//------------------------------------------------------------------------------
// Copyright (c) 2005, 2006 IBM Corporation 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:
// IBM Corporation - initial implementation
//------------------------------------------------------------------------------
package org.eclipse.epf.publishing.ui.internal.wizards;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.epf.publishing.services.PublishManager;
import org.eclipse.epf.publishing.ui.PublishingUIPlugin;
import org.eclipse.epf.publishing.ui.wizards.IPublishConfigWizardExtender;
import org.eclipse.epf.ui.wizards.NewWizardPageContribution;
import org.eclipse.epf.ui.wizards.ReplaceWizardPageContribution;
import org.eclipse.jface.wizard.IWizardPage;

/**
 * Manages the "org.eclipse.epf.publishing.ui.publishConfigWizard" extension
 * point.
 * 
 * @author Kelvin Low
 * @since 1.0
 */
public class PublishConfigWizardExtensionManager {

	/**
	 * The extension point namespace.
	 */
	public static final String EXTENSION_POINT_NAMESPACE = "org.eclipse.epf.publishing.ui"; //$NON-NLS-1$

	/**
	 * The extension point name.
	 */
	public static final String EXTENSION_POINT_NAME = "publishConfigWizard"; //$NON-NLS-1$

	// The shared instance.
	private static PublishConfigWizardExtensionManager instance = new PublishConfigWizardExtensionManager();

	// An extender of the Publish Method Configuration wizard.
	private IPublishConfigWizardExtender wizardExtender;

	/**
	 * Creates a new instance.
	 */
	private PublishConfigWizardExtensionManager() {
		processExtensionPoint();
	}

	/**
	 * Returns the shared instance.
	 * 
	 * @return the shared instance
	 */
	public static PublishConfigWizardExtensionManager getInstance() {
		return instance;
	}

	/**
	 * Processes the "org.eclipse.epf.publishing.ui.publishConfigWizard"
	 * extension point.
	 */
	protected void processExtensionPoint() {
		IExtensionRegistry extensionRegistry = Platform.getExtensionRegistry();
		IExtensionPoint extensionPoint = extensionRegistry.getExtensionPoint(
				EXTENSION_POINT_NAMESPACE, EXTENSION_POINT_NAME);
		if (extensionPoint != null) {
			IExtension[] extensions = extensionPoint.getExtensions();
			for (int i = 0; i < extensions.length; i++) {
				IExtension extension = extensions[i];
				IConfigurationElement[] configElements = extension
						.getConfigurationElements();
				for (int j = 0; j < configElements.length; j++) {
					IConfigurationElement configElement = configElements[j];
					try {
						IPublishConfigWizardExtender extender = (IPublishConfigWizardExtender) configElement
								.createExecutableExtension("class"); //$NON-NLS-1$
						if (wizardExtender == null) {
							wizardExtender = extender;

							IConfigurationElement[] childConfigElements = configElement
									.getChildren("wizardPage"); //$NON-NLS-1$
							for (int k = 0; k < childConfigElements.length; k++) {
								IConfigurationElement childConfigElement = childConfigElements[k];
								IWizardPage wizardPage = (IWizardPage) childConfigElement
										.createExecutableExtension("class"); //$NON-NLS-1$
								String type = childConfigElement
										.getAttribute("type"); //$NON-NLS-1$
								String target = childConfigElement
										.getAttribute("target"); //$NON-NLS-1$
								String insert = childConfigElement
										.getAttribute("insert"); //$NON-NLS-1$
								if (wizardPage != null && type != null
										&& type.length() > 0) {
									if (type.equals("replace")) { //$NON-NLS-1$
										wizardExtender
												.addReplaceWizardPageContribution(new ReplaceWizardPageContribution(
														wizardPage, target));
									} else if (type.equals("new")) { //$NON-NLS-1$
										boolean insertAfter = true;
										if (insert != null
												&& insert.equals("before")) { //$NON-NLS-1$
											insertAfter = false;
										}
										wizardExtender
												.addNewWizardPageContribution(new NewWizardPageContribution(
														wizardPage, target,
														insertAfter));
									}
								}
							}

							childConfigElements = configElement
									.getChildren("publisher"); //$NON-NLS-1$
							if (childConfigElements.length > 0) {
								IConfigurationElement childConfigElement = childConfigElements[0];
								PublishManager publisher = (PublishManager) childConfigElement
										.createExecutableExtension("class"); //$NON-NLS-1$	
								wizardExtender.setPublisher(publisher);
							}

							return;
						}
					} catch (Exception e) {
						PublishingUIPlugin.getDefault().getLogger().logError(e);
					}
				}
			}
		}
	}

	/**
	 * Gets the Publish Method Configuration wizard extender loaded via the
	 * "org.eclipse.epf.publishing.ui.publishConfigWizard" extension point.
	 * 
	 * @return an Export MSP wizard extender or <code>null</code>
	 */
	public IPublishConfigWizardExtender getWizardExtender() {
		return wizardExtender;
	}

}