using UnityEngine;
using CnControls;

public enum SurfaceDetection
{
    RayCast,
    SphereCast
}

public class VehicleController : MonoBehaviour
{
    [SerializeField] float currentSpeed = 0f;
    [SerializeField] float steeringAI = 0f;
    [SerializeField] bool isAIControlled = false;
    [SerializeField] SurfaceDetection groundDetection = SurfaceDetection.RayCast;
    [SerializeField] LayerMask driveableSurface = -1;
    [SerializeField] float maxSpeed = 100f;
    [SerializeField] float baseAcceleration = 10f;
    [SerializeField] float steeringSensitivity = 10f;
    [SerializeField] float gravityForce = 9.8f;
    [SerializeField] float downforce = 5f;
    [SerializeField] float brakeThreshold = 30f;
    [SerializeField] float targetStoppingDistance = 5f;
    [SerializeField] bool allowAirControl = false;
    [SerializeField] AnimationCurve _frictionCurve = new AnimationCurve();
    [SerializeField] AnimationCurve _turnCurve = new AnimationCurve();

    [SerializeField, Range(0, 10)] float bodyTiltAmount = 0.5f;
    [SerializeField] Transform carBodyVisual = null;
    [SerializeField, Range(0.1f, 1f)] float skidMarkWidth = 0.25f;
    [SerializeField, Range(0.1f, 10f)] float skidMarkDuration = 5f;
    [SerializeField] Transform wheelFrontLeft = null;
    [SerializeField] Transform wheelFrontRight = null;
    [SerializeField] Transform wheelRearLeft = null;
    [SerializeField] Transform wheelRearRight = null;
    [SerializeField] Transform frontLeftAxle = null;
    [SerializeField] Transform frontRightAxle = null;
    [SerializeField] GameObject speedVisualEffects = null;

    [SerializeField] Rigidbody sphereRigidbody = null;
    [SerializeField] PhysicMaterial wheelFrictionMaterial = null;
    [SerializeField] Transform cameraFollowTarget = null;

    private bool isRunning = false;
    private bool isOnGround = false;
    private bool hasTurboBoost = true;
    public bool nosActive = false;

    private float accelerationInput = 0f;
    private float brakeInput = 0f;
    private float accelerationForce = 0f;
    private float steeringSign = 0f;
    private float inputHorizontal = 0f;
    private float inputVertical = 0f;
    private float wheelRadius = 0f;
    private float desiredTurnAngle = 0f;
    private float distanceToTarget = 0f;
    private float angleDifference = 0f;
    private float maxGroundDistance = 0f;
    private float counterSteerValue = 0f;
    private float steeringMultiplier = 0f;

    private Vector3 velocityLocal = Vector3.zero;
    private Vector3 forwardDirection = Vector3.zero;
    private Vector3 directionToTarget = Vector3.zero;
    private Vector3 movementDirection = Vector3.zero;

    private RaycastHit surfaceHit;
    private Rigidbody vehicleRigidbody = null;
    private VehicleTracker targetTracker = null;

    public bool AIControlled => isAIControlled;
    public bool Running => isRunning;
    public bool Grounded => isOnGround;
    public float SkidWidth => skidMarkWidth;
    public float SkidDuration => skidMarkDuration;
    public float CurrentSpeed => velocityLocal.z;
    public float MaximumSpeed => maxSpeed;
    public bool InputsActive => inputHorizontal != 0 || inputVertical != 0 || nosActive;
    public NOSController nosController; 
    [SerializeField] private CarData carData;

    internal float SteeringSensitivity
    {
        get => steeringSensitivity;
        set => steeringSensitivity = value;
    }

    public Vector3 LocalVelocity => velocityLocal;
    public Transform FollowTarget => cameraFollowTarget;
    [Range(0.3f, 1f)] public float steeringFactor = 1f;

    private void Awake()
    {
        vehicleRigidbody = GetComponent<Rigidbody>();
        targetTracker = GetComponent<VehicleTracker>();
        wheelRadius = sphereRigidbody.GetComponent<SphereCollider>().radius;
        nosController = GetComponent<NOSController>();
        //        maxGroundDistance = 1.1f;
        maxGroundDistance = wheelRadius + 0.5f;
        //InitializeVehicle();
    }
    public void InitializeWithData(CarData data)
    {
        carData = data;
        InitializeVehicle();
    }


    public void InitializeVehicle()
    {
        isRunning = true;

        if (carData != null)
        {
            maxSpeed = carData.maxSpeed;
            baseAcceleration = carData.acceleration;
            steeringSensitivity = carData.handling;
            downforce = carData.traction;

            // Optional: normalize handling (20–60 ➜ 0.0–1.0 range for internal use)
            steeringFactor = Mathf.InverseLerp(20f, 60f, carData.handling);
        }

        accelerationForce = baseAcceleration;
    }


    public void StopVehicle()
    {
        isRunning = false;
        velocityLocal = Vector3.zero;
        currentSpeed = 0f;
        steeringAI = 0f;
    }

    private void Update()
    {
        if (!isRunning) return;
        ProcessInputs();
        ApplyControls();
        UpdateVisuals();
    }

    private void FixedUpdate()
    {
        if (!isRunning) return;
        CheckGround();
        HandleMovement();
    }

    private void ProcessInputs()
    {
        if (isAIControlled)
        {
            // --- Get AI-relevant steering info ---
            Vector3 targetPoint = targetTracker.TargetPos;
            targetPoint.y = transform.position.y;

            Vector3 directionToTarget = (targetPoint - transform.position).normalized;
            float angleToTarget = Vector3.Angle(transform.forward, directionToTarget);
            float distanceToTarget = Vector3.Distance(transform.position, targetPoint);

            // --- Dynamic throttle logic ---
            if (distanceToTarget < targetStoppingDistance)
            {
                inputVertical = 0f; // Stop when close enough
            }
            else if (angleToTarget > 60f)
            {
                inputVertical = 0.3f; // Slow down for sharp turns
            }
            else if (angleToTarget > 30f)
            {
                inputVertical = 0.6f; // Moderate turn
            }
            else
            {
                inputVertical = 0.95f; // Full throttle
            }

            inputHorizontal = 0f; // Let AI use steeringAI instead
        }
        else
        {
            inputVertical = CnInputManager.GetAxis("Vertical");
            inputHorizontal = CnInputManager.GetAxis("Horizontal");
        }
    }


    private void UpdateVisuals()
    {
        counterSteerValue = (Mathf.Abs(velocityLocal.x) > 20f) ? -1f : 1f;
        float steerAngle = 45f * counterSteerValue * steeringAI;

        ApplySteeringRotation(wheelFrontLeft, steerAngle);
        ApplySteeringRotation(wheelFrontRight, steerAngle);

        float wheelSpin = CurrentSpeed * 0.75f;
        frontLeftAxle?.Rotate(Vector3.right * wheelSpin);
        frontRightAxle?.Rotate(Vector3.right * wheelSpin);
        wheelRearLeft?.Rotate(Vector3.right * wheelSpin);
        wheelRearRight?.Rotate(Vector3.right * wheelSpin);

        if (speedVisualEffects)
            speedVisualEffects.SetActive(velocityLocal.z > 10);
    }

    private void ApplySteeringRotation(Transform wheel, float steerAngle)
    {
        if (wheel == null) return;

        Quaternion targetRot = Quaternion.Euler(0f, steerAngle, 0f);
        wheel.localRotation = Quaternion.Slerp(wheel.localRotation, targetRot, 0.1f);
    }

    private void ApplyControls()
    {
        Vector3 targetPoint = targetTracker.TargetPos;
        targetPoint.y = transform.position.y;
        directionToTarget = (targetPoint - transform.position).normalized;
        forwardDirection = transform.forward.normalized;

        desiredTurnAngle = Mathf.Abs(Vector3.Angle(forwardDirection, Vector3.ProjectOnPlane(directionToTarget, transform.up)));
        distanceToTarget = Vector3.Distance(transform.position, targetTracker.TargetPos);
        movementDirection = (targetTracker.TargetPos - transform.position).normalized;
        float alignment = Vector3.Dot(transform.forward, movementDirection);
        angleDifference = Vector3.Angle(transform.forward, movementDirection);

        brakeInput = 0f;

        if (distanceToTarget > targetStoppingDistance)
        {
            accelerationInput = alignment > 0f ? inputVertical : (distanceToTarget > 5f ? inputVertical : -1f);
            steeringAI = (Vector3.SignedAngle(transform.forward, movementDirection, Vector3.up) > 0f ? 1f : -1f)
                        * _turnCurve.Evaluate(desiredTurnAngle / 160f);
        }
        else
        {
            steeringAI = 0f;
        }

        if (!isAIControlled)
            steeringAI += inputHorizontal;

        currentSpeed = Mathf.Round(CurrentSpeed);
    }

    private void CheckGround()
    {
        //isOnGround = true;

        if (groundDetection == SurfaceDetection.RayCast)
        {
            isOnGround = Physics.Raycast(sphereRigidbody.position, Vector3.down, out surfaceHit, maxGroundDistance, driveableSurface)
                      || Physics.Raycast(sphereRigidbody.position + Vector3.forward * 3f, Vector3.down, out surfaceHit, maxGroundDistance, driveableSurface)
                      || Physics.Raycast(sphereRigidbody.position - Vector3.forward * 3f, Vector3.down, out surfaceHit, maxGroundDistance, driveableSurface);
        }
        else if (groundDetection == SurfaceDetection.SphereCast)
        {
            isOnGround = Physics.SphereCast(sphereRigidbody.position + wheelRadius * Vector3.up, wheelRadius + 0.25f, -transform.up, out surfaceHit, maxGroundDistance, driveableSurface);
        }
        else isOnGround = false;
    }

    private void HandleMovement()
    {
        velocityLocal = vehicleRigidbody.transform.InverseTransformDirection(vehicleRigidbody.velocity);

        if (float.IsNaN(velocityLocal.z) || float.IsInfinity(velocityLocal.z))
        {
            velocityLocal = Vector3.zero;
        }

        if (angleDifference > brakeThreshold && velocityLocal.z > 15f)
        {
            wheelFrictionMaterial.dynamicFriction = 0.01f;
        }
        else
        {
            wheelFrictionMaterial.dynamicFriction = _frictionCurve.Evaluate(Mathf.Abs(velocityLocal.x / 100));
        }

        steeringMultiplier = _turnCurve.Evaluate(velocityLocal.magnitude / maxSpeed);

        if (Grounded)
        {
            steeringSign = Mathf.Sign(velocityLocal.z);

            if (Mathf.Abs(accelerationInput) > 0.1f)
                vehicleRigidbody.AddTorque(Vector3.up * (steeringAI * steeringSign * steeringSensitivity * 100f * steeringMultiplier * steeringFactor));

            if (Mathf.Abs(accelerationInput) > 0.1f)
                sphereRigidbody.velocity = Vector3.Lerp(sphereRigidbody.velocity, vehicleRigidbody.transform.forward * (accelerationInput * maxSpeed), accelerationForce / 10f * Time.fixedDeltaTime);

            sphereRigidbody.AddForce(-transform.up * (downforce * sphereRigidbody.mass));
            vehicleRigidbody.MoveRotation(
                Quaternion.Slerp(
                    vehicleRigidbody.rotation,
                    Quaternion.FromToRotation(vehicleRigidbody.transform.up, surfaceHit.normal) * vehicleRigidbody.transform.rotation,
                    0.12f
                )
            );
        }
        else
        {
            if (allowAirControl)
                vehicleRigidbody.AddTorque(Vector3.up * (steeringAI * steeringSensitivity * 100f * steeringMultiplier * steeringFactor));

            sphereRigidbody.velocity = Vector3.Lerp(
                sphereRigidbody.velocity,
                (vehicleRigidbody.transform.forward * (accelerationInput * maxSpeed)) + Vector3.down * (gravityForce * 9.8f),
                (accelerationForce / 25f) * Time.deltaTime
            );
        }
    }

    internal void DisableVehicle()
    {
        enabled = false;
        sphereRigidbody.gameObject.SetActive(false);
        sphereRigidbody.velocity = Vector3.zero;
        sphereRigidbody.Sleep();
        vehicleRigidbody.velocity = Vector3.zero;
        vehicleRigidbody.Sleep();
    }

    public void ActivateNOS()
    {
        ActivateNOS(true);
    }

    public void ActivateNOS(bool active, float bonusAcceleration = 10f)
    {
        nosActive = active;
        accelerationForce = active ? accelerationForce + bonusAcceleration : baseAcceleration;
    }

    internal void EnableVehicle()
    {
        enabled = true;
        sphereRigidbody.gameObject.SetActive(true);
    }
    private void OnCollisionEnter(Collision collision)
    {
        Debug.Log("collision with: " + collision.gameObject.name, collision.gameObject);
    }
}