using UnityEngine;

public enum DriveType { FWD, RWD, AWD }

public class CarController : MonoBehaviour
{
    public float SpeedKmH => rb.linearVelocity.magnitude * 3.6f;
    
    [Header("Drive Settings")]
    public DriveType driveType = DriveType.AWD;
    [SerializeField] private float motorForce = 1500f;
    [SerializeField] private float brakeForce = 3000f;
    [SerializeField] private float maxSteerAngle = 30f;

    [Header("Grip Settings (Friction Stiffness)")]
    [Tooltip("Сцепление для переднего привода (FWD)")]
    [SerializeField] private float fwdFrontGrip = 1.2f;
    [SerializeField] private float fwdRearGrip = 2.0f;

    [Tooltip("Сцепление для заднего привода (RWD)")]
    [SerializeField] private float rwdFrontGrip = 2.0f;
    [SerializeField] private float rwdRearGrip = 1.2f; 

    [Tooltip("Сцепление для полного привода (AWD)")]
    [SerializeField] private float awdFrontGrip = 2.5f;
    [SerializeField] private float awdRearGrip = 2.5f;
    
    [Header("Wheel Colliders")]
    [SerializeField] private WheelCollider frontLeftCollider;
    [SerializeField] private WheelCollider frontRightCollider;
    [SerializeField] private WheelCollider rearLeftCollider;
    [SerializeField] private WheelCollider rearRightCollider;

    [Header("Wheel Meshes")]
    [SerializeField] private Transform frontLeftMesh;
    [SerializeField] private Transform frontRightMesh;
    [SerializeField] private Transform rearLeftMesh;
    [SerializeField] private Transform rearRightMesh;

    private Rigidbody rb;
    
    // Входящие данные от игрока
    private float inputVertical;
    private float inputHorizontal;
    private bool inputHandbrake;

    private void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    public void ProcessInput(float vertical, float horizontal, bool handbrake)
    {
        inputVertical = vertical;
        inputHorizontal = horizontal;
        inputHandbrake = handbrake;
    }

    private void FixedUpdate()
    {
        HandleSteering();
        HandleMotorAndBrakes();
        UpdateWheelPoses();
    }

    private void HandleSteering()
    {
        float steerAngle = maxSteerAngle * inputHorizontal;
        frontLeftCollider.steerAngle = steerAngle;
        frontRightCollider.steerAngle = steerAngle;
    }

    private void HandleMotorAndBrakes()
    {
        float currentMotorTorque = 0f;
        float currentBrakeTorque = 0f;

        // Определяем, куда физически движется машина (вперед или назад)
        float localVelocityZ = transform.InverseTransformDirection(rb.linearVelocity).z;

        // ЛОГИКА ГАЗА (W)
        if (inputVertical > 0)
        {
            if (localVelocityZ < -1f) // Если катимся назад, а жмем W -> Тормозим
                currentBrakeTorque = brakeForce;
            else // Иначе едем вперед
                currentMotorTorque = inputVertical * motorForce;
        }
        // ЛОГИКА ТОРМОЗА И ЗАДНЕГО ХОДА (S)
        else if (inputVertical < 0)
        {
            if (localVelocityZ > 1f) // Если едем вперед, а жмем S -> Тормозим
                currentBrakeTorque = brakeForce;
            else // Иначе сдаем назад (inputVertical отрицательный, поэтому момент тоже отрицательный)
                currentMotorTorque = inputVertical * motorForce;
        }

        // ЛОГИКА РУЧНИКА (Пробел)
        if (inputHandbrake)
        {
            currentMotorTorque = 0f; // Глушим газ
            currentBrakeTorque = brakeForce * 2f; // Ручник хватает сильнее обычного тормоза
        }

        ApplyBrakes(currentBrakeTorque, inputHandbrake);
        ApplyMotor(currentMotorTorque);
    }
    
    private void ApplyMotor(float torque)
    {
        // Получаем базовые настройки трения
        WheelFrictionCurve frontFriction = frontLeftCollider.sidewaysFriction;
        WheelFrictionCurve rearFriction = rearLeftCollider.sidewaysFriction;

        switch (driveType)
        {
            case DriveType.FWD: 
                frontLeftCollider.motorTorque = torque;
                frontRightCollider.motorTorque = torque;
                rearLeftCollider.motorTorque = 0;
                rearRightCollider.motorTorque = 0;

                frontFriction.stiffness = fwdFrontGrip;
                rearFriction.stiffness = fwdRearGrip; 
                break;

            case DriveType.RWD: 
                frontLeftCollider.motorTorque = 0;
                frontRightCollider.motorTorque = 0;
                rearLeftCollider.motorTorque = torque;
                rearRightCollider.motorTorque = torque;

                frontFriction.stiffness = rwdFrontGrip;
                rearFriction.stiffness = rwdRearGrip; 
                break;

            case DriveType.AWD: 
                float halfTorque = torque / 2f;
                frontLeftCollider.motorTorque = halfTorque;
                frontRightCollider.motorTorque = halfTorque;
                rearLeftCollider.motorTorque = halfTorque;
                rearRightCollider.motorTorque = halfTorque;

                frontFriction.stiffness = awdFrontGrip;
                rearFriction.stiffness = awdRearGrip;
                break;
        }

        // Применяем измененное трение к колесам
        frontLeftCollider.sidewaysFriction = frontFriction;
        frontRightCollider.sidewaysFriction = frontFriction;
        rearLeftCollider.sidewaysFriction = rearFriction;
        rearRightCollider.sidewaysFriction = rearFriction;
    }

    private void ApplyBrakes(float brake, bool isHandbrake)
    {
        if (isHandbrake)
        {
            // Ручник блокирует только задние колеса (эффект заноса)
            frontLeftCollider.brakeTorque = 0;
            frontRightCollider.brakeTorque = 0;
            rearLeftCollider.brakeTorque = brake;
            rearRightCollider.brakeTorque = brake;
        }
        else
        {
            // Обычный тормоз (S) срабатывает на все колеса, передок сильнее
            frontLeftCollider.brakeTorque = brake;
            frontRightCollider.brakeTorque = brake;
            rearLeftCollider.brakeTorque = brake * 0.5f;
            rearRightCollider.brakeTorque = brake * 0.5f;
        }
    }

    private void UpdateWheelPoses()
    {
        UpdateWheelPose(frontLeftCollider, frontLeftMesh);
        UpdateWheelPose(frontRightCollider, frontRightMesh);
        UpdateWheelPose(rearLeftCollider, rearLeftMesh);
        UpdateWheelPose(rearRightCollider, rearRightMesh);
    }

    private void UpdateWheelPose(WheelCollider collider, Transform mesh)
    {
        if (mesh == null) return;
        collider.GetWorldPose(out Vector3 pos, out Quaternion rot);
        mesh.position = pos;
        mesh.rotation = rot;
    }
}