#!/usr/bin/env node
// Prints the image-edit request for the clean hero photo. It does not call any API.
// Usage: node scripts/build-input.mjs --image https://... --product "over-ear headphones"
//   [--pose "floating at a slight three-quarter angle"] [--background "..."] [--share 75]
import { readFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

const root = join(dirname(fileURLToPath(import.meta.url)), '..')
const usage = 'Usage: node scripts/build-input.mjs --image https://... --product "name" [--pose "..."] [--background "..."] [--share 75]'
const allowed = new Set(['image', 'product', 'pose', 'background', 'share'])
const options = {}
const args = process.argv.slice(2)
for (let index = 0; index < args.length; index += 2) {
  const key = args[index]
  const value = args[index + 1]
  if (!key.startsWith('--') || !allowed.has(key.slice(2))) {
    console.error(`Unknown option "${key}".\n${usage}`)
    process.exit(1)
  }
  if (value === undefined || value.startsWith('--')) {
    console.error(`Option ${key} needs a value.\n${usage}`)
    process.exit(1)
  }
  options[key.slice(2)] = value
}
if (!options.image || !options.product) {
  console.error(usage)
  process.exit(1)
}
if (!/^(https:\/\/|data:image\/)/.test(options.image)) {
  console.error('The product photo must be a public https URL or a data:image/ URI.')
  process.exit(1)
}
const share = Number(options.share ?? 75)
if (!(share >= 40 && share <= 80)) {
  console.error('--share must be between 40 and 80 (percent of the frame width the product fills).')
  process.exit(1)
}

const template = readFileSync(join(root, 'assets/prompt-template.md'), 'utf8').trim()
const settings = JSON.parse(readFileSync(join(root, 'assets/generation-input.json'), 'utf8'))
const prompt = template
  .replace('{{product}}', () => options.product)
  .replace('{{pose}}', () => options.pose ?? 'floating upright, seen from the front and turned about 25 degrees so that two sides of the product show, with a soft shadow far beneath')
  .replace('{{background}}', () => options.background ?? settings.default_background)
  .replace('{{share}}', () => String(share))

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