// @ts-check
const debug = require('debug')('@cypress/react')
const loadConfig = require('next/dist/next-server/server/config').default
const getNextJsBaseWebpackConfig = require('next/dist/build/webpack-config')
.default
const webpackPreprocessor = require('@cypress/webpack-preprocessor')
const findWebpack = require('find-webpack')

async function getNextWebpackConfig (config) {
  const coverageIsDisabled =
    config && config.env && config.env.coverage === false

  debug('coverage is disabled? %o', { coverageIsDisabled })

  const nextConfig = await loadConfig('development', config.projectRoot)
  const nextWebpackConfig = await getNextJsBaseWebpackConfig(
    config.projectRoot,
    {
      buildId: `@cypress/react-${Math.random().toString()}`,
      config: nextConfig,
      dev: false,
      isServer: false,
      pagesDir: config.projectRoot,
      entrypoints: {},
      rewrites: [],
    },
  )

  debug('resolved next.js webpack options: %o', nextWebpackConfig)
  // Using mode over `dev` true to get rid of next's react-refresh-plugin wrapping
  // We need do not need all the HMR and webpack dev middlewares as well
  nextWebpackConfig.mode = 'development'

  findWebpack.cleanForCypress(
    {
      coverage: !coverageIsDisabled,
      // insert Babel plugin to mock named imports
      // disable because causes an error with double definitions
      // https://github.com/bahmutov/@cypress/react/issues/439
      looseModules: false,
    },
    nextWebpackConfig,
  )

  debug('final webpack options %o', nextWebpackConfig)

  return nextWebpackConfig
}

let webpackConfigCache = null

/** Resolving next.js webpack and all config with plugin takes long, so cache the webpack configuration */
async function getCachedWebpackPreprocessor (config) {
  // ⛔️ ⛔️ Comment this `if` for debugging
  if (webpackConfigCache !== null) {
    return webpackConfigCache
  }

  const webpackOptions = await getNextWebpackConfig(config)

  webpackConfigCache = webpackPreprocessor({ webpackOptions })

  debug('created and cached webpack preprocessor based on next.config.js')

  return webpackConfigCache
}

module.exports = (config) => {
  return async (fileEvent) => {
    const preprocessor = await getCachedWebpackPreprocessor(config)

    return preprocessor(fileEvent)
  }
}