Copyright (c) 2012, 2017 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) 2012, 2017 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.osgi.internal.framework;

import java.io.IOException;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import org.eclipse.osgi.framework.eventmgr.ListenerQueue;
import org.eclipse.osgi.framework.log.FrameworkLogEntry;
import org.eclipse.osgi.framework.util.SecureAction;
import org.eclipse.osgi.internal.framework.legacy.PackageAdminImpl;
import org.eclipse.osgi.internal.framework.legacy.StartLevelImpl;
import org.eclipse.osgi.internal.hookregistry.ClassLoaderHook;
import org.eclipse.osgi.internal.hookregistry.HookRegistry;
import org.eclipse.osgi.internal.location.EquinoxLocations;
import org.eclipse.osgi.internal.log.EquinoxLogServices;
import org.eclipse.osgi.internal.messages.Msg;
import org.eclipse.osgi.internal.serviceregistry.ServiceRegistry;
import org.eclipse.osgi.signedcontent.SignedContentFactory;
import org.eclipse.osgi.storage.Storage;
import org.eclipse.osgi.util.ManifestElement;
import org.eclipse.osgi.util.NLS;
import org.osgi.framework.AdminPermission;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;
import org.osgi.service.packageadmin.PackageAdmin;
import org.osgi.service.startlevel.StartLevel;
import org.osgi.util.tracker.ServiceTracker;

@SuppressWarnings("deprecation")
public class EquinoxContainer implements ThreadFactory, Runnable {
	public static final String NAME = "org.eclipse.osgi"; //$NON-NLS-1$
	static final SecureAction secureAction = AccessController.doPrivileged(SecureAction.createSecureAction());

	private final EquinoxConfiguration equinoxConfig;
	private final EquinoxLogServices logServices;
	private final Storage storage;
	private final PackageAdmin packageAdmin;
	private final StartLevel startLevel;
	private final Set<String> bootDelegation;
	private final String[] bootDelegationStems;
	private final boolean bootDelegateAll;
	private final boolean isProcessClassRecursionSupportedByAll;
	private final EquinoxEventPublisher eventPublisher;

	private final Object monitor = new Object();

	private final ClassLoader bootLoader;
	private ServiceRegistry serviceRegistry;
	private ContextFinder contextFinder;

	private ServiceTracker<SignedContentFactory, SignedContentFactory> signedContentFactory;

	private ScheduledExecutorService executor;
	private StorageSaver storageSaver;

	public EquinoxContainer(Map<String, ?> configuration) {
		ClassLoader platformClassLoader = null;
		try {
			Method getPlatformClassLoader = ClassLoader.class.getMethod("getPlatformClassLoader"); //$NON-NLS-1$
			platformClassLoader = (ClassLoader) getPlatformClassLoader.invoke(null);
		} catch (Throwable t) {
			// try everything possible to not fail
			platformClassLoader = new ClassLoader(Object.class.getClassLoader()) {
				/* boot class loader */};
		}
		this.bootLoader = platformClassLoader;
		this.equinoxConfig = new EquinoxConfiguration(configuration, new HookRegistry(this));
		this.logServices = new EquinoxLogServices(this.equinoxConfig);
		this.equinoxConfig.logMessages(this.logServices);
		this.equinoxConfig.getHookRegistry().initialize();
		try {
			this.storage = Storage.createStorage(this);
		} catch (IOException | BundleException e) {
			throw new RuntimeException("Error initializing storage.", e); //$NON-NLS-1$
		}
		this.packageAdmin = new PackageAdminImpl(storage.getModuleContainer());
		this.startLevel = new StartLevelImpl(storage.getModuleContainer());
		this.eventPublisher = new EquinoxEventPublisher(this);

		// set the boot delegation according to the osgi boot delegation property
		// TODO unfortunately this has to be done after constructing storage so the vm profile is loaded
		// TODO ideally this should be in equinox configuration or perhaps in storage
		String bootDelegationProp = equinoxConfig.getConfiguration(Constants.FRAMEWORK_BOOTDELEGATION);
		String[] bootPackages = ManifestElement.getArrayFromList(bootDelegationProp, ","); //$NON-NLS-1$
		HashSet<String> exactMatch = new HashSet<>(bootPackages.length);
		List<String> stemMatch = new ArrayList<>(bootPackages.length);
		boolean delegateAllValue = false;
		for (String bootPackage : bootPackages) {
			if (bootPackage.equals("*")) { //$NON-NLS-1$
				delegateAllValue = true;
				exactMatch.clear();
				stemMatch.clear();
				break;
			} else if (bootPackage.endsWith("*")) { //$NON-NLS-1$
				if (bootPackage.length() > 2 && bootPackage.endsWith(".*")) { //$NON-NLS-1$
					stemMatch.add(bootPackage.substring(0, bootPackage.length() - 1));
				}
			} else {
				exactMatch.add(bootPackage);
			}
		}
		bootDelegateAll = delegateAllValue;
		bootDelegation = exactMatch;
		bootDelegationStems = stemMatch.isEmpty() ? null : stemMatch.toArray(new String[stemMatch.size()]);

		// Detect if all hooks can support recursive class processing
		boolean supportRecursion = true;
		for (ClassLoaderHook hook : equinoxConfig.getHookRegistry().getClassLoaderHooks()) {
			supportRecursion &= hook.isProcessClassRecursionSupported();
		}
		isProcessClassRecursionSupportedByAll = supportRecursion;
	}

	public Storage getStorage() {
		return storage;
	}

	public EquinoxConfiguration getConfiguration() {
		return equinoxConfig;
	}

	public EquinoxLocations getLocations() {
		return equinoxConfig.getEquinoxLocations();
	}

	public EquinoxLogServices getLogServices() {
		return logServices;
	}

	public PackageAdmin getPackageAdmin() {
		return packageAdmin;
	}

	public StartLevel getStartLevel() {
		return startLevel;
	}

	public SignedContentFactory getSignedContentFactory() {
		ServiceTracker<SignedContentFactory, SignedContentFactory> current;
		synchronized (this.monitor) {
			current = signedContentFactory;
		}
		return current == null ? null : current.getService();
	}

	public boolean isBootDelegationPackage(String name) {
		if (bootDelegateAll)
			return true;
		if (bootDelegation.contains(name))
			return true;
		if (bootDelegationStems != null)
			for (String bootDelegationStem : bootDelegationStems) {
				if (name.startsWith(bootDelegationStem)) {
					return true;
				}
			}
		return false;
	}

	public boolean isProcessClassRecursionSupportedByAll() {
		return isProcessClassRecursionSupportedByAll;
	}

	void init() {
		eventPublisher.init();
		synchronized (this.monitor) {
			serviceRegistry = new ServiceRegistry(this);
			initializeContextFinder();
			executor = Executors.newScheduledThreadPool(1, this);
			// be sure to initialize the executor threads
			executor.execute(this);
			storageSaver = new StorageSaver(this);
		}
	}

	void close() {
		StorageSaver currentSaver;
		Storage currentStorage;
		ScheduledExecutorService currentExecutor;
		synchronized (this.monitor) {
			serviceRegistry = null;
			currentSaver = storageSaver;
			currentStorage = storage;
			currentExecutor = executor;
		}
		// do this outside of the lock to avoid deadlock
		currentSaver.close();
		currentStorage.close();
		// Must be done last since it will result in termination of the 
		// framework active thread.
		currentExecutor.shutdown();
	}

	private void initializeContextFinder() {
		Thread current = Thread.currentThread();
		try {
			ClassLoader parent = null;
			// check property for specified parent
			String type = equinoxConfig.getConfiguration(EquinoxConfiguration.PROP_CONTEXTCLASSLOADER_PARENT);
			if (EquinoxConfiguration.CONTEXTCLASSLOADER_PARENT_APP.equals(type))
				parent = ClassLoader.getSystemClassLoader();
			else if (EquinoxConfiguration.CONTEXTCLASSLOADER_PARENT_BOOT.equals(type))
				parent = bootLoader;
			else if (EquinoxConfiguration.CONTEXTCLASSLOADER_PARENT_FWK.equals(type))
				parent = EquinoxContainer.class.getClassLoader();
			else if (EquinoxConfiguration.CONTEXTCLASSLOADER_PARENT_EXT.equals(type)) {
				ClassLoader appCL = ClassLoader.getSystemClassLoader();
				if (appCL != null)
					parent = appCL.getParent();
			} else { // default is ccl (null or any other value will use ccl)
				parent = current.getContextClassLoader();
			}
			contextFinder = new ContextFinder(parent, bootLoader);
			current.setContextClassLoader(contextFinder);
			return;
		} catch (Exception e) {
			logServices.log(NAME, FrameworkLogEntry.INFO, NLS.bind(Msg.CANNOT_SET_CONTEXTFINDER, null), e);
		}

	}

	public EquinoxEventPublisher getEventPublisher() {
		synchronized (this.monitor) {
			return eventPublisher;
		}
	}

	ScheduledExecutorService getScheduledExecutor() {
		synchronized (this.monitor) {
			return executor;
		}
	}

	public ServiceRegistry getServiceRegistry() {
		synchronized (this.monitor) {
			return serviceRegistry;
		}
	}

	public ContextFinder getContextFinder() {
		synchronized (this.monitor) {
			return contextFinder;
		}
	}

	public <K, V, E> ListenerQueue<K, V, E> newListenerQueue() {
		return eventPublisher.newListenerQueue();
	}

	void checkAdminPermission(Bundle bundle, String action) {
		if (bundle == null)
			return;
		SecurityManager sm = System.getSecurityManager();
		if (sm != null)
			sm.checkPermission(new AdminPermission(bundle, action));
	}

	public void handleRuntimeError(Throwable t) {
		// TODO need to call some hook here
	}

	void systemStart(BundleContext bc) {
		synchronized (this.monitor) {
			signedContentFactory = new ServiceTracker<>(bc, SignedContentFactory.class, null);
		}
		signedContentFactory.open();
	}

	void systemStop(BundleContext bc) {
		ServiceTracker<SignedContentFactory, SignedContentFactory> current;
		synchronized (this.monitor) {
			current = signedContentFactory;
		}
		if (current != null) {
			current.close();
		}
	}

	@Override
	public String toString() {
		String UUID = equinoxConfig == null ? null : equinoxConfig.getConfiguration(Constants.FRAMEWORK_UUID);
		return "Equinox Container: " + UUID; //$NON-NLS-1$
	}

	StorageSaver getStorageSaver() {
		synchronized (this.monitor) {
			return storageSaver;
		}
	}

	@Override
	public Thread newThread(Runnable r) {
		String type = equinoxConfig.getConfiguration(EquinoxConfiguration.PROP_ACTIVE_THREAD_TYPE, EquinoxConfiguration.ACTIVE_THREAD_TYPE_NORMAL);
		Thread t = new Thread(r, "Active Thread: " + toString()); //$NON-NLS-1$
		if (EquinoxConfiguration.ACTIVE_THREAD_TYPE_NORMAL.equals(type)) {
			t.setDaemon(false);
		} else {
			t.setDaemon(true);
		}
		t.setPriority(Thread.NORM_PRIORITY);
		return t;
	}

	@Override
	public void run() {
		// Do nothing; just used to ensure the active thread is created during init
	}

	public ClassLoader getBootLoader() {
		return bootLoader;
	}
}