// 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.action;

import java.io.IOException;
import java.util.Map;
import java.util.Set;

import com.google.common.base.Strings;
import com.google.common.collect.Maps;
import com.google.inject.Inject;
import com.googlesource.gerrit.plugins.hooks.its.ItsFacade;
import com.googlesource.gerrit.plugins.hooks.workflow.ActionRequest;
import com.googlesource.gerrit.plugins.hooks.workflow.Property;

/**
 * Adds a short predefined comments to an issue.
 *
 * Comments are added for merging, abandoning, restoring of changes and adding
 * of patch sets.
 */
public class AddStandardComment implements Action {
  public interface Factory {
    AddStandardComment create();
  }

  private final ItsFacade its;

  @Inject
  public AddStandardComment(ItsFacade its) {
    this.its = its;
  }

  private String formatPerson(String prefix, Map<String, String> map) {
    String ret = Strings.nullToEmpty(map.get(prefix + "-name"));
    if (ret.isEmpty()) {
      ret = Strings.nullToEmpty(map.get(prefix + "-username"));
    }
    return ret;
  }

  private String getCommentChangeEvent(String Action, String prefix,
      Map<String, String> map) {
    String ret = "";
    String changeNumber = Strings.nullToEmpty(map.get("change-number"));
    if (!changeNumber.isEmpty()) {
      changeNumber += " ";
    }
    ret += "Change " + changeNumber + Action;
    String submitter = formatPerson(prefix, map);
    if (!submitter.isEmpty()) {
      ret += " by " + submitter;
    }
    String subject = Strings.nullToEmpty(map.get("subject"));
    if (!subject.isEmpty()) {
      ret += ":\n" + subject;
    }
    String reason = Strings.nullToEmpty(map.get("reason"));
    if (!reason.isEmpty()) {
      ret += "\n\nReason:\n" + reason;
    }
    String url = Strings.nullToEmpty(map.get("change-url"));
    if (!url.isEmpty()) {
      ret += "\n\n" + its.createLinkForWebui(url, url);
    }
    return ret;
  }

  private String getCommentChangeAbandoned(Map<String, String> map) {
    return getCommentChangeEvent("abandoned", "abandoner", map);
  }

  private String getCommentChangeMerged(Map<String, String> map) {
    return getCommentChangeEvent("merged", "submitter", map);
  }

  private String getCommentChangeRestored(Map<String, String> map) {
    return getCommentChangeEvent("restored", "restorer", map);
  }

  private String getCommentPatchSetCreated(Map<String, String> map) {
    return getCommentChangeEvent("had a related patch set uploaded",
        "uploader", map);
  }

  @Override
  public void execute(String issue, ActionRequest actionRequest,
      Set<Property> properties) throws IOException {
    String comment = "";
    Map<String, String> map = Maps.newHashMap();
    for (Property property : properties) {
      String current = property.getValue();
      if (!Strings.isNullOrEmpty(current))
      {
        String key = property.getKey();
        String old = Strings.nullToEmpty(map.get(key));
        if (!old.isEmpty()) {
          old += ", ";
        }
        map.put(key, old + current);
      }
    }
    String eventType = map.get("event-type");
    if ("change-abandoned".equals(eventType)) {
      comment = getCommentChangeAbandoned(map);
    } else if ("change-merged".equals(eventType)) {
      comment = getCommentChangeMerged(map);
    } else if ("change-restored".equals(eventType)) {
      comment = getCommentChangeRestored(map);
    } else if ("patchset-created".equals(eventType)) {
      comment = getCommentPatchSetCreated(map);
    }
    if (!Strings.isNullOrEmpty(comment)) {
      its.addComment(issue, comment);
    }
  }
}