using UnityEngine;
using UnityEngine.AI;
using UnityEngine.InputSystem;

public enum MovementType
{
    PointAndClick,
    DirectionalInput
}

[RequireComponent(typeof(NavMeshAgent))]
public class PlayerMovement : MonoBehaviour
{
    [Header("Movement Settings")]
    [SerializeField] private float lookSpeed = 10f;
    [SerializeField] private float gamepadRotationSpeed = 300f;
    [SerializeField] private float minimumInputThreshold = 0.1f;
    [SerializeField] private MovementType movementType = MovementType.DirectionalInput;
    [SerializeField] private BoolSharedField directionalInputMode;
    public BoolSharedField DirectionalInputMode => directionalInputMode;

    [Header("Controller Settings")]
    [SerializeField] private float gamepadDeadzone = 0.2f;

    [Header("Debug Visualization")]
    [SerializeField] private bool showDebugVisuals = false;

    // Input System variables
    private PlayerInput playerInput;
    private Vector2 moveInput;
    private Vector2 aimInput;
    private bool isMouseAiming;

    private Transform target;
    private NavMeshAgent agent;
    private Vector3 direction = Vector3.zero;
    private Quaternion lookRotation = Quaternion.identity;
    private Camera mainCamera;
    private Plane groundPlane;
    private Vector3 lastAimDirection;
    private bool isUsingGamepad;
    private Vector3 currentMoveDirection;
    private bool isMoving;
    private ProjectileSpawnLocationController aimController;
    private Vector3 currentAimPoint;

    public Vector2 currentMovementDirection = new Vector2();
    public Vector2 currentAimDirection = new Vector2();
    public Vector2 lastAimDirection2 = new Vector2();
    public Vector2 relativeMovementDirection = new Vector2();

    private Vector3 mouseAimPoint;
    private bool hasMouseAimPoint;

    private float startingAgentSpeed;
    public float StartingAgentSpeed => startingAgentSpeed;

    private float startingAgentAngularSpeed;
    public float StartingAgentAngularSpeed => startingAgentAngularSpeed;

    private float startingAgentAcceleration;
    public float StartingAgentAcceleration => startingAgentAcceleration;

    private void Awake()
    {
        agent = GetComponent<NavMeshAgent>();
        mainCamera = Camera.main;
        groundPlane = new Plane(Vector3.up, Vector3.zero);
        aimController = GetComponentInChildren<ProjectileSpawnLocationController>();
        lastAimDirection = transform.forward;
        directionalInputMode.Value = true;
        movementType = MovementType.DirectionalInput;

        startingAgentSpeed = agent.speed;
        startingAgentAngularSpeed = agent.angularSpeed;
        startingAgentAcceleration = agent.acceleration;

        // Initialize Input System
        playerInput = GetComponent<PlayerInput>();
        if (playerInput == null)
        {
            Debug.LogWarning("PlayerInput component not found. Add PlayerInput component to use Input System.");
        }
    }

    void Start()
    {
        SetupAgentForDirectionalMovement();
    }

    // Input callbacks - these will be called by Unity's SendMessage system
    public void OnMove(InputValue value)
    {
        moveInput = value.Get<Vector2>();
        currentMovementDirection = moveInput;
    }

    public void OnStick(InputValue value)
    {
        aimInput = value.Get<Vector2>();
        currentAimDirection = aimInput;

        // Detect gamepad usage
        if (aimInput.magnitude > gamepadDeadzone)
        {
            isUsingGamepad = true;
            hasMouseAimPoint = false;
        }
    }

    public void OnLook(InputValue value)
    {
        // This gets called when mouse moves, indicating mouse usage
        isUsingGamepad = false;
    }

    private void Update()
    {
        SetMovementType(directionalInputMode.Value ? MovementType.DirectionalInput : MovementType.PointAndClick);

        if (movementType == MovementType.DirectionalInput)
        {
            // Handle movement
            HandleDirectionalMovement();

            // Handle aiming based on input method
            if (!isUsingGamepad)
            {
                HandleMouseAiming();
            }
            else
            {
                HandleGamepadAiming();
            }

            HandleRelativeForAnimation();
        }
        else if (target != null)
        {
            HandlePointAndClickMovement();
        }

        // Handle channeled ability rotation
        if (CastBarHandler.Instance.currentAbility is ChanneledAbility &&
            CastBarHandler.Instance.castBar.activeSelf)
        {
            var channelAbility = (ChanneledAbility)CastBarHandler.Instance.currentAbility;
            if (channelAbility.allowAiming)
            {
                InstantFaceCast(aimController.GetLookat());
            }
        }
    }

    private void HandleDirectionalMovement()
    {
        if (agent.isStopped) return;

        Vector3 cameraForward = mainCamera.transform.forward;
        Vector3 cameraRight = mainCamera.transform.right;
        cameraForward.y = 0f;
        cameraRight.y = 0f;
        cameraForward.Normalize();
        cameraRight.Normalize();

        currentMoveDirection = (cameraForward * currentMovementDirection.y +
                              cameraRight * currentMovementDirection.x).normalized;
        isMoving = currentMoveDirection.magnitude >= minimumInputThreshold;

        if (isMoving)
        {
            agent.SetDestination(transform.position + currentMoveDirection);
        }
        else
        {
            agent.velocity = Vector3.zero;
            agent.SetDestination(transform.position);
        }

        // If we're using mouse aim, maintain character rotation even while moving
        if (!isUsingGamepad && hasMouseAimPoint)
        {
            Vector3 aimDirection = (mouseAimPoint - transform.position).normalized;
            if (aimDirection != Vector3.zero)
            {
                transform.rotation = Quaternion.LookRotation(aimDirection);
            }
        }
    }

    private void HandleGamepadAiming()
    {
        if (currentAimDirection.magnitude > gamepadDeadzone)
        {
            Vector3 cameraForward = mainCamera.transform.forward;
            Vector3 cameraRight = mainCamera.transform.right;
            cameraForward.y = 0f;
            cameraRight.y = 0f;

            Vector3 aimDirection = (cameraForward * currentAimDirection.y + cameraRight * currentAimDirection.x).normalized;
            lastAimDirection = aimDirection;
            lastAimDirection2.x = aimDirection.x;
            lastAimDirection2.y = aimDirection.z;

            Quaternion targetRotation = Quaternion.LookRotation(aimDirection);
            transform.rotation = Quaternion.RotateTowards(
                transform.rotation,
                targetRotation,
                gamepadRotationSpeed * Time.deltaTime
            );
        }
        else if (lastAimDirection != Vector3.zero)
        {
            Quaternion targetRotation = Quaternion.LookRotation(lastAimDirection);
            transform.rotation = Quaternion.RotateTowards(
                transform.rotation,
                targetRotation,
                gamepadRotationSpeed * Time.deltaTime
            );
        }
    }

    private void HandleRelativeForAnimation()
    {
        // Calculate forward/backward movement relative to aim direction
        relativeMovementDirection.y = Vector2.Dot(lastAimDirection2, currentMovementDirection);

        // Calculate strafe movement relative to aim direction
        relativeMovementDirection.x = lastAimDirection2.x * currentMovementDirection.y -
                                    lastAimDirection2.y * currentMovementDirection.x;
    }

    private void HandleMouseAiming()
    {
        // Get the current mouse position directly from the Input System
        Vector3 screenMousePosition = Mouse.current.position.ReadValue();
        Ray ray = mainCamera.ScreenPointToRay(screenMousePosition);

        if (groundPlane.Raycast(ray, out float distance))
        {
            mouseAimPoint = ray.GetPoint(distance);
            mouseAimPoint.y = transform.position.y;
            hasMouseAimPoint = true;

            Vector3 aimDirection = (mouseAimPoint - transform.position).normalized;
            if (aimDirection != Vector3.zero)
            {
                lastAimDirection = aimDirection;
                lastAimDirection2.x = aimDirection.x;
                lastAimDirection2.y = aimDirection.z;

                transform.rotation = Quaternion.LookRotation(aimDirection);
            }
        }
    }

    private void HandlePointAndClickMovement()
    {
        agent.SetDestination(target.position);
        FacePoint(agent.destination);
    }

    private void SetupAgentForDirectionalMovement()
    {
        agent.updateRotation = false;
        agent.stoppingDistance = 0f;
        agent.acceleration = startingAgentAcceleration;
        agent.angularSpeed = startingAgentAngularSpeed;
    }

    #region Public Methods

    public void SetMovementType(MovementType type)
    {
        movementType = type;
        if (movementType == MovementType.DirectionalInput)
        {
            SetupAgentForDirectionalMovement();
        }
        else
        {
            agent.updateRotation = true;
            agent.stoppingDistance = 0.25f;
            agent.acceleration = startingAgentAcceleration;
            agent.angularSpeed = startingAgentAngularSpeed;
        }
    }

    public void ToggleAgentMoving(bool busy)
    {
        agent.isStopped = busy;
        if (busy)
        {
            agent.SetDestination(transform.position);
        }
    }

    public void MoveToPoint(Vector3 point)
    {
        agent.SetDestination(point);
        FacePoint(point);
    }

    public void FollowTarget(Interactable newTarget)
    {
        agent.stoppingDistance = newTarget.radius * 0.8f;
        agent.updateRotation = false;
        target = newTarget.interactionTransform;
        FaceTarget();
    }

    public void StopFollowingTarget()
    {
        agent.stoppingDistance = 0f;
        agent.updateRotation = true;
        target = null;
    }

    public void FaceAttack(int index)
    {
        if (target != null)
            FaceTarget();
    }

    public void FacePoint(Vector3 point)
    {
        direction = (point - transform.position).normalized;
        direction.y = 0f;
        lookRotation = Quaternion.LookRotation(direction);
        transform.rotation = Quaternion.Slerp(transform.rotation, lookRotation, Time.deltaTime * lookSpeed);
    }

    public void FaceTarget()
    {
        if (target == null) return;

        direction = (target.position - transform.position).normalized;
        direction.y = 0f;
        lookRotation = Quaternion.LookRotation(direction);
        transform.rotation = Quaternion.Slerp(transform.rotation, lookRotation, Time.deltaTime * lookSpeed);
    }

    public void InstantFaceTarget()
    {
        if (target != null)
        {
            direction = (target.position - transform.position).normalized;
            direction.y = 0f;
            lookRotation = Quaternion.LookRotation(direction);
            transform.rotation = lookRotation;
        }
    }

    public void InstantFaceCast(Vector3 lookat)
    {
        transform.forward = lookat;
    }

    public void StopLocomotion(int index)
    {
        StopFollowingTarget();
        agent.SetDestination(transform.position);
    }

    #endregion

    #region Debug

    private void OnDrawGizmos()
    {
        if (!showDebugVisuals) return;

        // Draw movement direction
        Gizmos.color = Color.blue;
        Gizmos.DrawRay(transform.position, currentMoveDirection * 2f);

        // Draw aim direction
        Gizmos.color = Color.red;
        Gizmos.DrawRay(transform.position, lastAimDirection * 2f);

        // Draw aim point if using mouse
        if (!isUsingGamepad)
        {
            Gizmos.color = Color.yellow;
            Gizmos.DrawWireSphere(currentAimPoint, 0.2f);
        }
    }

    #endregion
}