import time
from unittest.mock import MagicMock

from duck_preview.telemetry.collector import TelemetryCollector


def test_metrics_empty():
    collector = TelemetryCollector()
    metrics = collector.metrics()
    assert metrics == {"fps": 0, "frame_time_ms": 0.0, "frame_count": 0}


def test_metrics_after_frames():
    collector = TelemetryCollector()
    mock = MagicMock()
    for _ in range(30):
        collector.on_frame(mock)
        time.sleep(0.002)

    metrics = collector.metrics()
    assert metrics["frame_count"] >= 30
    assert metrics["frame_time_ms"] > 0