/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.scm.provider.git.gitexe.command.branch;

import java.io.File;
import java.util.Map;

import org.apache.maven.scm.ScmException;
import org.apache.maven.scm.ScmFileSet;
import org.apache.maven.scm.ScmFileStatus;
import org.apache.maven.scm.ScmResult;
import org.apache.maven.scm.command.branch.AbstractBranchCommand;
import org.apache.maven.scm.command.branch.BranchScmResult;
import org.apache.maven.scm.provider.ScmProviderRepository;
import org.apache.maven.scm.provider.git.command.GitCommand;
import org.apache.maven.scm.provider.git.gitexe.command.GitCommandLineUtils;
import org.apache.maven.scm.provider.git.gitexe.command.list.GitListCommand;
import org.apache.maven.scm.provider.git.gitexe.command.list.GitListConsumer;
import org.apache.maven.scm.provider.git.repository.GitScmProviderRepository;
import org.codehaus.plexus.util.cli.CommandLineUtils;
import org.codehaus.plexus.util.cli.Commandline;

/**
 * @author <a href="mailto:struberg@yahoo.de">Mark Struberg</a>
 */
public class GitBranchCommand extends AbstractBranchCommand implements GitCommand {
    private final Map<String, String> environmentVariables;

    public GitBranchCommand(Map<String, String> environmentVariables) {
        this.environmentVariables = environmentVariables;
    }

    /**
     * {@inheritDoc}
     */
    public ScmResult executeBranchCommand(ScmProviderRepository repo, ScmFileSet fileSet, String branch, String message)
            throws ScmException {
        if (branch == null || branch.trim().isEmpty()) {
            throw new ScmException("branch name must be specified");
        }

        if (!fileSet.getFileList().isEmpty()) {
            throw new ScmException("This provider doesn't support branching subsets of a directory");
        }

        GitScmProviderRepository repository = (GitScmProviderRepository) repo;

        Commandline cl = createCommandLine(repository, fileSet.getBasedir(), branch);

        CommandLineUtils.StringStreamConsumer stdout = new CommandLineUtils.StringStreamConsumer();
        CommandLineUtils.StringStreamConsumer stderr = new CommandLineUtils.StringStreamConsumer();
        int exitCode;

        exitCode = GitCommandLineUtils.execute(cl, stdout, stderr);
        if (exitCode != 0) {
            return new BranchScmResult(cl.toString(), "The git-branch command failed.", stderr.getOutput(), false);
        }

        if (repo.isPushChanges()) {
            // and now push the branch to the upstream repository
            Commandline clPush = createPushCommandLine(repository, fileSet, branch);

            exitCode = GitCommandLineUtils.execute(clPush, stdout, stderr);
            if (exitCode != 0) {
                return new BranchScmResult(
                        clPush.toString(), "The git-push command failed.", stderr.getOutput(), false);
            }
        }

        // as last action we search for the branched files
        GitListConsumer listConsumer = new GitListConsumer(fileSet.getBasedir(), ScmFileStatus.TAGGED);

        Commandline clList = GitListCommand.createCommandLine(repository, fileSet.getBasedir());

        exitCode = GitCommandLineUtils.execute(clList, listConsumer, stderr);
        if (exitCode != 0) {
            return new BranchScmResult(
                    clList.toString(), "The git-ls-files command failed.", stderr.getOutput(), false);
        }

        return new BranchScmResult(cl.toString(), listConsumer.getListedFiles());
    }

    // ----------------------------------------------------------------------
    //
    // ----------------------------------------------------------------------

    public static Commandline createCommandLine(
            GitScmProviderRepository repository, File workingDirectory, String branch) {
        Commandline cl = GitCommandLineUtils.getBaseGitCommandLine(workingDirectory, "branch");

        cl.createArg().setValue(branch);

        return cl;
    }

    public Commandline createPushCommandLine(GitScmProviderRepository repository, ScmFileSet fileSet, String branch) {
        Commandline cl = GitCommandLineUtils.getBaseGitCommandLine(
                fileSet.getBasedir(), "push", repository, environmentVariables);

        cl.createArg().setValue(repository.getPushUrl());
        cl.createArg().setValue("refs/heads/" + branch);

        return cl;
    }

    /**
     * Helper function to detect the current branch.
     */
    public static String getCurrentBranch(GitScmProviderRepository repository, ScmFileSet fileSet) throws ScmException {
        Commandline cl = GitCommandLineUtils.getBaseGitCommandLine(fileSet.getBasedir(), "symbolic-ref");
        cl.createArg().setValue("HEAD");

        CommandLineUtils.StringStreamConsumer stderr = new CommandLineUtils.StringStreamConsumer();
        GitCurrentBranchConsumer cbConsumer = new GitCurrentBranchConsumer();
        int exitCode;

        exitCode = GitCommandLineUtils.execute(cl, cbConsumer, stderr);

        if (exitCode != 0) {
            throw new ScmException("Detecting the current branch failed: " + stderr.getOutput());
        }

        return cbConsumer.getBranchName();
    }
}
