const { each } = require('lodash')
const webpack = require('webpack')
const VueSSRClientPlugin = require('vue-server-renderer/client-plugin')
const HTMLPlugin = require('html-webpack-plugin')
const FriendlyErrorsWebpackPlugin = require('friendly-errors-webpack-plugin')
const UglifyJSPlugin = require('uglifyjs-webpack-plugin')
const ProgressBarPlugin = require('progress-bar-webpack-plugin')
const ProgressPlugin = require('webpack/lib/ProgressPlugin')
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer')
const { resolve } = require('path')
const { existsSync } = require('fs')
const Debug = require('debug')
const Chalk = require('chalk')
const base = require('./base.config.js')

const debug = Debug('nuxt:build')
debug.color = 2 // Force green color

/*
|--------------------------------------------------------------------------
| Webpack Client Config
|
| Generate public/dist/client-vendor-bundle.js
| Generate public/dist/client-bundle.js
|
| In production, will generate public/dist/style.css
|--------------------------------------------------------------------------
*/
module.exports = function webpackClientConfig() {
  let config = base.call(this, { name: 'client', isServer: false })

  // Entry points
  config.entry.app = resolve(this.options.buildDir, 'client.js')
  config.entry.vendor = this.vendor()

  // Add CommonChunks plugin
  commonChunksPlugin.call(this, config)

  // Env object defined in nuxt.config.js
  let env = {}
  each(this.options.env, (value, key) => {
    env['process.env.' + key] = (['boolean', 'number'].indexOf(typeof value) !== -1 ? value : JSON.stringify(value))
  })

  // Generate output HTML for SPA
  config.plugins.push(
    new HTMLPlugin({
      filename: 'index.spa.html',
      template: this.options.appTemplatePath,
      inject: true,
      chunksSortMode: 'dependency'
    })
  )

  // Generate output HTML for SSR
  if (this.options.build.ssr) {
    config.plugins.push(
      new HTMLPlugin({
        filename: 'index.ssr.html',
        template: this.options.appTemplatePath,
        inject: false // Resources will be injected using bundleRenderer
      })
    )
  }

  // Generate vue-ssr-client-manifest
  config.plugins.push(
    new VueSSRClientPlugin({
      filename: 'vue-ssr-client-manifest.json'
    })
  )

  // Extract webpack runtime & manifest
  config.plugins.push(
    new webpack.optimize.CommonsChunkPlugin({
      name: 'manifest',
      minChunks: Infinity,
      filename: this.getFileName('manifest')
    })
  )

  // Define Env
  config.plugins.push(
    new webpack.DefinePlugin(Object.assign(env, {
      'process.env.NODE_ENV': JSON.stringify(env.NODE_ENV || (this.options.dev ? 'development' : 'production')),
      'process.env.VUE_ENV': JSON.stringify('client'),
      'process.mode': JSON.stringify(this.options.mode),
      'process.browser': true,
      'process.client': true,
      'process.server': false,
      'process.static': this.isStatic
    }))
  )

  // Build progress bar
  if (this.options.build.profile) {
    config.plugins.push(new ProgressPlugin({
      profile: true
    }))
  } else {
    config.plugins.push(new ProgressBarPlugin({
      complete: Chalk.green('█'),
      incomplete: Chalk.white('█'),
      format: '  :bar ' + Chalk.green.bold(':percent') + ' :msg',
      clear: false
    }))
  }

  const shouldClearConsole = this.options.build.stats !== false &&
                             this.options.build.stats !== 'errors-only'

  // Add friendly error plugin
  config.plugins.push(new FriendlyErrorsWebpackPlugin({ clearConsole: shouldClearConsole }))

  // --------------------------------------
  // Dev specific config
  // --------------------------------------
  if (this.options.dev) {
    // https://webpack.js.org/plugins/named-modules-plugin
    config.plugins.push(new webpack.NamedModulesPlugin())

    // Add HMR support
    config.entry.app = [
      // https://github.com/glenjamin/webpack-hot-middleware#config
      `webpack-hot-middleware/client?name=client&reload=true&timeout=30000&path=${this.options.router.base}/__webpack_hmr`.replace(/\/\//g, '/'),
      config.entry.app
    ]
    config.plugins.push(
      new webpack.HotModuleReplacementPlugin(),
      new webpack.NoEmitOnErrorsPlugin()
    )

    // DllReferencePlugin
    if (this.options.build.dll) {
      dllPlugin.call(this, config)
    }
  }

  // --------------------------------------
  // Production specific config
  // --------------------------------------
  if (!this.options.dev) {
    // Scope Hoisting
    if (this.options.build.scopeHoisting === true) {
      config.plugins.push(new webpack.optimize.ModuleConcatenationPlugin())
    }

    // https://webpack.js.org/plugins/hashed-module-ids-plugin
    config.plugins.push(new webpack.HashedModuleIdsPlugin())

    // Minify JS
    // https://github.com/webpack-contrib/uglifyjs-webpack-plugin
    if (this.options.build.uglify !== false) {
      config.plugins.push(
        new UglifyJSPlugin(Object.assign({
          // cache: true,
          sourceMap: true,
          parallel: true,
          extractComments: {
            filename: 'LICENSES'
          },
          uglifyOptions: {
            output: {
              comments: /^\**!|@preserve|@license|@cc_on/
            }
          }
        }, this.options.build.uglify))
      )
    }

    // Webpack Bundle Analyzer
    if (this.options.build.analyze) {
      config.plugins.push(new BundleAnalyzerPlugin(Object.assign({}, this.options.build.analyze)))
    }
  }

  // Extend config
  if (typeof this.options.build.extend === 'function') {
    const isDev = this.options.dev
    const extendedConfig = this.options.build.extend.call(this, config, {
      get dev() {
        console.warn('dev has been deprecated in build.extend(), please use isDev') // eslint-disable-line no-console
        return isDev
      },
      isDev,
      isClient: true
    })
    // Only overwrite config when something is returned for backwards compatibility
    if (extendedConfig !== undefined) {
      config = extendedConfig
    }
  }

  return config
}

// --------------------------------------------------------------------------
// Adds Common Chunks Plugin
// --------------------------------------------------------------------------
function commonChunksPlugin(config) {
  // Create explicit vendor chunk
  config.plugins.unshift(
    new webpack.optimize.CommonsChunkPlugin({
      name: 'vendor',
      filename: this.getFileName('vendor'),
      minChunks(module, count) {
        // A module is extracted into the vendor chunk when...
        return (
          // If it's inside node_modules
          /node_modules/.test(module.context) &&
          // Do not externalize if the request is a CSS file or a Vue file which can potentially emit CSS assets!
          !/\.(css|less|scss|sass|styl|stylus|vue)$/.test(module.request)
        )
      }
    })
  )
}

// --------------------------------------------------------------------------
// Adds DLL plugin
// https://github.com/webpack/webpack/tree/master/examples/dll-user
// --------------------------------------------------------------------------
function dllPlugin(config) {
  const _dlls = []
  const vendorEntries = this.vendorEntries()
  const dllDir = resolve(this.options.cacheDir, config.name + '-dll')
  Object.keys(vendorEntries).forEach(v => {
    const dllManifestFile = resolve(dllDir, v + '-manifest.json')
    if (existsSync(dllManifestFile)) {
      _dlls.push(v)
      config.plugins.push(
        new webpack.DllReferencePlugin({
          // context: this.options.rootDir,
          manifest: dllManifestFile // Using full path to allow finding .js dll file
        })
      )
    }
  })
  if (_dlls.length) {
    debug('Using dll for ' + _dlls.join(','))
  }
}