using UnityEngine.InputSystem;
using UnityEngine.InputSystem.Controls;

namespace Ashwild.Player
{
    /// <summary>
    /// The physical keyboard layouts we tell apart at first launch. Unknown means no keyboard was
    /// present or probing was inconclusive — callers treat it like QWERTY (apply no profile).
    /// </summary>
    public enum KeyboardLayout
    {
        Unknown,
        Qwerty,
        Azerty
    }

    /// <summary>
    /// Classifies the current OS keyboard layout by probing <see cref="Keyboard.current"/>. The
    /// primary signal is the layout-aware display name of the physical Q/W keys (AZERTY labels them
    /// A/Z); the OS-reported layout string is a fallback. Pure and side-effect-free — the caller
    /// decides what to do with the result.
    /// </summary>
    public static class KeyboardLayoutDetector
    {
        #region Public API

        /// <summary>
        /// Returns the detected layout, or <see cref="KeyboardLayout.Unknown"/> when no keyboard is
        /// connected or the probes disagree with nothing conclusive.
        /// </summary>
        public static KeyboardLayout Detect()
        {
            Keyboard keyboard = Keyboard.current;
            if (keyboard == null) return KeyboardLayout.Unknown;

            string q = Label(keyboard[Key.Q]);
            string w = Label(keyboard[Key.W]);

            if (q == "a" || w == "z") return KeyboardLayout.Azerty;
            if (q == "q" || w == "w") return KeyboardLayout.Qwerty;

            return FromLayoutString(keyboard.keyboardLayout);
        }

        #endregion

        #region Internal Helpers

        /// <summary>
        /// The lower-cased, trimmed display name of a key control, or empty when unavailable.
        /// </summary>
        private static string Label(KeyControl key)
        {
            if (key == null) return string.Empty;
            string display = key.displayName;
            return string.IsNullOrEmpty(display) ? string.Empty : display.Trim().ToLowerInvariant();
        }

        /// <summary>
        /// Last-resort classification from the OS layout name (e.g. "French" / "AZERTY").
        /// </summary>
        private static KeyboardLayout FromLayoutString(string layout)
        {
            if (string.IsNullOrEmpty(layout)) return KeyboardLayout.Unknown;
            string l = layout.ToLowerInvariant();
            if (l.Contains("azerty") || l.Contains("french") || l.Contains("belg")) return KeyboardLayout.Azerty;
            return KeyboardLayout.Unknown;
        }

        #endregion
    }
}