text: /**
   * @license 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.
   */
  'use strict';
  
  const fs = require('fs');
  const path = require('path');
  const util = require('util');
  
  const opn = require('opn');
  const args = require('yargs')
    .example('node $0 ./out-dir')
    .help('help')
    .demand(1)
    .argv;
  
  const constants = require('./constants');
  const utils = require('./utils');
  const Metrics = require('../lighthouse-core/lib/traces/pwmetrics-events');
  
  const outFolder = args._[0];
  const outPath = path.resolve(__dirname, outFolder);
  
  /**
   * Analyzes output generated from the measure step and
   * generates a summary file for consumption by chart.js.
   */
  function main() {
    const allResults = [];
    fs.readdirSync(outPath).forEach(siteDir => {
      const sitePath = path.resolve(outPath, siteDir);
      if (!utils.isDir(sitePath)) {
        return;
      }
      allResults.push({site: siteDir, results: analyzeSite(sitePath)});
    });
    const generatedResults = groupByMetrics(allResults);
    fs.writeFileSync(
      path.resolve(outPath, constants.GENERATED_RESULTS_FILENAME),
      `var generatedResults = ${JSON.stringify(generatedResults)}`
    );
    const chartsPath = path.resolve(__dirname, constants.CHARTS_FOLDER);
    utils.copy(path.resolve(chartsPath, constants.CHARTS_HTML_FILENAME), outPath);
    utils.copy(path.resolve(chartsPath, constants.CHARTS_JS_FILENAME), outPath);
    utils.copy(path.resolve(chartsPath, constants.CHARTS_LOADER_FILENAME), outPath);
  
    if (process.env.CI) {
      return;
    }
    console.log('Opening the charts web page...');  // eslint-disable-line no-console
    opn(path.resolve(outPath, constants.CHARTS_HTML_FILENAME));
  }
  
  main();
  
  /**
   * Aggregates all the run results for a particular site.
   * @param {string} sitePath
   * @return {!RunResults}
   */
  function analyzeSite(sitePath) {
    console.log('Analyzing', sitePath); // eslint-disable-line no-console
    const runResults = [];
    fs.readdirSync(sitePath).sort((a, b) => a.localeCompare(b)).forEach(runDir => {
      const resultsPath = path.resolve(sitePath, runDir, constants.LIGHTHOUSE_RESULTS_FILENAME);
      if (!utils.isFile(resultsPath)) {
        return;
      }
      const metrics = readResult(resultsPath);
      const prettymetrics = util.inspect(metrics, {colors: true, breakLength: Infinity});
      console.log(`Metrics for ${runDir}:`, prettymetrics); // eslint-disable-line no-console
      runResults.push({
        runId: runDir,
        metrics,
      });
    });
    return runResults;
  }
  
  /**
   * Extracts the metrics data from a lighthouse json report.
   * @param {string} resultPath
   * @return {!Array<!Metric>}
   */
  function readResult(lighthouseReportPath) {
    const data = JSON.parse(fs.readFileSync(lighthouseReportPath));
    const metrics = Metrics.metricsDefinitions.map(metric => ({
      name: metric.name,
      id: metric.id,
      timing: metric.getTiming(data.audits),
    }));
    const timings = Object.keys(constants.TIMING_NAME_MAP).map(timingName => ({
      name: constants.TIMING_NAME_MAP[timingName],
      id: 'timing' + timingName,
      timing: data.timing[timingName],
    }));
    return [...metrics, ...timings];
  }
  
  /**
   * Aggregates site results by performance metric because it's
   * informative to compare a suite of sites for a particular metric.
   * @param {!Array<!SiteResults>} results
   * @return {!ResultsByMetric}
   */
  function groupByMetrics(results) {
    const metricNames = Metrics.metricsDefinitions.map(metric => metric.name)
        .concat(Object.keys(constants.TIMING_NAME_MAP).map(key => constants.TIMING_NAME_MAP[key]));
  
    return metricNames.reduce((acc, metricName, index) => {
      acc[metricName] = results.map(siteResult => ({
        site: siteResult.site,
        metrics: siteResult.results.map(runResult => ({
          timing: runResult.metrics[index].timing,
        })),
      }));
      return acc;
    }, {});
  }
  
  /**
   * @typedef {{site: string, results: !RunResults}}
   */
  let SiteResults; // eslint-disable-line no-unused-vars
  
  /**
   * @typedef {!Array<{runId: string, metrics: !Array<!Metric>}>}
   */
  let RunResults; // eslint-disable-line no-unused-vars
  
  /**
   * @typedef {{name: string, id: string, timing: number}}
   */
  let Metric; // eslint-disable-line no-unused-vars
  
  /**
   * @typedef {!Object<string, !Array<{site: string, metrics: !Array<{timing: number}>}>}
   */
  let ResultsByMetric; // eslint-disable-line no-unused-vars
  