const helpers = require('./helpers')
const webpackMerge = require('webpack-merge') // used to merge webpack configs
const commonConfig = require('./webpack.common.js') // the settings that are common to prod and dev
const path = require('path')

/**
 * Webpack Plugins
 */
const DefinePlugin = require('webpack/lib/DefinePlugin')
const NamedModulesPlugin = require('webpack/lib/NamedModulesPlugin')
const LoaderOptionsPlugin = require('webpack/lib/LoaderOptionsPlugin')

/**
 * Webpack Constants
 */
const ENV = process.env.ENV = process.env.NODE_ENV = 'development'
const HOST = process.env.HOST || 'localhost'
const PORT = process.env.PORT || 3000
const HMR = helpers.hasProcessFlag('hot')
const METADATA = webpackMerge(commonConfig({env: ENV}).metadata, {
  host: HOST,
  port: PORT,
  ENV: ENV,
  HMR: HMR
})

/**
 * Webpack configuration
 *
 * See: http://webpack.github.io/docs/configuration.html#cli
 */
module.exports = function (env) {
  return webpackMerge(commonConfig({ env: ENV }), {
    /**
    * Developer tool to enhance debugging
    *
    * See: http://webpack.github.io/docs/configuration.html#devtool
    * See: https://github.com/webpack/docs/wiki/build-performance#sourcemaps
    */
    devtool: 'cheap-module-source-map',

    /**
    * Options affecting the output of the compilation.
    *
    * See: http://webpack.github.io/docs/configuration.html#output
    */
    output: {
      /**
      * The output directory as absolute path (required).
      *
      * See: http://webpack.github.io/docs/configuration.html#output-path
      */
      path: helpers.root('dist'),

      /**
      * Specifies the name of each output file on disk.
      * IMPORTANT: You must not specify an absolute path here!
      *
      * See: http://webpack.github.io/docs/configuration.html#output-filename
      */
      filename: '[name].bundle.js',

      /**
      * The filename of the SourceMaps for the JavaScript files.
      * They are inside the output.path directory.
      *
      * See: http://webpack.github.io/docs/configuration.html#output-sourcemapfilename
      */
      sourceMapFilename: '[name].map',

      /** The filename of non-entry chunks as relative path
      * inside the output.path directory.
      *
      * See: http://webpack.github.io/docs/configuration.html#output-chunkfilename
      */
      chunkFilename: '[id].chunk.js',

      library: 'ac_[name]',
      libraryTarget: 'var',

      publicPath: '/client/'
    },

    externals: {
      webtorrent: 'WebTorrent'
    },

    plugins: [

      /**
      * Plugin: DefinePlugin
      * Description: Define free variables.
      * Useful for having development builds with debug logging or adding global constants.
      *
      * Environment helpers
      *
      * See: https://webpack.github.io/docs/list-of-plugins.html#defineplugin
      */
      // NOTE: when adding more properties, make sure you include them in custom-typings.d.ts
      new DefinePlugin({
        'ENV': JSON.stringify(METADATA.ENV),
        'HMR': METADATA.HMR,
        'process.env': {
          'ENV': JSON.stringify(METADATA.ENV),
          'NODE_ENV': JSON.stringify(METADATA.ENV),
          'HMR': METADATA.HMR
        }
      }),

      /**
      * Plugin: NamedModulesPlugin (experimental)
      * Description: Uses file names as module name.
      *
      * See: https://github.com/webpack/webpack/commit/a04ffb928365b19feb75087c63f13cadfc08e1eb
      */
      new NamedModulesPlugin(),

      /**
      * Plugin LoaderOptionsPlugin (experimental)
      *
      * See: https://gist.github.com/sokra/27b24881210b56bbaff7
      */
      new LoaderOptionsPlugin({
        debug: true,
        options: {

          /**
          * Static analysis linter for TypeScript advanced options configuration
          * Description: An extensible linter for the TypeScript language.
          *
          * See: https://github.com/wbuchwalter/tslint-loader
          */
          tslint: {
            emitErrors: false,
            failOnHint: false,
            resourcePath: 'src'
          },

          // FIXME: Remove
          // https://github.com/bholloway/resolve-url-loader/issues/36
          // https://github.com/jtangelder/sass-loader/issues/289
          context: __dirname,
          output: {
            path: helpers.root('dist')
          }

        }
      })

    ],

    /**
    * Webpack Development Server configuration
    * Description: The webpack-dev-server is a little node.js Express server.
    * The server emits information about the compilation state to the client,
    * which reacts to those events.
    *
    * See: https://webpack.github.io/docs/webpack-dev-server.html
    */
    devServer: {
      port: METADATA.port,
      host: METADATA.host,
      historyApiFallback: true,
      watchOptions: {
        aggregateTimeout: 300,
        poll: 1000
      },
      outputPath: helpers.root('dist')
    },

    /*
    * Include polyfills or mocks for various node stuff
    * Description: Node configuration
    *
    * See: https://webpack.github.io/docs/configuration.html#node
    */
    node: {
      global: true,
      crypto: 'empty',
      process: true,
      module: false,
      clearImmediate: false,
      setImmediate: false
    }
  })
}