/**
 * 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 child_process = require('child_process');
const {promisify} = require('util');

const fsAccess = promisify(fs.access);
const exec = promisify(child_process.exec);

const fileExists = async filePath => fsAccess(filePath).then(() => true).catch(() => false);

/*
 * Now Puppeteer is built with TypeScript, we need to ensure that
 * locally we have the generated output before trying to install.
 *
 * For users installing puppeteer this is fine, they will have the
 * generated lib/ directory as we ship it when we publish to npm.
 *
 * However, if you're cloning the repo to contribute, you won't have the
 * generated lib/ directory so this script checks if we need to run
 * TypeScript first to ensure the output exists and is in the right
 * place.
 */
async function compileTypeScript() {
  return exec('npm run tsc').catch(err => {
    console.error('Error running TypeScript', err);
    process.exit(1);
  });
}

async function ensureLibDirectoryExists() {
  const libPath = path.join(__dirname, 'lib');
  const libExists = await fileExists(libPath);
  if (libExists) return;

  logPolitely('Compiling TypeScript before install...');
  await compileTypeScript();
}


/**
 * This file is part of public API.
 *
 * By default, the `puppeteer` package runs this script during the installation
 * process unless one of the env flags is provided.
 * `puppeteer-core` package doesn't include this step at all. However, it's
 * still possible to install a supported browser using this script when
 * necessary.
 */
const supportedProducts = {
  'chrome': 'Chromium',
  'firefox': 'Firefox Nightly'
};

async function download() {
  await ensureLibDirectoryExists();

  const downloadHost = process.env.PUPPETEER_DOWNLOAD_HOST || process.env.npm_config_puppeteer_download_host || process.env.npm_package_config_puppeteer_download_host;
  const puppeteer = require('./index');
  const product = process.env.PUPPETEER_PRODUCT || process.env.npm_config_puppeteer_product || process.env.npm_package_config_puppeteer_product || 'chrome';
  const browserFetcher = puppeteer.createBrowserFetcher({ product, host: downloadHost });
  const revision = await getRevision();
  await fetchBinary(revision);

  function getRevision() {
    if (product === 'chrome') {
      return process.env.PUPPETEER_CHROMIUM_REVISION || process.env.npm_config_puppeteer_chromium_revision || process.env.npm_package_config_puppeteer_chromium_revision
        || require('./package.json').puppeteer.chromium_revision;
    } else if (product === 'firefox') {
      puppeteer._preferredRevision = require('./package.json').puppeteer.firefox_revision;
      return getFirefoxNightlyVersion(browserFetcher.host()).catch(error => { console.error(error); process.exit(1); });
    } else {
      throw new Error(`Unsupported product ${product}`);
    }
  }

  function fetchBinary(revision) {
    const revisionInfo = browserFetcher.revisionInfo(revision);

    // Do nothing if the revision is already downloaded.
    if (revisionInfo.local) {
      logPolitely(`${supportedProducts[product]} is already in ${revisionInfo.folderPath}; skipping download.`);
      return;
    }

    // Override current environment proxy settings with npm configuration, if any.
    const NPM_HTTPS_PROXY = process.env.npm_config_https_proxy || process.env.npm_config_proxy;
    const NPM_HTTP_PROXY = process.env.npm_config_http_proxy || process.env.npm_config_proxy;
    const NPM_NO_PROXY = process.env.npm_config_no_proxy;

    if (NPM_HTTPS_PROXY)
      process.env.HTTPS_PROXY = NPM_HTTPS_PROXY;
    if (NPM_HTTP_PROXY)
      process.env.HTTP_PROXY = NPM_HTTP_PROXY;
    if (NPM_NO_PROXY)
      process.env.NO_PROXY = NPM_NO_PROXY;

    /**
     * @param {!Array<string>}
     * @return {!Promise}
     */
    function onSuccess(localRevisions) {
      logPolitely(`${supportedProducts[product]} (${revisionInfo.revision}) downloaded to ${revisionInfo.folderPath}`);
      localRevisions = localRevisions.filter(revision => revision !== revisionInfo.revision);
      const cleanupOldVersions = localRevisions.map(revision => browserFetcher.remove(revision));
      Promise.all([...cleanupOldVersions]);
    }

    /**
     * @param {!Error} error
     */
    function onError(error) {
      console.error(`ERROR: Failed to set up ${supportedProducts[product]} r${revision}! Set "PUPPETEER_SKIP_DOWNLOAD" env variable to skip download.`);
      console.error(error);
      process.exit(1);
    }

    let progressBar = null;
    let lastDownloadedBytes = 0;
    function onProgress(downloadedBytes, totalBytes) {
      if (!progressBar) {
        const ProgressBar = require('progress');
        progressBar = new ProgressBar(`Downloading ${supportedProducts[product]} r${revision} - ${toMegabytes(totalBytes)} [:bar] :percent :etas `, {
          complete: '=',
          incomplete: ' ',
          width: 20,
          total: totalBytes,
        });
      }
      const delta = downloadedBytes - lastDownloadedBytes;
      lastDownloadedBytes = downloadedBytes;
      progressBar.tick(delta);
    }

    return browserFetcher.download(revisionInfo.revision, onProgress)
        .then(() => browserFetcher.localRevisions())
        .then(onSuccess)
        .catch(onError);
  }

  function toMegabytes(bytes) {
    const mb = bytes / 1024 / 1024;
    return `${Math.round(mb * 10) / 10} Mb`;
  }

  function getFirefoxNightlyVersion(host) {
    const https = require('https');
    const promise = new Promise((resolve, reject) => {
      let data = '';
      logPolitely(`Requesting latest Firefox Nightly version from ${host}`);
      https.get(host + '/', r => {
        if (r.statusCode >= 400)
          return reject(new Error(`Got status code ${r.statusCode}`));
        r.on('data', chunk => {
          data += chunk;
        });
        r.on('end', parseVersion);
      }).on('error', reject);

      function parseVersion() {
        const regex = /firefox\-(?<version>\d\d)\..*/gm;
        let result = 0;
        let match;
        while ((match = regex.exec(data)) !== null) {
          const version = parseInt(match.groups.version, 10);
          if (version > result)
            result = version;
        }
        if (result)
          resolve(result.toString());
        else reject(new Error('Firefox version not found'));
      }
    });
    return promise;
  }
}

function logPolitely(toBeLogged) {
  const logLevel = process.env.npm_config_loglevel;
  const logLevelDisplay = ['silent', 'error', 'warn'].indexOf(logLevel) > -1;

  if (!logLevelDisplay)
    console.log(toBeLogged);
}

if (process.env.PUPPETEER_SKIP_DOWNLOAD) {
  logPolitely('**INFO** Skipping browser download. "PUPPETEER_SKIP_DOWNLOAD" environment variable was found.');
  return;
}
if (process.env.NPM_CONFIG_PUPPETEER_SKIP_DOWNLOAD || process.env.npm_config_puppeteer_skip_download) {
  logPolitely('**INFO** Skipping browser download. "PUPPETEER_SKIP_DOWNLOAD" was set in npm config.');
  return;
}
if (process.env.NPM_PACKAGE_CONFIG_PUPPETEER_SKIP_DOWNLOAD || process.env.npm_package_config_puppeteer_skip_download) {
  logPolitely('**INFO** Skipping browser download. "PUPPETEER_SKIP_DOWNLOAD" was set in project config.');
  return;
}
if (process.env.PUPPETEER_SKIP_CHROMIUM_DOWNLOAD) {
  logPolitely('**INFO** Skipping browser download. "PUPPETEER_SKIP_CHROMIUM_DOWNLOAD" environment variable was found.');
  return;
}
if (process.env.NPM_CONFIG_PUPPETEER_SKIP_CHROMIUM_DOWNLOAD || process.env.npm_config_puppeteer_skip_chromium_download) {
  logPolitely('**INFO** Skipping browser download. "PUPPETEER_SKIP_CHROMIUM_DOWNLOAD" was set in npm config.');
  return;
}
if (process.env.NPM_PACKAGE_CONFIG_PUPPETEER_SKIP_CHROMIUM_DOWNLOAD || process.env.npm_package_config_puppeteer_skip_chromium_download) {
  logPolitely('**INFO** Skipping browser download. "PUPPETEER_SKIP_CHROMIUM_DOWNLOAD" was set in project config.');
  return;
}

download();