/*******************************************************************************
 * Copyright (c) 2008-2011 Chair for Applied Software Engineering,
 * Technische Universitaet Muenchen.
 * 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:
 ******************************************************************************/
package org.eclipse.emf.emfstore.client.model;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.Platform;
import org.eclipse.emf.edit.domain.EditingDomain;
import org.eclipse.emf.emfstore.client.model.connectionmanager.KeyStoreManager;
import org.eclipse.emf.emfstore.client.model.util.ConfigurationProvider;
import org.eclipse.emf.emfstore.client.model.util.DefaultWorkspaceLocationProvider;
import org.eclipse.emf.emfstore.common.model.util.ModelUtil;
import org.eclipse.emf.emfstore.server.LocationProvider;
import org.eclipse.emf.emfstore.server.model.ClientVersionInfo;
import org.osgi.framework.Bundle;

/**
 * Represents the current Workspace Configuration.
 * 
 * @author koegel
 */
public final class Configuration {

	private static final String CLIENT_NAME = "emfstore eclipse client";
	private static final String MODEL_VERSION_FILENAME = "modelReleaseNumber";
	private static final String UPS = ".ups";
	private static final String UOC = ".uoc";
	private static final String PROJECT_FOLDER = "project";
	private static final String PS = "ps-";
	private static final String UPF = ".upf";
	private static final String PLUGIN_BASEDIR = "pluginData";
	private static boolean testing;
	private static LocationProvider locationProvider;
	private static EditingDomain editingDomain;

	private Configuration() {
		// nothing to do
	}

	/**
	 * Get the Workspace directory.
	 * 
	 * @return the workspace directory path string
	 */
	public static String getWorkspaceDirectory() {
		String workspaceDirectory = getLocationProvider().getWorkspaceDirectory();
		File workspace = new File(workspaceDirectory);
		if (!workspace.exists()) {
			workspace.mkdirs();
		}
		if (!workspaceDirectory.endsWith(File.separator)) {
			return workspaceDirectory + File.separatorChar;
		}
		return workspaceDirectory;
	}

	/**
	 * Returns the registered {@link LocationProvider} or if not existent, the {@link DefaultWorkspaceLocationProvider}.
	 * 
	 * @return workspace location provider
	 */
	public static LocationProvider getLocationProvider() {
		if (locationProvider == null) {
			IConfigurationElement[] rawExtensions = Platform.getExtensionRegistry().getConfigurationElementsFor(
				"org.eclipse.emf.emfstore.client.workspaceLocationProvider");
			for (IConfigurationElement extension : rawExtensions) {
				try {
					Object executableExtension = extension.createExecutableExtension("providerClass");
					if (executableExtension instanceof LocationProvider) {
						locationProvider = (LocationProvider) executableExtension;
					}
				} catch (CoreException e) {
					String message = "Error while instantiating location provider, switching to default location!";
					ModelUtil.logWarning(message, e);
				}
			}
			if (locationProvider == null) {
				locationProvider = new DefaultWorkspaceLocationProvider();
			}
		}

		return locationProvider;
	}

	/**
	 * Get the Workspace file path.
	 * 
	 * @return the workspace file path string
	 */
	public static String getWorkspacePath() {
		return getWorkspaceDirectory() + "workspace.ucw";
	}

	/**
	 * Get the default resource save options.
	 * 
	 * @return the resource save options
	 */
	public static Map<Object, Object> getResourceSaveOptions() {
		// MK: the options below should only be used with resourcemodification
		// tracking enabled
		// if (resourceSaveOptions == null) {
		// resourceSaveOptions = new HashMap<Object, Object>();
		// resourceSaveOptions.put(Resource.OPTION_SAVE_ONLY_IF_CHANGED,
		// Resource.OPTION_SAVE_ONLY_IF_CHANGED_MEMORY_BUFFER);
		// }
		return null;
	}

	/**
	 * Get the default server info.
	 * 
	 * @return server info
	 */
	public static List<ServerInfo> getDefaultServerInfos() {
		IConfigurationElement[] rawExtensions = Platform.getExtensionRegistry().getConfigurationElementsFor(
			"org.eclipse.emf.emfstore.client.defaultConfigurationProvider");
		for (IConfigurationElement extension : rawExtensions) {
			try {
				ConfigurationProvider provider = (ConfigurationProvider) extension
					.createExecutableExtension("providerClass");
				List<ServerInfo> defaultServerInfos = provider.getDefaultServerInfos();
				if (defaultServerInfos != null) {
					return defaultServerInfos;
				}
			} catch (CoreException e) {
				// fail silently
			}
		}

		ArrayList<ServerInfo> result = new ArrayList<ServerInfo>();
		result.add(getLocalhostServerInfo());
		return result;
	}

	private static ServerInfo getLocalhostServerInfo() {
		ServerInfo serverInfo = ModelFactory.eINSTANCE.createServerInfo();
		serverInfo.setName("Localhost Server");
		serverInfo.setPort(8080);
		serverInfo.setUrl("localhost");
		serverInfo.setCertificateAlias(KeyStoreManager.DEFAULT_CERTIFICATE);

		Usersession superUsersession = ModelFactory.eINSTANCE.createUsersession();
		superUsersession.setServerInfo(serverInfo);
		superUsersession.setPassword("super");
		superUsersession.setSavePassword(true);
		superUsersession.setUsername("super");
		serverInfo.setLastUsersession(superUsersession);

		return serverInfo;
	}

	/**
	 * Returns maximum number of model elements allowed per resource.
	 * 
	 * @return the maximum number
	 */
	public static int getMaxMECountPerResource() {
		return 1000;
	}

	/**
	 * Returns maximum size of of a resource file on expand.
	 * 
	 * @return the maximum number
	 */
	public static int getMaxResourceFileSizeOnExpand() {
		return 50000;
	}

	/**
	 * Get the client version as in the org.eclipse.emf.emfstore.client manifest
	 * file.
	 * 
	 * @return the client version number
	 */
	public static ClientVersionInfo getClientVersion() {
		ClientVersionInfo clientVersionInfo = org.eclipse.emf.emfstore.server.model.ModelFactory.eINSTANCE
			.createClientVersionInfo();
		clientVersionInfo.setName(CLIENT_NAME);

		Bundle emfStoreBundle = Platform.getBundle("org.eclipse.emf.emfstore.client");
		String emfStoreVersionString = (String) emfStoreBundle.getHeaders().get(
			org.osgi.framework.Constants.BUNDLE_VERSION);

		clientVersionInfo.setVersion(emfStoreVersionString);
		return clientVersionInfo;
	}

	/**
	 * Determine if this is a release version or not.
	 * 
	 * @return true if it is a release version
	 */
	public static boolean isReleaseVersion() {
		return !isInternalReleaseVersion() && !getClientVersion().getVersion().endsWith("qualifier");
	}

	/**
	 * Determines if this is an internal release or not.
	 * 
	 * @return true if it is an internal release
	 */
	public static boolean isInternalReleaseVersion() {
		return getClientVersion().getVersion().endsWith("internal");
	}

	/**
	 * Determines if this is an developer version or not.
	 * 
	 * @return true if it is a developer version
	 */
	public static boolean isDeveloperVersion() {
		return !isReleaseVersion() && !isInternalReleaseVersion();
	}

	/**
	 * Return the file extension for project space files.
	 * 
	 * @return the file extension
	 */
	public static String getProjectSpaceFileExtension() {
		return UPS;
	}

	/**
	 * Return the file extension for operation composite files.
	 * 
	 * @return the file extension
	 */
	public static String getOperationCompositeFileExtension() {
		return UOC;
	}

	/**
	 * Return the name of the project folder.
	 * 
	 * @return the folder name
	 */
	public static String getProjectFolderName() {
		return PROJECT_FOLDER;
	}

	/**
	 * Return the prefix of the project space directory.
	 * 
	 * @return the prefix
	 */
	public static String getProjectSpaceDirectoryPrefix() {
		return PS;
	}

	/**
	 * Return project fragement file extension.
	 * 
	 * @return the file extension
	 */
	public static String getProjectFragmentFileExtension() {
		return UPF;
	}

	/**
	 * Return the name of the model release number file. This file identifies
	 * the release number of the model in the workspace.
	 * 
	 * @return the file name
	 */
	public static String getModelReleaseNumberFileName() {
		return getWorkspaceDirectory() + MODEL_VERSION_FILENAME;
	}

	/**
	 * If we are running tests. In this case the workspace will be created in
	 * USERHOME/.emfstore.test.
	 * 
	 * @param testing
	 *            the testing to set
	 */
	public static void setTesting(boolean testing) {
		Configuration.testing = testing;
	}

	/**
	 * @return if we are running tests. In this case the workspace will be
	 *         created in USERHOME/.emfstore.test.
	 */
	public static boolean isTesting() {
		return testing;
	}

	/**
	 * Return the path of the plugin data directory inside the emfstore
	 * workspace (trailing file separator included).
	 * 
	 * @return the plugin data directory absolute path as string
	 */
	public static String getPluginDataBaseDirectory() {
		return getWorkspaceDirectory() + PLUGIN_BASEDIR + File.separatorChar;
	}

	/**
	 * Retrieve the editing domain. Will return null until the domain is
	 * initialized by the WorkspaceManager.
	 * 
	 * @return the workspace editing domain
	 */
	public static EditingDomain getEditingDomain() {
		return Configuration.editingDomain;
	}

	/**
	 * Sets the EditingDomain.
	 * 
	 * @param editingDomain
	 *            new domain.
	 */
	public static void setEditingDomain(EditingDomain editingDomain) {
		Configuration.editingDomain = editingDomain;
	}

	/**
	 * Determines whether to use resource splitting.
	 * 
	 * @return true of resource splitting is enabled.
	 */
	public static boolean useCrossResourceRefs() {
		IConfigurationElement[] rawExtensions = Platform.getExtensionRegistry().getConfigurationElementsFor(
			"org.eclipse.emf.emfstore.client.persistence.options");
		for (IConfigurationElement extension : rawExtensions) {
			return new Boolean(extension.getAttribute("crossReference"));
		}
		return true;
	}
}