/**
 * Fractafrag Renderer — Headless Chromium shader render service.
 * 
 * Accepts GLSL code via POST /render, renders in an isolated browser context,
 * returns thumbnail + preview video.
 * 
 * Full implementation in Track C.
 */

import express from 'express';
import { writeFileSync, mkdirSync, existsSync } from 'fs';
import path from 'path';

const app = express();
app.use(express.json({ limit: '1mb' }));

const PORT = 3100;
const OUTPUT_DIR = process.env.OUTPUT_DIR || '/renders';
const MAX_DURATION = parseInt(process.env.MAX_RENDER_DURATION || '8', 10);

// Ensure output directory exists
if (!existsSync(OUTPUT_DIR)) {
  mkdirSync(OUTPUT_DIR, { recursive: true });
}

// Health check
app.get('/health', (req, res) => {
  res.json({ status: 'ok', service: 'renderer' });
});

// Render endpoint (stub — Track C)
app.post('/render', async (req, res) => {
  const { glsl, duration = 5, width = 640, height = 360, fps = 30 } = req.body;

  if (!glsl) {
    return res.status(400).json({ error: 'Missing glsl field' });
  }

  // TODO: Track C implementation
  // 1. Launch Puppeteer page
  // 2. Inject GLSL into shader template HTML
  // 3. Capture frames for `duration` seconds
  // 4. Encode to WebM/MP4 + extract thumbnail
  // 5. Write to OUTPUT_DIR
  // 6. Return URLs

  res.status(501).json({
    error: 'Renderer implementation coming in Track C',
    thumbnail_url: null,
    preview_url: null,
  });
});

app.listen(PORT, '0.0.0.0', () => {
  console.log(`Renderer service listening on :${PORT}`);
  console.log(`Output dir: ${OUTPUT_DIR}`);
  console.log(`Max render duration: ${MAX_DURATION}s`);
});