using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.LowLevel;

/// <summary>
/// Tracks which input device was most recently active, globally, across the whole game.
/// NPCStandIn (and any other UI that shows button prompts) reads InputDeviceTracker.Current
/// to decide whether to show "[F]", "(X)", "(✕)", etc.
/// Requires the Input System package (Window > Package Manager > Input System),
/// and Project Settings > Player > Active Input Handling set to
/// "Input System Package (New)" or "Both".
/// </summary>
public static class InputDeviceTracker
{
    public enum DeviceType { Keyboard, Xbox, PlayStation, Generic }

    public static DeviceType Current { get; private set; } = DeviceType.Keyboard;

    [RuntimeInitializeOnLoadMethod]
    static void Init()
    {
        InputSystem.onEvent += OnEvent;
    }

    static void OnEvent(InputEventPtr eventPtr, InputDevice device)
    {
        // Only care about actual state changes (button/stick/key presses), not noise.
        if (!eventPtr.IsA<StateEvent>() && !eventPtr.IsA<DeltaStateEvent>()) return;

        switch (device)
        {
            case Keyboard:
            case Mouse:
                Current = DeviceType.Keyboard;
                break;

            case Gamepad gp:
                string n = gp.displayName.ToLowerInvariant();
                if (n.Contains("dualshock") || n.Contains("dualsense") || n.Contains("playstation"))
                    Current = DeviceType.PlayStation;
                else if (n.Contains("xbox") || n.Contains("xinput"))
                    Current = DeviceType.Xbox;
                else
                    Current = DeviceType.Generic;
                break;
        }
    }
}