using UnityEngine;
using UnityEngine.InputSystem;

/// <summary>
/// Терминал лифта в 3D мире.
/// Игрок может подойти, увидеть подсказку и нажать [E] для открытия UI цифрового ввода кода.
/// </summary>
public class ElevatorTerminal : MonoBehaviour
{
    [Header("Дистанция взаимодействия")]
    public float interactionDistance = 3.8f;

    [Header("Индикаторы")]
    public Light statusLight;
    public MeshRenderer screenRenderer;

    private static Transform cachedPlayerTransform;

    private void Start()
    {
        LocatePlayer();
        UpdateLightColor(false);

        if (LevelCodeManager.Instance != null)
        {
            LevelCodeManager.Instance.OnElevatorUnlocked += HandleUnlocked;
        }

        var col = GetComponent<Collider>();
        if (col == null)
        {
            var sc = gameObject.AddComponent<SphereCollider>();
            sc.isTrigger = true;
            sc.radius = interactionDistance;
        }
    }

    private void OnDestroy()
    {
        if (LevelCodeManager.Instance != null)
        {
            LevelCodeManager.Instance.OnElevatorUnlocked -= HandleUnlocked;
        }
    }

    private Transform LocatePlayer()
    {
        if (cachedPlayerTransform != null) return cachedPlayerTransform;

        var pm = Object.FindAnyObjectByType<PlayerMovement>();
        if (pm != null) { cachedPlayerTransform = pm.transform; return cachedPlayerTransform; }

        var ph = Object.FindAnyObjectByType<PlayerHealth>();
        if (ph != null) { cachedPlayerTransform = ph.transform; return cachedPlayerTransform; }

        var pTag = GameObject.FindWithTag("Player");
        if (pTag != null) { cachedPlayerTransform = pTag.transform; return cachedPlayerTransform; }

        var pName = GameObject.Find("Player");
        if (pName != null) { cachedPlayerTransform = pName.transform; return cachedPlayerTransform; }

        if (Camera.main != null) { return Camera.main.transform; }

        return null;
    }

    private void HandleUnlocked()
    {
        UpdateLightColor(true);
    }

    private void UpdateLightColor(bool isUnlocked)
    {
        if (statusLight != null)
        {
            statusLight.color = isUnlocked ? new Color(0.2f, 1f, 0.4f) : new Color(1f, 0.85f, 0.1f);
        }
    }

    private void Update()
    {
        if (ElevatorKeypadUI.Instance != null && ElevatorKeypadUI.Instance.IsOpen) return;
        if (Time.timeScale == 0f) return;

        Transform player = LocatePlayer();
        if (player == null) return;

        float dist3D = Vector3.Distance(transform.position, player.position);
        float distXZ = Vector2.Distance(new Vector2(transform.position.x, transform.position.z), 
                                        new Vector2(player.position.x, player.position.z));

        bool inRange = dist3D <= interactionDistance || distXZ <= (interactionDistance * 0.9f);

        if (inRange)
        {
            if (CheckInteractInput())
            {
                Interact();
            }
        }
    }

    private void OnTriggerStay(Collider other)
    {
        if (ElevatorKeypadUI.Instance != null && ElevatorKeypadUI.Instance.IsOpen) return;
        if (Time.timeScale == 0f) return;

        if (other.CompareTag("Player") || other.GetComponentInParent<PlayerMovement>() != null)
        {
            if (CheckInteractInput())
            {
                Interact();
            }
        }
    }

    private bool CheckInteractInput()
    {
        var keyboard = Keyboard.current;
        if (keyboard != null)
        {
            if (keyboard.eKey.wasPressedThisFrame || 
                keyboard.fKey.wasPressedThisFrame || 
                keyboard.enterKey.wasPressedThisFrame)
            {
                return true;
            }
        }

#if ENABLE_LEGACY_INPUT_MANAGER
        if (Input.GetKeyDown(KeyCode.E) || Input.GetKeyDown(KeyCode.F) || Input.GetKeyDown(KeyCode.Return))
        {
            return true;
        }
#endif

        return false;
    }

    public void Interact()
    {
        bool isUnlocked = LevelCodeManager.Instance != null && LevelCodeManager.Instance.IsElevatorUnlocked;

        if (isUnlocked)
        {
            if (LevelSuccessUI.Instance != null)
            {
                LevelSuccessUI.Instance.ShowSuccessScreen();
            }
        }
        else
        {
            if (ElevatorKeypadUI.Instance != null)
            {
                ElevatorKeypadUI.Instance.OpenKeypad();
            }
            else
            {
                Debug.LogError("[ElevatorTerminal] ElevatorKeypadUI.Instance is NULL!");
            }
        }
    }
}