'use strict'
const MiniCssPlugin = require('mini-css-extract-plugin')
const dotenv = require('dotenv')
const { join, resolve } = require('path')
const argv = require('minimist')(process.argv.slice(2))
const rootResolve = (...pathSegments) => join(__dirname, '..', ...pathSegments)

function getEnv() {
  return argv['m']
}
function getEnvPath() {
  if (String(typeof getEnv()) === 'boolean' || String(typeof getEnv()) === 'undefined') {
    return rootResolve('env/.env')
  }
  return rootResolve(`env/${getEnv()}.env`)
}
function getConfig() {
  return dotenv.config({ path: getEnvPath() }).parsed
}

// 获取环境
exports.getEnv = getEnv()
// 获取配置
exports.getConfig = getConfig()

exports.cssLoaders = function (options) {
  options = options || {}
  const esbuildCss = {
    loader: 'esbuild-loader',
    options: {
      loader: 'css',
      minify: options.minifyCss,
    },
  }

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

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

  // 这里就是生成loader和其对应的配置
  function generateLoaders(loader, loaderOptions) {
    const loaders = [cssLoader, postcssLoader, esbuildCss]

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

    // 当配置信息中开启此项时，启用css分离压缩
    // 这一项在生产环境时，是默认开启的
    if (options.extract) {
      return [MiniCssPlugin.loader].concat(loaders)
    } else {
      // 如果不开启则让vue-style-loader来处理
      return ['vue-style-loader'].concat(loaders)
    }
  }

  // https://vue-loader.vuejs.org/en/configurations/extract-css.html
  return {
    css: generateLoaders(),
    postcss: generateLoaders(),
    less: generateLoaders('less'),
    sass: generateLoaders('sass', { indentedSyntax: true }),
    scss: generateLoaders('sass', {
      sassOptions: {
        // 关键配置：添加 node_modules 到解析路径
        includePaths: [resolve(__dirname, 'node_modules')],
      },
    }),
    stylus: generateLoaders('stylus'),
    styl: generateLoaders('stylus'),
  }
}

// 根据上面的函数遍历出来的各个css预处理器的loader进行最后的拼装
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,
    })
  }

  return output
}