using System;

using System.Collections.Generic;

using NUnit.Framework;

​

public enum TrafficLightColor {

    Red,

    Yellow,

    Green

}

​

public class Intersection {

    public string Name { get; set; }

    public int[] SensorData { get; set; } // Vehicle density on each lane

    public bool EmergencyVehicleDetected { get; set; }

    public int PedestrianCount { get; set; }

​

    public Intersection(string name, int laneCount) {

        Name = name;

        SensorData = new int[laneCount];

    }

}

​

public class TrafficLight {

    public TrafficLightColor CurrentColor { get; set; }

    public int GreenDuration { get; set; } // Duration in seconds

}

​

public class SmartTrafficSystem

{

    private Dictionary<string, TrafficLight> trafficLights = new Dictionary<string, TrafficLight>();

    private Dictionary<string, Intersection> intersections = new Dictionary<string, Intersection>();

    private const int DefaultGreenDuration = 30;

    private const int MaxGreenDuration = 60;

    private const int MinGreenDuration = 10;

​

    public void AddIntersection(Intersection intersection, int numberOfLanes)

    {

        intersections[intersection.Name] = intersection;

        trafficLights[intersection.Name + "_Lane1"] = new TrafficLight { CurrentColor = TrafficLightColor.Red, GreenDuration = DefaultGreenDuration };

    }

​

    public void UpdateIntersectionData(string intersectionName, int[] sensorData, bool emergencyVehicleDetected, int pedestrianCount)

    {

        if (intersections.ContainsKey(intersectionName))

        {

            intersections[intersectionName].SensorData = sensorData;

            intersections[intersectionName].EmergencyVehicleDetected = emergencyVehicleDetected;

            intersections[intersectionName].PedestrianCount = pedestrianCount;

        }

    }

​

    public TrafficLightColor GetTrafficLightState(string intersectionName)

    {

       if(trafficLights.TryGetValue(intersectionName + "_Lane1", out var light))

       {

            return light.CurrentColor;

       }

        return TrafficLightColor.Red;

    }

​

    public int GetTrafficLightGreenDuration(string intersectionName)

    {

        if (trafficLights.TryGetValue(intersectionName + "_Lane1", out var light))

        {

            return light.GreenDuration;

        }

        return DefaultGreenDuration;

    }

​

    public void AdjustTrafficLights()

    {

        foreach (var intersectionPair in intersections)

        {

            string intersectionName = intersectionPair.Key;

            Intersection intersection = intersectionPair.Value;

​

            if (intersection.EmergencyVehicleDetected)

            {

                // Prioritize emergency vehicles

                trafficLights[intersectionName + "_Lane1"].CurrentColor = TrafficLightColor.Green;

                trafficLights[intersectionName + "_Lane1"].GreenDuration = MaxGreenDuration; // Give maximum green time

            }

            else

            {

                // Adjust based on vehicle density and pedestrian count

                int totalDensity = 0;

                foreach (int density in intersection.SensorData)

                {

                    totalDensity += density;

                }

​

                int baseDuration = DefaultGreenDuration;

​

                // Adjust for pedestrian count

                baseDuration += intersection.PedestrianCount / 10; // Example: 1 second extra per 10 pedestrians

                baseDuration = Math.Min(baseDuration, MaxGreenDuration); // Cap at max duration

​

                // Adjust for traffic density

                if (totalDensity > 50)

                {

                    baseDuration += 10;

                    baseDuration = Math.Min(baseDuration, MaxGreenDuration);

                }

​

                trafficLights[intersectionName + "_Lane1"].GreenDuration = baseDuration;

                trafficLights[intersectionName + "_Lane1"].CurrentColor = TrafficLightColor.Green; // Example - always setting to green for simplicity.

​

            }

        }

    }

}

​

​

public class SmartTrafficSystemTests

{

    [Test]

    public void EmergencyVehiclePrioritized()

    {

        SmartTrafficSystem trafficSystem = new SmartTrafficSystem();

        Intersection intersection = new Intersection("TestIntersection", 2);

        trafficSystem.AddIntersection(intersection, 2);

        trafficSystem.UpdateIntersectionData("TestIntersection", new int[] { 5, 5 }, true, 0);

        trafficSystem.AdjustTrafficLights();

​

        Assert.That(trafficSystem.GetTrafficLightState("TestIntersection"), Is.EqualTo(TrafficLightColor.Green));

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("TestIntersection"), Is.EqualTo(60));

    }

​

    [Test]

    public void HighPedestrianTrafficIncreasesCrossingTime()

    {

        SmartTrafficSystem trafficSystem = new SmartTrafficSystem();

        Intersection intersection = new Intersection("TestIntersection", 2);

        trafficSystem.AddIntersection(intersection, 2);

        trafficSystem.UpdateIntersectionData("TestIntersection", new int[] { 5, 5 }, false, 50);

        trafficSystem.AdjustTrafficLights();

​

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("TestIntersection"), Is.EqualTo(35)); // Default + 5 seconds for pedestrians

    }

​

    [Test]

    public void StandardTrafficFlowAdjustment()

    {

        SmartTrafficSystem trafficSystem = new SmartTrafficSystem();

        Intersection intersection = new Intersection("TestIntersection", 2);

        trafficSystem.AddIntersection(intersection, 2);

        trafficSystem.UpdateIntersectionData("TestIntersection", new int[] { 30, 30 }, false, 0);

        trafficSystem.AdjustTrafficLights();

​

        Assert.That(trafficSystem.GetTrafficLightState("TestIntersection"), Is.EqualTo(TrafficLightColor.Green));

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("TestIntersection"), Is.EqualTo(30));

        trafficSystem.UpdateIntersectionData("TestIntersection", new int[] { 60, 60 }, false, 0);

        trafficSystem.AdjustTrafficLights();

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("TestIntersection"), Is.EqualTo(40));

    }

​

    [Test]

    public void AddIntersection_AddsIntersectionAndTrafficLight()

    {

        // Arrange

        SmartTrafficSystem trafficSystem = new SmartTrafficSystem();

        Intersection intersection = new Intersection("Intersection1", 4);

​

        // Act

        trafficSystem.AddIntersection(intersection, 4);

​

        // Assert

        Assert.That(trafficSystem.GetTrafficLightState("Intersection1"), Is.EqualTo(TrafficLightColor.Red));

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("Intersection1"), Is.EqualTo(30));

    }

​

    [Test]

    public void UpdateIntersectionData_UpdatesDataCorrectly()

    {

        // Arrange

        SmartTrafficSystem trafficSystem = new SmartTrafficSystem();

        Intersection intersection = new Intersection("Intersection1", 4);

        trafficSystem.AddIntersection(intersection, 4);

​

        // Act

        int[] newSensorData = { 10, 20, 30, 40 };

        bool newEmergencyVehicleDetected = true;

        int newPedestrianCount = 15;

        trafficSystem.UpdateIntersectionData("Intersection1", newSensorData, newEmergencyVehicleDetected, newPedestrianCount);

​

        // Adjust traffic lights to reflect updated data.

        trafficSystem.AdjustTrafficLights();

​

        //Manually fetch data to verify that the system holds the data.  Since the properties are set directly and not exposed, this is harder to verify directly.  Verify through side effects.

        Assert.That(trafficSystem.GetTrafficLightState("Intersection1"), Is.EqualTo(TrafficLightColor.Green));

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("Intersection1"), Is.EqualTo(60)); // Due to emergency vehicle.

    }

​

     [Test]

    public void AdjustTrafficLights_SetsGreenLightAndCorrectDuration()

    {

        // Arrange

        SmartTrafficSystem trafficSystem = new SmartTrafficSystem();

        Intersection intersection = new Intersection("Intersection1", 4);

        trafficSystem.AddIntersection(intersection, 4);

​

        // Act

        int[] newSensorData = { 10, 20, 30, 40 };

        bool newEmergencyVehicleDetected = false;

        int newPedestrianCount = 15;

        trafficSystem.UpdateIntersectionData("Intersection1", newSensorData, newEmergencyVehicleDetected, newPedestrianCount);

​

        trafficSystem.AdjustTrafficLights();

​

        // Assert

        Assert.That(trafficSystem.GetTrafficLightState("Intersection1"), Is.EqualTo(TrafficLightColor.Green));

        Assert.That(trafficSystem.GetTrafficLightGreenDuration("Intersection1"), Is.EqualTo(31)); // default + 1 for pedestrians, capped at max.

    }

}

​

public static class Program

{

    public static void Main(string[] args)

    {

        new NUnitLite.AutoRun().Execute(["--noc" /*no colored output for .Net Fiddle*/]);

    }

}