/*
 * Created by Artyom Manchenkov
 * artyom@manchenkoff.me
 * manchenkoff.me © 2019
 */

// import plugins
const path = require('path');
const webpack = require('webpack');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const CopyPlugin = require('copy-webpack-plugin');
const ImageminPlugin = require('imagemin-webpack-plugin').default;

/**
 * Base webpack configuration
 *
 * @param env -> env parameters
 * @param argv -> CLI arguments, 'argv.mode' is the current webpack mode (development | production)
 * @returns object
 */
module.exports = (env, argv) => {
  let isProduction = argv.mode === 'production';

  let config = {
    // absolute path to the base directory
    context: path.resolve(__dirname, 'src'),

    // development server with hot-reload
    devServer: {
      publicPath: '/dist/',
      watchContentBase: true,
      compress: true,
    },

    // entry files to compile (relative to the base dir)
    entry: ['./js/app.js', './scss/app.scss'],

    // enable development source maps
    // * will be overwritten by 'source-maps' in production mode
    devtool: 'inline-source-map',

    // path to store compiled JS bundle
    output: {
      // bundle relative name
      filename: 'js/app.js',
      // base build directory
      path: path.resolve(__dirname, 'dist'),
      // path to build relative asset links
      publicPath: '../',
    },

    // plugins configurations
    plugins: [
      // save compiled SCSS into separated CSS file
      new MiniCssExtractPlugin({
        filename: 'css/style.css',
      }),

      // copy static assets directory
      new CopyPlugin([
        { from: 'static', to: 'static' },
        { from: 'index.html', to: 'index.html' },
      ]),

      // image optimization
      new ImageminPlugin({
        // disable for dev builds
        disable: !isProduction,
        test: /\.(jpe?g|png|gif)$/i,
        pngquant: { quality: '70-85' },
        optipng: { optimizationLevel: 9 },
      }),

      // provide jQuery and Popper.js dependencies
      new webpack.ProvidePlugin({
        $: 'jquery',
        jQuery: 'jquery',
        jquery: 'jquery',
        'window.jQuery': 'jquery',
        Popper: ['popper.js', 'default'],
      }),
    ],

    // production mode optimization
    optimization: {
      minimizer: [
        // CSS optimizer
        new OptimizeCSSAssetsPlugin(),
        // JS optimizer by default
        new TerserPlugin(),
      ],
    },

    // custom loaders configuration
    module: {
      rules: [
        // styles loader
        {
          test: /\.(sa|sc|c)ss$/,
          use: [MiniCssExtractPlugin.loader, 'css-loader', 'sass-loader'],
        },

        // images loader
        {
          test: /\.(png|jpe?g|gif)$/,
          loaders: [
            {
              loader: 'file-loader',
              options: {
                name: 'img/[name].[ext]',
              },
            },
            {
              loader: 'image-webpack-loader',
              options: {
                disable: !isProduction,
                mozjpeg: {
                  progressive: true,
                  quality: 65,
                },
                pngquant: {
                  quality: '65-90',
                  speed: 4,
                },
                optipng: { enabled: false },
                gifsicle: { interlaced: false },
                webp: { quality: 75 },
              },
            },
          ],
        },

        // fonts loader
        {
          test: /\.(woff|woff2|eot|ttf|otf)$/,
          use: [
            {
              loader: 'file-loader',
              options: {
                name: 'fonts/[name].[ext]',
              },
            },
          ],
        },

        // svg inline 'data:image' loader
        {
          test: /\.svg$/,
          loader: 'svg-url-loader',
        },
      ],
    },
  };

  // PRODUCTION ONLY configuration
  if (isProduction) {
    config.plugins.push(
      // clean 'dist' directory
      new CleanWebpackPlugin()
    );
  }

  return config;
};