using System;
using UnityEngine;
using UnityEngine.SceneManagement;
using Input;

namespace UI
{
    public class PauseMenu : MonoBehaviour
    {
        private static PauseMenu _instance;
        private static bool _isQuitting;

        public static PauseMenu Instance
        {
            get
            {
                if (_instance == null && Application.isPlaying && !_isQuitting)
                {
                    _instance = FindAnyObjectByType<PauseMenu>();
                    if (_instance == null)
                    {
                        var go = new GameObject("PauseMenu");
                        _instance = go.AddComponent<PauseMenu>();
                        // DontDestroyOnLoad(go);
                    }
                }
                return _instance;
            }
        }
        
        [Header("UI References")]
        [SerializeField] private GameObject pauseMenuPanel;
        [SerializeField] private GameObject pauseButton;

        public event Action OnGamePaused;
        public event Action OnGameResumed;
        
        private void Start()
        {
            // Subscribe to scene loaded events
            SceneManagerService.Instance.SceneLoadCompleted += SetPauseMenuByLevel;
            
            // Set initial state based on current scene
            SetPauseMenuByLevel(SceneManager.GetActiveScene().name);
            
            // Initialize pause menu state
            HidePauseMenu(false);
        }

        private void OnDestroy()
        {
            // Unsubscribe when destroyed
            if (SceneManagerService.Instance != null)
            {
                SceneManagerService.Instance.SceneLoadCompleted -= SetPauseMenuByLevel;
            }
        }

        void OnApplicationQuit()
        {
            _isQuitting = true;
        }
        
        /// <summary>
        /// Sets the pause menu game object active or inactive based on the current level
        /// </summary>
        /// <param name="levelName">The name of the level/scene</param>
        public void SetPauseMenuByLevel(string levelName)
        {
            if (string.IsNullOrEmpty(levelName))
                return;
                
            bool isMainMenu = levelName.ToLower().Contains("mainmenu");
            gameObject.SetActive(!isMainMenu);
            
            if(!isMainMenu)
                HidePauseMenu(false); // Ensure menu is hidden when switching to a game level
            
            Debug.Log($"[PauseMenu] Setting pause menu active: {!isMainMenu} for scene: {levelName}");
        }

        /// <summary>
        /// Shows the pause menu and hides the pause button. Sets input mode to UI.
        /// </summary>
        public void ShowPauseMenu()
        {
            if (pauseMenuPanel != null)
                pauseMenuPanel.SetActive(true);
            
            if (pauseButton != null)
                pauseButton.SetActive(false);
            
            // Change input mode to UI when menu is open
            InputManager.Instance.SetInputMode(InputMode.UI);
        }

        /// <summary>
        /// Hides the pause menu and shows the pause button. Sets input mode to Game.
        /// </summary>
        public void HidePauseMenu(bool resetInput = true)
        {
            if (pauseMenuPanel != null)
                pauseMenuPanel.SetActive(false);
            
            if (pauseButton != null)
                pauseButton.SetActive(true);
            
            // Change input mode back to Game when menu is closed
            if(resetInput)
                InputManager.Instance.SetInputMode(InputMode.Game);
        }

        /// <summary>
        /// Resumes the game by hiding the pause menu.
        /// </summary>
        public void ResumeGame()
        {
            HidePauseMenu();
        }

        /// <summary>
        /// Exits to the main menu scene.
        /// </summary>
        public async void ExitToMainMenu()
        {
            // Replace with the actual scene name as set in Build Settings
            var progress = new Progress<float>(p => Debug.Log($"Loading progress: {p * 100:F0}%"));
            await SceneManagerService.Instance.SwitchSceneAsync("MainMenu", progress);
        }

        /// <summary>
        /// Exits the application.
        /// </summary>
        public void ExitGame()
        {
#if UNITY_EDITOR
            UnityEditor.EditorApplication.isPlaying = false;
#else
            Application.Quit();
#endif
        }
        
        /// <summary>
        /// Loads a level based on the selection from a dropdown menu.
        /// Connect this to a Dropdown's onValueChanged event and pass the selected option text.
        /// </summary>
        /// <param name="levelSelection">The selected level name or identifier from the dropdown</param>
        public async void LoadLevel(int levelSelection)
        {
            // Hide the pause menu before loading a new level
            HidePauseMenu();
            
            // Replace with the actual scene name as set in Build Settings
            var progress = new Progress<float>(p => Debug.Log($"Loading progress: {p * 100:F0}%"));
            switch (levelSelection)
            {
                case 0:
                    await SceneManagerService.Instance.SwitchSceneAsync("MainMenu", progress);
                    break;
                case 1:
                    await SceneManagerService.Instance.SwitchSceneAsync("AppleHillsOverworld", progress);
                    break;
                case 2:
                    await SceneManagerService.Instance.SwitchSceneAsync("Quarry", progress);
                    break;
                case 3:
                    await SceneManagerService.Instance.SwitchSceneAsync("DivingForPictures", progress);
                    break;
            }
        }
    }
}