import fs from 'node:fs/promises'
import { join } from 'node:path'
import src2img from 'src2img'

const src = `path/to/sources`
const out = `path/to/out`

const names = await fs.readdir(src)
const srcs = Promise.all(
  names.map(async name => ({
    name,
    src: await fs.readFile(join(src, name), `utf8`),
  })),
)

const images = await src2img({
  // Font size and unit control the size and quality of the image.
  fontSize: 20,
  fontSizeUnit: `pt`,
  padding: 3,
  // Using 'px' does not scale with font size.
  paddingUnit: `vw`,
  // Png or jpeg
  type: `png`,
  src: srcs.map(({ src }) => [
    src,
    // https://prismjs.com/index.html#languages-list
    `javascript`,
    // See https://www.npmjs.com/package/filename2prism for getting alias from
    // filename.
  ]),
})

await Promise.all(
  images.map((image, i) =>
    fs.writeFile(
      join(out, `${srcs[i].name.replaceAll(/\.[^.]+$/gu, ``)}.png`),
      image,
    ),
  ),
)