"""uptime-kuma — recipe-specific functional test (Phase 2 P3).

uptime-kuma's defining feature is **real-time monitoring** delivered over Socket.IO. The
recipe routes /socket.io/* to the app. A working uptime-kuma must complete the Engine.IO v4
polling handshake at `/socket.io/?EIO=4&transport=polling`:
- HTTP 200
- Body starts with `0{` — the Engine.IO `open` packet (type 0) + JSON metadata (sid, upgrades,
  pingInterval, pingTimeout)

Non-vacuous: a working HTTP front-end with a wedged Socket.IO backend returns 404 or 502 here.
A misrouted nginx returns 404. Only a correctly-wired uptime-kuma + Engine.IO listener responds
with the Engine.IO open packet.
"""

from __future__ import annotations

import json
import os
import ssl
import sys
import urllib.request

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "..", "runner"))
from harness import http as harness_http  # noqa: E402


def test_socketio_polling_handshake(live_app):
    """GET /socket.io/?EIO=4&transport=polling → 200, body starts with '0{' + valid JSON."""
    url = f"https://{live_app}/socket.io/?EIO=4&transport=polling"

    ctx = ssl.create_default_context()
    ctx.check_hostname = False
    ctx.verify_mode = ssl.CERT_NONE

    def _fetch():
        req = urllib.request.Request(url, method="GET")
        try:
            with urllib.request.urlopen(req, timeout=15, context=ctx) as r:
                if r.status != 200:
                    return None
                body = r.read().decode(errors="replace")
        except Exception:  # noqa: BLE001
            return None
        if not body.startswith("0"):
            return None
        # Body shape: `<length>:<packet>` or just the packet on EIO v4. We accept either.
        # Locate the leading `0{` (Engine.IO open packet)
        idx = body.find("0{")
        if idx < 0:
            return None
        json_str = body[idx + 1 :]  # skip the leading "0"
        # The JSON may be followed by other Engine.IO frames; take everything to the last '}'
        end = json_str.rfind("}")
        if end < 0:
            return None
        try:
            parsed = json.loads(json_str[: end + 1])
        except (json.JSONDecodeError, ValueError):
            return None
        # Engine.IO v4 'open' packet carries sid, upgrades, pingInterval, pingTimeout
        if not isinstance(parsed, dict) or "sid" not in parsed:
            return None
        return parsed

    info = harness_http.assert_converges(
        _fetch, f"GET {url} returns Engine.IO open packet", max_wait=60, interval=3
    )
    # Standard Engine.IO open-packet fields
    assert "sid" in info, f"no sid in handshake: {info!r}"
    assert "pingInterval" in info, f"no pingInterval in handshake: {info!r}"