath() {
		IScriptFolder oldPackage = getPackage();
		IPath oldPackageName = createPath(oldPackage.getElementName());
		IPath newPackageName = createPath(getNewName());
		return getResourcePath().removeLastSegments(oldPackageName.segmentCount()).append(newPackageName);
	}

	private static IPath createPath(String packageName) {
		return new Path(packageName.replace('.', IPath.SEPARATOR));
	}

	protected IPath createNewPath(IScriptFolder oldPackage) {
		IPath oldPackagePath = createPath(oldPackage.getElementName());
		IPath newPackagePath = createPath(getNewName(oldPackage));
		return oldPackage.getPath().removeLastSegments(oldPackagePath.segmentCount()).append(newPackagePath);
	}

	private String getNewName(IScriptFolder subpackage) {
		return getNewName() + subpackage.getElementName().substring(getOldName().length());
	}

	@Override
	public String getName() {
		String msg = fRenameSubpackages ? RefactoringCoreMessages.RenamePackageChange_name_with_subpackages
				: RefactoringCoreMessages.RenamePackageChange_name;
		return Messages.format(msg, getOldName(), getNewName());
	}

	@Override
	protected Change createUndoChange(long stampToRestore) throws CoreException {
		IScriptFolder pack = getPackage();
		if (pack == null)
			return new NullChange();
		Map stamps = new HashMap();
		if (!fRenameSubpackages) {
			addStamps(stamps, pack.getSourceModules());
		} else {
			IScriptFolder[] allPackages = ModelElementUtil.getPackageAndSubpackages(pack);
			for (int i = 0; i < allPackages.length; i++) {
				IScriptFolder currentPackage = allPackages[i];
				addStamps(stamps, currentPackage.getSourceModules());
			}
		}
		return new RenameScriptFolderChange(null, createNewPath(), getNewName(), getOldName(), getComment(),
				stampToRestore, stamps, fRenameSubpackages);
		// Note: This reverse change only works if the renamePackage change did
		// not merge the source package into an existing target.
	}

	private void addStamps(Map stamps, ISourceModule[] units) {
		for (int i = 0; i < units.length; i++) {
			IResource resource = units[i].getResource();
			long stamp = IResource.NULL_STAMP;
			if (resource != null && (stamp = resource.getModificationStamp()) != IResource.NULL_STAMP) {
				stamps.put(resource, Long.valueOf(stamp));
			}
		}
	}

	@Override
	protected void doRename(IProgressMonitor pm) throws CoreException {
		IScriptFolder pack = getPackage();
		if (pack == null)
			return;

		if (!fRenameSubpackages) {
			renamePackage(pack, pm, createNewPath(), getNewName());
		} else {
			IScriptFolder[] allPackages = ModelElementUtil.getPackageAndSubpackages(pack);

			pm.beginTask("", allPackages.length); //$NON-NLS-1$
			try {
				for (int i = 0; i < allPackages.length; i++) {
					IScriptFolder currentPackage = allPackages[i];
					renamePackage(currentPackage, new SubProgressMonitor(pm, 1), createNewPath(currentPackage),
							getNewName(currentPackage));
				}
			} finally {
				pm.done();
			}
		}
	}

	private void renamePackage(IScriptFolder pack, IProgressMonitor pm, IPath newPath, String newName)
			throws ModelException, CoreException {
		pack.rename(newName, false, pm);
		if (fSourceModuleStamps != null) {
			IScriptFolder newPack = (IScriptFolder) DLTKCore
					.create(ResourcesPlugin.getWorkspace().getRoot().getFolder(newPath));
			if (newPack.exists()) {
				ISourceModule[] units = newPack.getSourceModules();
				for (int i = 0; i < units.length; i++) {
					IResource resource = units[i].getResource();
					if (resource != null) {
						Long stamp = (Long) fSourceModuleStamps.get(resource);
						if (stamp != null) {
							resource.revertModificationStamp(stamp.longValue());
						}
					}
				}
			}
		}
	}

	private IScriptFolder getPackage() {
		return (IScriptFolder) getModifiedElement();
	}
}