#!/usr/bin/env node
import { spawn } from 'node:child_process';
import { access } from 'node:fs/promises';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const args = process.argv.slice(2);
if (!args.length || args.includes('--help')) {
  console.log(`Usage: npm run blender:export -- INPUT.blend --output OUTPUT.glb [options]
  --blender PATH         Blender binary (or FORMA_BLENDER; default: blender)
  --scene NAME           Scene to export
  --objects GLOB         Export matching objects; repeat for several patterns
  --bake-materials       Bake procedural/animated surface inputs to UV atlases
  --resolution 128       Pixels per baked frame, 16–1024
  --samples 8            Cycles samples per bake, 1–256
  --lighting compat     Unitless lights for Forma; spec preserves physical units
  --start-frame N --end-frame N --frame-step N
  --allow-lossy          Accept approximations listed in OUTPUT.report.json
See docs/BLENDER.md for supported features and limitations.`);
  process.exit(args.length ? 0 : 1);
}
const input = path.resolve(args.shift());
if (!/\.blend$/i.test(input)) throw Error('Input must be a .blend file');
await access(input);
const binaryFlag = args.indexOf('--blender');
let binary = process.env.FORMA_BLENDER || 'blender';
if (binaryFlag >= 0) {
  if (!args[binaryFlag + 1]) throw Error('--blender requires a path');
  binary = args[binaryFlag + 1]; args.splice(binaryFlag, 2);
}
const outputFlag = args.indexOf('--output');
if (outputFlag < 0 || !args[outputFlag + 1] || !/\.glb$/i.test(args[outputFlag + 1])) throw Error('--output OUTPUT.glb is required');
const output = path.resolve(args[outputFlag + 1]);
if (output === input) throw Error('Output must differ from input');
args[outputFlag + 1] = output;
const script = fileURLToPath(new URL('../blender/export_forma.py', import.meta.url));
const child = spawn(binary, ['--background', '--factory-startup', '--disable-autoexec', input, '--python-exit-code', '1', '--python', script, '--', ...args], { stdio: 'inherit', shell: false });
child.on('error', error => { console.error(`Cannot start Blender: ${error.message}. Set FORMA_BLENDER or --blender.`); process.exitCode = 1; });
child.on('exit', (code, signal) => { process.exitCode = code ?? (signal ? 1 : 0); });
process.once('SIGINT', () => child.kill('SIGINT'));
process.once('SIGTERM', () => child.kill('SIGTERM'));