Copyright (c) 2000, 2013 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core;

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.jdt.core.IClasspathContainer;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.internal.core.util.Util;
import org.osgi.service.prefs.BackingStoreException;

/**
 *
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class UserLibraryManager {

	public final static String CP_USERLIBRARY_PREFERENCES_PREFIX = JavaCore.PLUGIN_ID+".userLibrary."; //$NON-NLS-1$

	private Map userLibraries;

	public UserLibraryManager() {
		initialize();
	}

	/*
	 * Gets the library for a given name or <code>null</code> if no such library exists.
	 */
	public synchronized UserLibrary getUserLibrary(String libName) {
		return (UserLibrary) this.userLibraries.get(libName);
	}

	/*
	 * Returns the names of all defined user libraries. The corresponding classpath container path
	 * is the name appended to the CONTAINER_ID.
	 */
	public synchronized String[] getUserLibraryNames() {
		Set set = this.userLibraries.keySet();
		return (String[]) set.toArray(new String[set.size()]);
	}

	private void initialize() {
		this.userLibraries = new HashMap();
		IEclipsePreferences instancePreferences = JavaModelManager.getJavaModelManager().getInstancePreferences();
		String[] propertyNames;
		try {
			propertyNames = instancePreferences.keys();
		} catch (BackingStoreException e) {
			Util.log(e, "Exception while initializing user libraries"); //$NON-NLS-1$
			return;
		}

		boolean preferencesNeedFlush = false;
		for (int i = 0, length = propertyNames.length; i < length; i++) {
			String propertyName = propertyNames[i];
			if (propertyName.startsWith(CP_USERLIBRARY_PREFERENCES_PREFIX)) {
				String propertyValue = instancePreferences.get(propertyName, null);
				if (propertyValue != null) {
					String libName= propertyName.substring(CP_USERLIBRARY_PREFERENCES_PREFIX.length());
					StringReader reader = new StringReader(propertyValue);
					UserLibrary library;
					try {
						library = UserLibrary.createFromString(reader);
					} catch (IOException | ClasspathEntry.AssertionFailedException e) {
						Util.log(e, "Exception while initializing user library " + libName); //$NON-NLS-1$
						instancePreferences.remove(propertyName);
						preferencesNeedFlush = true;
						continue;
					}
					this.userLibraries.put(libName, library);
				}
			}
		}
		if (preferencesNeedFlush) {
			try {
				instancePreferences.flush();
			} catch (BackingStoreException e) {
				Util.log(e, "Exception while flusing instance preferences"); //$NON-NLS-1$
			}
		}
	}

	public void updateUserLibrary(String libName, String encodedUserLibrary) {
		try {
			// find affected projects
			IPath containerPath = new Path(JavaCore.USER_LIBRARY_CONTAINER_ID).append(libName);
			IJavaProject[] allJavaProjects = JavaCore.create(ResourcesPlugin.getWorkspace().getRoot()).getJavaProjects();
			ArrayList affectedProjects = new ArrayList();
			for (int i= 0; i < allJavaProjects.length; i++) {
				IJavaProject javaProject = allJavaProjects[i];
				IClasspathEntry[] entries= javaProject.getRawClasspath();
				for (int j= 0; j < entries.length; j++) {
					IClasspathEntry entry = entries[j];
					if (entry.getEntryKind() == IClasspathEntry.CPE_CONTAINER) {
						if (containerPath.equals(entry.getPath())) {
							affectedProjects.add(javaProject);
							break;
						}
					}
				}
			}

			// decode user library
			UserLibrary userLibrary = encodedUserLibrary == null ? null : UserLibrary.createFromString(new StringReader(encodedUserLibrary));

			synchronized (this) {
				// update user libraries map
				if (userLibrary != null) {
					this.userLibraries.put(libName, userLibrary);
				} else {
					this.userLibraries.remove(libName);
				}
			}

			// update affected projects
			int length = affectedProjects.size();
			if (length == 0)
				return;
			IJavaProject[] projects = new IJavaProject[length];
			affectedProjects.toArray(projects);
			IClasspathContainer[] containers = new IClasspathContainer[length];
			if (userLibrary != null) {
				UserLibraryClasspathContainer container = new UserLibraryClasspathContainer(libName);
				for (int i = 0; i < length; i++) {
					containers[i] = container;
				}
			}
			JavaCore.setClasspathContainer(containerPath, projects, containers, null);
		} catch (JavaModelException e) {
			Util.log(e, "Exception while setting user library '"+ libName +"'."); //$NON-NLS-1$ //$NON-NLS-2$
		} catch (IOException | ClasspathEntry.AssertionFailedException ase) {
			Util.log(ase, "Exception while decoding user library '"+ libName +"'."); //$NON-NLS-1$ //$NON-NLS-2$
		}
		
	}

	public void removeUserLibrary(String libName)  {
		synchronized (this.userLibraries) {
			IEclipsePreferences instancePreferences = JavaModelManager.getJavaModelManager().getInstancePreferences();
			String propertyName = CP_USERLIBRARY_PREFERENCES_PREFIX+libName;
			instancePreferences.remove(propertyName);
			try {
				instancePreferences.flush();
			} catch (BackingStoreException e) {
				Util.log(e, "Exception while removing user library " + libName); //$NON-NLS-1$
			}
		}
		// this.userLibraries was updated during the PreferenceChangeEvent (see preferenceChange(...))
	}

	public void setUserLibrary(String libName, IClasspathEntry[] entries, boolean isSystemLibrary)  {
		synchronized (this.userLibraries) {
			IEclipsePreferences instancePreferences = JavaModelManager.getJavaModelManager().getInstancePreferences();
			String propertyName = CP_USERLIBRARY_PREFERENCES_PREFIX+libName;
			try {
				String propertyValue = UserLibrary.serialize(entries, isSystemLibrary);
				instancePreferences.put(propertyName, propertyValue); // sends out a PreferenceChangeEvent (see preferenceChange(...))
			} catch (IOException e) {
				Util.log(e, "Exception while serializing user library " + libName); //$NON-NLS-1$
				return;
			}
			try {
				instancePreferences.flush();
			} catch (BackingStoreException e) {
				Util.log(e, "Exception while saving user library " + libName); //$NON-NLS-1$
			}
		}
		// this.userLibraries was updated during the PreferenceChangeEvent (see preferenceChange(...))
	}

}