/*
    * Copyright (C) 2012, Matthias Sohn <matthias.sohn@sap.com>
    * 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.api;
  
  import java.io.IOException;
  import java.text.MessageFormat;
  import java.text.ParseException;
  import java.util.Date;
  import java.util.Properties;
  
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.internal.storage.dfs.DfsGarbageCollector;
  import org.eclipse.jgit.internal.storage.dfs.DfsRepository;
  import org.eclipse.jgit.internal.storage.file.FileRepository;
  import org.eclipse.jgit.internal.storage.file.GC;
  import org.eclipse.jgit.internal.storage.file.GC.RepoStatistics;
  import org.eclipse.jgit.lib.ConfigConstants;
  import org.eclipse.jgit.lib.ProgressMonitor;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.lib.StoredConfig;
  import org.eclipse.jgit.storage.pack.PackConfig;
  import org.eclipse.jgit.util.GitDateParser;
  
  /**
   * A class used to execute a {@code gc} command. It has setters for all
   * supported options and arguments of this command and a {@link #call()} method
   * to finally execute the command. Each instance of this class should only be
   * used for one invocation of the command (means: one call to {@link #call()})
   *
   * @since 2.2
   * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-gc.html"
   *      >Git documentation about gc</a>
   */
  public class GarbageCollectCommand extends GitCommand<Properties> {
  	/**
  	 * Default value of maximum delta chain depth during aggressive garbage
  	 * collection: {@value}
  	 *
  	 * @since 3.6
  	 */
  	public static final int DEFAULT_GC_AGGRESSIVE_DEPTH = 250;
  
  	/**
  	 * Default window size during packing during aggressive garbage collection:
  	 * * {@value}
  	 *
  	 * @since 3.6
  	 */
  	public static final int DEFAULT_GC_AGGRESSIVE_WINDOW = 250;
  
  	private ProgressMonitor monitor;
  
  	private Date expire;
  
  	private PackConfig pconfig;
  
  	/**
 	 * @param repo
 	 */
 	protected GarbageCollectCommand(Repository repo) {
 		super(repo);
 		pconfig = new PackConfig(repo);
 	}
 
 	/**
 	 * @param monitor
 	 *            a progress monitor
 	 * @return this instance
 	 */
 	public GarbageCollectCommand setProgressMonitor(ProgressMonitor monitor) {
 		this.monitor = monitor;
 		return this;
 	}
 
 	/**
 	 * During gc() or prune() each unreferenced, loose object which has been
 	 * created or modified after <code>expire</code> will not be pruned. Only
 	 * older objects may be pruned. If set to null then every object is a
 	 * candidate for pruning. Use {@link GitDateParser} to parse time formats
 	 * used by git gc.
 	 *
 	 * @param expire
 	 *            minimal age of objects to be pruned.
 	 * @return this instance
 	 */
 	public GarbageCollectCommand setExpire(Date expire) {
 		this.expire = expire;
 		return this;
 	}
 
 	/**
 	 * Whether to use aggressive mode or not. If set to true JGit behaves more
 	 * similar to native git's "git gc --aggressive". If set to
 	 * <code>true</code> compressed objects found in old packs are not reused
 	 * but every object is compressed again. Configuration variables
 	 * pack.window and pack.depth are set to 250 for this GC.
 	 *
 	 * @since 3.6
 	 * @param aggressive
 	 *            whether to turn on or off aggressive mode
 	 * @return this instance
 	 */
 	public GarbageCollectCommand setAggressive(boolean aggressive) {
 		if (aggressive) {
 			StoredConfig repoConfig = repo.getConfig();
 			pconfig.setDeltaSearchWindowSize(repoConfig.getInt(
 					ConfigConstants.CONFIG_GC_SECTION,
 					ConfigConstants.CONFIG_KEY_AGGRESSIVE_WINDOW,
 					DEFAULT_GC_AGGRESSIVE_WINDOW));
 			pconfig.setMaxDeltaDepth(repoConfig.getInt(
 					ConfigConstants.CONFIG_GC_SECTION,
 					ConfigConstants.CONFIG_KEY_AGGRESSIVE_DEPTH,
 					DEFAULT_GC_AGGRESSIVE_DEPTH));
 			pconfig.setReuseObjects(false);
 		} else
 			pconfig = new PackConfig(repo);
 		return this;
 	}
 
 	/**
 	 * Whether to preserve old pack files instead of deleting them.
 	 *
 	 * @since 4.7
 	 * @param preserveOldPacks
 	 *            whether to preserve old pack files
 	 * @return this instance
 	 */
 	public GarbageCollectCommand setPreserveOldPacks(boolean preserveOldPacks) {
 		if (pconfig == null)
 			pconfig = new PackConfig(repo);
 
 		pconfig.setPreserveOldPacks(preserveOldPacks);
 		return this;
 	}
 
 	/**
 	 * Whether to prune preserved pack files in the preserved directory.
 	 *
 	 * @since 4.7
 	 * @param prunePreserved
 	 *            whether to prune preserved pack files
 	 * @return this instance
 	 */
 	public GarbageCollectCommand setPrunePreserved(boolean prunePreserved) {
 		if (pconfig == null)
 			pconfig = new PackConfig(repo);
 
 		pconfig.setPrunePreserved(prunePreserved);
 		return this;
 	}
 
 	@Override
 	public Properties call() throws GitAPIException {
 		checkCallable();
 
 		try {
 			if (repo instanceof FileRepository) {
 				GC gc = new GC((FileRepository) repo);
 				gc.setPackConfig(pconfig);
 				gc.setProgressMonitor(monitor);
 				if (this.expire != null)
 					gc.setExpire(expire);
 
 				try {
 					gc.gc();
 					return toProperties(gc.getStatistics());
 				} catch (ParseException e) {
 					throw new JGitInternalException(JGitText.get().gcFailed, e);
 				}
 			} else if (repo instanceof DfsRepository) {
 				DfsGarbageCollector gc =
 					new DfsGarbageCollector((DfsRepository) repo);
 				gc.setPackConfig(pconfig);
 				gc.pack(monitor);
 				return new Properties();
 			} else {
 				throw new UnsupportedOperationException(MessageFormat.format(
 						JGitText.get().unsupportedGC,
 						repo.getClass().toString()));
 			}
 		} catch (IOException e) {
 			throw new JGitInternalException(JGitText.get().gcFailed, e);
 		}
 	}
 
 	/**
 	 * Computes and returns the repository statistics.
 	 *
 	 * @return the repository statistics
 	 * @throws GitAPIException
 	 *             thrown if the repository statistics cannot be computed
 	 * @since 3.0
 	 */
 	public Properties getStatistics() throws GitAPIException {
 		try {
 			if (repo instanceof FileRepository) {
 				GC gc = new GC((FileRepository) repo);
 				return toProperties(gc.getStatistics());
 			} else {
 				return new Properties();
 			}
 		} catch (IOException e) {
 			throw new JGitInternalException(
 					JGitText.get().couldNotGetRepoStatistics, e);
 		}
 	}
 
 	@SuppressWarnings("boxing")
 	private static Properties toProperties(RepoStatistics stats) {
 		Properties p = new Properties();
 		p.put("numberOfLooseObjects", stats.numberOfLooseObjects); //$NON-NLS-1$
 		p.put("numberOfLooseRefs", stats.numberOfLooseRefs); //$NON-NLS-1$
 		p.put("numberOfPackedObjects", stats.numberOfPackedObjects); //$NON-NLS-1$
 		p.put("numberOfPackedRefs", stats.numberOfPackedRefs); //$NON-NLS-1$
 		p.put("numberOfPackFiles", stats.numberOfPackFiles); //$NON-NLS-1$
 		p.put("sizeOfLooseObjects", stats.sizeOfLooseObjects); //$NON-NLS-1$
 		p.put("sizeOfPackedObjects", stats.sizeOfPackedObjects); //$NON-NLS-1$
 		return p;
 	}
 }