package org.eclipse.equinox.internal.p2.extensionlocation;

import java.io.File;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import org.eclipse.core.runtime.*;
import org.eclipse.equinox.internal.provisional.p2.artifact.repository.*;
import org.eclipse.equinox.internal.provisional.p2.core.ProvisionException;
import org.eclipse.equinox.internal.provisional.p2.directorywatcher.DirectoryWatcher;
import org.eclipse.equinox.internal.provisional.p2.directorywatcher.RepositoryListener;
import org.eclipse.equinox.internal.provisional.p2.metadata.IArtifactKey;
import org.eclipse.equinox.internal.provisional.spi.p2.artifact.repository.SimpleArtifactRepositoryFactory;
import org.eclipse.equinox.internal.provisional.spi.p2.core.repository.AbstractRepository;
import org.osgi.framework.BundleContext;

public class ExtensionLocationArtifactRepository extends AbstractRepository implements IFileArtifactRepository {

	//private static final String PROFILE_EXTENSION = "profile.extension"; //$NON-NLS-1$
	private static final String ECLIPSE = "eclipse"; //$NON-NLS-1$
	private static final String FEATURES = "features"; //$NON-NLS-1$
	private static final String PLUGINS = "plugins"; //$NON-NLS-1$
	private static final String FILE = "file"; //$NON-NLS-1$
	private final IFileArtifactRepository artifactRepository;

	public ExtensionLocationArtifactRepository(URL location, IProgressMonitor monitor) throws ProvisionException {
		super("Extension: " + location.toExternalForm(), null, null, location, null, null); //$NON-NLS-1$

		File base = getBaseDirectory(location);
		File plugins = new File(base, PLUGINS);
		File features = new File(base, FEATURES);

		BundleContext context = Activator.getContext();
		String stateDirName = Integer.toString(location.toExternalForm().hashCode());
		File bundleData = context.getDataFile(null);
		File stateDir = new File(bundleData, stateDirName);
		URL localRepositoryURL;
		try {
			localRepositoryURL = stateDir.toURL();
		} catch (MalformedURLException e) {
			// unexpected
			throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, "Failed to create local repository", e)); //$NON-NLS-1$
		}

		artifactRepository = (IFileArtifactRepository) initializeArtifactRepository(localRepositoryURL, "extension location implementation - " + location.toExternalForm()); //$NON-NLS-1$

		DirectoryWatcher watcher = new DirectoryWatcher(new File[] {plugins, features});
		RepositoryListener listener = new RepositoryListener(context, null, artifactRepository);
		watcher.addListener(listener);
		watcher.poll();
	}

	private IArtifactRepository initializeArtifactRepository(URL stateDirURL, String repositoryName) {
		SimpleArtifactRepositoryFactory factory = new SimpleArtifactRepositoryFactory();
		try {
			return factory.load(stateDirURL, null);

		} catch (ProvisionException e) {
			//fall through and create a new repository
		}
		IArtifactRepository repository = factory.create(stateDirURL, repositoryName, null);
		//repository.setProperty(PROFILE_EXTENSION, "true");
		return repository;
	}

	public static void validate(URL location, IProgressMonitor monitor) throws ProvisionException {
		getBaseDirectory(location);
	}

	public static File getBaseDirectory(URL url) throws ProvisionException {
		if (!FILE.equals(url.getProtocol()))
			throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_NOT_FOUND, "location must use file protocol", null));

		File base = new File(url.getPath());
		if (!base.isDirectory())
			throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_NOT_FOUND, "location not a directory", null));

		if (isBaseDirectory(base))
			return base;

		File eclipseBase = new File(base, ECLIPSE);
		if (isBaseDirectory(eclipseBase))
			return eclipseBase;

		throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_NOT_FOUND, "location is not an extension", null));
	}

	private static boolean isBaseDirectory(File base) {
		File plugins = new File(base, PLUGINS);
		File features = new File(base, FEATURES);

		return plugins.isDirectory() || features.isDirectory();
	}

	public void addDescriptor(IArtifactDescriptor descriptor) {
		throw new UnsupportedOperationException();
	}

	public void addDescriptors(IArtifactDescriptor[] descriptors) {
		throw new UnsupportedOperationException();
	}

	public void removeAll() {
		throw new UnsupportedOperationException();
	}

	public void removeDescriptor(IArtifactDescriptor descriptor) {
		throw new UnsupportedOperationException();
	}

	public void removeDescriptor(IArtifactKey key) {
		throw new UnsupportedOperationException();
	}

	public boolean contains(IArtifactDescriptor descriptor) {
		return artifactRepository.contains(descriptor);
	}

	public boolean contains(IArtifactKey key) {
		return artifactRepository.contains(key);
	}

	public IStatus getArtifact(IArtifactDescriptor descriptor, OutputStream destination, IProgressMonitor monitor) {
		return artifactRepository.getArtifact(descriptor, destination, monitor);
	}

	public IArtifactDescriptor[] getArtifactDescriptors(IArtifactKey key) {
		return artifactRepository.getArtifactDescriptors(key);
	}

	public IArtifactKey[] getArtifactKeys() {
		return artifactRepository.getArtifactKeys();
	}

	public IStatus getArtifacts(IArtifactRequest[] requests, IProgressMonitor monitor) {
		return artifactRepository.getArtifacts(requests, monitor);
	}

	public OutputStream getOutputStream(IArtifactDescriptor descriptor) throws ProvisionException {
		return artifactRepository.getOutputStream(descriptor);
	}

	public File getArtifactFile(IArtifactKey key) {
		return artifactRepository.getArtifactFile(key);
	}

	public File getArtifactFile(IArtifactDescriptor descriptor) {
		return artifactRepository.getArtifactFile(descriptor);
	}
}