src/production/generateAudio.mts

import path from "node:path"

import { v4 as uuidv4 } from "uuid"
import tmpDir from "temp-dir"
import puppeteer from "puppeteer"

import { downloadFileToTmp } from "../utils/downloadFileToTmp.mts"
import { moveFileFromTmpToPending } from "../utils/moveFileFromTmpToPending.mts"

const instances: string[] = [
  process.env.VC_AUDIO_GENERATION_SPACE_API_URL
]

// TODO we should use an inference endpoint instead
export async function generateAudio(prompt: string, audioFileName: string) {
  const instance = instances.shift()
  instances.push(instance)

  const browser = await puppeteer.launch({
    headless: true,
    protocolTimeout: 120000,
  })

  try {
    const page = await browser.newPage()

    await page.goto(instance, {
      waitUntil: "networkidle2",
    })

    await new Promise(r => setTimeout(r, 3000))

    const firstTextboxInput = await page.$('input[data-testid="textbox"]')

    await firstTextboxInput.type(prompt)

    // console.log("looking for the button to submit")
    const submitButton = await page.$("button.lg")

    // console.log("clicking on the button")
    await submitButton.click()

    await page.waitForSelector("a[download]", {
      timeout: 120000, // no need to wait for too long, generation is quick
    })

    const audioRemoteUrl = await page.$$eval("a[download]", el => el.map(x => x.getAttribute("href"))[0])


    // it is always a good idea to download to a tmp dir before saving to the pending dir
    // because there is always a risk that the download will fail
    
    const tmpFileName = `${uuidv4()}.mp4`

    await downloadFileToTmp(audioRemoteUrl, tmpFileName)
    await moveFileFromTmpToPending(tmpFileName, audioFileName)
  } catch (err) {
    throw err
  } finally {
    await browser.close()
  }
}