/*
 * Copyright 2006 Mask@ Project.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.maskat.ide.wizards;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.InvocationTargetException;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.wizard.Wizard;
import org.eclipse.ui.INewWizard;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWizard;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.ide.IDE;
import org.maskat.ide.MaskatIDEUtil;
import org.maskat.ide.editors.MaskatEditor;

/**
 * This is a sample new wizard. Its role is to create a new file resource in the
 * provided container. If the container resource (a folder or a project) is
 * selected in the workspace when the wizard is opened, it will accept it as the
 * target container. The wizard creates one
 */
public class NewLayoutFileWizard extends Wizard implements INewWizard {
	private NewLayoutFileWizardPage page;

	private ISelection selection;

	/**
	 * Constructor for NewLayoutFileWizard.
	 */
	public NewLayoutFileWizard() {
		super();
		this.setWindowTitle("Maskat Layout File Wizard");
		setNeedsProgressMonitor(true);
	}

	/**
	 * Adding the page to the wizard.
	 */

	public void addPages() {
		page = new NewLayoutFileWizardPage(selection);
		addPage(page);
	}

	/**
	 * This method is called when 'Finish' button is pressed in the wizard. We
	 * will create an operation and run it using wizard as execution context.
	 */
	public boolean performFinish() {
		final String containerName = page.getContainerName();
		final String fileName = page.getFileName();
		final String layoutName = page.getLayoutName();
		IRunnableWithProgress op = new IRunnableWithProgress() {
			public void run(IProgressMonitor monitor) throws InvocationTargetException {
				try {
					doFinish(containerName, fileName, layoutName, monitor);
				} catch (CoreException e) {
					throw new InvocationTargetException(e);
				} finally {
					monitor.done();
				}
			}
		};
		try {
			getContainer().run(true, false, op);
		} catch (InterruptedException e) {
			return false;
		} catch (InvocationTargetException e) {
			Throwable realException = e.getTargetException();
			MessageDialog.openError(getShell(), "Error", realException.getMessage());
			return false;
		}
		return true;
	}

	/**
	 * The worker method. It will find the container, create the file if missing
	 * or just replace its contents, and open the editor on the newly created
	 * file.
	 */

	private void doFinish(String containerName, String fileName, String layoutName,
			IProgressMonitor monitor) throws CoreException {
		// create a sample file
		monitor.beginTask("Creating " + fileName, 2);
		IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
		IResource resource = root.findMember(new Path(containerName));
		if (!resource.exists() || !(resource instanceof IContainer)) {
			throwCoreException("Container \"" + containerName + "\" does not exist.");
		}
		IContainer container = (IContainer) resource;
		final IFile file = container.getFile(new Path(fileName));
		try {
			InputStream stream = openContentStream(layoutName);
			if (file.exists()) {
				throwCoreException("File already exists. Choose another name.");
			} else {
				file.create(stream, true, monitor);
			}
			stream.close();
		} catch (IOException e) {
		}
		monitor.worked(1);
		monitor.setTaskName("Opening file for editing...");
		getShell().getDisplay().asyncExec(new Runnable() {
			public void run() {
				IWorkbenchPage page = PlatformUI.getWorkbench()
						.getActiveWorkbenchWindow().getActivePage();
				try {
					IDE.openEditor(page, file, MaskatEditor.ID, true);
				} catch (PartInitException e) {
				}
			}
		});
		monitor.worked(1);
	}

	/**
	 * We will initialize file contents with a sample text.
	 * 
	 * @throws UnsupportedEncodingException
	 */

	private InputStream openContentStream(String layoutName)
			throws UnsupportedEncodingException {
		layoutName = layoutName.replaceAll("<", "&lt;").replaceAll(">", "&gt;")
				.replaceAll("\"", "&quot;");
		String lineSeparator = System.getProperty("line.separator");
		String contents = "<?xml version='1.0' encoding='UTF-16LE'?>" + lineSeparator
				+ "<!DOCTYPE layoutDef SYSTEM \"layoutDef.dtd\">" + lineSeparator
				+ "<layoutDef>" + lineSeparator + "   <layout name=\"" + layoutName
				+ "\" >" + lineSeparator + "   </layout>" + lineSeparator
				+ "</layoutDef>";
		return new ByteArrayInputStream(MaskatIDEUtil.addBOMSignature_LE(contents
				.getBytes("UTF-16LE")));
	}

	private void throwCoreException(String message) throws CoreException {
		IStatus status = new Status(IStatus.ERROR, "org.maskat.ide.gef", IStatus.OK,
				message, null);
		throw new CoreException(status);
	}

	/**
	 * We will accept the selection in the workbench to see if we can initialize
	 * from it.
	 * 
	 * @see IWorkbenchWizard#init(IWorkbench, IStructuredSelection)
	 */
	public void init(IWorkbench workbench, IStructuredSelection selection) {
		this.selection = selection;
	}
}