Copyright (c) 2014 Konrad Kügler
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,
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/*******************************************************************************
 * Copyright (c) 2014 Konrad Kügler
 * 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.merge;

import java.io.IOException;

import org.eclipse.jgit.api.MergeCommand.FastForwardMode;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.Config.SectionParser;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.Repository;

Holds configuration for merging into a given branch
Since:
3.3/**
 * Holds configuration for merging into a given branch
 *
 * @since 3.3
 */
public class MergeConfig {

	
Get merge configuration for the current branch of the repository
Params:
repo –  a Repository object.
Returns:
merge configuration for the current branch of the repository/**
	 * Get merge configuration for the current branch of the repository
	 *
	 * @param repo
	 *            a {@link org.eclipse.jgit.lib.Repository} object.
	 * @return merge configuration for the current branch of the repository
	 */
	public static MergeConfig getConfigForCurrentBranch(Repository repo) {
		try {
			String branch = repo.getBranch();
			if (branch != null)
				return repo.getConfig().get(getParser(branch));
		} catch (IOException e) {
			// ignore
		}
		// use defaults if branch can't be determined
		return new MergeConfig();
	}

	
Get a parser for use with Config.get(SectionParser<Object>) 
Params:
branch –  short branch name to get the configuration for, as returned e.g. by Repository.getBranch()
Returns:
a parser for use with Config.get(SectionParser<Object>)/**
	 * Get a parser for use with
	 * {@link org.eclipse.jgit.lib.Config#get(SectionParser)}
	 *
	 * @param branch
	 *            short branch name to get the configuration for, as returned
	 *            e.g. by {@link org.eclipse.jgit.lib.Repository#getBranch()}
	 * @return a parser for use with
	 *         {@link org.eclipse.jgit.lib.Config#get(SectionParser)}
	 */
	public static final SectionParser<MergeConfig> getParser(
			final String branch) {
		return new MergeConfigSectionParser(branch);
	}

	private final FastForwardMode fastForwardMode;

	private final boolean squash;

	private final boolean commit;

	private MergeConfig(String branch, Config config) {
		String[] mergeOptions = getMergeOptions(branch, config);
		fastForwardMode = getFastForwardMode(config, mergeOptions);
		squash = isMergeConfigOptionSet("--squash", mergeOptions); //$NON-NLS-1$
		commit = !isMergeConfigOptionSet("--no-commit", mergeOptions); //$NON-NLS-1$
	}

	private MergeConfig() {
		fastForwardMode = FastForwardMode.FF;
		squash = false;
		commit = true;
	}

	
Get the fast forward mode configured for this branch
Returns:
the fast forward mode configured for this branch/**
	 * Get the fast forward mode configured for this branch
	 *
	 * @return the fast forward mode configured for this branch
	 */
	public FastForwardMode getFastForwardMode() {
		return fastForwardMode;
	}

	
Whether merges into this branch are configured to be squash merges, false
otherwise
Returns:
true if merges into this branch are configured to be squash
        merges, false otherwise/**
	 * Whether merges into this branch are configured to be squash merges, false
	 * otherwise
	 *
	 * @return true if merges into this branch are configured to be squash
	 *         merges, false otherwise
	 */
	public boolean isSquash() {
		return squash;
	}

	
Whether --no-commit option is not set. 
Returns:
false if --no-commit is configured for this branch, true otherwise (even if --squash is configured)/**
	 * Whether {@code --no-commit} option is not set.
	 *
	 * @return {@code false} if --no-commit is configured for this branch,
	 *         {@code true} otherwise (even if --squash is configured)
	 */
	public boolean isCommit() {
		return commit;
	}

	private static FastForwardMode getFastForwardMode(Config config,
			String[] mergeOptions) {
		for (String option : mergeOptions) {
			for (FastForwardMode mode : FastForwardMode.values())
				if (mode.matchConfigValue(option))
					return mode;
		}
		FastForwardMode ffmode = FastForwardMode.valueOf(config.getEnum(
				ConfigConstants.CONFIG_KEY_MERGE, null,
				ConfigConstants.CONFIG_KEY_FF, FastForwardMode.Merge.TRUE));
		return ffmode;
	}

	private static boolean isMergeConfigOptionSet(String optionToLookFor,
			String[] mergeOptions) {
		for (String option : mergeOptions) {
			if (optionToLookFor.equals(option))
				return true;
		}
		return false;
	}

	private static String[] getMergeOptions(String branch, Config config) {
		String mergeOptions = config.getString(
				ConfigConstants.CONFIG_BRANCH_SECTION, branch,
				ConfigConstants.CONFIG_KEY_MERGEOPTIONS);
		if (mergeOptions != null)
			return mergeOptions.split("\\s"); //$NON-NLS-1$
		else
			return new String[0];
	}

	private static class MergeConfigSectionParser implements
			SectionParser<MergeConfig> {

		private final String branch;

		public MergeConfigSectionParser(String branch) {
			this.branch = branch;
		}

		@Override
		public MergeConfig parse(Config cfg) {
			return new MergeConfig(branch, cfg);
		}

		@Override
		public boolean equals(Object obj) {
			if (obj instanceof MergeConfigSectionParser)
				return branch.equals(((MergeConfigSectionParser) obj).branch);
			else
				return false;
		}

		@Override
		public int hashCode() {
			return branch.hashCode();
		}

	}

}