import java.io.IOException;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import org.junit.jupiter.api.Test;

import sd.config.SimulationConfig;
import sd.engine.SimulationEngine;
import sd.model.Event;
import sd.model.EventType;
import sd.model.Intersection;
import sd.model.TrafficLight;
import sd.model.TrafficLightState;
import sd.model.Vehicle;
import sd.model.VehicleType;
import sd.util.StatisticsCollector;
import sd.util.VehicleGenerator;

/**
 * Basic tests for the simulation components.
 */
class SimulationTest {
    
    @Test
    void testConfigurationLoading() throws IOException {
        SimulationConfig config = new SimulationConfig("src/main/resources/simulation.properties");
        
        assertEquals(60.0, config.getSimulationDuration());
        assertEquals("POISSON", config.getArrivalModel());
        assertEquals(0.5, config.getArrivalRate());
        assertEquals(10.0, config.getStatisticsUpdateInterval());
    }
    
    @Test
    void testVehicleGeneration() throws IOException {
        SimulationConfig config = new SimulationConfig("src/main/resources/simulation.properties");
        VehicleGenerator generator = new VehicleGenerator(config);
        
        Vehicle vehicle = generator.generateVehicle("TEST1", 0.0);
        
        assertNotNull(vehicle);
        assertEquals("TEST1", vehicle.getId());
        assertNotNull(vehicle.getType());
        assertNotNull(vehicle.getRoute());
        assertTrue(!vehicle.getRoute().isEmpty());
    }
    
    @Test
    void testEventOrdering() {
        Event e1 = new Event(5.0, EventType.VEHICLE_ARRIVAL, null, "Cr1");
        Event e2 = new Event(3.0, EventType.VEHICLE_ARRIVAL, null, "Cr2");
        Event e3 = new Event(7.0, EventType.TRAFFIC_LIGHT_CHANGE, null, "Cr1");
        
        assertTrue(e2.compareTo(e1) < 0); // e2 should come before e1
        assertTrue(e1.compareTo(e3) < 0); // e1 should come before e3
    }
    
    @Test
    void testIntersectionVehicleQueue() {
        Intersection intersection = new Intersection("TestCr");
        TrafficLight light = new TrafficLight("TestCr-N", "North", 30.0, 30.0);
        
        intersection.addTrafficLight(light);
        
        Vehicle v1 = new Vehicle("V1", VehicleType.LIGHT, 0.0, 
            java.util.Arrays.asList("TestCr", "S"));
        
        intersection.configureRoute("S", "North");
        
        // Advance route to next destination
        v1.advanceRoute();
        
        intersection.receiveVehicle(v1);
        
        assertEquals(1, intersection.getTotalQueueSize());
        assertEquals(1, intersection.getTotalVehiclesReceived());
    }
    
    @Test
    void testTrafficLightStateChange() {
        TrafficLight light = new TrafficLight("Test-Light", "North", 30.0, 30.0);
        
        assertEquals(TrafficLightState.RED, light.getState());
        
        light.changeState(TrafficLightState.GREEN);
        assertEquals(TrafficLightState.GREEN, light.getState());
        
        light.changeState(TrafficLightState.RED);
        assertEquals(TrafficLightState.RED, light.getState());
    }
    
    @Test
    void testSimulationEngineInitialization() throws IOException {
        SimulationConfig config = new SimulationConfig("src/main/resources/simulation.properties");
        SimulationEngine engine = new SimulationEngine(config);
        
        engine.initialize();
        
        assertNotNull(engine.getIntersections());
        assertEquals(5, engine.getIntersections().size());
        
        // Check that intersections have traffic lights
        for (Intersection intersection : engine.getIntersections().values()) {
            assertEquals(3, intersection.getTrafficLights().size()); // North, South, East, West
        }
    }
    
    @Test
    void testStatisticsCollector() throws IOException {
        SimulationConfig config = new SimulationConfig("src/main/resources/simulation.properties");
        StatisticsCollector collector = new StatisticsCollector(config);
        
        Vehicle v1 = new Vehicle("V1", VehicleType.LIGHT, 0.0, 
            java.util.Arrays.asList("Cr1", "Cr2", "S"));
        
        collector.recordVehicleGeneration(v1, 0.0);
        assertEquals(1, collector.getTotalVehiclesGenerated());
        
        collector.recordVehicleArrival(v1, "Cr1", 1.0);
        
        collector.recordVehicleExit(v1, 10.0);
        assertEquals(1, collector.getTotalVehiclesCompleted());
    }
}