'use strict'
const path = require('path')
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
// const packageConfig = require('./package.json')

exports.cssLoaders = function (options) {
  options = options || {}

  const cssLoader = {
    loader: 'css-loader',
    options: {
      sourceMap: options.sourceMap
    }
  }

  const postcssLoader = {
    loader: 'postcss-loader',
    options: {
      sourceMap: options.sourceMap
    }
  }

  // generate loader string to be used with extract text plugin
  function generateLoaders(loader, loaderOptions) {
    const loaders = options.usePostCSS ? [cssLoader, postcssLoader] : [cssLoader]

    if (loader) {
      loaders.push({
        loader: loader + '-loader',
        options: Object.assign({}, loaderOptions, {
          sourceMap: options.sourceMap
        })
      })
    }

    if (options.extract) {
      loaders.unshift({
        loader: MiniCssExtractPlugin.loader,
        options: {},
      })
      return loaders;
    } else {
      return ['vue-style-loader'].concat(loaders)
    }
  }
  
  // https://vue-loader.vuejs.org/en/configurations/extract-css.html
  return {
    css: generateLoaders(),
    postcss: generateLoaders(),
    less: generateLoaders('less', { javascriptEnabled: true }),
    sass: generateLoaders('sass', { indentedSyntax: true }),
    scss: generateLoaders('sass'),
    stylus: generateLoaders('stylus'),
    styl: generateLoaders('stylus')
  }
}

// Generate loaders for standalone style files (outside of .vue)
exports.styleLoaders = function (options) {
  const output = []
  const loaders = exports.cssLoaders(options)

  for (const extension in loaders) {
    const loader = loaders[extension]
    output.push({
      test: new RegExp('\\.' + extension + '$'),
      use: loader
    })
  }
  // console.log(' styleLoaders : ' , JSON.stringify(output));
  return output
}

// exports.createNotifierCallback = () => {
//   const notifier = require('node-notifier')

//   return (severity, errors) => {
//     if (severity !== 'error') return

//     const error = errors[0]
//     const filename = error.file && error.file.split('!').pop()

//     notifier.notify({
//       title: packageConfig.name,
//       message: severity + ': ' + error.name,
//       subtitle: filename || '',
//       icon: path.join(__dirname, 'logo.png')
//     })
//   }
// }