using GameCore.ECS;
using GameCore.ECS.Interfaces;
using GameCore.Events;
using GameCore.Input;
using GameCore.Player;

namespace GameCore.Combat;

public class WeaponSwapSystem : ISystem
{
    public void Update(World world, float deltaTime)
    {
        var entities = world.GetEntitiesWith<InputStateComponent>();
        foreach (var entity in entities)
        {
            var input = world.GetComponent<InputStateComponent>(entity);
            var equipment = world.GetComponent<EquipmentComponent>(entity);

            if (input == null || equipment == null || equipment.EquippableWeaponItemIds.Count <= 1)
                continue;

            var direction = SwapDirection.None;
            if (input.IsSwapWeaponNext) direction = SwapDirection.Next;
            if (input.IsSwapWeaponPrevious) direction = SwapDirection.Previous;

            if (direction != SwapDirection.None)
            {
                var newIndex = equipment.CurrentWeaponIndex + (int)direction;
                var weaponCount = equipment.EquippableWeaponItemIds.Count;

                if (newIndex >= weaponCount) newIndex = 0;
                if (newIndex < 0) newIndex = weaponCount - 1;

                if (newIndex != equipment.CurrentWeaponIndex)
                {
                    equipment.CurrentWeaponIndex = newIndex;
                    var newWeaponId = equipment.EquippableWeaponItemIds[newIndex];
                    world.PublishEvent(new EquipWeaponEvent(entity, newWeaponId));
                }
            }
        }
    }

    private enum SwapDirection
    {
        None = 0,
        Next = 1,
        Previous = -1
    }
}