using System.Collections.Generic;
using UnityEngine;

public class MoveAction : 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;
    [SerializeField] private int MaxMoveDistance = 4;
    private Unit unit;
    public Vector3 TargetPosition { get; set; }

    private void Awake() {
        unit = GetComponent<Unit>();
        TargetPosition = transform.position;
    }

    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);
        }
    }

    public bool IsValidActionGridPosition(GridPosition gridPosition) => GetValidActionGridPositionList().Contains(gridPosition);

    private List<GridPosition> GetValidActionGridPositionList() {
        List<GridPosition> validGridPositionList = new();
        GridPosition unitGridPosition = unit.GridPosition;
        for (int x = -MaxMoveDistance; x <= MaxMoveDistance; x++) {
            for (int z = -MaxMoveDistance; z <= MaxMoveDistance; z++) {
                GridPosition offsetGridPosition = new(x, z);
                GridPosition testGridPosition = unitGridPosition + offsetGridPosition;

                if (!LevelGrid.Instance.IsValidGridPosition(testGridPosition)) continue; //Only return valid grid positions
                if (unitGridPosition == testGridPosition) continue; //Same grid position where the unit is already at
                if (LevelGrid.Instance.HasAnyUnitOnGridPosition(testGridPosition)) continue; //Grid position already accopied with anther unit

                validGridPositionList.Add(testGridPosition);
            }
        }

        return validGridPositionList;
    }

    public void Move(GridPosition gridPosition) => TargetPosition = LevelGrid.Instance.GetWorldPosition(gridPosition);
}