using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using BaseGames.Core;
using BaseGames.Localization;

namespace BaseGames.UI.Settings
{
    /// <summary>
    /// 数据驱动设置面板：据 <see cref="SettingsSchemaSO"/> 生成控件行并绑定 <see cref="ISettingsService"/>。
    ///
    /// 取代硬编码的 <see cref="BaseGames.UI.SettingsPanelController"/>：策划改表即可增删 / 重排 / 改标签 / 分节，
    /// 无需改代码。每行据 <see cref="SettingKey"/> 自动选用 Slider / Toggle / Dropdown 行预制件，
    /// 并复用通用控件 <see cref="UISlider"/> / <see cref="UIDropdown"/>。
    ///
    /// 控件来源：行预制件由 <c>SettingsPanelScaffold</c> 生成（标签为 <see cref="LocalizedText"/>）。
    /// </summary>
    public class DataDrivenSettingsPanel : UIPanelBase
    {
        public enum ControlKind { Slider, Toggle, Dropdown }

        [Header("数据表")]
        [SerializeField] private SettingsSchemaSO _schema;

        [Header("行布局")]
        [Tooltip("生成的行的父节点（通常挂 VerticalLayoutGroup）。")]
        [SerializeField] private Transform  _container;
        [SerializeField] private GameObject _headerPrefab;
        [SerializeField] private GameObject _sliderRowPrefab;
        [SerializeField] private GameObject _toggleRowPrefab;
        [SerializeField] private GameObject _dropdownRowPrefab;

        // FPS 下拉的取值集合（与 SettingsPanelController 一致）
        private static readonly int[] FpsOptions = { 30, 60, 120, -1 };
        private static readonly Language[] LanguageOptions =
            { Language.ChineseSimplified, Language.English, Language.Japanese, Language.Korean };
        private static readonly string[] LanguageNativeNames =
            { "简体中文", "English", "日本語", "한국어" };

        private ISettingsService     _settings;
        private ILocalizationService _loc;
        private readonly List<GameObject> _spawned = new();

        // ── 生命周期 ──────────────────────────────────────────────────────────
        protected override void OnPanelOpen()
        {
            _settings = GetService<ISettingsService>();
            _loc      = GetService<ILocalizationService>();
            Build();
        }

        protected override void OnPanelClose() => Clear();

        // ── 构建 ──────────────────────────────────────────────────────────────
        /// <summary>据 schema 重建所有行。可在无 ISettingsService 时调用（仅生成行 + 标签，不绑定）。</summary>
        public void Build()
        {
            Clear();
            if (_schema == null || _container == null) return;

            foreach (var item in _schema.Items)
            {
                GameObject prefab = item.isHeader ? _headerPrefab : PrefabFor(KindOf(item.key));
                if (prefab == null) continue;

                var go = Instantiate(prefab, _container);
                _spawned.Add(go);

                SetLabel(go, item.labelKey);
                if (!item.isHeader && _settings != null)
                    BindControl(go, item.key);
            }
        }

        private void Clear()
        {
            foreach (var go in _spawned) if (go != null) Destroy(go);
            _spawned.Clear();
        }

        private GameObject PrefabFor(ControlKind kind) => kind switch
        {
            ControlKind.Slider   => _sliderRowPrefab,
            ControlKind.Toggle   => _toggleRowPrefab,
            ControlKind.Dropdown => _dropdownRowPrefab,
            _                    => null,
        };

        private static void SetLabel(GameObject row, string labelKey)
        {
            var loc = row.GetComponentInChildren<LocalizedText>(true);
            if (loc != null) loc.SetKey(labelKey);
        }

        // ── 控件类型映射 ──────────────────────────────────────────────────────
        public static ControlKind KindOf(SettingKey key) => key switch
        {
            SettingKey.MasterVolume or SettingKey.BGMVolume or SettingKey.SFXVolume
                or SettingKey.AmbientVolume or SettingKey.UIScale => ControlKind.Slider,
            SettingKey.VSync or SettingKey.ScreenShake            => ControlKind.Toggle,
            SettingKey.TargetFPS or SettingKey.ColorblindMode or SettingKey.Language => ControlKind.Dropdown,
            _                                                     => ControlKind.Slider,
        };

        // ── 绑定派发 ──────────────────────────────────────────────────────────
        private void BindControl(GameObject row, SettingKey key)
        {
            switch (KindOf(key))
            {
                case ControlKind.Slider:   BindSlider(row, key);   break;
                case ControlKind.Toggle:   BindToggle(row, key);   break;
                case ControlKind.Dropdown: BindDropdown(row, key); break;
            }
        }

        private void BindSlider(GameObject row, SettingKey key)
        {
            var ui = row.GetComponentInChildren<UISlider>(true);
            if (ui == null) return;
            var data = _settings.Current;

            switch (key)
            {
                case SettingKey.MasterVolume:
                    ui.Bind(0f, 1f, data.MasterVolume,  v => _settings.SetMasterVolume(v),  Percent); break;
                case SettingKey.BGMVolume:
                    ui.Bind(0f, 1f, data.BGMVolume,     v => _settings.SetBGMVolume(v),     Percent); break;
                case SettingKey.SFXVolume:
                    ui.Bind(0f, 1f, data.SFXVolume,     v => _settings.SetSFXVolume(v),     Percent); break;
                case SettingKey.AmbientVolume:
                    ui.Bind(0f, 1f, data.AmbientVolume, v => _settings.SetAmbientVolume(v), Percent); break;
                case SettingKey.UIScale:
                    ui.Bind(0.8f, 1.5f, data.UIScale,   v => _settings.SetUIScale(v),       Percent); break;
            }
        }

        private void BindToggle(GameObject row, SettingKey key)
        {
            var toggle = row.GetComponentInChildren<Toggle>(true);
            if (toggle == null) return;
            var data = _settings.Current;
            toggle.onValueChanged.RemoveAllListeners();
            switch (key)
            {
                case SettingKey.VSync:
                    toggle.isOn = data.VSync;
                    toggle.onValueChanged.AddListener(v => _settings.SetVSync(v));
                    break;
                case SettingKey.ScreenShake:
                    toggle.isOn = data.ScreenShakeEnabled;
                    toggle.onValueChanged.AddListener(v => _settings.SetScreenShakeEnabled(v));
                    break;
            }
        }

        private void BindDropdown(GameObject row, SettingKey key)
        {
            var ui = row.GetComponentInChildren<UIDropdown>(true);
            if (ui == null) return;
            var data = _settings.Current;

            switch (key)
            {
                case SettingKey.TargetFPS:
                {
                    var opts = new List<string> { "30", "60", "120", Loc("SET_FPS_UNLIMITED", "无限") };
                    int idx = Array.IndexOf(FpsOptions, data.TargetFPS); if (idx < 0) idx = 1;
                    ui.Bind(opts, idx, i => _settings.SetTargetFrameRate(FpsOptions[Mathf.Clamp(i, 0, FpsOptions.Length - 1)]));
                    break;
                }
                case SettingKey.ColorblindMode:
                {
                    int count = Enum.GetValues(typeof(ColorblindMode)).Length;
                    var opts = new List<string>(count);
                    for (int i = 0; i < count; i++)
                        opts.Add(Loc($"SET_COLORBLIND_{i}", ((ColorblindMode)i).ToString()));
                    ui.Bind(opts, (int)data.ColorblindMode,
                        i => _settings.SetColorblindMode((ColorblindMode)Mathf.Clamp(i, 0, count - 1)));
                    break;
                }
                case SettingKey.Language:
                {
                    var opts = new List<string>(LanguageNativeNames);
                    int idx = _loc != null ? Array.IndexOf(LanguageOptions, _loc.CurrentLanguage) : 0;
                    if (idx < 0) idx = 0;
                    ui.Bind(opts, idx, i =>
                        GetService<ILocalizationService>()?.SetLanguage(LanguageOptions[Mathf.Clamp(i, 0, LanguageOptions.Length - 1)]));
                    break;
                }
            }
        }

        // ── 工具 ──────────────────────────────────────────────────────────────
        private static string Percent(float v) => Mathf.RoundToInt(v * 100f) + "%";

        private string Loc(string key, string fallback)
        {
            if (_loc != null && _loc.TryGet(key, out var v, LocalizationTable.UI)) return v;
            return fallback;
        }

        protected override GameObject ResolveFirstSelected()
        {
            foreach (var go in _spawned)
            {
                if (go == null) continue;
                var sel = go.GetComponentInChildren<Selectable>(true);
                if (sel != null) return sel.gameObject;
            }
            return null;
        }
    }
}