// Do this as the first thing so that any code reading it knows the right env.
process.env.NODE_ENV = 'production';

// Load environment variables from .env file. Suppress warnings using silent
// if this file is missing. dotenv will never modify any environment variables
// that have already been set.
// https://github.com/motdotla/dotenv
require('dotenv').config({ silent: true });

const chalk = require('chalk');
const fs = require('fs-extra');
const path = require('path');
const exec = require('child_process').execFileSync;
const filesize = require('filesize');
const gzipSize = require('gzip-size').sync;
const rimrafSync = require('rimraf').sync;
const webpack = require('webpack');
const config = require('../config/webpack.config.prod');
const paths = require('../config/paths');
const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
const recursive = require('recursive-readdir');
const stripAnsi = require('strip-ansi');

// Warn and crash if required files are missing
if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
  process.exit(1);
}

// Input: /User/dan/app/build/static/js/main.82be8.js
// Output: /static/js/main.js
function removeFileNameHash(fileName) {
  return fileName
    .replace(paths.appBuild, '')
    .replace(/\/?(.*)(\.\w+)(\.js|\.css)/, (match, p1, p2, p3) => p1 + p3);
}

// Input: 1024, 2048
// Output: "(+1 KB)"
function getDifferenceLabel(currentSize, previousSize) {
  const FIFTY_KILOBYTES = 1024 * 50;
  const difference = currentSize - previousSize;
  const fileSize = !Number.isNaN(difference) ? filesize(difference) : 0;
  if (difference >= FIFTY_KILOBYTES) {
    return chalk.red(`+${fileSize}`);
  } else if (difference < FIFTY_KILOBYTES && difference > 0) {
    return chalk.yellow(`+${fileSize}`);
  } else if (difference < 0) {
    return chalk.green(fileSize);
  } else {
    return '';
  }
}

// First, read the current file sizes in build directory.
// This lets us display how much they changed later.
recursive(paths.appBuild, (err, fileNames) => {
  const previousSizeMap = (fileNames || [])
    .filter(fileName => /\.(js|css)$/.test(fileName))
    .reduce((memo, fileName) => {
      const contents = fs.readFileSync(fileName);
      const key = removeFileNameHash(fileName);
      memo[key] = gzipSize(contents);
      return memo;
    }, {});

  // Remove all content but keep the directory so that
  // if you're in it, you don't end up in Trash
  rimrafSync(`${paths.appBuild}/*`);

  // Start the webpack build
  build(previousSizeMap);

  // Merge with the public folder
  copyPublicFolder();

  fs.mkdirSync(paths.appBuildLib);

  fs.copySync(
    path.join(paths.appRoot, 'docs-dist.json'),
    path.join(paths.appBuild, 'docs-dist.json')
  );
  const libPkgPath = path.join(paths.libRoot, 'package.json');

  const navLibPackageJson = require(libPkgPath);


  exec('babel', [ 'src', '--out-dir', paths.appBuildLib], {cwd: paths.appRoot});

  fs.readdirSync(paths.appBuildLib).forEach((module) => {
    const modulePath = path.join(paths.appBuildLib, module);
    let moduleData = fs.readFileSync(modulePath, {encoding: 'utf8'});
    // This is a dangerous shameful hack but it allows the website source to use a standard-looking import:
    moduleData = moduleData.split("require('react-navigation'").join("require('../react-navigation/react-navigation.web'");
    fs.writeFileSync(modulePath, moduleData);
  });

  const libPath = path.join(paths.appBuild, 'react-navigation');
  fs.mkdirSync(libPath);

  fs.copySync(
    path.join(paths.libRoot, 'lib'),
    libPath
  );

  // fs.writeFileSync(path.join(libPath, 'package.json'), JSON.stringify(Object.assign({}, navLibPackageJson, {
  //   main: 'lib/react-navigation',
  // }), null, 2));

  fs.writeFileSync(path.join(paths.appBuild, 'package.json'), JSON.stringify(Object.assign({
    version: '1.0.0',
    name: 'web-build',
  }, appPackageJson.server, {
    dependencies: Object.assign({}, appPackageJson.dependencies, navLibPackageJson.dependencies, appPackageJson.server.dependencies, {
      'react-navigation': '',
    }),
  }), null, 2));

});

// Print a detailed summary of build files.
function printFileSizes(stats, previousSizeMap) {
  const assets = stats.toJson().assets
    .filter(asset => /\.(js|css)$/.test(asset.name))
    .map((asset) => {
      const fileContents = fs.readFileSync(`${paths.appBuildPublic}/${asset.name}`);
      const size = gzipSize(fileContents);
      const previousSize = previousSizeMap[removeFileNameHash(asset.name)];
      const difference = getDifferenceLabel(size, previousSize);
      return {
        folder: path.join('build', path.dirname(asset.name)),
        name: path.basename(asset.name),
        size,
        sizeLabel: filesize(size) + (difference ? ` (${difference})` : ''),
      };
    });
  assets.sort((a, b) => b.size - a.size);
  const longestSizeLabelLength = Math.max.apply(null,
    assets.map(a => stripAnsi(a.sizeLabel).length)
  );
  assets.forEach((asset) => {
    let sizeLabel = asset.sizeLabel;
    const sizeLength = stripAnsi(sizeLabel).length;
    if (sizeLength < longestSizeLabelLength) {
      const rightPadding = ' '.repeat(longestSizeLabelLength - sizeLength);
      sizeLabel += rightPadding;
    }
    console.log(
      `  ${sizeLabel
      }  ${chalk.dim(asset.folder + path.sep)}${chalk.cyan(asset.name)}`
    );
  });
}

// Print out errors
function printErrors(summary, errors) {
  console.log(chalk.red(summary));
  console.log();
  errors.forEach((err) => {
    console.log(err.message || err);
    console.log();
  });
}

var appPackageJson = require(paths.appPackageJson);

// Create the production build and print the deployment instructions.
function build(previousSizeMap) {
  console.log('Creating an optimized production build...');
  webpack(config).run((err, stats) => {
    if (err) {
      printErrors('Failed to compile.', [err]);
      process.exit(1);
    }

    if (stats.compilation.errors.length) {
      printErrors('Failed to compile.', stats.compilation.errors);
      process.exit(1);
    }

    console.log(chalk.green('Compiled successfully.'));
    console.log();

    console.log('File sizes after gzip:');
    console.log();
    printFileSizes(stats, previousSizeMap);
    console.log();

    const openCommand = process.platform === 'win32' ? 'start' : 'open';
    const homepagePath = appPackageJson.homepage;
    const publicPath = config.output.publicPath;
    if (homepagePath && homepagePath.indexOf('.github.io/') !== -1) {
      // "homepage": "http://user.github.io/project"
      console.log(`The project was built assuming it is hosted at ${chalk.green(publicPath)}.`);
      console.log(`You can control this with the ${chalk.green('homepage')} field in your ${chalk.cyan('package.json')}.`);
      console.log();
      console.log(`The ${chalk.cyan('build')} folder is ready to be deployed.`);
      console.log(`To publish it at ${chalk.green(homepagePath)}, run:`);
      console.log();
      console.log(`  ${chalk.cyan('npm')} install --save-dev gh-pages`);
      console.log();
      console.log(`Add the following script in your ${chalk.cyan('package.json')}.`);
      console.log();
      console.log(`    ${chalk.dim('// ...')}`);
      console.log(`    ${chalk.yellow('"scripts"')}: {`);
      console.log(`      ${chalk.dim('// ...')}`);
      console.log(`      ${chalk.yellow('"deploy"')}: ${chalk.yellow('"gh-pages -d build"')}`);
      console.log('    }');
      console.log();
      console.log('Then run:');
      console.log();
      console.log(`  ${chalk.cyan('npm')} run deploy`);
      console.log();
    } else if (publicPath !== '/') {
      // "homepage": "http://mywebsite.com/project"
      console.log(`The project was built assuming it is hosted at ${chalk.green(publicPath)}.`);
      console.log(`You can control this with the ${chalk.green('homepage')} field in your ${chalk.cyan('package.json')}.`);
      console.log();
      console.log(`The ${chalk.cyan('build')} folder is ready to be deployed.`);
      console.log();
    } else {
      // no homepage or "homepage": "http://mywebsite.com"
      console.log('The project was built assuming it is hosted at the server root.');
      if (homepagePath) {
        // "homepage": "http://mywebsite.com"
        console.log(`You can control this with the ${chalk.green('homepage')} field in your ${chalk.cyan('package.json')}.`);
        console.log();
      } else {
        // no homepage
        console.log(`To override this, specify the ${chalk.green('homepage')} in your ${chalk.cyan('package.json')}.`);
        console.log('For example, add this to build it for GitHub Pages:');
        console.log();
        console.log(`  ${chalk.green('"homepage"')}${chalk.cyan(': ')}${chalk.green('"http://myname.github.io/myapp"')}${chalk.cyan(',')}`);
        console.log();
      }
      console.log(`The ${chalk.cyan('build')} folder is ready to be deployed.`);
      console.log('You may also serve it locally with a static server:');
      console.log();
      console.log(`  ${chalk.cyan('npm')} install -g pushstate-server`);
      console.log(`  ${chalk.cyan('pushstate-server')} build`);
      console.log(`  ${chalk.cyan(openCommand)} http://localhost:9000`);
      console.log();
    }
  });
}

function copyPublicFolder() {
  fs.copySync(paths.appPublic, paths.appBuildPublic, {
    dereference: true,
    filter: file => file !== paths.appHtml,
  });
}