const { readFileSync } = require('fs');
const { resolve } = require('path');

const { BannerPlugin, EnvironmentPlugin } = require('webpack');
const WorkerPlugin = require('worker-plugin');

const { merge } = require('webpack-merge');
const {
  argv: { mode },
} = require('yargs');

const { name: filename, version } = require('./package.json');

const banner = readFileSync(resolve('./_includes/header.txt'), 'utf-8');

const ASSET_PATH = '/assets/js/';

const envConfig = (() => {
  switch (mode) {
    case 'production':
      return {
        devtool: false,
        plugins: [
          new WorkerPlugin({ globalObject: 'self' }),
          new BannerPlugin({ banner, raw: true }),
          new EnvironmentPlugin({
            DEBUG: false,
            ASSET_PATH,
            GET_CLAPS_API: 'https://worker.getclaps.app',
          }),
        ],
      };

    default:
      return {
        devtool: 'source-map',
        plugins: [
          new WorkerPlugin({ globalObject: 'self' }),
          new EnvironmentPlugin({
            DEBUG: true,
            ASSET_PATH,
            GET_CLAPS_API: 'https://worker.getclaps.dev',
          }),
        ],
      };
  }
})();

const sharedPreset = {
  modules: false,
  useBuiltIns: 'entry',
  corejs: 2,
};

const babelPresetLegacy = {
  babelrc: false,
  presets: [
    [
      '@babel/preset-env',
      {
        ...sharedPreset,
        targets: {
          ie: '11',
        },
      },
    ],
  ],
};

const babelPresetModern = {
  babelrc: false,
  presets: [
    [
      '@babel/preset-env',
      {
        ...sharedPreset,
        targets: {
          esmodules: true,
        },
      },
    ],
  ],
};

const sharedConfig = {
  entry: resolve('./_js/src/entry.js'),

  output: {
    path: resolve('./assets/js'),
    publicPath: ASSET_PATH,
  },
  resolve: {
    modules: [
      resolve('./_js'),
      resolve('./node_modules'),
      ...(process.env.NODE_PATH ? [resolve(process.env.NODE_PATH)] : []),
    ],
    extensions: ['.json', '.js'],
    symlinks: true,
  },
  optimization: {
    splitChunks: {
      // chunks: 'all',
      // minSize: 30000,
      // maxSize: 0,
      // minChunks: 1,
      // maxAsyncRequests: 5,
      // maxInitialRequests: 3,
      // automaticNameDelimiter: '~',
      // automaticNameMaxLength: 30,
      // name: true,
      // cacheGroups: {
      //   vendors: {
      //     test: /[\\/]node_modules[\\/]/,
      //     priority: -10
      //   },
      //   default: {
      //     minChunks: 2,
      //     priority: -20,
      //     reuseExistingChunk: true
      //   }
      // }
    },
  },
  performance: {
    hints: 'warning',
    maxEntrypointSize: 512000,
    maxAssetSize: 512000,
  },
};

module.exports = [
  merge(envConfig, sharedConfig, {
    output: {
      filename: `${filename}-${version}.js`,
      chunkFilename: `[name]-${filename}-${version}.js`,
    },
    module: {
      rules: [
        {
          test: /(\.jsx|\.js)$/,
          loader: 'babel-loader',
          options: babelPresetModern,
        },
        {
          test: /modernizr-custom/,
          use: 'null-loader',
        },
        {
          test: /@webcomponents\/(template|url|webcomponents-platform)/,
          use: 'null-loader',
        },
      ],
    },
  }),
  merge(envConfig, sharedConfig, {
    output: {
      filename: `LEGACY-${filename}-${version}.js`,
      chunkFilename: `LEGACY-[name]-${filename}-${version}.js`,
    },
    module: {
      rules: [
        {
          test: /(\.jsx|\.js)$/,
          loader: 'babel-loader',
          options: babelPresetLegacy,
        },
      ],
    },
  }),
];