import execa from 'execa'
import { existsSync, readFileSync, writeFileSync } from 'fs'
import { join, resolve } from 'path'
import { bin_name, log } from '..'
import {
  ARCHITECTURE,
  BUILD_TARGETS,
  CONFIGS_DIR,
  ENGINE_DIR,
} from '../constants'
import { dispatch } from '../utils'

const platform: any = {
  win32: 'windows',
  darwin: 'macos',
  linux: 'linux',
}

const applyConfig = async (os: string, arch: string) => {
  log.info('Applying mozconfig...')

  let commonConfig = readFileSync(
    resolve(CONFIGS_DIR, 'common', 'mozconfig'),
    'utf-8'
  )

  const changesetPrefix = commonConfig
    .split('\n')
    .find((ln) => ln.startsWith('export MOZ_SOURCE_CHANGESET='))

  const changeset = changesetPrefix?.replace(/export MOZ_SOURCE_CHANGESET=/, '')

  const { stdout: gitSha } = await execa('git', ['rev-parse', 'HEAD'])

  console.log(changeset, gitSha)

  if (changeset) commonConfig = commonConfig.replace(changeset, gitSha)

  writeFileSync(resolve(CONFIGS_DIR, 'common', 'mozconfig'), commonConfig)

  const osConfig = readFileSync(
    resolve(CONFIGS_DIR, os, arch === 'i686' ? 'mozconfig-i686' : 'mozconfig'),
    'utf-8'
  )

  // Allow a custom config to be placed in /mozconfig. This will not be committed
  // to origin
  const customConfig = existsSync(join(process.cwd(), 'mozconfig'))
    ? readFileSync(join(process.cwd(), 'mozconfig')).toString()
    : ''

  const mergedConfig = `# This file is automatically generated. You should only modify this if you know what you are doing!\n\n${commonConfig}\n\n${osConfig}\n\n${customConfig}`

  writeFileSync(resolve(ENGINE_DIR, 'mozconfig'), mergedConfig)

  log.info(`Config for this \`${os}\` build:`)

  mergedConfig.split('\n').map((ln) => {
    if (ln.startsWith('mk') || ln.startsWith('ac') || ln.startsWith('export'))
      log.info(
        `\t${ln
          .replace(/mk_add_options /, '')
          .replace(/ac_add_options /, '')
          .replace(/export /, '')}`
      )
  })
}

const genericBuild = async (os: string, tier: string) => {
  log.info(`Building for "${os}"...`)

  log.warning(
    `If you get any dependency errors, try running |${bin_name} bootstrap|.`
  )

  await dispatch(`./mach`, ['build'].concat(tier ? [tier] : []), ENGINE_DIR)
}

const parseDate = (d: number) => {
  d = d / 1000
  var h = Math.floor(d / 3600)
  var m = Math.floor((d % 3600) / 60)
  var s = Math.floor((d % 3600) % 60)

  var hDisplay = h > 0 ? h + (h == 1 ? ' hour, ' : ' hours, ') : ''
  var mDisplay = m > 0 ? m + (m == 1 ? ' minute, ' : ' minutes, ') : ''
  var sDisplay = s > 0 ? s + (s == 1 ? ' second' : ' seconds') : ''
  return hDisplay + mDisplay + sDisplay
}

const success = (date: number) => {
  // mach handles the success messages
  console.log()
  log.info(`Total build time: ${parseDate(Date.now() - date)}.`)
}

interface Options {
  arch: string
}

export const build = async (tier: string, options: Options) => {
  let d = Date.now()

  // Host build

  const prettyHost = platform[process.platform as any]

  if (BUILD_TARGETS.includes(prettyHost)) {
    let arch = '64bit'

    if (options.arch) {
      if (!ARCHITECTURE.includes(options.arch))
        return log.error(
          `We do not support "${
            options.arch
          }" build right now.\nWe only currently support ${JSON.stringify(
            ARCHITECTURE
          )}.`
        )
      else arch = options.arch
    }

    applyConfig(prettyHost, options.arch)

    setTimeout(async () => {
      await genericBuild(prettyHost, tier).then((_) => success(d))
    }, 2500)
  }
}