#!/usr/bin/env python3
"""
Minimal signaling server for NAT-traversal demos.
Run:  python signaling.py           # listens on 0.0.0.0:8000
Dependencies:  none (std-lib only).

API
----
POST /register     JSON {"id": "...", "ip": "...", "port": int}
GET  /peer/<id>    ->  JSON {"ip": "...", "port": int}

Security, persistence, auth, etc. are intentionally *omitted*.
"""

from http.server import HTTPServer, BaseHTTPRequestHandler
import json

peers: dict[str, dict[str, str | int]] = {}        # in-memory registry


class SignalingHandler(BaseHTTPRequestHandler):
    def _json_response(self, code: int, payload: dict | str):
        self.send_response(code)
        self.send_header("Content-Type", "application/json")
        self.end_headers()
        body = payload if isinstance(payload, str) else json.dumps(payload)
        self.wfile.write(body.encode())

    # ---- POST /register ----------------------------------------------------
    def do_POST(self):
        if self.path != "/register":
            self._json_response(404, {"error": "unknown endpoint"})
            return

        length = int(self.headers.get("Content-Length", 0))
        try:
            data = json.loads(self.rfile.read(length))
            pid, ip, port = data["id"], data["ip"], int(data["port"])
        except Exception as e:
            self._json_response(400, {"error": f"bad json: {e}"})
            return

        peers[pid] = {"ip": ip, "port": port}
        self._json_response(200, {"status": "ok"})

    # ---- GET /peer/<id> ----------------------------------------------------
    def do_GET(self):
        if not self.path.startswith("/peer/"):
            self._json_response(404, {"error": "unknown endpoint"})
            return

        pid = self.path[len("/peer/") :]
        info = peers.get(pid)
        if info is None:
            self._json_response(404, {"error": f"peer '{pid}' not found"})
        else:
            self._json_response(200, info)


if __name__ == "__main__":
    print("🔥 Signaling server running on http://0.0.0.0:8000")
    HTTPServer(("0.0.0.0", 8000), SignalingHandler).serve_forever()