using UnityEngine;
using UnityEngine.EventSystems;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem.UI;
#endif

namespace Invector
{
    /// <summary>
    /// Selects a single UI input backend, preferring the Input System when both are available.
    /// Keeps the StandaloneInputModule configuration for projects using the legacy backend.
    /// </summary>
    [DisallowMultipleComponent]
    [RequireComponent(typeof(EventSystem))]
    [DefaultExecutionOrder(-1000)]
    public class vEventSystemInputBackend : MonoBehaviour
    {
        private void Awake()
        {
            Configure();
        }

        public void Configure()
        {
            var legacy = GetComponent<StandaloneInputModule>();
#if ENABLE_INPUT_SYSTEM
            if (legacy != null) legacy.enabled = false;
            var current = GetComponent<InputSystemUIInputModule>();
            if (current == null) current = gameObject.AddComponent<InputSystemUIInputModule>();
            if (current.actionsAsset == null) current.AssignDefaultActions();
            current.enabled = true;
#else
            // A serialized Input System module can remain after switching to legacy-only input.
            foreach (var module in GetComponents<BaseInputModule>())
            {
                if (module.GetType().FullName == "UnityEngine.InputSystem.UI.InputSystemUIInputModule")
                    module.enabled = false;
            }
            if (legacy == null) legacy = gameObject.AddComponent<StandaloneInputModule>();
            legacy.enabled = true;
#endif
        }
    }
}