/*
 * The MIT License
 * 
 * Copyright (c) 2004-2011, Oracle Corporation, Kohsuke Kawaguchi, Anton Kozak, Nikita Levyankov
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package hudson.scm;

import hudson.FilePath;
import hudson.Launcher;
import hudson.Extension;
import hudson.model.AbstractBuild;
import hudson.model.AbstractProject;
import hudson.model.BuildListener;
import hudson.model.TaskListener;
import net.sf.json.JSONObject;
import org.kohsuke.stapler.StaplerRequest;

import java.io.File;
import java.io.IOException;

/**
 * No {@link SCM}.
 *
 * @author Kohsuke Kawaguchi
 */
public class NullSCM extends SCM {
    public SCMRevisionState calcRevisionsFromBuild(AbstractBuild<?, ?> build, Launcher launcher, TaskListener listener) throws IOException, InterruptedException {
        return null;
    }

    protected PollingResult compareRemoteRevisionWith(AbstractProject project, Launcher launcher, FilePath workspace, TaskListener listener, SCMRevisionState baseline) throws IOException, InterruptedException {
        return PollingResult.NO_CHANGES;
    }

    public boolean checkout(AbstractBuild<?,?> build, Launcher launcher, FilePath remoteDir, BuildListener listener, File changeLogFile) throws IOException, InterruptedException {
        return createEmptyChangeLog(changeLogFile, listener, "log");
    }

    public ChangeLogParser createChangeLogParser() {
        return new NullChangeLogParser();
    }

    @Extension
    public static class DescriptorImpl extends SCMDescriptor<NullSCM> {
        public DescriptorImpl() {
            super(null);
        }

        public String getDisplayName() {
            return Messages.NullSCM_DisplayName();
        }

        @Override
        public SCM newInstance(StaplerRequest req, JSONObject formData) throws FormException {
            return new NullSCM();
        }
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        return !(o == null || getClass() != o.getClass());
    }

    @Override
    public int hashCode() {
        return 56;
    }
}