"""Tests for the MQTT → Server-Sent Events bridge used by the web process."""

import json
import queue


def test_forward_event_delivers_payload_to_sse_subscribers():
    """forward_event should hand the payload to every connected SSE client."""
    from vigilar.web.blueprints import events as events_bp
    from vigilar.web.sse_bridge import forward_event

    q: queue.Queue = queue.Queue(maxsize=10)
    events_bp._sse_subscribers.append(q)
    try:
        payload = {
            "type": "MOTION_START",
            "source_id": "cam1",
            "severity": "WARNING",
            "ts": 1234,
        }
        forward_event("vigilar/events/published", payload)

        raw = q.get_nowait()
        assert raw.startswith("data: ")
        # Strip "data: " prefix and trailing double newline
        data = json.loads(raw[len("data: "):].rstrip())
        assert data["type"] == "MOTION_START"
        assert data["source_id"] == "cam1"
    finally:
        if q in events_bp._sse_subscribers:
            events_bp._sse_subscribers.remove(q)


def test_start_sse_bridge_subscribes_to_events_published(monkeypatch):
    """start_sse_bridge must connect a bus and subscribe forward_event
    to Topics.EVENTS_PUBLISHED — that is the single entry point for the
    web process to observe classified events from the events subsystem."""
    from vigilar.config import VigilarConfig
    from vigilar.constants import Topics
    from vigilar.web import sse_bridge

    class FakeBus:
        def __init__(self, config, client_id):
            self.client_id = client_id
            self.subscriptions: list[tuple[str, object]] = []
            self.connected = False

        def subscribe(self, topic, handler):
            self.subscriptions.append((topic, handler))

        def connect(self):
            self.connected = True

    monkeypatch.setattr(sse_bridge, "MessageBus", FakeBus)

    bus = sse_bridge.start_sse_bridge(VigilarConfig())

    assert bus.connected is True
    assert len(bus.subscriptions) == 1
    topic, handler = bus.subscriptions[0]
    assert topic == Topics.EVENTS_PUBLISHED
    assert handler is sse_bridge.forward_event