// Copyright (C) 2013 The Android Open Source Project
//
// Licensed 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 com.googlesource.gerrit.plugins.hooks.workflow;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jgit.lib.Config;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.gerrit.common.data.GitWebType;
import com.google.gerrit.common.data.ParameterizedString;
import com.google.gerrit.httpd.GitWebConfig;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.events.RefUpdatedEvent;
import com.google.inject.Inject;
import com.googlesource.gerrit.plugins.hooks.its.ItsFacade;

public class GerritHookFilterAddRelatedLinkToGitWeb extends GerritHookFilter {

  Logger log = LoggerFactory
      .getLogger(GerritHookFilterAddRelatedLinkToGitWeb.class);

  @Inject
  @GerritServerConfig
  private Config gerritConfig;

  @Inject
  private ItsFacade its;

  @Inject
  private GitWebConfig gitWebConfig;


  @Override
  public void doFilter(RefUpdatedEvent hook) throws IOException {

    String gitComment = getComment(hook.refUpdate.project,  hook.refUpdate.newRev);
    log.debug("Git commit " + hook.refUpdate.newRev + ": " + gitComment);

    URL gitUrl = getGitUrl(hook);
    if (gitUrl == null) {
      return;
    }
    String[] issues = getIssueIds(gitComment);

    for (String issue : issues) {
      log.debug("Adding GitWeb URL " + gitUrl + " to issue " + issue);

      its.addRelatedLink(issue, gitUrl, "Git: "
          + hook.refUpdate.newRev);
    }
  }


  /**
   * generates the URL to GitWeb for the event
   *
   * @return if null is returned, the configuration does not allow to come up
   * with a GitWeb url. In that case, a message describing the problematic
   * setting has been logged.
   */
  private URL getGitUrl(RefUpdatedEvent hook) throws MalformedURLException,
      UnsupportedEncodingException {
    String gerritCanonicalUrl =
        gerritConfig.getString("gerrit", null, "canonicalWebUrl");
    if (gerritCanonicalUrl == null) {
      log.info( "No canonicalWebUrl configured. Skipping GitWeb link generation");
      return null;
    }
    if(!gerritCanonicalUrl.endsWith("/")) {
      gerritCanonicalUrl += "/";
    }

    String gitWebUrl = gitWebConfig.getUrl();
    if (gitWebUrl == null) {
      log.info( "No url for GitWeb found. Skipping GitWeb link generation");
      return null;
    }
    if (!gitWebUrl.startsWith("http")) {
      gitWebUrl = gerritCanonicalUrl + gitWebUrl;
    }

    GitWebType gitWebType = gitWebConfig.getGitWebType();
    String revUrl = gitWebType.getRevision();

    ParameterizedString pattern = new ParameterizedString(revUrl);
    final Map<String, String> p = new HashMap<String, String>();
    p.put("project", URLEncoder.encode(
        gitWebType.replacePathSeparator(hook.refUpdate.project), "US-ASCII"));
    p.put("commit", hook.refUpdate.newRev);
    return new URL(gitWebUrl + pattern.replace(p));
  }
}