using System;
using System.Collections.Generic;
using System.Reflection;
using Cielonos.MainGame;
using Cielonos.Settings;
using Cielonos.Settings.UI;
using SLSUtilities.UI;
using TMPro;
using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.UI;

namespace Cielonos.UI
{
    /// <summary>
    /// 设置界面页面（单页滚动式 + 右侧面板）。
    /// <para>
    /// <b>左侧：</b>所有设置分类在同一页面中按顺序展示，每个分类前插入标题。
    /// 通过反射读取各设置类的公共字段，按类型自动选择 Entry Prefab 实例化。
    /// 同时支持手动添加的按钮条目（如"Key Bindings"按钮）。
    /// </para>
    /// <para>
    /// <b>右侧：</b>包含两种面板状态：
    /// <list type="number">
    ///   <item>说明面板（<see cref="descriptionPanel"/>）：鼠标悬停条目时显示说明文本，离开后隐藏。</item>
    ///   <item>详情页面（如 <see cref="keyBindingPage"/>）：点击按钮后打开的二级 UIPage，
    ///         打开期间悬停说明被抑制，需手动关闭。</item>
    /// </list>
    /// </para>
    /// </summary>
    public class SettingsUIPage : UIPageBase
    {
        // ──────────────────── Entry Prefabs ──────────────────

        [Header("Entry Prefabs")]
        [Tooltip("bool 字段使用的 Toggle 条目预制体，需挂载 SettingsEntryToggle。")]
        [SerializeField] private GameObject toggleEntryPrefab;

        [Tooltip("带 [Range] 的 int 字段使用的 Slider 条目预制体，需挂载 SettingsEntrySlider。")]
        [SerializeField] private GameObject sliderEntryPrefab;

        [Tooltip("enum 字段使用的 Dropdown 条目预制体，需挂载 SettingsEntryDropdown。")]
        [SerializeField] private GameObject dropdownEntryPrefab;

        [Tooltip("按钮条目预制体，需挂载 SettingsEntryButton。")]
        [SerializeField] private GameObject buttonEntryPrefab;

        // ──────────────────── Section Header ──────────────────

        [Header("Section Header")]
        [Tooltip("分类标题预制体，需包含 TMP_Text 组件。")]
        [SerializeField] private GameObject sectionHeaderPrefab;

        // ──────────────────── Left Content ────────────────────

        [Header("Left Content")]
        [Tooltip("条目的父容器，应挂载 VerticalLayoutGroup 和 ContentSizeFitter。")]
        [SerializeField] private RectTransform contentContainer;

        // ──────────────────── Right Panel ─────────────────────

        [Header("Right Panel - Description")]
        [Tooltip("右侧悬停说明面板，显示条目的标题和说明文本。")]
        [SerializeField] private SettingsDescriptionPanel descriptionPanel;

        [Header("Right Panel - Detail Pages")]
        [Tooltip("键位绑定二级页面。")]
        [SerializeField] private KeyBindingPage keyBindingPage;

        // ──────────────────── Input ───────────────────────────

        [Header("Input")]
        [Tooltip("用于键位绑定页面的 InputActionAsset。为空时从 Player 获取。")]
        [SerializeField] private InputActionAsset inputActionAsset;

        // ──────────────────── 底部按钮 ────────────────────

        [Header("Bottom Buttons")]
        [SerializeField] private Button resetButton;
        [SerializeField] private Button backButton;

        // ──────────────────── 运行时状态 ──────────────────

        private readonly List<SettingsEntryBase> activeFieldEntries = new();
        private readonly List<SettingsEntryButton> activeButtonEntries = new();
        private readonly List<GameObject> spawnedObjects = new();

        /// <summary>是否有详情页面处于打开状态（抑制悬停说明）。</summary>
        private bool isDetailPageOpen;

        // ──────────────────── 分类定义 ────────────────────

        /// <summary>
        /// 分类定义：显示名称、设置实例、Apply/Reset 回调、附加按钮列表。
        /// </summary>
        private struct SectionDefinition
        {
            public string displayName;
            public object settingsInstance;
            public Action applyAction;
            public Action resetAction;
            public List<ButtonDefinition> buttons;
        }

        /// <summary>
        /// 手动添加的按钮条目定义。
        /// </summary>
        private struct ButtonDefinition
        {
            public string label;
            public string description;
            public Action onClick;
        }

        // ──────────────────── 生命周期 ────────────────────

        protected override void Start()
        {
            base.Start();

            resetButton?.onClick.AddListener(OnResetClicked);
            backButton?.onClick.AddListener(OnBackClicked);

            // 监听详情页面的开关状态
            if (keyBindingPage != null)
            {
                keyBindingPage.PageOpened += OnDetailPageOpened;
                keyBindingPage.PageClosed += OnDetailPageClosed;
            }
        }

        protected override void OnPageOpened()
        {
            BuildAllSections();
        }

        protected override void OnPageClosed()
        {
            // 先关闭可能打开的详情页面
            if (isDetailPageOpen && keyBindingPage != null && keyBindingPage.IsOpen)
                keyBindingPage.Close();

            ClearAll();
            descriptionPanel?.Hide();
            GameSettingsManager.Instance?.Save();
        }

        // ──────────────────── 详情页面状态 ────────────────

        private void OnDetailPageOpened()
        {
            isDetailPageOpen = true;
            descriptionPanel?.Hide();
        }

        private void OnDetailPageClosed()
        {
            isDetailPageOpen = false;
        }

        // ──────────────────── 悬停回调 ────────────────────

        private void HandleHoverEnter(string title, string description)
        {
            if (isDetailPageOpen) return;
            descriptionPanel?.Show(title, description);
        }

        private void HandleHoverExit()
        {
            if (isDetailPageOpen) return;
            descriptionPanel?.Hide();
        }

        // ──────────────────── 分类定义构建 ────────────────

        /// <summary>
        /// 构建所有分类定义。扩展时在此处追加。
        /// </summary>
        private List<SectionDefinition> BuildSectionDefinitions()
        {
            var manager = GameSettingsManager.Instance;
            if (manager == null) return null;

            return new List<SectionDefinition>
            {
                new()
                {
                    displayName = "Gameplay",
                    settingsInstance = manager.gameplay,
                    applyAction = manager.ApplyGameplay,
                    resetAction = manager.ResetGameplayToDefault
                },
                new()
                {
                    displayName = "Graphics",
                    settingsInstance = manager.graphics,
                    applyAction = manager.ApplyGraphics,
                    resetAction = manager.ResetGraphicsToDefault
                },
                new()
                {
                    displayName = "Sound",
                    settingsInstance = manager.sound,
                    applyAction = manager.ApplySound,
                    resetAction = manager.ResetSoundToDefault
                },
                new()
                {
                    displayName = "Controls",
                    settingsInstance = manager.controls,
                    applyAction = manager.ApplyControls,
                    resetAction = manager.ResetControlsToDefault,
                    buttons = new List<ButtonDefinition>
                    {
                        new()
                        {
                            label = "Key Bindings",
                            description = "Customize keyboard and mouse bindings for all game actions.",
                            onClick = OpenKeyBindingPage
                        }
                    }
                }
            };
        }

        // ──────────────────── 条目生成 ────────────────────

        /// <summary>
        /// 构建所有分类的标题、字段条目和按钮条目。
        /// </summary>
        private void BuildAllSections()
        {
            ClearAll();

            var sections = BuildSectionDefinitions();
            if (sections == null)
            {
                Debug.LogError("[SettingsUIPage] GameSettingsManager not found.");
                return;
            }

            foreach (var section in sections)
            {
                BuildSection(section);
            }
        }

        /// <summary>
        /// 构建单个分类的标题、字段条目和按钮条目。
        /// </summary>
        private void BuildSection(SectionDefinition section)
        {
            FieldInfo[] fields = section.settingsInstance.GetType()
                .GetFields(BindingFlags.Public | BindingFlags.Instance);

            // 预扫描：确认该分类至少有一个可显示的字段或按钮
            bool hasVisibleContent = section.buttons is { Count: > 0 };

            if (!hasVisibleContent)
            {
                foreach (FieldInfo field in fields)
                {
                    if (field.GetCustomAttribute<SettingsIgnoreAttribute>() == null
                        && ResolvePrefab(field) != null)
                    {
                        hasVisibleContent = true;
                        break;
                    }
                }
            }

            if (!hasVisibleContent) return;

            // 插入分类标题
            SpawnSectionHeader(section.displayName);

            // 生成字段条目
            Action applyAction = section.applyAction;

            foreach (FieldInfo field in fields)
            {
                if (field.GetCustomAttribute<SettingsIgnoreAttribute>() != null)
                    continue;

                GameObject prefab = ResolvePrefab(field);
                if (prefab == null)
                {
                    Debug.LogWarning(
                        $"[SettingsUIPage] No matching prefab for field '{field.Name}' " +
                        $"(type: {field.FieldType.Name}). Skipping.");
                    continue;
                }

                GameObject entryObj = Instantiate(prefab, contentContainer);
                var entry = entryObj.GetComponent<SettingsEntryBase>();
                if (entry == null)
                {
                    Debug.LogError(
                        $"[SettingsUIPage] Prefab for field '{field.Name}' " +
                        "is missing a SettingsEntryBase component.");
                    Destroy(entryObj);
                    continue;
                }

                entry.Initialize(section.settingsInstance, field, () => applyAction?.Invoke());
                RegisterFieldEntryHover(entry);
                activeFieldEntries.Add(entry);
                spawnedObjects.Add(entryObj);
            }

            // 生成按钮条目
            if (section.buttons != null)
            {
                foreach (var btnDef in section.buttons)
                {
                    SpawnButtonEntry(btnDef);
                }
            }
        }

        /// <summary>
        /// 为字段条目注册悬停回调。
        /// </summary>
        private void RegisterFieldEntryHover(SettingsEntryBase entry)
        {
            entry.OnHoverEnter = HandleHoverEnter;
            entry.OnHoverExit = HandleHoverExit;
        }

        /// <summary>
        /// 实例化按钮条目。
        /// </summary>
        private void SpawnButtonEntry(ButtonDefinition def)
        {
            if (buttonEntryPrefab == null)
            {
                Debug.LogWarning("[SettingsUIPage] buttonEntryPrefab is not assigned.");
                return;
            }

            GameObject entryObj = Instantiate(buttonEntryPrefab, contentContainer);
            var buttonEntry = entryObj.GetComponent<SettingsEntryButton>();
            if (buttonEntry == null)
            {
                Debug.LogError("[SettingsUIPage] buttonEntryPrefab is missing SettingsEntryButton.");
                Destroy(entryObj);
                return;
            }

            buttonEntry.Initialize(def.label, def.description, def.onClick);
            buttonEntry.OnHoverEnter = HandleHoverEnter;
            buttonEntry.OnHoverExit = HandleHoverExit;
            activeButtonEntries.Add(buttonEntry);
            spawnedObjects.Add(entryObj);
        }

        /// <summary>
        /// 实例化分类标题预制体。
        /// </summary>
        private void SpawnSectionHeader(string title)
        {
            if (sectionHeaderPrefab == null)
            {
                Debug.LogWarning("[SettingsUIPage] sectionHeaderPrefab is not assigned.");
                return;
            }

            GameObject headerObj = Instantiate(sectionHeaderPrefab, contentContainer);
            var headerText = headerObj.GetComponentInChildren<TMP_Text>();
            if (headerText != null)
                headerText.text = title;

            spawnedObjects.Add(headerObj);
        }

        /// <summary>
        /// 根据字段类型选择对应的预制体。
        /// </summary>
        private GameObject ResolvePrefab(FieldInfo field)
        {
            Type fieldType = field.FieldType;

            if (fieldType == typeof(bool))
                return toggleEntryPrefab;

            if (fieldType == typeof(int))
                return sliderEntryPrefab;

            if (fieldType.IsEnum)
                return dropdownEntryPrefab;

            return null;
        }

        // ──────────────────── 详情页面入口 ────────────────

        private void OpenKeyBindingPage()
        {
            if (keyBindingPage == null)
            {
                Debug.LogWarning("[SettingsUIPage] keyBindingPage is not assigned.");
                return;
            }

            // 优先使用配置的 InputActionAsset，否则尝试从 Player 获取
            InputActionAsset asset = inputActionAsset;
            if (asset == null)
            {
                var player = MainGameManager.Player;
                if (player != null)
                    asset = player.inputSc.inputActions.asset;
            }

            if (asset != null)
            {
                keyBindingPage.Open(asset);
            }
            else
            {
                Debug.LogError("[SettingsUIPage] No InputActionAsset available for KeyBindingPage.");
            }
        }

        // ──────────────────── 底部按钮回调 ────────────────

        private void OnResetClicked()
        {
            GameSettingsManager.Instance?.ResetAllToDefault();
            BuildAllSections();
        }

        private void OnBackClicked()
        {
            Close();
        }

        // ──────────────────── 清理 ────────────────────────

        private void ClearAll()
        {
            foreach (var obj in spawnedObjects)
            {
                if (obj != null)
                    Destroy(obj);
            }

            activeFieldEntries.Clear();
            activeButtonEntries.Clear();
            spawnedObjects.Clear();
        }

        private void OnDestroy()
        {
            if (keyBindingPage != null)
            {
                keyBindingPage.PageOpened -= OnDetailPageOpened;
                keyBindingPage.PageClosed -= OnDetailPageClosed;
            }
        }
    }
}