#!/usr/bin/env node
// Prints the image-edit request for the ad art. It calls no API.
// Usage: node scripts/build-input.mjs --image https://... --product "amber glass dropper bottle, cream label HALDEN" \
//   (--scene "describe the backdrop and props" | --preset skincare|food-pack|tech|apparel|home|supplements) [--format 4:5|1:1|9:16]
import { readFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

function parseArgs(argv, known) {
  const out = {}
  for (let i = 0; i < argv.length; i += 1) {
    const k = argv[i]
    if (!k.startsWith('--')) fail(`Unexpected argument '${k}'.`)
    const name = k.slice(2)
    if (!known.includes(name)) fail(`Unknown flag --${name}. Known: ${known.map((x) => '--' + x).join(', ')}`)
    const v = argv[i + 1]
    if (v === undefined || v.startsWith('--')) fail(`Flag --${name} needs a value.`)
    out[name] = v
    i += 1
  }
  return out
}
function fail(message) { console.error(message); process.exit(1) }
function checkImage(value) {
  if (!/^https:\/\//.test(value) && !/^data:image\//.test(value)) fail('--image must be a public https URL or an image data URI.')
}

const root = join(dirname(fileURLToPath(import.meta.url)), '..')
const o = parseArgs(process.argv.slice(2), ['image', 'product', 'scene', 'preset', 'format'])
if (!o.image || !o.product || (!o.scene && !o.preset)) fail('Usage: node scripts/build-input.mjs --image https://... --product "what it is, label text" (--scene "backdrop and props" | --preset skincare|food-pack|tech|apparel|home|supplements) [--format 4:5|1:1|9:16]')
checkImage(o.image)

const settings = JSON.parse(readFileSync(join(root, 'assets/generation-input.json'), 'utf8'))
const format = o.format ?? '4:5'
const size = settings.sizes[format]
if (!size) fail('--format must be 1:1, 4:5 or 9:16')
const composition = settings.composition[format]
if (o.preset && !settings.presets[o.preset]) fail('--preset must be one of: ' + Object.keys(settings.presets).join(', '))
const scene = o.scene ?? settings.presets[o.preset]
const template = readFileSync(join(root, 'assets/prompt-template.md'), 'utf8').trim()
const prompt = template
  .replace('{{product}}', () => o.product)
  .replace('{{scene}}', () => scene)
  .replace('{{composition}}', () => composition)

console.log(JSON.stringify({
  model: settings.model,
  input: { ...settings.input, image_size: size, image_urls: [o.image], prompt },
}, null, 2))