import express from "express";
import cors from "cors";
import { readFileSync } from "fs";
import https from "https";

const app = express();
app.use(cors());
app.use(express.json({ limit: "50mb" }));

const PORT = 11434;
const HF_TOKEN = process.env.HF_TOKEN || process.env.OPENAI_API_KEY || "";
const PAYMENTS_URL = "https://scottzillasystems-scottzilla-payments.hf.space";

// ─── Load model catalog ──────────────────────────────────────────────────────
const catalog = JSON.parse(readFileSync("models.json", "utf-8"));
const models = catalog.models;
const aliasMap = new Map(models.map((m) => [m.alias, m]));
const hfIdMap = new Map(models.map((m) => [m.hf_id, m]));

function resolveModel(name) {
  if (!name) return models[0];
  const lower = name.toLowerCase().replace(/^scottzillasystems\//, "");
  return aliasMap.get(lower) || hfIdMap.get(name) ||
    models.find((m) => m.hf_id.toLowerCase().includes(lower)) ||
    models.find((m) => m.name.toLowerCase().includes(lower)) ||
    models.find((m) => m.capabilities?.some((c) => c === lower)) || null;
}

function routeByCapability(messages) {
  const text = messages.map((m) => m.content).join(" ").toLowerCase();
  if (/\b(image|picture|photo|draw|edit image|generate image)\b/.test(text))
    return resolveModel("qwen3-vl-8b-abliterated") || resolveModel("qwen3.5-9b");
  if (/\b(code|python|javascript|function|debug|program|script)\b/.test(text))
    return resolveModel("qwen3-coder-abliterated");
  if (/\b(uncensor|abliterat|jailbreak|unrestrict|nsfw)\b/.test(text))
    return resolveModel("qwen3.6-27b-abliterated");
  if (/\b(think|reason|math|logic|proof|step.by.step)\b/.test(text))
    return resolveModel("qwen3.5-40b-uncensored");
  if (/\b(creative|story|roleplay|write|fiction|narrative)\b/.test(text))
    return resolveModel("cydonia-24b");
  return resolveModel("qwen3.5-9b");
}

// ─── Payment verification middleware ─────────────────────────────────────────
// Free tier: 25 req/day on chatgpt-5 only, no key needed
// Paid tiers: validated through scottzilla-payments
let freeUsageToday = new Map(); // ip → count

async function verifyApiKey(key) {
  try {
    const resp = await fetch(`${PAYMENTS_URL}/api/keys/verify/${key}`);
    if (!resp.ok) return null;
    return await resp.json();
  } catch { return null; }
}

async function recordUsage(key, model) {
  try {
    await fetch(`${PAYMENTS_URL}/api/usage/record`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ api_key: key, model }),
    });
  } catch {}
}

async function authMiddleware(req, res, next) {
  const authHeader = req.headers.authorization || req.headers["x-api-key"] || "";
  const key = authHeader.replace(/^Bearer\s+/i, "").trim();

  // No key → free tier (25 req/day, chatgpt-5 only)
  if (!key || key === HF_TOKEN) {
    const ip = req.ip || req.headers["x-forwarded-for"] || "unknown";
    const today = new Date().toISOString().split("T")[0];
    const usageKey = `${ip}:${today}`;
    const used = freeUsageToday.get(usageKey) || 0;
    if (used >= 25) {
      return res.status(429).json({
        error: "Free tier limit reached (25/day). Get an API key at " + PAYMENTS_URL,
        upgrade_url: PAYMENTS_URL,
      });
    }
    freeUsageToday.set(usageKey, used + 1);
    req.tier = "free";
    req.allowedModels = ["chatgpt-5"];
    return next();
  }

  // Validate API key
  const keyData = await verifyApiKey(key);
  if (!keyData || !keyData.valid) {
    return res.status(401).json({ error: "Invalid API key. Get one at " + PAYMENTS_URL });
  }
  if (!keyData.within_limit) {
    return res.status(429).json({
      error: `Rate limit exceeded for ${keyData.tier_name} tier. Upgrade at ${PAYMENTS_URL}`,
      usage: keyData.usage_today,
      limit: keyData.limit_today,
    });
  }

  req.tier = keyData.tier;
  req.apiKey = key;
  req.allowedModels = keyData.models;
  next();
}

// ─── HF Router proxy ────────────────────────────────────────────────────────
async function hfChat(routerModel, messages, stream = false, params = {}) {
  const body = JSON.stringify({
    model: routerModel, messages, stream,
    max_tokens: params.max_tokens || 2048,
    temperature: params.temperature || 0.7,
    top_p: params.top_p || 0.95,
  });
  return new Promise((resolve, reject) => {
    const req = https.request({
      hostname: "router.huggingface.co", path: "/v1/chat/completions", method: "POST",
      headers: { "Content-Type": "application/json", Authorization: `Bearer ${HF_TOKEN}`, "Content-Length": Buffer.byteLength(body) },
    }, (res) => {
      if (stream) return resolve(res);
      let data = ""; res.on("data", (c) => data += c);
      res.on("end", () => { try { resolve(JSON.parse(data)); } catch { resolve({ error: data }); } });
    });
    req.on("error", reject); req.end(body);
  });
}

// ─── Public endpoints (no auth) ──────────────────────────────────────────────
app.get("/", (req, res) => {
  res.json({
    status: "Scottzilla Gateway ⚡ operational",
    models: models.length,
    pricing: PAYMENTS_URL,
    endpoints: [
      "GET  /api/tags, /v1/models — list models",
      "POST /api/chat, /v1/chat/completions — chat (requires API key for paid models)",
      "GET  /api/library — full catalog",
      "GET  /api/route?q=... — smart route preview",
    ],
    free_tier: "25 requests/day on chatgpt-5 — no key needed",
    get_api_key: PAYMENTS_URL + "/api/keys/create",
  });
});

app.get("/api/tags", (req, res) => {
  res.json({ models: models.map((m) => ({
    name: m.alias, model: m.alias, modified_at: new Date().toISOString(), size: (m.size_gb || 0) * 1e9, digest: m.hf_id,
    details: { parent_model: m.hf_id, format: m.arch, family: m.arch, parameter_size: m.params || "unknown" },
  }))});
});

app.get("/v1/models", (req, res) => {
  res.json({ object: "list", data: models.map((m) => ({
    id: m.alias, object: "model", created: Math.floor(Date.now() / 1000), owned_by: "ScottzillaSystems",
    hf_id: m.hf_id, capabilities: m.capabilities, params: m.params,
  }))});
});

app.get("/api/library", (req, res) => res.json(catalog));

app.get("/api/route", (req, res) => {
  const q = req.query.q || "";
  const pick = routeByCapability([{ role: "user", content: q }]);
  res.json({ query: q, routed_to: pick ? { alias: pick.alias, name: pick.name, hf_id: pick.hf_id, capabilities: pick.capabilities } : null });
});

app.post("/api/show", (req, res) => {
  const entry = resolveModel(req.body.name || req.body.model);
  if (!entry) return res.status(404).json({ error: "model not found" });
  res.json({
    modelfile: `# ${entry.name}\nFROM ${entry.hf_id}\nPARAMETER temperature 0.7`,
    parameters: "temperature 0.7\ntop_p 0.95", template: "{{ .System }}\n{{ .Prompt }}",
    details: { parent_model: entry.hf_id, format: entry.arch, family: entry.arch, parameter_size: entry.params || "unknown", capabilities: entry.capabilities },
  });
});

// ─── Auth-gated chat endpoints ───────────────────────────────────────────────
app.post("/api/chat", authMiddleware, async (req, res) => {
  try {
    const { model: modelName, messages, options } = req.body;
    const entry = modelName === "auto" ? routeByCapability(messages) : (resolveModel(modelName) || routeByCapability(messages));
    if (!entry) return res.status(404).json({ error: `Model not found: ${modelName}` });

    // Check model access
    if (req.tier === "free" && !req.allowedModels.includes(entry.alias) && !req.allowedModels.includes("all")) {
      return res.status(403).json({ error: `${entry.name} requires a paid plan. Free tier allows: ${req.allowedModels.join(", ")}`, upgrade: PAYMENTS_URL });
    }

    const routerModel = entry.router_model || "Qwen/Qwen3.5-9B";
    const result = await hfChat(routerModel, messages, false, options || {});
    const content = result.choices?.[0]?.message?.content || "";

    if (req.apiKey) recordUsage(req.apiKey, entry.alias);

    res.json({ model: entry.alias, created_at: new Date().toISOString(), message: { role: "assistant", content }, done: true,
      _meta: { hf_id: entry.hf_id, router_model: routerModel, tier: req.tier } });
  } catch (err) { res.status(500).json({ error: err.message }); }
});

app.post("/api/generate", authMiddleware, async (req, res) => {
  try {
    const { model: modelName, prompt, options } = req.body;
    const messages = [{ role: "user", content: prompt }];
    const entry = modelName === "auto" ? routeByCapability(messages) : (resolveModel(modelName) || routeByCapability(messages));
    if (!entry) return res.status(404).json({ error: `Model not found: ${modelName}` });

    if (req.tier === "free" && !req.allowedModels.includes(entry.alias) && !req.allowedModels.includes("all")) {
      return res.status(403).json({ error: `${entry.name} requires a paid plan.`, upgrade: PAYMENTS_URL });
    }

    const routerModel = entry.router_model || "Qwen/Qwen3.5-9B";
    const result = await hfChat(routerModel, messages, false, options || {});
    if (req.apiKey) recordUsage(req.apiKey, entry.alias);

    res.json({ model: entry.alias, created_at: new Date().toISOString(), response: result.choices?.[0]?.message?.content || "", done: true });
  } catch (err) { res.status(500).json({ error: err.message }); }
});

app.post("/v1/chat/completions", authMiddleware, async (req, res) => {
  try {
    const { model: modelName, messages, stream, temperature, max_tokens, top_p } = req.body;
    const entry = modelName === "auto" ? routeByCapability(messages) : (resolveModel(modelName) || routeByCapability(messages));
    if (!entry) return res.status(404).json({ error: { message: `Model not found: ${modelName}`, type: "invalid_request_error" } });

    if (req.tier === "free" && !req.allowedModels.includes(entry.alias) && !req.allowedModels.includes("all")) {
      return res.status(403).json({ error: { message: `${entry.name} requires a paid plan. Upgrade at ${PAYMENTS_URL}`, type: "insufficient_quota" } });
    }

    const routerModel = entry.router_model || "Qwen/Qwen3.5-9B";

    if (stream) {
      res.setHeader("Content-Type", "text/event-stream");
      res.setHeader("Cache-Control", "no-cache");
      const upstream = await hfChat(routerModel, messages, true, { temperature, max_tokens, top_p });
      upstream.on("data", (chunk) => res.write(chunk));
      upstream.on("end", () => { if (req.apiKey) recordUsage(req.apiKey, entry.alias); res.end(); });
      upstream.on("error", () => res.end());
      return;
    }

    const result = await hfChat(routerModel, messages, false, { temperature, max_tokens, top_p });
    if (req.apiKey) recordUsage(req.apiKey, entry.alias);

    res.json({ ...result, model: entry.alias, _scottzilla: { hf_id: entry.hf_id, router_model: routerModel, tier: req.tier, capabilities: entry.capabilities } });
  } catch (err) { res.status(500).json({ error: { message: err.message, type: "server_error" } }); }
});

// ─── Start ───────────────────────────────────────────────────────────────────
app.listen(PORT, "0.0.0.0", () => {
  console.log(`⚡ Scottzilla Gateway listening on :${PORT}`);
  console.log(`   ${models.length} models | Payments: ${PAYMENTS_URL}`);
  console.log(`   Free tier: 25 req/day on chatgpt-5 (no key needed)`);
  console.log(`   Paid tiers: validated through scottzilla-payments`);
});