Copyright (c) 2014 Konrad Kügler and others
This program and the accompanying materials are made available under the
terms of the Eclipse Distribution License v. 1.0 which is available at
https://www.eclipse.org/org/documents/edl-v10.php.
SPDX-License-Identifier: BSD-3-Clause
/*******************************************************************************
 * Copyright (c) 2014 Konrad Kügler and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *******************************************************************************/
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"); //$NON-NLS-1$
		}
		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);
			}
			return false;
		}

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

	}

}