import unittest
import time
from unittest.mock import MagicMock
from performance_monitor import PerformanceMonitor

class TestPerformanceMonitor(unittest.TestCase):
    def setUp(self):
        self.monitor = PerformanceMonitor()

    def test_frame_time_collection(self):
        # Simulate frames for 1.1 seconds to trigger FPS calculation
        start = time.time()
        while time.time() - start < 1.1:
            self.monitor.start_frame()
            time.sleep(0.01)  # ~100 FPS
            self.monitor.end_frame()
        
        metrics = self.monitor.get_metrics()
        self.assertAlmostEqual(metrics['last_frame_time_ms'], 10, delta=10)
        self.assertGreater(metrics['fps'], 0)

    def test_cpu_usage_collection(self):
        metrics = self.monitor.get_metrics()
        self.assertIn('cpu_percent', metrics)
        self.assertIsInstance(metrics['cpu_percent'], float)

    def test_input_lag_collection(self):
        self.monitor.start_frame()
        self.monitor.record_input_event()
        time.sleep(0.02)  # 20ms lag
        self.monitor.end_frame()
        
        metrics = self.monitor.get_metrics()
        self.assertGreaterEqual(metrics['input_lag_ms'], 20)
        self.assertLess(metrics['input_lag_ms'], 40)

    def test_alerts_triggering(self):
        mock_callback = MagicMock()
        self.monitor.alert_callback = mock_callback
        self.monitor.thresholds['frame_time_ms'] = 5.0  # Low threshold
        self.monitor._alert_cooldown = 0  # No cooldown for test
        
        self.monitor.start_frame()
        time.sleep(0.01)  # 10ms > 5ms
        self.monitor.end_frame()
        
        mock_callback.assert_called_once()
        self.assertIn("Frame time high", mock_callback.call_args[0][0])

if __name__ == '__main__':
    unittest.main()