import webpack from 'webpack';
import cssnano from 'cssnano';
import HtmlWebpackPlugin from 'html-webpack-plugin';
import ExtractTextPlugin from 'extract-text-webpack-plugin';
import config from '../config';
import _debug from 'debug';

const debug = _debug('app:webpack:config');
const paths = config.utils_paths;
const {__DEV__, __PROD__, __TEST__} = config.globals;

debug('Create configuration.');
const webpackConfig = {
  name: 'client',
  target: 'web',
  devtool: config.compiler_devtool,
  resolve: {
    root: paths.base(config.dir_client),
    extensions: ['', '.js', '.jsx', '.json']
  },
  module: {}
};
// ------------------------------------
// Entry Points
// ------------------------------------
const APP_ENTRY_PATH = paths.base(config.dir_client) + '/main.js';

webpackConfig.entry = {
  app: __DEV__
    ? [APP_ENTRY_PATH, `webpack-hot-middleware/client?path=${config.compiler_public_path}__webpack_hmr`]
    : [APP_ENTRY_PATH],
  vendor: config.compiler_vendor
};

// ------------------------------------
// Bundle Output
// ------------------------------------
webpackConfig.output = {
  filename: `[name].[${config.compiler_hash_type}].js`,
  path: paths.base(config.dir_dist),
  publicPath: config.compiler_public_path
};

// ------------------------------------
// Plugins
// ------------------------------------
webpackConfig.plugins = [
  new webpack.DefinePlugin(config.globals),
  new HtmlWebpackPlugin({
    template: paths.client('index.html'),
    hash: false,
    favicon: paths.client('static/favicon.ico'),
    filename: 'index.html',
    inject: 'body',
    minify: {
      collapseWhitespace: true
    }
  })
];

if (__DEV__) {
  debug('Enable plugins for live development (HMR, NoErrors).');
  webpackConfig.plugins.push(
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NoErrorsPlugin()
  );
} else if (__PROD__) {
  debug('Enable plugins for production (OccurenceOrder, Dedupe & UglifyJS).');
  webpackConfig.plugins.push(
    new webpack.optimize.OccurrenceOrderPlugin(),
    new webpack.optimize.DedupePlugin(),
    new webpack.optimize.UglifyJsPlugin({
      compress: {
        unused: true,
        dead_code: true,
        warnings: false
      }
    })
  );
}

// Don't split bundles during testing, since we only want import one bundle
if (!__TEST__) {
  webpackConfig.plugins.push(new webpack.optimize.CommonsChunkPlugin({
    names: ['vendor']
  }));
}

// ------------------------------------
// Pre-Loaders
// ------------------------------------
/*
[ NOTE ]
We no longer use eslint-loader due to it severely impacting build
times for larger projects. `npm run lint` still exists to aid in
deploy processes (such as with CI), and it's recommended that you
use a linting plugin for your IDE in place of this loader.

If you do wish to continue using the loader, you can uncomment
the code below and run `npm i --save-dev eslint-loader`. This code
will be removed in a future release.

webpackConfig.module.preLoaders = [{
  test: /\.(js|jsx)$/,
  loader: 'eslint',
  exclude: /node_modules/
}]

webpackConfig.eslint = {
  configFile: paths.base('.eslintrc'),
  emitWarning: __DEV__
}
*/

// ------------------------------------
// Loaders
// ------------------------------------
// JavaScript / JSON
webpackConfig.module.loaders = [{
  test: /\.(js|jsx)$/,
  exclude: /node_modules/,
  loader: 'babel',
  query: {
    cacheDirectory: true,
    plugins: ['transform-runtime'],
    presets: ['es2015', 'react', 'stage-0'],
    env: {
      development: {
        plugins: [
          ['react-transform', {
            transforms: [{
              transform: 'react-transform-hmr',
              imports: ['react'],
              locals: ['module']
            }, {
              transform: 'react-transform-catch-errors',
              imports: ['react', 'redbox-react']
            }]
          }]
        ]
      },
      production: {
        plugins: [
          'transform-react-remove-prop-types',
          'transform-react-constant-elements'
        ]
      }
    }
  }
},
{
  test: /\.json$/,
  loader: 'json'
}];

// ------------------------------------
// Style Loaders
// ------------------------------------
// We use cssnano with the postcss loader, so we tell
// css-loader not to duplicate minimization.
const BASE_CSS_LOADER = 'css?sourceMap&-minimize';

// Add any packge names here whose styles need to be treated as CSS modules.
// These paths will be combined into a single regex.
const PATHS_TO_TREAT_AS_CSS_MODULES = [
  // 'react-toolbox', (example)
];

// If config has CSS modules enabled, treat this project's styles as CSS modules.
if (config.compiler_css_modules) {
  PATHS_TO_TREAT_AS_CSS_MODULES.push(
    paths.base(config.dir_client).replace(/[\^\$\.\*\+\-\?\=\!\:\|\\\/\(\)\[\]\{\}\,]/g, '\\$&')
  );
}

const isUsingCSSModules = !!PATHS_TO_TREAT_AS_CSS_MODULES.length;
const cssModulesRegex = new RegExp(`(${PATHS_TO_TREAT_AS_CSS_MODULES.join('|')})`);

// Loaders for styles that need to be treated as CSS modules.
if (isUsingCSSModules) {
  const cssModulesLoader = [
    BASE_CSS_LOADER,
    'modules',
    'importLoaders=1',
    'localIdentName=[name]__[local]___[hash:base64:5]'
  ].join('&');

  webpackConfig.module.loaders.push({
    test: /\.scss$/,
    include: cssModulesRegex,
    loaders: [
      'style',
      cssModulesLoader,
      'postcss',
      'sass?sourceMap'
    ]
  });

  webpackConfig.module.loaders.push({
    test: /\.css$/,
    include: cssModulesRegex,
    loaders: [
      'style',
      cssModulesLoader,
      'postcss'
    ]
  });
}

// Loaders for files that should not be treated as CSS modules.
const excludeCSSModules = isUsingCSSModules ? cssModulesRegex : false;
webpackConfig.module.loaders.push({
  test: /\.scss$/,
  exclude: excludeCSSModules,
  loaders: [
    'style',
    BASE_CSS_LOADER,
    'postcss',
    'sass?sourceMap'
  ]
});
webpackConfig.module.loaders.push({
  test: /\.css$/,
  exclude: excludeCSSModules,
  loaders: [
    'style',
    BASE_CSS_LOADER,
    'postcss'
  ]
});

// ------------------------------------
// Style Configuration
// ------------------------------------
webpackConfig.sassLoader = {
  includePaths: paths.client('styles')
};

webpackConfig.postcss = [
  cssnano({
    autoprefixer: {
      add: true,
      remove: true,
      browsers: ['last 2 versions']
    },
    discardComments: {
      removeAll: true
    },
    discardUnused: false,
    mergeIdents: false,
    reduceIdents: false,
    safe: true,
    sourcemap: true
  })
];

// File loaders
/* eslint-disable */
webpackConfig.module.loaders.push(
  { test: /\.woff(\?.*)?$/,  loader: 'url?prefix=fonts/&name=[path][name].[ext]&limit=10000&mimetype=application/font-woff' },
  { test: /\.woff2(\?.*)?$/, loader: 'url?prefix=fonts/&name=[path][name].[ext]&limit=10000&mimetype=application/font-woff2' },
  { test: /\.otf(\?.*)?$/,   loader: 'file?prefix=fonts/&name=[path][name].[ext]&limit=10000&mimetype=font/opentype' },
  { test: /\.ttf(\?.*)?$/,   loader: 'url?prefix=fonts/&name=[path][name].[ext]&limit=10000&mimetype=application/octet-stream' },
  { test: /\.eot(\?.*)?$/,   loader: 'file?prefix=fonts/&name=[path][name].[ext]' },
  { test: /\.svg(\?.*)?$/,   loader: 'url?prefix=fonts/&name=[path][name].[ext]&limit=10000&mimetype=image/svg+xml' },
  { test: /\.(png|jpg|gif)$/,    loader: 'url?limit=8192' }
)
/* eslint-enable */

// ------------------------------------
// Finalize Configuration
// ------------------------------------
// when we don't know the public path (we know it only when HMR is enabled [in development]) we
// need to use the extractTextPlugin to fix this issue:
// http://stackoverflow.com/questions/34133808/webpack-ots-parsing-error-loading-fonts/34133809#34133809
if (!__DEV__) {
  debug('Apply ExtractTextPlugin to CSS loaders.');
  webpackConfig.module.loaders.filter((loader) =>
    loader.loaders && loader.loaders.find((name) => /css/.test(name.split('?')[0]))
  ).forEach((loader) => {
    const [first, ...rest] = loader.loaders;
    loader.loader = ExtractTextPlugin.extract(first, rest.join('!'));
    delete loader.loaders;
  });

  webpackConfig.plugins.push(
    new ExtractTextPlugin('[name].[contenthash].css', {
      allChunks: true
    })
  );
}

export default webpackConfig;
