using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// Bidirectional mapping between legacy UnityEngine.KeyCode and Unity Input System
/// keyboard control paths (e.g. KeyCode.D &lt;-&gt; "&lt;Keyboard&gt;/d").
///
/// The gameplay binding store persists paths (Input System canonical format), while
/// most game/UI code still speaks KeyCode. This map keeps both representations in sync
/// without changing any judgement/binding business logic.
/// </summary>
public static class InputSystemKeyMap
{
    // KeyCode -> Input System control name (the part after "<Keyboard>/").
    private static readonly Dictionary<KeyCode, string> keyCodeToControl = new Dictionary<KeyCode, string>();
    private static readonly Dictionary<string, KeyCode> controlToKeyCode = new Dictionary<string, KeyCode>();

    private const string KeyboardPrefix = "<Keyboard>/";

    static InputSystemKeyMap()
    {
        // Letters
        for (char c = 'a'; c <= 'z'; c++)
        {
            KeyCode kc = (KeyCode)System.Enum.Parse(typeof(KeyCode), char.ToUpper(c).ToString());
            Register(kc, c.ToString());
        }

        // Top-row digits (KeyCode.Alpha0..9 -> "1".."0")
        Register(KeyCode.Alpha0, "0");
        Register(KeyCode.Alpha1, "1");
        Register(KeyCode.Alpha2, "2");
        Register(KeyCode.Alpha3, "3");
        Register(KeyCode.Alpha4, "4");
        Register(KeyCode.Alpha5, "5");
        Register(KeyCode.Alpha6, "6");
        Register(KeyCode.Alpha7, "7");
        Register(KeyCode.Alpha8, "8");
        Register(KeyCode.Alpha9, "9");

        // Numpad
        Register(KeyCode.Keypad0, "numpad0");
        Register(KeyCode.Keypad1, "numpad1");
        Register(KeyCode.Keypad2, "numpad2");
        Register(KeyCode.Keypad3, "numpad3");
        Register(KeyCode.Keypad4, "numpad4");
        Register(KeyCode.Keypad5, "numpad5");
        Register(KeyCode.Keypad6, "numpad6");
        Register(KeyCode.Keypad7, "numpad7");
        Register(KeyCode.Keypad8, "numpad8");
        Register(KeyCode.Keypad9, "numpad9");
        Register(KeyCode.KeypadDivide, "numpadDivide");
        Register(KeyCode.KeypadMultiply, "numpadMultiply");
        Register(KeyCode.KeypadMinus, "numpadMinus");
        Register(KeyCode.KeypadPlus, "numpadPlus");
        Register(KeyCode.KeypadEnter, "numpadEnter");
        Register(KeyCode.KeypadPeriod, "numpadPeriod");
        Register(KeyCode.KeypadEquals, "numpadEquals");

        // Whitespace / editing
        Register(KeyCode.Space, "space");
        Register(KeyCode.Return, "enter");
        Register(KeyCode.Tab, "tab");
        Register(KeyCode.Backspace, "backspace");
        Register(KeyCode.Delete, "delete");
        Register(KeyCode.Escape, "escape");

        // Modifiers
        Register(KeyCode.LeftShift, "leftShift");
        Register(KeyCode.RightShift, "rightShift");
        Register(KeyCode.LeftControl, "leftCtrl");
        Register(KeyCode.RightControl, "rightCtrl");
        Register(KeyCode.LeftAlt, "leftAlt");
        Register(KeyCode.RightAlt, "rightAlt");
        Register(KeyCode.LeftCommand, "leftMeta");
        Register(KeyCode.RightCommand, "rightMeta");
        Register(KeyCode.CapsLock, "capsLock");

        // Arrows
        Register(KeyCode.UpArrow, "upArrow");
        Register(KeyCode.DownArrow, "downArrow");
        Register(KeyCode.LeftArrow, "leftArrow");
        Register(KeyCode.RightArrow, "rightArrow");

        // Navigation
        Register(KeyCode.Home, "home");
        Register(KeyCode.End, "end");
        Register(KeyCode.PageUp, "pageUp");
        Register(KeyCode.PageDown, "pageDown");
        Register(KeyCode.Insert, "insert");

        // Punctuation / symbols
        Register(KeyCode.Quote, "quote");
        Register(KeyCode.Semicolon, "semicolon");
        Register(KeyCode.Comma, "comma");
        Register(KeyCode.Period, "period");
        Register(KeyCode.Slash, "slash");
        Register(KeyCode.Backslash, "backslash");
        Register(KeyCode.LeftBracket, "leftBracket");
        Register(KeyCode.RightBracket, "rightBracket");
        Register(KeyCode.Minus, "minus");
        Register(KeyCode.Equals, "equals");
        Register(KeyCode.BackQuote, "backquote");

        // Function keys
        Register(KeyCode.F1, "f1");
        Register(KeyCode.F2, "f2");
        Register(KeyCode.F3, "f3");
        Register(KeyCode.F4, "f4");
        Register(KeyCode.F5, "f5");
        Register(KeyCode.F6, "f6");
        Register(KeyCode.F7, "f7");
        Register(KeyCode.F8, "f8");
        Register(KeyCode.F9, "f9");
        Register(KeyCode.F10, "f10");
        Register(KeyCode.F11, "f11");
        Register(KeyCode.F12, "f12");
    }

    private static void Register(KeyCode kc, string control)
    {
        keyCodeToControl[kc] = control;
        if (!controlToKeyCode.ContainsKey(control))
            controlToKeyCode[control] = kc;
    }

    /// <summary>KeyCode -> full Input System path (e.g. "&lt;Keyboard&gt;/d"). Null if unmapped/None.</summary>
    public static string KeyCodeToPath(KeyCode key)
    {
        if (key == KeyCode.None) return null;
        if (keyCodeToControl.TryGetValue(key, out string control))
            return KeyboardPrefix + control;
        return null;
    }

    /// <summary>Full Input System path -> KeyCode. Returns KeyCode.None if unmapped.</summary>
    public static KeyCode PathToKeyCode(string path)
    {
        if (string.IsNullOrEmpty(path)) return KeyCode.None;
        string control = path.StartsWith(KeyboardPrefix) ? path.Substring(KeyboardPrefix.Length) : path;
        if (controlToKeyCode.TryGetValue(control, out KeyCode kc))
            return kc;
        return KeyCode.None;
    }
}