using UnityEngine;
using UnityEngine.AI;

[RequireComponent(typeof(NavMeshAgent))]
public class NavMeshMovementController : MonoBehaviour
{
    [Header("Movement")]
    public float stopDistanceTolerance = 0.1f;
    
    [Header("Rotation")]
    public bool enableSmartRotation = true;
    public float rotationSpeed = 10f;

    NavMeshAgent agent;
    Vector3 lastVelocity = Vector3.zero;
    Vector3? lookAtTarget = null; // Optional target to face when stopped

    void Awake()
    {
        agent = GetComponent<NavMeshAgent>();
        if (agent != null)
        {
            agent.updateRotation = false; // We handle rotation manually
        }
    }

    void Update()
    {
        if (agent == null) return;

        // Update rotation based on movement direction
        if (enableSmartRotation)
        {
            Vector3 vel = agent.velocity;
            if (vel.sqrMagnitude > 0.01f)
            {
                // Moving - rotate toward movement direction
                Quaternion targetRot = Quaternion.LookRotation(vel.normalized);
                transform.rotation = Quaternion.Slerp(transform.rotation, targetRot, rotationSpeed * Time.deltaTime);
            }
            else if (lookAtTarget.HasValue)
            {
                // Stopped - rotate toward look target if set
                Vector3 directionToTarget = (lookAtTarget.Value - transform.position).normalized;
                if (directionToTarget.sqrMagnitude > 0.01f)
                {
                    directionToTarget.y = 0; // Keep rotation on horizontal plane
                    Quaternion targetRot = Quaternion.LookRotation(directionToTarget);
                    transform.rotation = Quaternion.Slerp(transform.rotation, targetRot, rotationSpeed * Time.deltaTime);
                }
            }
            lastVelocity = vel;
        }

        // Auto-stop when reaching destination
        if (!agent.pathPending && agent.remainingDistance <= agent.stoppingDistance + stopDistanceTolerance)
        {
            agent.isStopped = true;
        }
    }

    public void MoveTo(Vector3 worldPosition)
    {
        if (agent == null) return;
        agent.isStopped = false;
        agent.SetDestination(worldPosition);
        lookAtTarget = null; // Clear look target when starting new movement
    }

    public void MoveToAndLookAt(Vector3 worldPosition, Vector3 lookTarget)
    {
        if (agent == null) return;
        agent.isStopped = false;
        agent.SetDestination(worldPosition);
        lookAtTarget = lookTarget; // Set look target for when we arrive
    }

    public void Stop()
    {
        if (agent == null) return;
        agent.isStopped = true;
    }

    public void SetLookTarget(Vector3 target)
    {
        lookAtTarget = target;
    }

    public void ClearLookTarget()
    {
        lookAtTarget = null;
    }

    public bool IsAtDestination(float tolerance = 0.1f)
    {
        if (agent == null) return true;
        return !agent.pathPending && agent.remainingDistance <= agent.stoppingDistance + tolerance;
    }

    public Vector3 GetVelocity() => lastVelocity;

    public float GetSpeed() => agent != null ? agent.velocity.magnitude : 0f;
}