/*
 * Copyright (C) 2011, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.internal.storage.dfs;

import java.io.IOException;
import java.io.InputStream;
import java.text.MessageFormat;
import java.util.Collections;

import org.eclipse.jgit.attributes.AttributesNode;
import org.eclipse.jgit.attributes.AttributesNodeProvider;
import org.eclipse.jgit.attributes.AttributesRule;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.ReflogReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.lib.StoredConfig;

/**
 * A Git repository on a DFS.
 */
public abstract class DfsRepository extends Repository {
	private final DfsConfig config;

	private final DfsRepositoryDescription description;

	/**
	 * Initialize a DFS repository.
	 *
	 * @param builder
	 *            description of the repository.
	 */
	protected DfsRepository(DfsRepositoryBuilder builder) {
		super(builder);
		this.config = new DfsConfig();
		this.description = builder.getRepositoryDescription();
	}

	/** {@inheritDoc} */
	@Override
	public abstract DfsObjDatabase getObjectDatabase();

	/**
	 * Get the description of this repository.
	 *
	 * @return the description of this repository.
	 */
	public DfsRepositoryDescription getDescription() {
		return description;
	}

	/**
	 * Check if the repository already exists.
	 *
	 * @return true if the repository exists; false if it is new.
	 * @throws java.io.IOException
	 *             the repository cannot be checked.
	 */
	public boolean exists() throws IOException {
		if (getRefDatabase() instanceof DfsRefDatabase) {
			return ((DfsRefDatabase) getRefDatabase()).exists();
		}
		return true;
	}

	/** {@inheritDoc} */
	@Override
	public void create(boolean bare) throws IOException {
		if (exists())
			throw new IOException(MessageFormat.format(
					JGitText.get().repositoryAlreadyExists, "")); //$NON-NLS-1$

		String master = Constants.R_HEADS + Constants.MASTER;
		RefUpdate.Result result = updateRef(Constants.HEAD, true).link(master);
		if (result != RefUpdate.Result.NEW)
			throw new IOException(result.name());
	}

	/** {@inheritDoc} */
	@Override
	public StoredConfig getConfig() {
		return config;
	}

	/** {@inheritDoc} */
	@Override
	public String getIdentifier() {
		return getDescription().getRepositoryName();
	}

	/** {@inheritDoc} */
	@Override
	public void scanForRepoChanges() throws IOException {
		getRefDatabase().refresh();
		getObjectDatabase().clearCache();
	}

	/** {@inheritDoc} */
	@Override
	public void notifyIndexChanged(boolean internal) {
		// Do not send notifications.
		// There is no index, as there is no working tree.
	}

	/** {@inheritDoc} */
	@Override
	public ReflogReader getReflogReader(String refName) throws IOException {
		throw new UnsupportedOperationException();
	}

	/** {@inheritDoc} */
	@Override
	public AttributesNodeProvider createAttributesNodeProvider() {
		// TODO Check if the implementation used in FileRepository can be used
		// for this kind of repository
		return new EmptyAttributesNodeProvider();
	}

	private static class EmptyAttributesNodeProvider implements
			AttributesNodeProvider {
		private EmptyAttributesNode emptyAttributesNode = new EmptyAttributesNode();

		@Override
		public AttributesNode getInfoAttributesNode() throws IOException {
			return emptyAttributesNode;
		}

		@Override
		public AttributesNode getGlobalAttributesNode() throws IOException {
			return emptyAttributesNode;
		}

		private static class EmptyAttributesNode extends AttributesNode {

			public EmptyAttributesNode() {
				super(Collections.<AttributesRule> emptyList());
			}

			@Override
			public void parse(InputStream in) throws IOException {
				// Do nothing
			}
		}
	}
}