/**
 * @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.
 */
(function(window, GrDiffBuilder) {
  'use strict';

  // Prevent redefinition.
  if (window.GrDiffBuilderSideBySide) { return; }

  /** @constructor */
  function GrDiffBuilderSideBySide(diff, prefs, outputEl, layers) {
    GrDiffBuilder.call(this, diff, prefs, outputEl, layers);
  }
  GrDiffBuilderSideBySide.prototype = Object.create(GrDiffBuilder.prototype);
  GrDiffBuilderSideBySide.prototype.constructor = GrDiffBuilderSideBySide;

  GrDiffBuilderSideBySide.prototype.buildSectionElement = function(group) {
    const sectionEl = this._createElement('tbody', 'section');
    sectionEl.classList.add(group.type);
    if (this._isTotal(group)) {
      sectionEl.classList.add('total');
    }
    if (group.dueToRebase) {
      sectionEl.classList.add('dueToRebase');
    }
    if (group.ignoredWhitespaceOnly) {
      sectionEl.classList.add('ignoredWhitespaceOnly');
    }
    const pairs = group.getSideBySidePairs();
    for (let i = 0; i < pairs.length; i++) {
      sectionEl.appendChild(this._createRow(sectionEl, pairs[i].left,
          pairs[i].right));
    }
    return sectionEl;
  };

  GrDiffBuilderSideBySide.prototype.addColumns = function(outputEl, fontSize) {
    const width = fontSize * 4;
    const colgroup = document.createElement('colgroup');

    // Add the blame column.
    let col = this._createElement('col', 'blame');
    colgroup.appendChild(col);

    // Add left-side line number.
    col = document.createElement('col');
    col.setAttribute('width', width);
    colgroup.appendChild(col);

    // Add left-side content.
    colgroup.appendChild(document.createElement('col'));

    // Add right-side line number.
    col = document.createElement('col');
    col.setAttribute('width', width);
    colgroup.appendChild(col);

    // Add right-side content.
    colgroup.appendChild(document.createElement('col'));

    outputEl.appendChild(colgroup);
  };

  GrDiffBuilderSideBySide.prototype._createRow = function(section, leftLine,
      rightLine) {
    const row = this._createElement('tr');
    row.classList.add('diff-row', 'side-by-side');
    row.setAttribute('left-type', leftLine.type);
    row.setAttribute('right-type', rightLine.type);
    row.tabIndex = -1;

    row.appendChild(this._createBlameCell(leftLine));

    this._appendPair(section, row, leftLine, leftLine.beforeNumber,
        GrDiffBuilder.Side.LEFT);
    this._appendPair(section, row, rightLine, rightLine.afterNumber,
        GrDiffBuilder.Side.RIGHT);
    return row;
  };

  GrDiffBuilderSideBySide.prototype._appendPair = function(section, row, line,
      lineNumber, side) {
    const lineNumberEl = this._createLineEl(line, lineNumber, line.type, side);
    lineNumberEl.classList.add(side);
    row.appendChild(lineNumberEl);
    const action = this._createContextControl(section, line);
    if (action) {
      row.appendChild(action);
    } else {
      const textEl = this._createTextEl(lineNumberEl, line, side);
      row.appendChild(textEl);
    }
  };

  GrDiffBuilderSideBySide.prototype._getNextContentOnSide = function(
      content, side) {
    let tr = content.parentElement.parentElement;
    while (tr = tr.nextSibling) {
      content = tr.querySelector(
          'td.content .contentText[data-side="' + side + '"]');
      if (content) { return content; }
    }
    return null;
  };

  window.GrDiffBuilderSideBySide = GrDiffBuilderSideBySide;
})(window, GrDiffBuilder);