'use strict';

const webpack = require('webpack');
const path = require('path');

const isDev = process.env.NODE_ENV !== 'production';
process.env.BABEL_ENV = process.env.NODE_ENV;

// ----- devtool

let devtool;
if (isDev) {
  // https://webpack.js.org/configuration/devtool/
  devtool = 'eval';
} else {
  // https://webpack.js.org/configuration/devtool/
  devtool = 'source-map';
}
module.exports.devtool = devtool;

// ---- entry

const entry = {
  // vendor: ['babel-polyfill'],
  app: ['./src/index.js']
};

module.exports.entry = entry;

// ---- output

const output = {
  path: path.resolve(__dirname, 'public'),
  filename: '[name].bundle.js',
  publicPath: ''
};

module.exports.output = output;

// ----- rules
const jsRule = {
  test: /\.js$/,
  exclude: /node_modules/,
  use: ['babel-loader']
};

const MiniCssExtractPlugin = require('mini-css-extract-plugin');

const cssExtractPlugin = new MiniCssExtractPlugin({
  filename: isDev ? '[name].bundle.css' : '[name].[chunkhash].css'
});

const LOCAL_IDENT_NAME_DEV = '[path]---[name]---[local]---[hash:base64:5]';
const LOCAL_IDENT_NAME_PROD = '[hash:base64:10]';
const localIdentName = isDev ? LOCAL_IDENT_NAME_DEV : LOCAL_IDENT_NAME_PROD;
const getCssLoaderOptions = (opt = {}) => ({
  minimize: true,
  localIdentName,
  ...opt
});

const cssnano = require('cssnano');
const loaders = {
  style: { loader: 'style-loader' },
  css: { loader: 'css-loader', options: getCssLoaderOptions() },
  cssModule: {
    loader: 'css-loader',
    options: getCssLoaderOptions({ modules: true })
  },
  postcss: {
    loader: 'postcss-loader',
    options: {
      plugins: () => [require('autoprefixer'), cssnano()]
    }
  },
  sass: {
    loader: 'sass-loader'
  }
};

const cssDevRule = {
  test: /\.css$/,
  exclude: /\.module\.css$/,
  use: [loaders.style, loaders.css, loaders.postcss]
};
const cssProdRule = {
  test: /\.css$/,
  exclude: /\.module\.css$/,
  use: [MiniCssExtractPlugin.loader, loaders.css, loaders.postcss]
};
const cssModulesDevRule = {
  test: /\.module\.css$/,
  use: [loaders.style, loaders.cssModule, loaders.postcss]
};

const cssModulesProdRule = {
  test: /\.module\.css$/,
  use: [MiniCssExtractPlugin.loader, loaders.cssModule, loaders.postcss]
};

const fileRule = {
  test: /\.(ttf|eot|woff|woff2)(\?.+)?$/,
  use: [
    {
      loader: 'file-loader',
      options: {
        name: '[name].[ext]'
      }
    }
  ]
};

const sassDevRule = {
  test: /\.scss$/,
  exclude: /\.module\.scss$/,
  use: [loaders.style, loaders.css, loaders.postcss, loaders.sass]
};

const sassProdRule = {
  test: /\.scss$/,
  exclude: /\.module\.scss$/,
  use: [MiniCssExtractPlugin.loader, loaders.css, loaders.postcss, loaders.sass]
};

const sassCssModuleDevRule = {
  test: /\.module\.scss$/,
  use: [loaders.style, loaders.cssModule, loaders.postcss, loaders.sass]
};

const sassCssModuleProdRule = {
  test: /\.module\.scss$/,
  use: [
    MiniCssExtractPlugin.loader,
    loaders.cssModule,
    loaders.postcss,
    loaders.sass
  ]
};

module.exports.jsRule = jsRule;
module.exports.fileRule = fileRule;
module.exports.cssDevRule = cssDevRule;
module.exports.cssProdRule = cssProdRule;
module.exports.cssModulesDevRule = cssModulesDevRule;
module.exports.cssModulesProdRule = cssModulesProdRule;
module.exports.sassDevRule = sassDevRule;
module.exports.sassProdRule = sassProdRule;
module.exports.sassCssModuleDevRule = sassCssModuleDevRule;
module.exports.sassCssModuleProdRule = sassCssModuleProdRule;

const rules = {
  js: jsRule,
  file: fileRule,
  css: isDev ? cssDevRule : cssProdRule,
  cssModules: isDev ? cssModulesDevRule : cssModulesProdRule,
  sass: isDev ? sassDevRule : sassProdRule,
  sassCssModules: isDev ? sassCssModuleDevRule : sassCssModuleProdRule
};
module.exports.rules = rules;

// ----- plugins

const UglifyJSPlugin = require('uglifyjs-webpack-plugin');

const definePlugin = new webpack.DefinePlugin({
  'process.env': {
    NODE_ENV: JSON.stringify('production')
  }
});

// webpack 4 enable optimization concatenateModules by default
// https://medium.com/webpack/webpack-4-mode-and-optimization-5423a6bc597a
// const moduleConcatPlugin = new webpack.optimize.ModuleConcatenationPlugin();

const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');
const bundleAnalyzerPlugin = new BundleAnalyzerPlugin({
  analyzerMode: 'static',
  reportFilename: 'report.html'
});

// prints more readable module names in the browser console on HMR updates

module.exports.definePlugin = definePlugin;

let plugins = [];
let pluginsCommon = [];
if (isDev) {
  // in webpack 4 / namedModules will be enabled by default
  plugins = [...pluginsCommon];
} else {
  plugins = [
    ...pluginsCommon,
    new webpack.HashedModuleIdsPlugin(),
    definePlugin,
    // see https://github.com/webpack-contrib/uglifyjs-webpack-plugin
    new UglifyJSPlugin({
      // enable parallelization.
      // default number of concurrent runs: os.cpus().length - 1.
      parallel: true,
      // enable file caching.
      // default path to cache directory:
      // node_modules/.cache/uglifyjs-webpack-plugin.
      cache: true
      // debug
      // uglifyOptions: {
      //   compress: false,
      //   mangle: false
      // }
    }),
    cssExtractPlugin,
    bundleAnalyzerPlugin
  ];
}
module.exports.plugins = plugins;