/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.dialogs;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.dialogs.*;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;

import java.util.List;
import java.util.Arrays;

/**
 * The common superclass for wizard import and export pages.
 * <p>
 * This class is not intended to be subclassed outside outside of the workbench.
 * </p>
 */
public abstract class WizardDataTransferPage
	extends WizardPage
	implements Listener, IOverwriteQuery {

	// constants
	protected static final int SIZING_TEXT_FIELD_WIDTH = 250;
	protected static final int COMBO_HISTORY_LENGTH = 5;
	/**
	 * Creates a new wizard page.
	 *
	 * @param pageName the name of the page
	 */
	protected WizardDataTransferPage(String pageName) {
		super(pageName);
	}

	/**
	 * Adds an entry to a history, while taking care of duplicate history items
	 * and excessively long histories.  The assumption is made that all histories
	 * should be of length <code>WizardDataTransferPage.COMBO_HISTORY_LENGTH</code>.
	 *
	 * @param history the current history
	 * @param newEntry the entry to add to the history
	 */
	protected String[] addToHistory(String[] history, String newEntry) {
		java.util.ArrayList l = new java.util.ArrayList(Arrays.asList(history));
		addToHistory(l, newEntry);
		String[] r = new String[l.size()];
		l.toArray(r);
		return r;
	}
	/**
	 * Adds an entry to a history, while taking care of duplicate history items
	 * and excessively long histories.  The assumption is made that all histories
	 * should be of length <code>WizardDataTransferPage.COMBO_HISTORY_LENGTH</code>.
	 *
	 * @param history the current history
	 * @param newEntry the entry to add to the history
	 */
	protected void addToHistory(List history, String newEntry) {
		history.remove(newEntry);
		history.add(0, newEntry);

		// since only one new item was added, we can be over the limit
		// by at most one item
		if (history.size() > COMBO_HISTORY_LENGTH)
			history.remove(COMBO_HISTORY_LENGTH);
	}
	/**
	 * Return whether the user is allowed to enter a new container name or just
	 * choose from existing ones.
	 * <p>
	 * Subclasses must implement this method.
	 * </p>
	 *
	 * @return <code>true</code> if new ones are okay, and <code>false</code>
	 *  if only existing ones are allowed
	 */
	protected abstract boolean allowNewContainerName();
	/**
	 * Creates a new label with a bold font.
	 *
	 * @param parent the parent control
	 * @param text the label text
	 * @return the new label control
	 */
	protected Label createBoldLabel(Composite parent, String text) {
		Label label = new Label(parent, SWT.NONE);
		label.setFont(JFaceResources.getBannerFont());
		label.setText(text);
		GridData data = new GridData();
		data.verticalAlignment = GridData.FILL;
		data.horizontalAlignment = GridData.FILL;
		label.setLayoutData(data);
		return label;
	}
	/**
	 * Creates the import/export options group controls.
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method does
	 * nothing. Subclasses wishing to define such components should reimplement
	 * this hook method.
	 * </p>
	 *
	 * @param parent the parent control
	 */
	protected void createOptionsGroupButtons(Group optionsGroup) {
	}
	/**
	 * Creates a new label with a bold font.
	 *
	 * @param parent the parent control
	 * @param text the label text
	 * @return the new label control
	 */
	protected Label createPlainLabel(Composite parent, String text) {
		Label label = new Label(parent, SWT.NONE);
		label.setText(text);
		label.setFont(parent.getFont());
		GridData data = new GridData();
		data.verticalAlignment = GridData.FILL;
		data.horizontalAlignment = GridData.FILL;
		label.setLayoutData(data);
		return label;
	}
	/**
	 * Creates a horizontal spacer line that fills the width of its container.
	 *
	 * @param parent the parent control
	 */
	protected void createSpacer(Composite parent) {
		Label spacer = new Label(parent, SWT.NONE);
		GridData data = new GridData();
		data.horizontalAlignment = GridData.FILL;
		data.verticalAlignment = GridData.BEGINNING;
		spacer.setLayoutData(data);
	}
	/**
	 * Returns whether this page is complete. This determination is made based upon
	 * the current contents of this page's controls.  Subclasses wishing to include
	 * their controls in this determination should override the hook methods 
	 * <code>validateSourceGroup</code> and/or <code>validateOptionsGroup</code>.
	 *
	 * @return <code>true</code> if this page is complete, and <code>false</code> if
	 *   incomplete
	 * @see #validateSourceGroup
	 * @see #validateOptionsGroup
	 */
	protected boolean determinePageCompletion() {
		boolean complete =
			validateSourceGroup()
				&& validateDestinationGroup()
				&& validateOptionsGroup();

		// Avoid draw flicker by not clearing the error
		// message unless all is valid.
		if (complete)
			setErrorMessage(null);

		return complete;
	}
	/**
	 * Get a path from the supplied text widget.
	 * @return org.eclipse.core.runtime.IPath
	 */
	protected IPath getPathFromText(Text textField) {
		String text = textField.getText();
		//Do not make an empty path absolute so as not to confuse with the root
		if (text.length() == 0)
			return new Path(text);
		else
			return (new Path(text)).makeAbsolute();
	}
	
	/**
	 * Queries the user to supply a container resource.
	 *
	 * @return the path to an existing or new container, or <code>null</code> if the
	 *    user cancelled the dialog
	 */
	protected IPath queryForContainer(
		IContainer initialSelection,
		String msg) {
			return queryForContainer(
				initialSelection,
				msg,
				null);
	}
		
	/**
	 * Queries the user to supply a container resource.
	 *
	 * @return the path to an existing or new container, or <code>null</code> if the
	 *    user cancelled the dialog
	 */
	protected IPath queryForContainer(
		IContainer initialSelection,
		String msg,
		String title) {
		ContainerSelectionDialog dialog =
			new ContainerSelectionDialog(
				getControl().getShell(),
				initialSelection,
				allowNewContainerName(),
				msg);
		if(title != null)
			dialog.setTitle(title);
		dialog.showClosedProjects(false);
		dialog.open();
		Object[] result = dialog.getResult();
		if (result != null && result.length == 1) {
			return (IPath) result[0];
		}
		return null;
	}
	/**
	 * The <code>WizardDataTransfer</code> implementation of this 
	 * <code>IOverwriteQuery</code> method asks the user whether the existing 
	 * resource at the given path should be overwritten.
	 *
	 * @param pathString 
	 * @return the user's reply: one of <code>"YES"</code>, <code>"NO"</code>, <code>"ALL"</code>, 
	 *   or <code>"CANCEL"</code>
	 */
	public String queryOverwrite(String pathString) {

		Path path = new Path(pathString);

		String messageString;
		//Break the message up if there is a file name and a directory
		//and there are at least 2 segments.
		if (path.getFileExtension() == null || path.segmentCount() < 2)
			messageString =
				IDEWorkbenchMessages.format(
					"WizardDataTransfer.existsQuestion", //$NON-NLS-1$
					new String[] { pathString });

		else
			messageString =
				IDEWorkbenchMessages.format(
					"WizardDataTransfer.overwriteNameAndPathQuestion", //$NON-NLS-1$
					new String[] {
						path.lastSegment(),
						path.removeLastSegments(1).toOSString()});

			final MessageDialog dialog = new MessageDialog(getContainer().getShell(), IDEWorkbenchMessages.getString("Question"), //$NON-NLS-1$
	null,
		messageString,
		MessageDialog.QUESTION,
		new String[] {
			IDialogConstants.YES_LABEL,
			IDialogConstants.YES_TO_ALL_LABEL,
			IDialogConstants.NO_LABEL,
			IDialogConstants.NO_TO_ALL_LABEL,
			IDialogConstants.CANCEL_LABEL },
		0);
		String[] response = new String[] { YES, ALL, NO, NO_ALL, CANCEL };
		//run in syncExec because callback is from an operation,
		//which is probably not running in the UI thread.
		getControl().getDisplay().syncExec(new Runnable() {
			public void run() {
				dialog.open();
			}
		});
		return dialog.getReturnCode() < 0
			? CANCEL
			: response[dialog.getReturnCode()];
	}
	/**
	 * Displays a Yes/No question to the user with the specified message and returns
	 * the user's response.
	 *
	 * @param message the question to ask
	 * @return <code>true</code> for Yes, and <code>false</code> for No
	 */
	protected boolean queryYesNoQuestion(String message) {
			MessageDialog dialog = new MessageDialog(getContainer().getShell(), IDEWorkbenchMessages.getString("Question"), //$NON-NLS-1$
	(Image) null,
		message,
		MessageDialog.NONE,
		new String[] { IDialogConstants.YES_LABEL, IDialogConstants.NO_LABEL },
		0);
		// ensure yes is the default

		return dialog.open() == 0;
	}
	/**
	 * Restores control settings that were saved in the previous instance of this
	 * page.  
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method does
	 * nothing. Subclasses may override this hook method.
	 * </p>
	 */
	protected void restoreWidgetValues() {
	}
	/**
	 * Saves control settings that are to be restored in the next instance of
	 * this page.  
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method does
	 * nothing. Subclasses may override this hook method.
	 * </p>
	 */
	protected void saveWidgetValues() {
	}
	/**
	 * Determine if the page is complete and update the page appropriately. 
	 */
	protected void updatePageCompletion() {
		boolean pageComplete = determinePageCompletion();
		setPageComplete(pageComplete);
		if (pageComplete) {
			setMessage(null);
		}
	}
	/**
	 * Updates the enable state of this page's controls.
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method does
	 * nothing. Subclasses may extend this hook method.
	 * </p>
	 */
	protected void updateWidgetEnablements() {
	}
	/**
	 * Returns whether this page's destination specification controls currently all
	 * contain valid values.
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method returns
	 * <code>true</code>. Subclasses may reimplement this hook method.
	 * </p>
	 *
	 * @return <code>true</code> indicating validity of all controls in the 
	 *   destination specification group
	 */
	protected boolean validateDestinationGroup() {
		return true;
	}
	/**
	 * Returns whether this page's options group's controls currently all contain
	 * valid values.
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method returns
	 * <code>true</code>. Subclasses may reimplement this hook method.
	 * </p>
	 *
	 * @return <code>true</code> indicating validity of all controls in the options
	 *   group
	 */
	protected boolean validateOptionsGroup() {
		return true;
	}
	/**
	 * Returns whether this page's source specification controls currently all
	 * contain valid values.
	 * <p>
	 * The <code>WizardDataTransferPage</code> implementation of this method returns
	 * <code>true</code>. Subclasses may reimplement this hook method.
	 * </p>
	 *
	 * @return <code>true</code> indicating validity of all controls in the 
	 *   source specification group
	 */
	protected boolean validateSourceGroup() {
		return true;
	}

	/**
	 *	Create the options specification widgets.
	 *
	 *	@param parent org.eclipse.swt.widgets.Composite
	 */
	protected void createOptionsGroup(Composite parent) {
		// options group
		Group optionsGroup = new Group(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		optionsGroup.setLayout(layout);
		optionsGroup.setLayoutData(
			new GridData(
				GridData.HORIZONTAL_ALIGN_FILL | GridData.GRAB_HORIZONTAL));
		optionsGroup.setText(IDEWorkbenchMessages.getString("WizardExportPage.options")); //$NON-NLS-1$
		optionsGroup.setFont(parent.getFont());

		createOptionsGroupButtons(optionsGroup);

	}

	/**
	 * Display an error dialog with the specified message.
	 *
	 * @param message the error message
	 */
	protected void displayErrorDialog(String message) {
		MessageDialog.openError(getContainer().getShell(), getErrorDialogTitle(), message); //$NON-NLS-1$
	}

	/**
	 * Display an error dislog with the information from the
	 * supplied exception.
	 * @param exception Throwable
	 */
	protected void displayErrorDialog(Throwable exception) {
		String message = exception.getMessage();
		//Some system exceptions have no message
		if (message == null)
			message =
				IDEWorkbenchMessages.format(
					"WizardDataTransfer.exceptionMessage", //$NON-NLS-1$
					new String[] { exception.toString()});
		displayErrorDialog(message);
	}

	/**
	 * Get the title for an error dialog. Subclasses should
	 * override.
	 */
	protected String getErrorDialogTitle() {
		return IDEWorkbenchMessages.getString(
			"WizardExportPage.internalErrorTitle"); //$NON-NLS-1$
	}

	
}