using UnityEngine;

public class Unit : MonoBehaviour {
    private const float moveSpeed = 4f;
    private const float rotationSpeed = 10f;
    private const float stoppingDistance = 0.1f;
    private static readonly int isWalking = Animator.StringToHash("IsWalking");

    [SerializeField] private Animator UnitAnimator;

    private Vector3 targetPosition;
    public GridPosition GridPosition { get; private set; }

    private void Awake() => targetPosition = transform.position;

    private void Start() {
        GridPosition = LevelGrid.Instance.GetGridPosition(transform.position);
        LevelGrid.Instance.AddUnitAtGridPosition(GridPosition, this);
    }

    private void Update() {
        if (Vector3.Distance(targetPosition, transform.position) > stoppingDistance) {
            Vector3 moveDirection = (targetPosition - transform.position).normalized;
            transform.position += moveSpeed * Time.deltaTime * moveDirection;
            transform.forward = Vector3.Lerp(transform.forward, moveDirection, rotationSpeed * Time.deltaTime);
            UnitAnimator.SetBool(isWalking, true);
        }
        else {
            UnitAnimator.SetBool(isWalking, false);
        }

        GridPosition newGridPosition = LevelGrid.Instance.GetGridPosition(transform.position);
        if (newGridPosition != GridPosition) {
            LevelGrid.Instance.UnitMovedGridPosition(this, GridPosition, newGridPosition);
            GridPosition = newGridPosition;
        }
    }

    public void Move(Vector3 newTargetPosition) => targetPosition = newTargetPosition;
}