/**
 * @license
 * Copyright (C) 2016 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.
 */

/** @polymerBehavior Gerrit.PathListBehavior */
export const PathListBehavior = {

  COMMIT_MESSAGE_PATH: '/COMMIT_MSG',
  MERGE_LIST_PATH: '/MERGE_LIST',

  /**
   * @param {string} a
   * @param {string} b
   * @return {number}
   */
  specialFilePathCompare(a, b) {
    // The commit message always goes first.
    if (a === PathListBehavior.COMMIT_MESSAGE_PATH) {
      return -1;
    }
    if (b === PathListBehavior.COMMIT_MESSAGE_PATH) {
      return 1;
    }

    // The merge list always comes next.
    if (a === PathListBehavior.MERGE_LIST_PATH) {
      return -1;
    }
    if (b === PathListBehavior.MERGE_LIST_PATH) {
      return 1;
    }

    const aLastDotIndex = a.lastIndexOf('.');
    const aExt = a.substr(aLastDotIndex + 1);
    const aFile = a.substr(0, aLastDotIndex) || a;

    const bLastDotIndex = b.lastIndexOf('.');
    const bExt = b.substr(bLastDotIndex + 1);
    const bFile = b.substr(0, bLastDotIndex) || b;

    // Sort header files above others with the same base name.
    const headerExts = ['h', 'hxx', 'hpp'];
    if (aFile.length > 0 && aFile === bFile) {
      if (headerExts.includes(aExt) && headerExts.includes(bExt)) {
        return a.localeCompare(b);
      }
      if (headerExts.includes(aExt)) {
        return -1;
      }
      if (headerExts.includes(bExt)) {
        return 1;
      }
    }
    return aFile.localeCompare(bFile) || a.localeCompare(b);
  },

  computeDisplayPath(path) {
    if (path === PathListBehavior.COMMIT_MESSAGE_PATH) {
      return 'Commit message';
    } else if (path === PathListBehavior.MERGE_LIST_PATH) {
      return 'Merge list';
    }
    return path;
  },

  isMagicPath(path) {
    return !!path &&
        (path === PathListBehavior.COMMIT_MESSAGE_PATH || path ===
            PathListBehavior.MERGE_LIST_PATH);
  },

  computeTruncatedPath(path) {
    return PathListBehavior.truncatePath(
        PathListBehavior.computeDisplayPath(path));
  },

  /**
   * Truncates URLs to display filename only
   * Example
   * // returns '.../text.html'
   * util.truncatePath.('dir/text.html');
   * Example
   * // returns 'text.html'
   * util.truncatePath.('text.html');
   *
   * @param {string} path
   * @param {number=} opt_threshold
   * @return {string} Returns the truncated value of a URL.
   */
  truncatePath(path, opt_threshold) {
    const threshold = opt_threshold || 1;
    const pathPieces = path.split('/');

    if (pathPieces.length <= threshold) { return path; }

    const index = pathPieces.length - threshold;
    // Character is an ellipsis.
    return `\u2026/${pathPieces.slice(index).join('/')}`;
  },
};

// TODO(dmfilippov) Remove the following lines with assignments
// Plugins can use the behavior because it was accessible with
// the global Gerrit... variable. To avoid breaking changes in plugins
// temporary assign global variables.
window.Gerrit = window.Gerrit || {};
window.Gerrit.PathListBehavior = PathListBehavior;