import express from "express";
import fetch from "node-fetch";
import { checkUserQuota, recordUserHit, enqueue } from "../lib/rateLimiter.js";

const router = express.Router();
const INVOKE_URL = "https://ai.api.nvidia.com/v1/genai/black-forest-labs/flux.1-dev";

// POST /api/image  { prompt, clientId }
router.post("/image", async (req, res) => {
  try {
    const { prompt, clientId = "anon" } = req.body;
    if (!prompt || !prompt.trim()) {
      return res.status(400).json({ error: "missing_prompt" });
    }

    // حد المستخدم: 3 صور / 3 ساعات
    const quota = checkUserQuota(clientId);
    if (!quota.allowed) {
      const mins = Math.ceil(quota.retryMs / 60000);
      return res.status(429).json({
        error: "rate_limited",
        message: `وصلت إلى حد 3 صور كل 3 ساعات. حاول مجدداً بعد ${mins} دقيقة.`,
        retryMs: quota.retryMs,
      });
    }

    // إعدادات واقعية ودقيقة جداً
    const payload = {
      prompt: `${prompt}, ultra realistic, highly detailed, photorealistic, 8k, sharp focus, natural lighting, professional photography`,
      mode: "base",
      cfg_scale: 3.5,
      width: 1024,
      height: 1024,
      seed: Math.floor(Math.random() * 1_000_000),
      steps: 50,
    };

    // عبر الطابور العالمي (<= 40/دقيقة)
    const data = await enqueue(async () => {
      const r = await fetch(INVOKE_URL, {
        method: "POST",
        headers: {
          Authorization: `Bearer ${process.env.NVIDIA_API_KEY}`,
          Accept: "application/json",
          "Content-Type": "application/json",
        },
        body: JSON.stringify(payload),
      });
      if (r.status !== 200) {
        const errBody = await r.text();
        throw new Error(`NVIDIA ${r.status}: ${errBody}`);
      }
      return r.json();
    });

    recordUserHit(clientId);

    // FLUX يرجع base64 في artifacts[0].base64 (أو image)
    const b64 =
      data?.artifacts?.[0]?.base64 ||
      data?.image ||
      data?.data?.[0]?.b64_json ||
      null;

    if (!b64) {
      return res.status(502).json({ error: "no_image", raw: data });
    }

    res.json({ image: `data:image/png;base64,${b64}`, remaining: quota.remaining - 1 });
  } catch (err) {
    console.error("image error:", err);
    res.status(500).json({ error: "image_failed", message: String(err?.message || err) });
  }
});

export default router;