using System;
using UnityEngine;
using UnityEngine.InputSystem;

public static class GlyphService
{
    // 缓存的设备提示数组，避免内存分配
    private static readonly string[] KeyboardHints = { "Keyboard", "Mouse" };
    private static readonly string[] XboxHints = { "XInput", "Xbox", "Gamepad" };
    private static readonly string[] PlayStationHints = { "DualShock", "DualSense", "PlayStation", "Gamepad" };
    private static readonly char[] TrimChars = { '{', '}', '<', '>', '\'', '"' };

    /// <summary>
    /// 获取输入图标数据库实例
    /// </summary>
    public static InputGlyphDatabase Database
    {
        get
        {
            if (_database == null)
            {
                _database = Resources.Load<InputGlyphDatabase>("InputGlyphDatabase");
            }

            return _database;
        }
    }

    private static InputGlyphDatabase _database;


    /// <summary>
    /// 获取输入操作的绑定控制路径
    /// </summary>
    /// <param name="action">输入操作</param>
    /// <param name="compositePartName">复合部分名称（可选）</param>
    /// <param name="deviceOverride">设备类型覆盖（可选）</param>
    /// <returns>绑定控制路径</returns>
    public static string GetBindingControlPath(InputAction action, string compositePartName = null, InputDeviceWatcher.InputDeviceCategory? deviceOverride = null)
    {
        if (action == null) return string.Empty;
        var binding = GetBindingControl(action, compositePartName, deviceOverride);
        return binding.hasOverrides ? binding.effectivePath : binding.path;
    }

    /// <summary>
    /// 尝试获取输入操作的 TextMeshPro 标签
    /// </summary>
    /// <param name="reference">输入操作引用</param>
    /// <param name="compositePartName">复合部分名称</param>
    /// <param name="device">设备类型</param>
    /// <param name="tag">输出的 TMP 标签</param>
    /// <param name="displayFallback">显示回退文本</param>
    /// <param name="db">数据库实例（可选）</param>
    /// <returns>是否成功获取</returns>
    public static bool TryGetTMPTagForActionPath(InputAction reference, string compositePartName, InputDeviceWatcher.InputDeviceCategory device, out string tag, out string displayFallback, InputGlyphDatabase db = null)
    {
        string path = GetBindingControlPath(reference, compositePartName, device);
        return TryGetTMPTagForActionPath(path, device, out tag, out displayFallback, db);
    }

    /// <summary>
    /// 尝试获取输入操作的 UI Sprite
    /// </summary>
    /// <param name="reference">输入操作引用</param>
    /// <param name="compositePartName">复合部分名称</param>
    /// <param name="device">设备类型</param>
    /// <param name="sprite">输出的 Sprite</param>
    /// <param name="db">数据库实例（可选）</param>
    /// <returns>是否成功获取</returns>
    public static bool TryGetUISpriteForActionPath(InputAction reference, string compositePartName, InputDeviceWatcher.InputDeviceCategory device, out Sprite sprite, InputGlyphDatabase db = null)
    {
        string path = GetBindingControlPath(reference, compositePartName, device);
        return TryGetUISpriteForActionPath(path, device, out sprite, db);
    }

    /// <summary>
    /// 根据控制路径尝试获取 TextMeshPro 标签
    /// </summary>
    /// <param name="controlPath">控制路径</param>
    /// <param name="device">设备类型</param>
    /// <param name="tag">输出的 TMP 标签</param>
    /// <param name="displayFallback">显示回退文本</param>
    /// <param name="db">数据库实例（可选）</param>
    /// <returns>是否成功获取</returns>
    public static bool TryGetTMPTagForActionPath(string controlPath, InputDeviceWatcher.InputDeviceCategory device, out string tag, out string displayFallback, InputGlyphDatabase db = null)
    {
        tag = null;
        displayFallback = null;
        db = db ?? Database;

        displayFallback = GetDisplayNameFromControlPath(controlPath);

        var sprite = db.FindSprite(controlPath, device) ?? db.FindSprite(controlPath, InputDeviceWatcher.InputDeviceCategory.Keyboard);

        var spriteName = sprite == null ? string.Empty : sprite.name;
        tag = $"<sprite name=\"{spriteName}\">";
        return true;
    }

    /// <summary>
    /// 根据控制路径尝试获取 UI Sprite
    /// </summary>
    /// <param name="controlPath">控制路径</param>
    /// <param name="device">设备类型</param>
    /// <param name="sprite">输出的 Sprite</param>
    /// <param name="db">数据库实例（可选）</param>
    /// <returns>是否成功获取</returns>
    public static bool TryGetUISpriteForActionPath(string controlPath, InputDeviceWatcher.InputDeviceCategory device, out Sprite sprite, InputGlyphDatabase db = null)
    {
        sprite = null;
        db = db ?? Database;
        if (string.IsNullOrEmpty(controlPath) || db == null) return false;
        sprite = db.FindSprite(controlPath, device) ?? db.FindSprite(controlPath, InputDeviceWatcher.InputDeviceCategory.Keyboard);
        return sprite != null;
    }


    /// <summary>
    /// 获取输入操作的绑定控制
    /// </summary>
    static InputBinding GetBindingControl(InputAction action, string compositePartName = null, InputDeviceWatcher.InputDeviceCategory? deviceOverride = null)
    {
        if (action == null) return default;

        var curCategory = deviceOverride ?? InputDeviceWatcher.CurrentCategory;
        var hints = GetDeviceHintsForCategory(curCategory);

        foreach (var b in action.bindings)
        {
            if (!string.IsNullOrEmpty(compositePartName))
            {
                if (!b.isPartOfComposite) continue;
                if (!string.Equals(b.name, compositePartName, StringComparison.OrdinalIgnoreCase)) continue;
            }

            // 替换 LINQ Any() 以避免委托分配
            if (!string.IsNullOrEmpty(b.path) && ContainsAnyHint(b.path, hints)) return b;
            if (!string.IsNullOrEmpty(b.effectivePath) && ContainsAnyHint(b.effectivePath, hints)) return b;
        }

        return default;
    }

    // 辅助方法，避免 LINQ Any() 的内存分配
    /// <summary>
    /// 检查路径是否包含任何提示字符串
    /// </summary>
    static bool ContainsAnyHint(string path, string[] hints)
    {
        for (int i = 0; i < hints.Length; i++)
        {
            if (path.IndexOf(hints[i], StringComparison.OrdinalIgnoreCase) >= 0)
                return true;
        }
        return false;
    }

    /// <summary>
    /// 根据设备类型获取设备提示字符串数组
    /// </summary>
    static string[] GetDeviceHintsForCategory(InputDeviceWatcher.InputDeviceCategory cat)
    {
        switch (cat)
        {
            case InputDeviceWatcher.InputDeviceCategory.Keyboard:
                return KeyboardHints;
            case InputDeviceWatcher.InputDeviceCategory.Xbox:
                return XboxHints;
            case InputDeviceWatcher.InputDeviceCategory.PlayStation:
                return PlayStationHints;
            default:
                return XboxHints;
        }
    }


    /// <summary>
    /// 从输入操作获取显示名称
    /// </summary>
    /// <param name="action">输入操作</param>
    /// <param name="compositePartName">复合部分名称（可选）</param>
    /// <param name="deviceOverride">设备类型覆盖</param>
    /// <returns>显示名称</returns>
    public static string GetDisplayNameFromInputAction(InputAction action, string compositePartName = null, InputDeviceWatcher.InputDeviceCategory deviceOverride = InputDeviceWatcher.InputDeviceCategory.Keyboard)
    {
        if (action == null) return string.Empty;
        var binding = GetBindingControl(action, compositePartName, deviceOverride);
        return binding.ToDisplayString();
    }

    /// <summary>
    /// 从控制路径获取显示名称
    /// </summary>
    /// <param name="controlPath">控制路径</param>
    /// <returns>显示名称</returns>
    public static string GetDisplayNameFromControlPath(string controlPath)
    {
        if (string.IsNullOrEmpty(controlPath)) return string.Empty;
        var parts = controlPath.Split('/');
        var last = parts[parts.Length - 1].Trim(TrimChars);
        return last;
    }
}