using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using TMPro;
using BaseGames.Core.Events;

namespace BaseGames.UI.HUD
{
    public class HUDController : MonoBehaviour
    {
        [Header("HP")]
        [SerializeField] private Transform  _hpContainer;
        [SerializeField] private GameObject _hpCellPrefab;

        [Header("Gauges")]
        [SerializeField] private Image    _soulGaugeFill;
        [SerializeField] private Image    _spiritGaugeFill;
        [SerializeField] private TMP_Text _lingZhuText;

        [Header("Spring Charges")]
        [SerializeField] private Transform  _springContainer;
        [SerializeField] private GameObject _springIconPrefab;

        [Header("Form")]
        [SerializeField] private Image[] _formIcons;

        [Header("Interact Prompt")]
        [Tooltip("独立 Widget 组件负责渲染图标+文本，HUDController 仅保留引用供编辑器配置检查")]
        [SerializeField] private InteractPromptWidget _interactPromptWidget;

        [Header("Event Channels - Subscribe")]
        [SerializeField] private IntEventChannelSO    _onHPChanged;
        [SerializeField] private IntEventChannelSO    _onMaxHPChanged;
        [SerializeField] private IntEventChannelSO    _onSoulPowerChanged;
        [SerializeField] private IntEventChannelSO    _onSpiritPowerChanged;
        [SerializeField] private IntEventChannelSO    _onLingZhuChanged;
        [SerializeField] private IntEventChannelSO    _onSpringChargesChanged;
        [SerializeField] private IntEventChannelSO    _onFormChanged;

        private readonly List<GameObject> _hpCells     = new();
        private readonly List<GameObject> _springIcons = new();
        private readonly CompositeDisposable _subs = new();
        private int _lastLingZhu = int.MinValue;

        private void OnEnable()
        {
            _onHPChanged?.Subscribe(UpdateHP).AddTo(_subs);
            _onMaxHPChanged?.Subscribe(RebuildHPCells).AddTo(_subs);
            _onSoulPowerChanged?.Subscribe(UpdateSoul).AddTo(_subs);
            _onSpiritPowerChanged?.Subscribe(UpdateSpirit).AddTo(_subs);
            _onLingZhuChanged?.Subscribe(UpdateLingZhu).AddTo(_subs);
            _onSpringChargesChanged?.Subscribe(RebuildSpringIcons).AddTo(_subs);
            _onFormChanged?.Subscribe(UpdateFormIcon).AddTo(_subs);
            // 交互提示由独立的 InteractPromptWidget 组件处理，HUDController 不再直接订阅
        }

        private void OnDisable() => _subs.Clear();

        private void UpdateHP(int current)
        {
            for (int i = 0; i < _hpCells.Count; i++)
                if (_hpCells[i] != null) _hpCells[i].SetActive(i < current);
        }

        private void RebuildHPCells(int max)
        {
            if (_hpContainer == null || _hpCellPrefab == null) return;
            // 复用现有 Cell，仅在数量不足时 Instantiate 补充，超出时 SetActive(false) 而非 Destroy
            for (int i = 0; i < max; i++)
            {
                if (i < _hpCells.Count)
                    _hpCells[i].SetActive(true);
                else
                    _hpCells.Add(Instantiate(_hpCellPrefab, _hpContainer));
            }
            for (int i = max; i < _hpCells.Count; i++)
                if (_hpCells[i] != null) _hpCells[i].SetActive(false);
        }

        private void UpdateSoul(int val)
        {
            if (_soulGaugeFill != null) _soulGaugeFill.fillAmount = val / 100f;
        }

        private void UpdateSpirit(int val)
        {
            if (_spiritGaugeFill != null) _spiritGaugeFill.fillAmount = val / 100f;
        }

        private void UpdateLingZhu(int val)
        {
            if (_lingZhuText == null || val == _lastLingZhu) return;
            _lastLingZhu = val;
            _lingZhuText.text = val.ToString();
        }

        private void RebuildSpringIcons(int charges)
        {
            if (_springContainer == null || _springIconPrefab == null) return;
            // 复用已有图标，超出数量时 SetActive(false)
            for (int i = 0; i < charges; i++)
            {
                if (i < _springIcons.Count)
                    _springIcons[i].SetActive(true);
                else
                    _springIcons.Add(Instantiate(_springIconPrefab, _springContainer));
            }
            for (int i = charges; i < _springIcons.Count; i++)
                if (_springIcons[i] != null) _springIcons[i].SetActive(false);
        }

        private void UpdateFormIcon(int formIndex)
        {
            if (_formIcons == null) return;
            for (int i = 0; i < _formIcons.Length; i++)
                if (_formIcons[i] != null) _formIcons[i].enabled = (i == formIndex);
        }
    }
}