import path from 'path';
import webpack from 'webpack';
import extend from 'extend';
import AssetsPlugin from 'assets-webpack-plugin';

const isDebug = !process.argv.includes('--release');
const isVerbose = process.argv.includes('--verbose');

//
// Common configuration chunk to be used for both
// client-side (client.js) and server-side (server.js) bundles
// -----------------------------------------------------------------------------

const config = {
  context: path.resolve(__dirname, '../src'),

  output: {
    path: path.resolve(__dirname, '../build/public/assets'),
    publicPath: '/assets/',
    sourcePrefix: '  ',
    pathinfo: isVerbose,
  },

  module: {
    loaders: [
      {
        test: /\.jsx?$/,
        loader: 'babel-loader',
        include: [
          path.resolve(__dirname, '../src'),
        ],
        query: {
          // https://github.com/babel/babel-loader#options
          cacheDirectory: isDebug,

          // https://babeljs.io/docs/usage/options/
          babelrc: false,
          presets: [
            // Latest stable ECMAScript features
            // https://github.com/babel/babel/tree/master/packages/babel-preset-latest
            'latest',
            // Experimental ECMAScript proposals
            // https://github.com/babel/babel/tree/master/packages/babel-preset-stage-0
            'stage-0',
            // JSX, Flow
            // https://github.com/babel/babel/tree/master/packages/babel-preset-react
            'react',
            ...isDebug ? [] : [
              // Optimize React code for the production build
              // https://github.com/thejameskyle/babel-react-optimize
              'react-optimize',
            ],
          ],
          plugins: [
            // Externalise references to helpers and builtins,
            // automatically polyfilling your code without polluting globals.
            // https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-runtime
            'transform-runtime',
            ...!isDebug ? [] : [
              // Adds component stack to warning messages
              // https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-react-jsx-source
              'transform-react-jsx-source',
              // Adds __self attribute to JSX which React will use for some warnings
              // https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-react-jsx-self
              'transform-react-jsx-self',
            ],
          ],
        },
      },
      {
        test: /\.js$/,
        loader: 'babel',
        include: path.resolve(__dirname, './node_modules/react-icons/md'),
        query: {
          presets: ['latest', 'react'],
        },
      },
      {
        test: /\.css/,
        loaders: [
          'isomorphic-style-loader',
          `css-loader?${JSON.stringify({
            // CSS Loader https://github.com/webpack/css-loader
            importLoaders: 1,
            sourceMap: isDebug,
            // CSS Modules https://github.com/css-modules/css-modules
            modules: true,
            localIdentName: isDebug ? '[name]-[local]-[hash:base64:5]' : '[hash:base64:5]',
            // CSS Nano http://cssnano.co/options/
            minimize: !isDebug,
            discardComments: { removeAll: true },
          })}`,
          'postcss-loader?pack=default',
        ],
      },
      {
        test: /\.md$/,
        loader: path.resolve(__dirname, './lib/markdown-loader.js'),
      },
      {
        test: /\.json$/,
        loader: 'json-loader',
      },
      {
        test: /\.txt$/,
        loader: 'raw-loader',
      },
      {
        test: /\.(ico|jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2)(\?.*)?$/,
        loader: 'file-loader',
        query: {
          name: isDebug ? '[path][name].[ext]?[hash:8]' : '[hash:8].[ext]',
        },
      },
      {
        test: /\.(mp4|webm|wav|mp3|m4a|aac|oga)(\?.*)?$/,
        loader: 'url-loader',
        query: {
          name: isDebug ? '[path][name].[ext]?[hash:8]' : '[hash:8].[ext]',
          limit: 10000,
        },
      },
    ],
  },

  resolve: {
    root: path.resolve(__dirname, '../src'),
    modulesDirectories: ['node_modules'],
    extensions: ['', '.webpack.js', '.web.js', '.js', '.jsx', '.json'],
  },

  // Don't attempt to continue if there are any errors.
  bail: !isDebug,

  cache: isDebug,
  debug: isDebug,

  stats: {
    colors: true,
    reasons: isDebug,
    hash: isVerbose,
    version: isVerbose,
    timings: true,
    chunks: isVerbose,
    chunkModules: isVerbose,
    cached: isVerbose,
    cachedAssets: isVerbose,
  },

  // The list of plugins for PostCSS
  // https://github.com/postcss/postcss
  postcss(bundler) {
    return {
      default: [
        // Transfer @import rule by inlining content, e.g. @import 'normalize.css'
        // https://github.com/jonathantneal/postcss-partial-import
        require('postcss-partial-import')({ addDependencyTo: bundler }),
        // Allow you to fix url() according to postcss to and/or from options
        // https://github.com/postcss/postcss-url
        require('postcss-url')(),
        // W3C variables, e.g. :root { --color: red; } div { background: var(--color); }
        // https://github.com/postcss/postcss-custom-properties
        require('postcss-custom-properties')(),
        // W3C CSS Custom Media Queries, e.g. @custom-media --small-viewport (max-width: 30em);
        // https://github.com/postcss/postcss-custom-media
        require('postcss-custom-media')(),
        // CSS4 Media Queries, e.g. @media screen and (width >= 500px) and (width <= 1200px) { }
        // https://github.com/postcss/postcss-media-minmax
        require('postcss-media-minmax')(),
        // W3C CSS Custom Selectors, e.g. @custom-selector :--heading h1, h2, h3, h4, h5, h6;
        // https://github.com/postcss/postcss-custom-selectors
        require('postcss-custom-selectors')(),
        // W3C calc() function, e.g. div { height: calc(100px - 2em); }
        // https://github.com/postcss/postcss-calc
        require('postcss-calc')(),
        // Allows you to nest one style rule inside another
        // https://github.com/jonathantneal/postcss-nesting
        require('postcss-nesting')(),
        // Unwraps nested rules like how Sass does it
        // https://github.com/postcss/postcss-nested
        require('postcss-nested')(),
        // W3C color() function, e.g. div { background: color(red alpha(90%)); }
        // https://github.com/postcss/postcss-color-function
        require('postcss-color-function')(),
        // Convert CSS shorthand filters to SVG equivalent, e.g. .blur { filter: blur(4px); }
        // https://github.com/iamvdo/pleeease-filters
        require('pleeease-filters')(),
        // Generate pixel fallback for "rem" units, e.g. div { margin: 2.5rem 2px 3em 100%; }
        // https://github.com/robwierzbowski/node-pixrem
        require('pixrem')(),
        // W3C CSS Level4 :matches() pseudo class, e.g. p:matches(:first-child, .special) { }
        // https://github.com/postcss/postcss-selector-matches
        require('postcss-selector-matches')(),
        // Transforms :not() W3C CSS Level 4 pseudo class to :not() CSS Level 3 selectors
        // https://github.com/postcss/postcss-selector-not
        require('postcss-selector-not')(),
        // Postcss flexbox bug fixer
        // https://github.com/luisrudge/postcss-flexbugs-fixes
        require('postcss-flexbugs-fixes')(),
        // Add vendor prefixes to CSS rules using values from caniuse.com
        // https://github.com/postcss/autoprefixer
        require('autoprefixer')({
          browsers: [
            '>1%',
            'last 4 versions',
            'Firefox ESR',
            'not ie < 9', // React doesn't support IE8 anyway
          ],
        }),
      ],
    };
  },
};

//
// Configuration for the client-side bundle (client.js)
// -----------------------------------------------------------------------------

const clientConfig = extend(true, {}, config, {
  entry: {
    client: './client.js',
  },

  output: {
    filename: isDebug ? '[name].js' : '[name].[chunkhash:8].js',
    chunkFilename: isDebug ? '[name].chunk.js' : '[name].[chunkhash:8].chunk.js',
  },

  target: 'web',

  plugins: [

    // Define free variables
    // https://webpack.github.io/docs/list-of-plugins.html#defineplugin
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': isDebug ? '"development"' : '"production"',
      'process.env.BROWSER': true,
      __DEV__: isDebug,
    }),

    // Emit a file with assets paths
    // https://github.com/sporto/assets-webpack-plugin#options
    new AssetsPlugin({
      path: path.resolve(__dirname, '../build'),
      filename: 'assets.js',
      processOutput: x => `module.exports = ${JSON.stringify(x, null, 2)};`,
    }),

    // Move modules that occur in multiple entry chunks to a new entry chunk (the commons chunk).
    // http://webpack.github.io/docs/list-of-plugins.html#commonschunkplugin
    new webpack.optimize.CommonsChunkPlugin({
      name: 'vendor',
      minChunks: module => /node_modules/.test(module.resource),
    }),

    ...isDebug ? [] : [
      // Assign the module and chunk ids by occurrence count
      // Consistent ordering of modules required if using any hashing ([hash] or [chunkhash])
      // https://webpack.github.io/docs/list-of-plugins.html#occurrenceorderplugin
      new webpack.optimize.OccurrenceOrderPlugin(true),

      // Search for equal or similar files and deduplicate them in the output
      // https://webpack.github.io/docs/list-of-plugins.html#dedupeplugin
      new webpack.optimize.DedupePlugin(),

      // Minimize all JavaScript output of chunks
      // https://github.com/mishoo/UglifyJS2#compressor-options
      new webpack.optimize.UglifyJsPlugin({
        compress: {
          screw_ie8: true, // React doesn't support IE8
          warnings: isVerbose,
          unused: true,
          dead_code: true,
        },
        mangle: {
          screw_ie8: true,
        },
        output: {
          comments: false,
          screw_ie8: true,
        },
      }),
    ],
  ],

  // Choose a developer tool to enhance debugging
  // http://webpack.github.io/docs/configuration.html#devtool
  devtool: isDebug ? 'cheap-module-source-map' : false,

  // Some libraries import Node modules but don't use them in the browser.
  // Tell Webpack to provide empty mocks for them so importing them works.
  // https://webpack.github.io/docs/configuration.html#node
  // https://github.com/webpack/node-libs-browser/tree/master/mock
  node: {
    fs: 'empty',
    net: 'empty',
    tls: 'empty',
  },
});

//
// Configuration for the server-side bundle (server.js)
// -----------------------------------------------------------------------------

const serverConfig = extend(true, {}, config, {
  entry: {
    server: './server.js',
  },

  output: {
    filename: '../../server.js',
    libraryTarget: 'commonjs2',
  },

  target: 'node',

  externals: [
    /^\.\/assets$/,
    (context, request, callback) => {
      const isExternal =
        request.match(/^[@a-z][a-z/.\-0-9]*$/i) &&
        !request.match(/\.(css|less|scss|sss)$/i);
      callback(null, Boolean(isExternal));
    },
  ],

  plugins: [
    // Define free variables
    // https://webpack.github.io/docs/list-of-plugins.html#defineplugin
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': isDebug ? '"development"' : '"production"',
      'process.env.BROWSER': false,
      __DEV__: isDebug,
    }),

    // Do not create separate chunks of the server bundle
    // https://webpack.github.io/docs/list-of-plugins.html#limitchunkcountplugin
    new webpack.optimize.LimitChunkCountPlugin({ maxChunks: 1 }),

    // Adds a banner to the top of each generated chunk
    // https://webpack.github.io/docs/list-of-plugins.html#bannerplugin
    new webpack.BannerPlugin('require("source-map-support").install();',
      { raw: true, entryOnly: false }),
  ],

  node: {
    console: false,
    global: false,
    process: false,
    Buffer: false,
    __filename: false,
    __dirname: false,
  },

  devtool: isDebug ? 'cheap-module-source-map' : 'source-map',
});

export default [clientConfig, serverConfig];