/*
 * 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.jgit.command.tag;

import java.util.ArrayList;
import java.util.List;

import org.apache.maven.scm.ScmException;
import org.apache.maven.scm.ScmFile;
import org.apache.maven.scm.ScmFileSet;
import org.apache.maven.scm.ScmFileStatus;
import org.apache.maven.scm.ScmResult;
import org.apache.maven.scm.ScmTagParameters;
import org.apache.maven.scm.command.tag.AbstractTagCommand;
import org.apache.maven.scm.command.tag.TagScmResult;
import org.apache.maven.scm.provider.ScmProviderRepository;
import org.apache.maven.scm.provider.git.command.GitCommand;
import org.apache.maven.scm.provider.git.jgit.command.JGitUtils;
import org.apache.maven.scm.provider.git.repository.GitScmProviderRepository;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.RefSpec;
import org.eclipse.jgit.treewalk.TreeWalk;

/**
 * @author <a href="mailto:struberg@yahoo.de">Mark Struberg</a>
 * @author Dominik Bartholdi (imod)
 * @since 1.9
 */
public class JGitTagCommand extends AbstractTagCommand implements GitCommand {

    public ScmResult executeTagCommand(ScmProviderRepository repo, ScmFileSet fileSet, String tag, String message)
            throws ScmException {
        return executeTagCommand(repo, fileSet, tag, new ScmTagParameters(message));
    }

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

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

        String escapedTagName = tag.trim().replace(' ', '_');

        Git git = null;
        try {
            git = JGitUtils.openRepo(fileSet.getBasedir());

            // tag the revision
            String tagMessage = scmTagParameters.getMessage();
            Ref tagRef = git.tag()
                    .setName(escapedTagName)
                    .setMessage(tagMessage)
                    .setForceUpdate(false)
                    .call();

            if (repo.isPushChanges()) {
                logger.info("push tag [" + escapedTagName + "] to remote...");
                JGitUtils.push(git, (GitScmProviderRepository) repo, new RefSpec(Constants.R_TAGS + escapedTagName));
            }

            // search for the tagged files
            RevWalk revWalk = new RevWalk(git.getRepository());
            RevCommit commit = revWalk.parseCommit(tagRef.getObjectId());
            revWalk.close();

            final TreeWalk walk = new TreeWalk(git.getRepository());
            walk.reset(); // drop the first empty tree, which we do not need here
            walk.setRecursive(true);
            walk.addTree(commit.getTree());

            List<ScmFile> taggedFiles = new ArrayList<>();
            while (walk.next()) {
                taggedFiles.add(new ScmFile(walk.getPathString(), ScmFileStatus.CHECKED_OUT));
            }
            walk.close();

            return new TagScmResult("JGit tag", taggedFiles);
        } catch (Exception e) {
            throw new ScmException("JGit tag failure!", e);
        } finally {
            JGitUtils.closeRepo(git);
        }
    }
}
