using System;
using Actions;
using Grid;
using UnityEngine;

public class Unit : MonoBehaviour {
    private const int ACTION_POINTS_MAX = 2;
    private int actionPoints = ACTION_POINTS_MAX;
    
    [SerializeField] private bool isEnemy;

    public GridPosition GridPosition { get; private set; }
    public MoveAction MoveAction { get; private set; }
    public SpinAction SpinAction { get; private set; }
    public BaseAction[] BaseActionArray { get; private set; }

    public int ActionPoints {
        get => actionPoints;
        private set {
            actionPoints = value;
            OnAnyActionPointsChanged?.Invoke(this, EventArgs.Empty);
        }
    }

    public bool IsEnemy => isEnemy;

    private void Awake() {
        MoveAction = GetComponent<MoveAction>();
        SpinAction = GetComponent<SpinAction>();
        BaseActionArray = GetComponents<BaseAction>();
    }

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

    private void Update() {
        GridPosition newGridPosition = LevelGrid.Instance.GetGridPosition(transform.position);
        if (newGridPosition == GridPosition) return;

        LevelGrid.Instance.UnitMovedGridPosition(this, GridPosition, newGridPosition);
        GridPosition = newGridPosition;
    }

    public static event EventHandler OnAnyActionPointsChanged;

    private void TurnSystem_OnTurnChanged(object sender, EventArgs e) {
        if (IsEnemy ^ TurnSystem.Instance.IsPlayerTurn || TurnSystem.Instance.IsPlayerTurn ^ IsEnemy) {
            ActionPoints = ACTION_POINTS_MAX;
        }
    }

    public bool TrySpendActionPointsToTakeAction(BaseAction baseAction) {
        if (!CanSpendActionPointsToTakeAction(baseAction)) return false;

        SpendActionPoints(baseAction.GetActionPointsCost());
        return true;
    }

    private bool CanSpendActionPointsToTakeAction(BaseAction baseAction) => ActionPoints >= baseAction.GetActionPointsCost();

    private void SpendActionPoints(int amount) => ActionPoints -= amount;

    public void Damage() => Debug.Log($"{transform} damaged!");

    public Vector3 GetWorldPosition() => transform.position;
}