using System;
using UnityEngine;

public class LevelManager : MonoBehaviour
{
    public static LevelManager Instance { get; private set; }

    [SerializeField] private bool _debugMode = false;
    [SerializeField] private Door _doorReference;

    private bool _keyCollected = false;
    private bool _levelComplete = false;

    public bool KeyCollected => _keyCollected;
    public bool LevelComplete => _levelComplete;

    public event EventHandler OnKeyCollected;
    public event EventHandler OnDoorUnlocked;
    public event EventHandler OnLevelComplete;

    private void Awake()
    {
        // Singleton pattern
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }

        Instance = this;
    }

    private void Start()
    {
        // Subscribe to GameManager key state changes
        if (GameManager.Instance != null)
        {
            GameManager.Instance.OnKeyStateChanged += HandleKeyStateChanged;
        }
    }

    public void NotifyKeyCollected()
    {
        if (_keyCollected)
            return;

        _keyCollected = true;

        if (_debugMode)
            Debug.Log("[LevelManager] Key collected!");

        OnKeyCollected?.Invoke(this, EventArgs.Empty);
        UnlockDoor();
    }

    public void UnlockDoor()
    {
        if (_doorReference == null)
        {
            Debug.LogWarning("[LevelManager] Door reference not assigned!");
            return;
        }

        _doorReference.OpenDoor();

        if (_debugMode)
            Debug.Log("[LevelManager] Door unlocked!");

        OnDoorUnlocked?.Invoke(this, EventArgs.Empty);
    }

    public void NotifyLevelComplete()
    {
        if (_levelComplete)
            return;

        _levelComplete = true;

        if (_debugMode)
            Debug.Log("[LevelManager] Level complete!");

        OnLevelComplete?.Invoke(this, EventArgs.Empty);

        // Also notify GameManager
        if (GameManager.Instance != null)
        {
            GameManager.Instance.CompletLevel();
        }
    }

    public void Reset()
    {
        _keyCollected = false;
        _levelComplete = false;

        if (_debugMode)
            Debug.Log("[LevelManager] Reset");
    }

    private void HandleKeyStateChanged(object sender, bool hasKey)
    {
        if (hasKey && !_keyCollected)
        {
            NotifyKeyCollected();
        }
    }

    private void OnDestroy()
    {
        if (GameManager.Instance != null)
        {
            GameManager.Instance.OnKeyStateChanged -= HandleKeyStateChanged;
        }
    }
}