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

namespace BaseGames.UI
{
    /// <summary>
    /// 图鉴面板（数据驱动，仿 <see cref="DataDrivenAbilityPanel"/>）。据 <see cref="BestiaryDatabaseSO"/> 列出全部敌人，
    /// 经 <see cref="IBestiaryService"/>(ServiceLocator) 读已发现态：已发现亮显，未发现 "???"+剪影+锁。
    /// 订阅 EVT_BestiaryUpdated 实时刷新；点击格子在右侧详情区展示名/描述/数值/击杀数；显示完成度 X/Y。
    /// 菜单态（无游戏，service=null）下全部显示未发现。
    /// </summary>
    public class BestiaryPanel : MonoBehaviour, IFocusable
    {
        [Header("数据 / 单元格")]
        [SerializeField] private BestiaryDatabaseSO _database;
        [Tooltip("敌人格的父节点（通常挂 GridLayoutGroup）。")]
        [SerializeField] private Transform          _container;
        [SerializeField] private BestiaryCellView   _cellPrefab;

        [Header("头部 / 关闭")]
        [Tooltip("完成度文本（X / Y）。")]
        [SerializeField] private TMP_Text _completionText;
        [SerializeField] private Button   _btnClose;

        [Header("详情区")]
        [SerializeField] private Image         _detailIcon;
        [SerializeField] private LocalizedText _detailName;
        [SerializeField] private TMP_Text      _detailDesc;
        [SerializeField] private TMP_Text      _detailStats;

        [Header("Event Channels")]
        [Tooltip("图鉴更新广播（payload=enemyId），用于实时刷新。对应 EVT_BestiaryUpdated。")]
        [SerializeField] private StringEventChannelSO _onBestiaryUpdated;

        private readonly List<(BestiaryCellView view, BestiaryDatabaseSO.Entry entry)> _cells = new();
        private readonly CompositeDisposable _subs = new();
        private IBestiaryService _service;

        private void Awake() => _btnClose?.onClick.AddListener(OnClose);

        private void OnEnable()
        {
            _onBestiaryUpdated?.Subscribe(_ => RefreshStates()).AddTo(_subs);
            _service = ServiceLocator.GetOrDefault<IBestiaryService>();   // 菜单态为 null → 全部未发现
            BuildList();
            ShowDetail(-1);
        }

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

        // ── 列表构建 ──────────────────────────────────────────────────────────
        public void BuildList()
        {
            ClearList();
            if (_database == null || _container == null || _cellPrefab == null) return;
            var entries = _database.Entries;
            if (entries == null) return;

            for (int i = 0; i < entries.Length; i++)
            {
                var entry = entries[i];
                var cell  = Instantiate(_cellPrefab, _container);
                cell.gameObject.SetActive(true);
                cell.Bind(entry.displayNameKey, entry.icon, IsDiscovered(entry));
                int idx = i;
                if (cell.SelectButton != null)
                    cell.SelectButton.onClick.AddListener(() => ShowDetail(idx));
                _cells.Add((cell, entry));
            }
            UpdateCompletion();
        }

        private void RefreshStates()
        {
            if (_service == null) _service = ServiceLocator.GetOrDefault<IBestiaryService>();
            foreach (var (view, entry) in _cells)
                if (view != null) view.SetDiscovered(IsDiscovered(entry));
            UpdateCompletion();
        }

        private bool IsDiscovered(BestiaryDatabaseSO.Entry entry)
            => _service != null && _service.IsDiscovered(entry.enemyId);

        private void UpdateCompletion()
        {
            if (_completionText == null) return;
            int total = _database != null && _database.Entries != null ? _database.Entries.Length : 0;
            int found = 0;
            foreach (var (_, entry) in _cells) if (IsDiscovered(entry)) found++;
            _completionText.text = $"{found} / {total}";
        }

        // ── 详情 ──────────────────────────────────────────────────────────────
        private void ShowDetail(int index)
        {
            bool valid = index >= 0 && index < _cells.Count;
            var entry = valid ? _cells[index].entry : default;
            bool discovered = valid && IsDiscovered(entry);

            if (_detailIcon != null)
            {
                _detailIcon.sprite  = discovered ? entry.icon : null;
                _detailIcon.enabled = discovered && entry.icon != null;
            }
            if (_detailName != null)
                _detailName.SetKey(!valid ? "" : (discovered ? entry.displayNameKey : "BESTIARY_LOCKED"));

            if (_detailDesc != null)
            {
                if (!valid) _detailDesc.text = "";
                else if (!discovered) _detailDesc.text = LocalizationManager.Get("BESTIARY_LOCKED_DESC", LocalizationTable.UI);
                else
                {
                    string d = LocalizationManager.Get(entry.descKey, LocalizationTable.UI);
                    _detailDesc.text = string.IsNullOrEmpty(d) || d == entry.descKey ? "" : d;
                }
            }

            if (_detailStats != null)
            {
                if (!valid || !discovered) { _detailStats.text = ""; }
                else
                {
                    int kills = _service != null ? _service.GetKillCount(entry.enemyId) : 0;
                    string hpLabel   = LocalizationManager.Get("BESTIARY_HP",    LocalizationTable.UI);
                    string killLabel = LocalizationManager.Get("BESTIARY_KILLS", LocalizationTable.UI);
                    var sb = new System.Text.StringBuilder();
                    if (entry.displayMaxHP > 0) sb.Append(hpLabel).Append(' ').Append(entry.displayMaxHP).Append("    ");
                    sb.Append(killLabel).Append(' ').Append(kills);
                    _detailStats.text = sb.ToString();
                }
            }
        }

        private void ClearList()
        {
            _cells.Clear();
            if (_container == null) return;
            for (int i = _container.childCount - 1; i >= 0; i--)
            {
                var c = _container.GetChild(i).gameObject;
                if (Application.isPlaying) Destroy(c); else DestroyImmediate(c);
            }
        }

        private void OnClose()
        {
            var uiMgr = ServiceLocator.GetOrDefault<UIManager>();
            if (uiMgr != null) uiMgr.CloseTopPanel();
            else gameObject.SetActive(false);
        }

        // ── IFocusable ────────────────────────────────────────────────────────
        public void OnFocusRestored()
        {
            GameObject target = _cells.Count > 0 && _cells[0].view != null && _cells[0].view.SelectButton != null
                ? _cells[0].view.SelectButton.gameObject
                : _btnClose != null ? _btnClose.gameObject : null;
            if (target != null) EventSystem.current?.SetSelectedGameObject(target);
        }
    }
}