text: const path = require('path');
  const webpack = require('webpack');
  const ExtractTextPlugin = require('extract-text-webpack-plugin');
  const HtmlWebpackPlugin = require('html-webpack-plugin');
  
  let og_image_url = process.env.RIOT_OG_IMAGE_URL;
  if (!og_image_url) og_image_url = 'https://riot.im/app/themes/riot/img/logos/riot-im-logo-1.png';
  
  module.exports = {
      entry: {
          // Load babel-polyfill first to avoid issues where some imports (namely react)
          // are potentially loaded before babel-polyfill.
          "bundle": ["babel-polyfill", "./src/vector/index.js"],
          "indexeddb-worker": "./src/vector/indexeddb-worker.js",
  
          // We ship olm.js as a separate lump of javascript. This makes it get
          // loaded via a separate <script/> tag in index.html (which loads it
          // into the browser global `Olm`, where js-sdk expects to find it).
          //
          // (we should probably make js-sdk load it asynchronously at some
          // point, so that it doesn't block the pageload, but that is a separate
          // problem)
          "olm": "./src/vector/olm-loader.js",
  
          // CSS themes
          "theme-light":  "./node_modules/matrix-react-sdk/res/themes/light/css/light.scss",
          "theme-dark":   "./node_modules/matrix-react-sdk/res/themes/dark/css/dark.scss",
          "theme-status": "./res/themes/status/css/status.scss",
      },
      module: {
          preLoaders: [
              { test: /\.js$/, loader: "source-map-loader" },
          ],
          loaders: [
              { test: /\.json$/, loader: "json" },
              { test: /\.js$/, loader: "babel", include: path.resolve('./src') },
              {
                  test: /\.scss$/,
  
                  // 1. postcss-loader turns the SCSS into normal CSS.
                  // 2. css-raw-loader turns the CSS into a javascript module
                  //    whose default export is a string containing the CSS.
                  //    (css-raw-loader is similar to css-loader, but the latter
                  //    would also drag in the imgs and fonts that our CSS refers to
                  //    as webpack inputs.)
                  // 3. ExtractTextPlugin turns that string into a separate asset.
                  loader: ExtractTextPlugin.extract("css-raw-loader!postcss-loader?config=postcss.config.js"),
              },
              {
                  // this works similarly to the scss case, without postcss.
                  test: /\.css$/,
                  loader: ExtractTextPlugin.extract("css-raw-loader"),
              },
          ],
          noParse: [
              // for cross platform compatibility use [\\\/] as the path separator
              // this ensures that the regex trips on both Windows and *nix
  
              // don't parse the languages within highlight.js. They cause stack
              // overflows (https://github.com/webpack/webpack/issues/1721), and
              // there is no need for webpack to parse them - they can just be
              // included as-is.
              /highlight\.js[\\\/]lib[\\\/]languages/,
  
              // olm takes ages for webpack to process, and it's already heavily
              // optimised, so there is little to gain by us uglifying it.
              /olm[\\\/](javascript[\\\/])?olm\.js$/,
          ],
      },
      output: {
          path: path.join(__dirname, "webapp"),
  
          // the generated js (and CSS, from the ExtractTextPlugin) are put in a
          // unique subdirectory for the build. There will only be one such
          // 'bundle' directory in the generated tarball; however, hosting
          // servers can collect 'bundles' from multiple versions into one
          // directory and symlink it into place - this allows users who loaded
          // an older version of the application to continue to access webpack
          // chunks even after the app is redeployed.
          //
          filename: "bundles/[hash]/[name].js",
          chunkFilename: "bundles/[hash]/[name].js",
          devtoolModuleFilenameTemplate: function(info) {
              // Reading input source maps gives only relative paths here for
              // everything. Until I figure out how to fix this, this is a
              // workaround.
              // We use the relative resource path with any '../'s on the front
              // removed which gives a tree with matrix-react-sdk and vector
              // trees smashed together, but this fixes everything being under
              // various levels of '.' and '..'
              // Also, sometimes the resource path is absolute.
              return path.relative(process.cwd(), info.resourcePath).replace(/^[\/\.]*/, '');
          },
      },
      resolve: {
          alias: {
              // alias any requires to the react module to the one in our path, otherwise
              // we tend to get the react source included twice when using npm link.
              "react": path.resolve('./node_modules/react'),
              "react-dom": path.resolve('./node_modules/react-dom'),
              "react-addons-perf": path.resolve('./node_modules/react-addons-perf'),
  
              // same goes for js-sdk
              "matrix-js-sdk": path.resolve('./node_modules/matrix-js-sdk'),
          },
      },
      externals: {
          // Don't try to bundle electron: leave it as a commonjs dependency
          // (the 'commonjs' here means it will output a 'require')
          "electron": "commonjs electron",
      },
      plugins: [
          new webpack.DefinePlugin({
              'process.env': {
                  NODE_ENV: JSON.stringify(process.env.NODE_ENV),
              },
          }),
  
          new ExtractTextPlugin("bundles/[hash]/[name].css", {
              allChunks: true,
          }),
  
          new HtmlWebpackPlugin({
              template: './src/vector/index.html',
  
              // we inject the links ourselves via the template, because
              // HtmlWebpackPlugin wants to put the script tags either at the
              // bottom of <head> or the bottom of <body>, and I'm a bit scared
              // about moving them.
              inject: false,
              vars: {
                  og_image_url: og_image_url,
              },
          }),
      ],
      devtool: 'source-map',
  
      // configuration for the webpack-dev-server
      devServer: {
          // serve unwebpacked assets from webapp.
          contentBase: './webapp',
  
          stats: {
              // don't fill the console up with a mahoosive list of modules
              chunks: false,
          },
      },
  };
  
  // olm is an optional dependency. Ignore it if it's not installed, to avoid a
  // scary-looking error.
  try {
      require('olm');
  } catch (e) {
      console.log("Olm is not installed; not shipping it");
      delete(module.exports.entry["olm"]);
  }
  