import { resolve } from 'path'
import consola from 'consola'
import { rollup, OutputOptions } from 'rollup'
import Hookable from 'hookable'
import prettyBytes from 'pretty-bytes'
import gzipSize from 'gzip-size'
import chalk from 'chalk'
import { emptyDir, readFile } from 'fs-extra'
import { getRollupConfig } from './rollup/config'
import { hl, prettyPath, serializeTemplate, writeFile } from './utils'
import { SLSOptions } from './config'

export async function build (options: SLSOptions) {
  console.log('\n')
  consola.info(`Generating bundle for ${hl(options.target)}`)

  const hooks = new Hookable()
  hooks.addHooks(options.hooks)

  // Compile html template
  const htmlSrc = resolve(options.buildDir, `views/${{ 2: 'app', 3: 'document' }[2]}.template.html`)
  const htmlTemplate = { src: htmlSrc, contents: '', dst: '', compiled: '' }
  htmlTemplate.dst = htmlTemplate.src.replace(/.html$/, '.js').replace('app.', 'document.')
  htmlTemplate.contents = await readFile(htmlTemplate.src, 'utf-8')
  htmlTemplate.compiled = serializeTemplate(htmlTemplate.contents)
  await hooks.callHook('template:document', htmlTemplate)
  await writeFile(htmlTemplate.dst, htmlTemplate.compiled)

  if (options.targetDir.startsWith(options.slsDir)) {
    emptyDir(options.slsDir)
  }

  options.rollupConfig = getRollupConfig(options)
  await hooks.callHook('rollup:before', options)
  const build = await rollup(options.rollupConfig).catch((error) => {
    error.message = '[serverless] Rollup Error: ' + error.message
    throw error
  })

  const { output } = await build.write(options.rollupConfig.output as OutputOptions)
  const size = prettyBytes(output[0].code.length)
  const zSize = prettyBytes(await gzipSize(output[0].code))
  consola.success('Generated', prettyPath((options.rollupConfig.output as any).file),
    chalk.gray(`(Size: ${size} Gzip: ${zSize})`)
  )

  await hooks.callHook('done', options)
}