'use strict';

// Modules
var webpack = require('webpack');
var autoprefixer = require('autoprefixer');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var CopyWebpackPlugin = require('copy-webpack-plugin');
var CompressionPlugin = require('compression-webpack-plugin');
var AssetsPlugin = require('assets-webpack-plugin');
var CopyWebpackPlugin = require('copy-webpack-plugin');
var path = require('path');
var UglifyJsPlugin = require('uglifyjs-webpack-plugin');

/**
 * Env
 * Get npm lifecycle event to identify the environment
 */
var ENV = process.env.npm_lifecycle_event;
var isTest = ENV === 'test' || ENV === 'test-watch';
var isProd = ENV === 'build';

module.exports = [function makeWebpackConfig() {
  /**
   * Config
   * Reference: http://webpack.github.io/docs/configuration.html
   * This is the object where all configuration gets set
   */
  var config = {};

  /**
   * Entry
   * Reference: http://webpack.github.io/docs/configuration.html#entry
   * Should be an empty object if it's generating a test build
   * Karma will set this when it's a test build
   */
  config.entry = isTest ? void 0 : {
    app: './app/index.js'

  };

  /**
   * Output
   * Reference: http://webpack.github.io/docs/configuration.html#output
   * Should be an empty object if it's generating a test build
   * Karma will handle setting it up for you when it's a test build
   */
  config.output = isTest ? {} : {
    // Absolute output directory
    path: __dirname + '/dist',

    // Output path from the view of the page
    // Uses webpack-dev-server in development
    publicPath: '/',

    // Filename for entry points
    // Only adds hash in build mode
    filename: isProd ? '[name].[hash].js' : '[name].bundle.js',

    // Filename for non-entry points
    // Only adds hash in build mode
    chunkFilename: isProd ? '[name].[hash].js' : '[name].bundle.js'
  };

  /**
   * Devtool
   * Reference: http://webpack.github.io/docs/configuration.html#devtool
   * Type of sourcemap to use per build type
   */
  if (isTest) {
    https:
        // unix.stackexchange.com/questions/144208/find-files-without-extension
        config.devtool = 'inline-source-map';
  } else if (isProd) {
    config.devtool = 'source-map';
  } else {
    config.devtool = 'eval-source-map';
  }

  /**
   * Loaders
   * Reference:
   * http://webpack.github.io/docs/configuration.html#module-loaders
   * List: http://webpack.github.io/docs/list-of-loaders.html
   * This handles most of the magic responsible for converting modules
   */

  // Initialize module
  config.module = {
    rules: [
      {
        // JS LOADER
        // Reference: https://github.com/babel/babel-loader
        // Transpile .js files using babel-loader
        // Compiles ES6 and ES7 into ES5 code
        test: /\.js$/,
        use: 'babel-loader',
        exclude: /node_modules/
      },
      {
        // CSS LOADER
        // Reference: https://github.com/webpack/css-loader
        // Allow loading css through js
        //
        // Reference: https://github.com/postcss/postcss-loader
        // Postprocess your css with PostCSS plugins
        test: /\.css$/,
        // Reference: https://github.com/webpack/extract-text-webpack-plugin
        // Extract css files in production builds
        //
        // Reference: https://github.com/webpack/style-loader
        // Use style-loader in development.

        loader: isTest ? 'null-loader' : ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: [
            {loader: 'css-loader', query: {sourceMap: true}},
            {loader: 'postcss-loader'}
          ],
        })
      },
      {
        // ASSET LOADER
        // Reference: https://github.com/webpack/file-loader
        // Copy png, jpg, jpeg, gif, svg, woff, woff2, ttf, eot files to
        // output
        // Rename the file using the asset hash
        // Pass along the updated reference to your code
        // You can add here any file extension you want to get copied to your
        // output
        test: /\.(png|jpg|jpeg|gif|svg|woff|woff2|ttf|eot|ico)$/,
        loader: 'file-loader',
        options: {
          name(file) {
            if (!isProd) {
              return '[path][name].[ext]';
            }

            return '[hash].[ext]';
          }
        }
      },
      {
        // HTML LOADER
        // Reference: https://github.com/webpack/raw-loader
        // Allow loading html through js
        test: /\.html$/,
        use: {loader: 'html-loader'}
      },
      // JSON LOADER
      {test: /\.json$/, loader: 'json-loader'}, {
        test: /\.scss$/,
        use: [
          {
            loader: 'style-loader'  // creates style nodes from JS strings
          },
          {
            loader: 'css-loader'  // translates CSS into CommonJS
          },
          {
            loader: 'sass-loader'  // compiles Sass to CSS
          }
        ]
      }
    ]
  };

  // ISTANBUL LOADER
  // https://github.com/deepsweet/istanbul-instrumenter-loader
  // Instrument JS files with istanbul-lib-instrument for subsequent code
  // coverage reporting
  // Skips node_modules and files that end with .spec.js
  if (isTest) {
    config.module.rules.push({
      enforce: 'pre',
      test: /\.js$/,
      exclude: [/node_modules/, /\.spec\.js$/],
      loader: 'istanbul-instrumenter-loader',
      query: {esModules: true}
    });
  }

  /**
   * PostCSS
   * Reference: https://github.com/postcss/autoprefixer-core
   * Add vendor prefixes to your css
   */
  // NOTE: This is now handled in the `postcss.config.js`
  //       webpack2 has some issues, making the config file necessary

  /**
   * Plugins
   * Reference: http://webpack.github.io/docs/configuration.html#plugins
   * List: http://webpack.github.io/docs/list-of-plugins.html
   */
  config.plugins = [new webpack.LoaderOptionsPlugin({
    test: /\.scss$/i,
    options: {postcss: {plugins: [autoprefixer]}},
    debug: !isProd
  })];

  // Skip rendering index.html in test mode
  if (!isTest) {
    // Reference: https://github.com/ampedandwired/html-webpack-plugin
    // Render index.html
    config.plugins.push(
        new HtmlWebpackPlugin({
          template: './app/index.html',
          inject: 'body',
          favicon: './app/assets/images/favicon.ico'
        }),

        // Reference: https://github.com/webpack/extract-text-webpack-plugin
        // Extract css files
        // Disabled when in test mode or not in build mode
        new ExtractTextPlugin(
            {filename: 'css/[name].css', disable: !isProd, allChunks: true}));
  }

  // Add build specific plugins
  if (isProd) {
    config.plugins.push(
        // Reference:
        // http://webpack.github.io/docs/list-of-plugins.html#uglifyjsplugin
        // Minify all javascript, switch loaders to minimizing mode
        new UglifyJsPlugin(),

        // Copy assets from the public folder
        // Reference: https://github.com/kevlened/copy-webpack-plugin
        new CopyWebpackPlugin([{from: __dirname + '/app/assets'}]),
        new CompressionPlugin({deleteOriginalAssets: true}));
  }

  /**
   * Dev server configuration
   * Reference: http://webpack.github.io/docs/configuration.html#devserver
   * Reference: http://webpack.github.io/docs/webpack-dev-server.html
   */
  config.devServer = {contentBase: './src/public', stats: 'minimal'};

  return config;
}()];