/**
 * Webpack production configuration (merged with common config).
 * it overrides webpack.common.js configuration and:
 * - Set mode to production (allow to minify css, js etc...)
 * - Add content hash to files name -> This way, each time bundled files content changed, file name will be different.
 *   This allow browsers to keep cached files which did not change
 * - Minify/Uglify JS and CSS files
 * - Split js into two bundles: vendors (js comming from node_modules) and bundle (our own js)
 *   This way, when we change our js, only our bundle is changed so browsers can keep vendors js in cache
 * - Allow Load css files (import './myCssFile.css') -> Css rules will be automatically added to index.html into a <style></style> tag.
 * - Allow to load fonts and images (import './myFont.eot'; import './someImage.jpg')
 * - Allow to load html angularjs partials (i.e all html files under src folder) as url ->
 *
 */
const merge = require('webpack-merge');
const common = require('./webpack.common');
const path = require('path');
const webpack = require('webpack');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');

module.exports = merge(common, {
  mode: 'production',
  devtool: 'source-map',
  output: {
    // Add a chunkhash to file name so it will not be cached by browsers when content changed
    filename: '[name].[hash].bundle.js',
    // Path where bundled files will be output
    path: path.resolve(__dirname, './build'),
    // Path at which output assets will be served
    publicPath: ''
  },
  resolve: {
    symlinks: true
  },
  plugins: [
    // Extract CSS into separated css files
    new MiniCssExtractPlugin({
      // Add a chunkhash to file name so it will not be cached by browsers when content changed
      filename: '[name].[hash].bundle.css'
    }),
    // see https://webpack.js.org/guides/caching#module-identifiers
    new webpack.HashedModuleIdsPlugin()
  ],
  optimization: {
    // See https://webpack.js.org/guides/caching
    runtimeChunk: 'single',
    splitChunks: {
      cacheGroups: {
        // Bundle all initial chunks from node_modules into a "vendors" js file
        vendor: {
          name: 'vendors',
          test: /node_modules/,
          chunks: 'initial'
        }
      }
    },
    minimizer: [
      // JS minifier/uglifier
      new TerserPlugin({
        parallel: true,
        sourceMap: true,
        // Remove comments as well
        terserOptions: { output: { comments: false } }
      }),
      // CSS minifier
      new OptimizeCSSAssetsPlugin({
        cssProcessorPluginOptions: {
          preset: ['default', { discardComments: { removeAll: true } }]
        }
      })
    ]
  },
  module: {
    rules: [
      // CSS files are bundled togethers
      {
        test: /\.css$/,
        use: [
          'style-loader',
          {
            loader: MiniCssExtractPlugin.loader,
            options: { publicPath: '' }
          },
          'css-loader'
        ]
      },
      {
        test: /\.(woff(2)?|ttf|eot)(\?v=\d+\.\d+\.\d+)?$/,
        use: {
          loader: 'url-loader'
        }
      },
      // Load images as URLs
      {
        test: /\.(png|svg|jpg|gif)$/,
        use: {
          loader: 'url-loader'
        }
      },
      // Load locales files
      {
        test: /\.json$/,
        type: 'javascript/auto',
        include: path.resolve(__dirname, 'src/assets/locales'),
        use: [
          {
            loader: 'file-loader',
            options: {
              name: '[name].[contenthash].[ext]',
              outputPath: 'locales'
            }
          }
        ]
      },
      // AngularJS templates are cached using cache template
      {
        test: /\.html$/,
        exclude: path.resolve(__dirname, './src/index.html'),
        use: [
          'ng-cache-loader?prefix=[dir]/[dir]',
          'extract-loader',
          {
            loader: 'html-loader',
            options: { minimize: true }
          }
        ]
      }
    ]
  }
});