package sd.dashboard;

import org.junit.jupiter.api.AfterEach;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import sd.config.SimulationConfig;
import sd.model.VehicleType;

/**
 * Unit tests for Dashboard Server components.
 */
class DashboardTest {
    
    private DashboardStatistics statistics;
    
    @BeforeEach
    void setUp() {
        statistics = new DashboardStatistics();
    }
    
    @AfterEach
    void tearDown() {
        statistics = null;
    }
    
    @Test
    void testInitialStatistics() {
        assertEquals(0, statistics.getTotalVehiclesGenerated(), 
            "Initial vehicles generated should be 0");
        assertEquals(0, statistics.getTotalVehiclesCompleted(), 
            "Initial vehicles completed should be 0");
        assertEquals(0.0, statistics.getAverageSystemTime(), 
            "Initial average system time should be 0.0");
        assertEquals(0.0, statistics.getAverageWaitingTime(), 
            "Initial average waiting time should be 0.0");
    }
    
    @Test
    void testVehicleCounters() {
        statistics.incrementVehiclesGenerated();
        assertEquals(1, statistics.getTotalVehiclesGenerated());
        
        statistics.updateVehiclesGenerated(10);
        assertEquals(10, statistics.getTotalVehiclesGenerated());
        
        statistics.incrementVehiclesCompleted();
        assertEquals(1, statistics.getTotalVehiclesCompleted());
    }
    
    @Test
    void testAverageCalculations() {
        // Add 3 completed vehicles with known times
        statistics.updateVehiclesCompleted(3);
        statistics.addSystemTime(3000); // 3000ms total
        statistics.addWaitingTime(1500); // 1500ms total
        
        assertEquals(1000.0, statistics.getAverageSystemTime(), 0.01,
            "Average system time should be 1000ms");
        assertEquals(500.0, statistics.getAverageWaitingTime(), 0.01,
            "Average waiting time should be 500ms");
    }
    
    @Test
    void testVehicleTypeStatistics() {
        statistics.incrementVehicleType(VehicleType.LIGHT);
        statistics.incrementVehicleType(VehicleType.LIGHT);
        statistics.incrementVehicleType(VehicleType.HEAVY);
        
        assertEquals(2, statistics.getVehicleTypeCount(VehicleType.LIGHT));
        assertEquals(1, statistics.getVehicleTypeCount(VehicleType.HEAVY));
        assertEquals(0, statistics.getVehicleTypeCount(VehicleType.BIKE));
    }
    
    @Test
    void testIntersectionStatistics() {
        statistics.updateIntersectionStats("Cr1", 10, 8, 2);
        
        DashboardStatistics.IntersectionStats stats = 
            statistics.getIntersectionStats("Cr1");
        
        assertNotNull(stats, "Intersection stats should not be null");
        assertEquals("Cr1", stats.getIntersectionId());
        assertEquals(10, stats.getTotalArrivals());
        assertEquals(8, stats.getTotalDepartures());
        assertEquals(2, stats.getCurrentQueueSize());
    }
    
    @Test
    void testMultipleIntersections() {
        statistics.updateIntersectionStats("Cr1", 10, 8, 2);
        statistics.updateIntersectionStats("Cr2", 15, 12, 3);
        statistics.updateIntersectionStats("Cr3", 5, 5, 0);
        
        assertEquals(3, statistics.getAllIntersectionStats().size(),
            "Should have 3 intersections");
    }
    
    @Test
    void testStatsUpdatePayload() {
        StatsUpdatePayload payload = new StatsUpdatePayload()
            .setTotalVehiclesGenerated(50)
            .setTotalVehiclesCompleted(20)
            .setIntersectionArrivals(30)
            .setIntersectionDepartures(25)
            .setIntersectionQueueSize(5);
        
        assertEquals(50, payload.getTotalVehiclesGenerated());
        assertEquals(20, payload.getTotalVehiclesCompleted());
        assertEquals(30, payload.getIntersectionArrivals());
        assertEquals(25, payload.getIntersectionDepartures());
        assertEquals(5, payload.getIntersectionQueueSize());
    }
    
    @Test
    void testStatsMessage() {
        StatsUpdatePayload payload = new StatsUpdatePayload()
            .setIntersectionArrivals(10);
        
        StatsMessage message = new StatsMessage("Cr1", payload);
        
        assertEquals("Cr1", message.getSourceNode());
        assertEquals("DashboardServer", message.getDestinationNode());
        assertEquals(sd.model.MessageType.STATS_UPDATE, message.getType());
        assertNotNull(message.getPayload());
    }
    
    @Test
    void testThreadSafety() throws InterruptedException {
        // Test concurrent updates
        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 100; i++) {
                statistics.incrementVehiclesGenerated();
            }
        });
        
        Thread t2 = new Thread(() -> {
            for (int i = 0; i < 100; i++) {
                statistics.incrementVehiclesGenerated();
            }
        });
        
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        
        assertEquals(200, statistics.getTotalVehiclesGenerated(),
            "Concurrent increments should total 200");
    }
    
    @Test
    void testDashboardServerCreation() throws Exception {
        SimulationConfig config = new SimulationConfig("simulation.properties");
        DashboardServer server = new DashboardServer(config);
        
        assertNotNull(server, "Server should be created successfully");
        assertNotNull(server.getStatistics(), "Statistics should be initialized");
        assertFalse(server.isRunning(), "Server should not be running initially");
    }
}