import { promisify } from 'util'
import { promises } from 'fs'
import { exec } from 'child_process'
import { v1 as uuidv1 } from 'uuid'
import { getDirPath, getDocPath, getTexCmd } from './utils'

const execPromise = promisify(exec)

async function copyToTemp(id: string, texDocument: string): Promise<void> {
  const dirPath = getDirPath(id)
  const docPath = getDocPath(id)

  await promises.mkdir(dirPath)
  await promises.writeFile(docPath, texDocument)
}

async function generateDoc(id: string): Promise<void> {
  const { cmd, options } = getTexCmd(id)
  try {
    const { stdout } = await execPromise(cmd, options)
    stdout.length && console.log('stdout:', stdout)
    console.log(`PDF ${id} generated`)
  } catch (error) {
    console.error(error.stdout)
    console.error(error.toString())
    throw new Error(error.message)
  }
}

export default async function (texDocument: string) {
  const id = uuidv1()
  await copyToTemp(id, texDocument)
  await generateDoc(id)
  return id
}