/**
 * 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.
 */

/**
 * @fileoverview Search developers.google.com/web for articles tagged
 * "Headless Chrome" and scrape results from the results page.
 */

'use strict';

const puppeteer = require('puppeteer');

(async() => {

const browser = await puppeteer.launch();
const page = await browser.newPage();

await page.goto('https://developers.google.com/web/');

// Type into search box.
await page.type('#searchbox input', 'Headless Chrome');

// Wait for suggest overlay to appear and click "show all results".
const allResultsSelector = '.devsite-suggest-all-results';
await page.waitForSelector(allResultsSelector);
await page.click(allResultsSelector);

// Wait for the results page to load and display the results.
const resultsSelector = '.gsc-results .gsc-thumbnail-inside a.gs-title';
await page.waitForSelector(resultsSelector);

// Extract the results from the page.
const links = await page.evaluate(resultsSelector => {
  const anchors = Array.from(document.querySelectorAll(resultsSelector));
  return anchors.map(anchor => {
    const title = anchor.textContent.split('|')[0].trim();
    return `${title} - ${anchor.href}`;
  });
}, resultsSelector);
console.log(links.join('\n'));

await browser.close();

})();