/*
 * 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.hg;

import javax.inject.Named;
import javax.inject.Singleton;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import org.apache.maven.scm.CommandParameters;
import org.apache.maven.scm.ScmException;
import org.apache.maven.scm.ScmFileSet;
import org.apache.maven.scm.command.add.AddScmResult;
import org.apache.maven.scm.command.blame.BlameScmResult;
import org.apache.maven.scm.command.branch.BranchScmResult;
import org.apache.maven.scm.command.changelog.ChangeLogScmResult;
import org.apache.maven.scm.command.checkin.CheckInScmResult;
import org.apache.maven.scm.command.checkout.CheckOutScmResult;
import org.apache.maven.scm.command.diff.DiffScmResult;
import org.apache.maven.scm.command.info.InfoScmResult;
import org.apache.maven.scm.command.list.ListScmResult;
import org.apache.maven.scm.command.remove.RemoveScmResult;
import org.apache.maven.scm.command.status.StatusScmResult;
import org.apache.maven.scm.command.tag.TagScmResult;
import org.apache.maven.scm.command.update.UpdateScmResult;
import org.apache.maven.scm.provider.AbstractScmProvider;
import org.apache.maven.scm.provider.ScmProviderRepository;
import org.apache.maven.scm.provider.hg.command.add.HgAddCommand;
import org.apache.maven.scm.provider.hg.command.blame.HgBlameCommand;
import org.apache.maven.scm.provider.hg.command.branch.HgBranchCommand;
import org.apache.maven.scm.provider.hg.command.changelog.HgChangeLogCommand;
import org.apache.maven.scm.provider.hg.command.checkin.HgCheckInCommand;
import org.apache.maven.scm.provider.hg.command.checkout.HgCheckOutCommand;
import org.apache.maven.scm.provider.hg.command.diff.HgDiffCommand;
import org.apache.maven.scm.provider.hg.command.info.HgInfoCommand;
import org.apache.maven.scm.provider.hg.command.inventory.HgListCommand;
import org.apache.maven.scm.provider.hg.command.remove.HgRemoveCommand;
import org.apache.maven.scm.provider.hg.command.status.HgStatusCommand;
import org.apache.maven.scm.provider.hg.command.tag.HgTagCommand;
import org.apache.maven.scm.provider.hg.command.update.HgUpdateCommand;
import org.apache.maven.scm.provider.hg.repository.HgScmProviderRepository;
import org.apache.maven.scm.repository.ScmRepositoryException;
import org.apache.maven.scm.repository.UnknownRepositoryStructure;

/**
 * <a href="https://www.mercurial-scm.org/">Mercurial (HG)</a> is a decentralized revision control system.
 *
 * @author <a href="mailto:thurner.rupert@ymono.net">thurner rupert</a>
 */
@Singleton
@Named("hg")
public class HgScmProvider extends AbstractScmProvider {
    /**
     * {@inheritDoc}
     */
    public String getScmSpecificFilename() {
        return ".hg";
    }

    private static class HgUrlParserResult {
        private final List<String> messages = new ArrayList<>();

        private ScmProviderRepository repository;
    }

    /**
     * {@inheritDoc}
     */
    public ScmProviderRepository makeProviderScmRepository(String scmSpecificUrl, char delimiter)
            throws ScmRepositoryException {
        HgUrlParserResult result = parseScmUrl(scmSpecificUrl);

        if (result.messages.size() > 0) {
            throw new ScmRepositoryException("The scm url is invalid.", result.messages);
        }

        return result.repository;
    }

    private HgUrlParserResult parseScmUrl(String scmSpecificUrl) {
        HgUrlParserResult result = new HgUrlParserResult();

        // ----------------------------------------------------------------------
        // Do some sanity checking of the SVN url
        // ----------------------------------------------------------------------

        if (scmSpecificUrl.startsWith("file")) {
            if (!scmSpecificUrl.startsWith("file:///") && !scmSpecificUrl.startsWith("file://localhost/")) {
                result.messages.add("An hg 'file' url must be on the form 'file:///' or 'file://localhost/'.");

                return result;
            }
        } else if (scmSpecificUrl.startsWith("https")) {
            if (!scmSpecificUrl.startsWith("https://")) {
                result.messages.add("An hg 'http' url must be on the form 'https://'.");

                return result;
            }
        } else if (scmSpecificUrl.startsWith("http")) {
            if (!scmSpecificUrl.startsWith("http://")) {
                result.messages.add("An hg 'http' url must be on the form 'http://'.");

                return result;
            }
        } else {
            try {
                new File(scmSpecificUrl);
            } catch (Throwable e) {
                result.messages.add("The filename provided is not valid");

                return result;
            }
        }

        result.repository = new HgScmProviderRepository(scmSpecificUrl);

        return result;
    }

    /**
     * {@inheritDoc}
     */
    public ScmProviderRepository makeProviderScmRepository(File path)
            throws ScmRepositoryException, UnknownRepositoryStructure {
        if (path == null) {
            throw new NullPointerException("Path argument is null");
        }

        if (!path.isDirectory()) {
            throw new ScmRepositoryException(path.getAbsolutePath() + " isn't a valid directory.");
        }

        File hgDir = new File(path, ".hg");

        if (!hgDir.exists()) {
            throw new ScmRepositoryException(path.getAbsolutePath() + " isn't a hg directory.");
        }

        return makeProviderScmRepository(path.getAbsolutePath(), ':');
    }

    /**
     * {@inheritDoc}
     */
    public List<String> validateScmUrl(String scmSpecificUrl, char delimiter) {
        HgUrlParserResult result = parseScmUrl(scmSpecificUrl);

        return result.messages;
    }

    /**
     * {@inheritDoc}
     */
    public String getScmType() {
        return "hg";
    }

    /**
     * {@inheritDoc}
     */
    public AddScmResult add(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgAddCommand command = new HgAddCommand();

        return (AddScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public ChangeLogScmResult changelog(
            ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters) throws ScmException {
        HgChangeLogCommand command = new HgChangeLogCommand();

        return (ChangeLogScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public CheckInScmResult checkin(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgCheckInCommand command = new HgCheckInCommand();

        return (CheckInScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public CheckOutScmResult checkout(
            ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters) throws ScmException {
        HgCheckOutCommand command = new HgCheckOutCommand();

        return (CheckOutScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public TagScmResult tag(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgTagCommand command = new HgTagCommand();

        return (TagScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public DiffScmResult diff(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgDiffCommand command = new HgDiffCommand();

        return (DiffScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public RemoveScmResult remove(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgRemoveCommand command = new HgRemoveCommand();

        return (RemoveScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public StatusScmResult status(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgStatusCommand command = new HgStatusCommand();

        return (StatusScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public UpdateScmResult update(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgUpdateCommand command = new HgUpdateCommand();

        return (UpdateScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    protected BlameScmResult blame(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgBlameCommand command = new HgBlameCommand();

        return (BlameScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * {@inheritDoc}
     */
    public BranchScmResult branch(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgBranchCommand command = new HgBranchCommand();

        return (BranchScmResult) command.execute(repository, fileSet, parameters);
    }

    /**
     * @since 1.5
     */
    @Override
    protected ListScmResult list(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgListCommand hgListCommand = new HgListCommand();

        return (ListScmResult) hgListCommand.executeCommand(repository, fileSet, parameters);
    }

    /**
     * Returns result of hg id -i.
     *
     * @see org.apache.maven.scm.provider.AbstractScmProvider#info(org.apache.maven.scm.provider.ScmProviderRepository, org.apache.maven.scm.ScmFileSet, org.apache.maven.scm.CommandParameters)
     * @since 1.5
     */
    @Override
    public InfoScmResult info(ScmProviderRepository repository, ScmFileSet fileSet, CommandParameters parameters)
            throws ScmException {
        HgInfoCommand infoCommand = new HgInfoCommand();

        return (InfoScmResult) infoCommand.execute(repository, fileSet, parameters);
    }
}
