package org.argeo.init.osgi;

import java.lang.System.Logger;
import java.lang.System.Logger.Level;
import java.lang.reflect.InvocationTargetException;
import java.net.URI;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.TreeMap;
import java.util.function.Consumer;

import org.argeo.api.init.InitConstants;
import org.argeo.api.init.RuntimeContext;
import org.argeo.api.init.RuntimeManager;
import org.argeo.internal.init.InternalState;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.FrameworkEvent;
import org.osgi.framework.connect.ConnectFrameworkFactory;
import org.osgi.framework.launch.Framework;

/**
 * Dynamically configures and launches multiple runtimes.
 */
class OsgiRuntimeManager implements RuntimeManager {
	private final static Logger logger = System.getLogger(OsgiRuntimeManager.class.getName());

	private final static long RUNTIME_SHUTDOWN_TIMEOUT = 60 * 1000;

	private final static String EQUINOX_FRAMEWORK_FACTORY_CLASS = "org.eclipse.osgi.launch.EquinoxFactory";

	private Path baseConfigArea;
	private Path baseWritableArea;
	private Map<String, String> configuration = new HashMap<>();

	private Map<String, OsgiRuntimeContext> runtimeContexts = new TreeMap<>();

	private ConnectFrameworkFactory frameworkFactory;

	OsgiRuntimeManager(BundleContext bundleContext) {
		try {
			@SuppressWarnings("unchecked")
			Class<? extends ConnectFrameworkFactory> frameworkFactoryClass = (Class<? extends ConnectFrameworkFactory>) Framework.class
					.getClassLoader().loadClass(EQUINOX_FRAMEWORK_FACTORY_CLASS);
			frameworkFactory = frameworkFactoryClass.getConstructor().newInstance();
		} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | IllegalArgumentException
				| InvocationTargetException | NoSuchMethodException | SecurityException e) {
			throw new IllegalStateException("Cannot create OSGi framework factory", e);
		}

		this.baseConfigArea = Paths
				.get(URI.create(bundleContext.getProperty(InitConstants.PROP_OSGI_SHARED_CONFIGURATION_AREA)))
				.getParent();
		this.baseWritableArea = Paths
				.get(URI.create(bundleContext.getProperty(InitConstants.PROP_OSGI_CONFIGURATION_AREA))).getParent()
				.getParent();

		logger.log(Level.TRACE, () -> "Runtime manager configuration: " + configuration);

//		System.out.println("java.library.path=" + System.getProperty("java.library.path"));
	}

	protected void shutdown() {
		// shutdowm runtimes
		Map<String, RuntimeContext> shutdowning = new HashMap<>(runtimeContexts);
		for (String id : new HashSet<>(runtimeContexts.keySet())) {
			logger.log(Logger.Level.DEBUG, "Shutting down runtime " + id + " ...");
			closeRuntime(id, true);
		}
		for (String id : shutdowning.keySet())
			try {
				RuntimeContext runtimeContext = shutdowning.get(id);
				runtimeContext.waitForStop(RUNTIME_SHUTDOWN_TIMEOUT);
			} catch (InterruptedException e) {
				// silent
			} catch (Exception e) {
				logger.log(Logger.Level.DEBUG, "Cannot wait for " + id + " to shutdown", e);
			}
		// shutdown manager runtime
		try {
			InternalState.getMainRuntimeContext().close();
			InternalState.getMainRuntimeContext().waitForStop(RUNTIME_SHUTDOWN_TIMEOUT);
//			logger.log(Logger.Level.INFO, "Argeo Init stopped with PID " + ProcessHandle.current().pid());
			System.out.flush();
		} catch (Exception e) {
			e.printStackTrace();
			Runtime.getRuntime().halt(1);
		}
	}

	OsgiRuntimeContext loadRuntime(String relPath, Consumer<Map<String, String>> configCallback) {
		closeRuntime(relPath, false);
		Path writableArea = baseWritableArea.resolve(relPath);
		Path configArea = baseConfigArea.resolve(relPath);
		Map<String, String> config = new HashMap<>();
		RuntimeManager.loadConfig(configArea, config);
		config.put(InitConstants.PROP_OSGI_CONFIGURATION_AREA, writableArea.resolve(STATE).toUri().toString());

		if (configCallback != null)
			configCallback.accept(config);

		// use config area if instance area is not set
		if (!config.containsKey(InitConstants.PROP_OSGI_INSTANCE_AREA))
			config.put(InitConstants.PROP_OSGI_INSTANCE_AREA, writableArea.resolve(DATA).toUri().toString());

		// create framework
		Framework framework = frameworkFactory.newFramework(config, null);
		try {
			framework.start();
		} catch (BundleException e) {
			throw new IllegalStateException("Cannot initialise framework", e);
		}
		OsgiRuntimeContext runtimeContext = new OsgiRuntimeContext(framework.getBundleContext());
		runtimeContexts.put(relPath, runtimeContext);
		return runtimeContext;
	}

	public void startRuntime(String relPath, Consumer<Map<String, String>> configCallback) {
		OsgiRuntimeContext runtimeContext = loadRuntime(relPath, configCallback);
		//runtimeContext.run();
		Framework framework = runtimeContext.getFramework();
		if (framework != null) {// in case the framework has closed very quickly after run
			framework.getBundleContext().addFrameworkListener((e) -> {
				if (e.getType() >= FrameworkEvent.STOPPED) {
					logger.log(Level.DEBUG, "Externally stopped runtime " + relPath + ". Unregistering...", e);
					runtimeContexts.remove(relPath);
				}
			});
		} else {
			closeRuntime(relPath, false);
		}
	}

	public void closeRuntime(String relPath, boolean async) {
		if (!runtimeContexts.containsKey(relPath))
			return;
		RuntimeContext runtimeContext = runtimeContexts.get(relPath);
		try {
			runtimeContext.close();
			if (!async) {
				runtimeContext.waitForStop(RUNTIME_SHUTDOWN_TIMEOUT);
				System.gc();
			}
		} catch (Exception e) {
			logger.log(Level.ERROR, "Cannot close runtime context " + relPath, e);
		} finally {
			runtimeContexts.remove(relPath);
		}

	}
}