/**
 * Copyright 2017 Google Inc. All rights reserved.
 *
 * 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.
 */

const fs = require('fs');
const path = require('path');
const expect = require('expect');
const GoldenUtils = require('./golden-utils');
const PROJECT_ROOT = fs.existsSync(path.join(__dirname, '..', 'package.json'))
  ? path.join(__dirname, '..')
  : path.join(__dirname, '..', '..');

const utils = (module.exports = {
  extendExpectWithToBeGolden: function (goldenDir, outputDir) {
    expect.extend({
      toBeGolden: (testScreenshot, goldenFilePath) => {
        const result = GoldenUtils.compare(
          goldenDir,
          outputDir,
          testScreenshot,
          goldenFilePath
        );

        return {
          message: () => result.message,
          pass: result.pass,
        };
      },
    });
  },

  /**
   * @returns {string}
   */
  projectRoot: function () {
    return PROJECT_ROOT;
  },

  /**
   * @param {!Page} page
   * @param {string} frameId
   * @param {string} url
   * @returns {!Frame}
   */
  attachFrame: async function (page, frameId, url) {
    const handle = await page.evaluateHandle(attachFrame, frameId, url);
    return await handle.asElement().contentFrame();

    async function attachFrame(frameId, url) {
      const frame = document.createElement('iframe');
      frame.src = url;
      frame.id = frameId;
      document.body.appendChild(frame);
      await new Promise((x) => (frame.onload = x));
      return frame;
    }
  },

  isFavicon: function (request) {
    return request.url().includes('favicon.ico');
  },

  /**
   * @param {!Page} page
   * @param {string} frameId
   */
  detachFrame: async function (page, frameId) {
    await page.evaluate(detachFrame, frameId);

    function detachFrame(frameId) {
      const frame = document.getElementById(frameId);
      frame.remove();
    }
  },

  /**
   * @param {!Page} page
   * @param {string} frameId
   * @param {string} url
   */
  navigateFrame: async function (page, frameId, url) {
    await page.evaluate(navigateFrame, frameId, url);

    function navigateFrame(frameId, url) {
      const frame = document.getElementById(frameId);
      frame.src = url;
      return new Promise((x) => (frame.onload = x));
    }
  },

  /**
   * @param {!Frame} frame
   * @param {string=} indentation
   * @returns {Array<string>}
   */
  dumpFrames: function (frame, indentation) {
    indentation = indentation || '';
    let description = frame.url().replace(/:\d{4}\//, ':<PORT>/');
    if (frame.name()) description += ' (' + frame.name() + ')';
    const result = [indentation + description];
    for (const child of frame.childFrames())
      result.push(...utils.dumpFrames(child, '    ' + indentation));
    return result;
  },

  /**
   * @param {!EventEmitter} emitter
   * @param {string} eventName
   * @returns {!Promise<!Object>}
   */
  waitEvent: function (emitter, eventName, predicate = () => true) {
    return new Promise((fulfill) => {
      emitter.on(eventName, function listener(event) {
        if (!predicate(event)) return;
        emitter.removeListener(eventName, listener);
        fulfill(event);
      });
    });
  },
});