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

namespace BaseGames.UI
{
    /// <summary>
    /// 工具栏 HUD（架构 09_ProgressionModule §7.5）。
    /// 显示 2 个工具槽的图标 + 剩余次数 + 冷却遮罩。
    /// </summary>
    public class ToolHUD : MonoBehaviour
    {
        [SerializeField] private ToolSlotUI[]            _slots;       // 2 个 ToolSlotUI 组件
        [SerializeField] private ToolUsedEventChannelSO   _onToolUsed;

        // 通过 ServiceLocator 解析：避免 UI 直接持有 ToolSlotManager 具体类型引用
        private IToolSlotService _slotManager;

        private readonly CompositeDisposable _subs = new();
        // 每个槽独立的冷却追踪协程；仅在冷却期间运行，避免每帧全槽轮询
        private Coroutine[] _cooldownCoroutines;

        private void Awake()
        {
            _cooldownCoroutines = _slots != null
                ? new Coroutine[_slots.Length]
                : System.Array.Empty<Coroutine>();
        }

        private void OnEnable()
        {
            _slotManager = ServiceLocator.GetOrDefault<IToolSlotService>();
            _onToolUsed?.Subscribe(RefreshSlot).AddTo(_subs);
        }

        private void OnDisable()
        {
            _subs.Clear();
            StopAllCoroutines();
            if (_cooldownCoroutines != null)
                for (int i = 0; i < _cooldownCoroutines.Length; i++)
                    _cooldownCoroutines[i] = null;
        }

        private void RefreshSlot(ToolUsedPayload payload)
        {
            int i = payload.SlotIndex;
            if (_slots == null || i < 0 || i >= _slots.Length) return;
            if (_slotManager == null) return;   // ToolSlotManager 尚未注册
            _slots[i].Refresh(
                _slotManager.GetTool(i),
                _slotManager.GetRemainingUses(i),
                _slotManager.GetCooldownRatio(i));

            // 启动（或重启）该槽的冷却追踪协程
            if (_cooldownCoroutines[i] != null) StopCoroutine(_cooldownCoroutines[i]);
            _cooldownCoroutines[i] = StartCoroutine(TrackCooldown(i));
        }

        /// <summary>
        /// 仅在该槽冷却未结束时每帧更新填充值；冷却归零后自动停止，不消耗额外 CPU。
        /// </summary>
        private System.Collections.IEnumerator TrackCooldown(int slotIndex)
        {
            while (_slotManager != null && _slotManager.GetCooldownRatio(slotIndex) > 0f)
            {
                _slots[slotIndex].SetCooldownFill(_slotManager.GetCooldownRatio(slotIndex));
                yield return null;
            }
            // 冷却结束，确保填充归零
            if (slotIndex < _slots.Length)
                _slots[slotIndex].SetCooldownFill(0f);
            _cooldownCoroutines[slotIndex] = null;
        }
    }

    /// <summary>
    /// 单个工具槽 UI：图标 + 剩余次数文本 + 冷却遮罩 Image（FillAmount）。
    /// </summary>
    public class ToolSlotUI : MonoBehaviour
    {
        [SerializeField] private Image    _icon;
        [SerializeField] private TMP_Text _usesText;
        [SerializeField] private Image    _cooldownMask;   // type = Filled, Image Type = Filled

        public void Refresh(BaseGames.Equipment.ToolSO tool, int remainingUses, float cooldownRatio)
        {
            if (_icon != null)
                _icon.sprite = tool != null ? tool.icon : null;

            if (_usesText != null)
                _usesText.text = remainingUses < 0 ? "∞" : remainingUses.ToString();

            SetCooldownFill(cooldownRatio);
        }

        public void SetCooldownFill(float ratio)
        {
            if (_cooldownMask != null)
                _cooldownMask.fillAmount = Mathf.Clamp01(ratio);
        }
    }
}