using UnityEngine;
using UnityEngine.UI;
using BaseGames.Core.Events;

namespace BaseGames.UI
{
    /// <summary>
    /// 输入设备图标切换器（架构 10_UIModule §12）。
    /// 订阅 EVT_InputDeviceChanged（BoolEventChannelSO，true = 手柄，false = 键鼠），
    /// 切换后广播给场景内所有 InputIconImage 组件。
    /// 通常挂在 UIRoot 或 UIManager 同一 GameObject 上。
    /// </summary>
    public class InputDeviceIconSwitcher : MonoBehaviour
    {
        [SerializeField] private InputDeviceIconSetSO _kbIconSet;
        [SerializeField] private InputDeviceIconSetSO _padIconSet;

        [Header("Event Channel")]
        [SerializeField] private BoolEventChannelSO _onDeviceChanged;  // EVT_InputDeviceChanged

        public static InputDeviceIconSetSO Current { get; private set; }

        private readonly CompositeDisposable _subs = new();

        private void Awake()     { Current = _kbIconSet; }
        private void OnEnable()  => _onDeviceChanged?.Subscribe(SwitchIconSet).AddTo(_subs);
        private void OnDisable() => _subs.Clear();

        private void SwitchIconSet(bool isGamepad)
        {
            Current = isGamepad ? _padIconSet : _kbIconSet;
            // 通知场景内所有图标 Image 刷新（包括非本对象子节点的其他 Canvas 区域）
            foreach (var img in FindObjectsByType<InputIconImage>(FindObjectsInactive.Include, FindObjectsSortMode.None))
                img.Refresh();
        }
    }

    // ─────────────────────────────────────────────────────────────────────────
    /// <summary>
    /// 单个按键图标 Image 组件。
    /// 记录 bindingPath，由 InputDeviceIconSwitcher 切换时自动刷新。
    /// </summary>
    [RequireComponent(typeof(Image))]
    public class InputIconImage : MonoBehaviour
    {
        [Tooltip("InputSystem 绑定路径，如 <Keyboard>/space 或 <Gamepad>/buttonSouth")]
        [SerializeField] private string _bindingPath;

        private Image _image;

        private void Awake() => _image = GetComponent<Image>();

        private void Start() => Refresh();

        public void Refresh()
        {
            if (_image == null || string.IsNullOrEmpty(_bindingPath)) return;
            var set = InputDeviceIconSwitcher.Current;
            if (set == null) return;
            var sprite = set.GetIcon(_bindingPath);
            if (sprite != null)
            {
                _image.sprite  = sprite;
                _image.enabled = true;
            }
        }
    }
}