const path = require('path');

const HtmlWebpackPlugin = require('html-webpack-plugin');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
const webpack = require('webpack');

module.exports = (config) => {

  if ('production' === config.mode) {
    return [config, module.exports.webpackConfig()];
  }
  else {
    return config;
  }
};

const SOURCE_PATH = process.env.SOURCE_PATH || '/var/node/src';
const OUTPUT_PATH = process.env.OUTPUT_PATH || '/var/node/dist';

module.exports.webpackConfig = function() {

  const config = {
    mode: 'production' !== process.env.NODE_ENV ? 'development' : 'production',
    entry: [
      '@babel/polyfill',
      path.join(SOURCE_PATH, 'frontend', 'index.js'),
    ],
    optimization: {},
    module: {
      rules: [
        {
          test: /\.js$/,
          exclude: /(node_modules|bower_components)/,
          use: {
            loader: 'babel-loader',
            options: {
              babelrcRoots: [
                OUTPUT_PATH,
              ],
              plugins: [
                '@babel/plugin-proposal-object-rest-spread',
              ],
              presets: [
                '@babel/preset-react',
                '@babel/preset-env',
              ],
            },
          },
        },
      ],
    },
    output: {
      filename: 'index.js',
      path: path.join(OUTPUT_PATH, 'frontend'),
    },
    plugins: [
      new HtmlWebpackPlugin({
        title: 'Truss',
        template: path.join(SOURCE_PATH, 'frontend', 'index.html'),
      }),
    ],
    resolve: {
      modules: [path.join(OUTPUT_PATH, 'node_modules')],
    }
  };

  if ('production' === config.mode) {
    config.optimization.minimizer = [
      new UglifyJsPlugin({cache: false})
    ];
  }
  else {
    config.plugins.push(new webpack.HotModuleReplacementPlugin());
  }

  return config;
}