using System;
using System.Collections.Generic;
using AppleHills.Core.Interfaces;
using AppleHills.Core.Settings;
using Bootstrap;
using Core.Settings;
using Input;
using UnityEngine;

namespace Core
{
    /// <summary>
    /// Singleton manager for global game state and settings. Provides accessors for various gameplay parameters.
    /// </summary>
    public class GameManager : MonoBehaviour
    {
        // Singleton implementation
        private static GameManager _instance;
        public static GameManager Instance => _instance;

        private bool _settingsLoaded;
        private bool _developerSettingsLoaded;
        
        // Pausable implementation (counter-based)
        private int _pauseCount;
        public bool IsPaused => _pauseCount > 0;
    
        // List of pausable components that have registered with the GameManager
        private List<IPausable> _pausableComponents = new List<IPausable>();
        private LogVerbosity _settingsLogVerbosity = LogVerbosity.Warning;
        private LogVerbosity _managerLogVerbosity = LogVerbosity.Warning;

        // Events for pause state changes
        public event Action OnGamePaused;
        public event Action OnGameResumed;

        void Awake()
        {
            _instance = this;
        
            // Create settings providers if it doesn't exist
            SettingsProvider.Instance.gameObject.name = "Settings Provider";
            DeveloperSettingsProvider.Instance.gameObject.name = "Developer Settings Provider";
        
            // Load all settings synchronously during Awake
            InitializeSettings();
            InitializeDeveloperSettings();
        
            // Register for post-boot initialization
            BootCompletionService.RegisterInitAction(InitializePostBoot);
        
            // DontDestroyOnLoad(gameObject);
        }

        private void Start()
        {
            _settingsLogVerbosity = DeveloperSettingsProvider.Instance.GetSettings<DebugSettings>().settingsLogVerbosity;
            _managerLogVerbosity = DeveloperSettingsProvider.Instance.GetSettings<DebugSettings>().gameManagerLogVerbosity;
        }

        private void InitializePostBoot()
        {
            // For post-boot correct initialization order
        }

        /// <summary>
        /// Register a component as pausable, so it receives pause/resume notifications
        /// </summary>
        /// <param name="component">The pausable component to register</param>
        public void RegisterPausableComponent(IPausable component)
        {
            if (component != null && !_pausableComponents.Contains(component))
            {
                _pausableComponents.Add(component);
            
                // If the game is already paused, pause the component immediately
                if (IsPaused)
                {
                    component.Pause();
                }
            
                LogDebugMessage($"Registered pausable component: {(component as MonoBehaviour)?.name ?? "Unknown"}");
            }
        }
    
        /// <summary>
        /// Unregister a pausable component
        /// </summary>
        /// <param name="component">The pausable component to unregister</param>
        public void UnregisterPausableComponent(IPausable component)
        {
            if (component != null && _pausableComponents.Contains(component))
            {
                _pausableComponents.Remove(component);
                LogDebugMessage($"Unregistered pausable component: {(component as MonoBehaviour)?.name ?? "Unknown"}");
            }
        }
    
        /// <summary>
        /// Request a pause. Multiple systems can request pause; the game only resumes when all requests are released.
        /// </summary>
        /// <param name="requester">Optional object requesting the pause (for logging)</param>
        public void RequestPause(object requester = null)
        {
            _pauseCount++;
            if (_pauseCount == 1)
            {
                ApplyPause(true);
            }

            LogDebugMessage($"Pause requested by {requester?.ToString() ?? "Unknown"}. pauseCount = {_pauseCount}");
        }

        /// <summary>
        /// Release a previously requested pause. If this brings the pause count to zero the game resumes.
        /// </summary>
        /// <param name="requester">Optional object releasing the pause (for logging)</param>
        public void ReleasePause(object requester = null)
        {
            _pauseCount = Mathf.Max(0, _pauseCount - 1);
            if (_pauseCount == 0)
            {
                ApplyPause(false);
            }

            LogDebugMessage($"Pause released by {requester?.ToString() ?? "Unknown"}. pauseCount = {_pauseCount}");
        }

        /// <summary>
        /// Apply pause/resume state to registered components and global systems.
        /// </summary>
        /// <param name="shouldPause">True to pause; false to resume</param>
        private void ApplyPause(bool shouldPause)
        {
            // Only affect timescale if debug setting allows it
            var debugSettings = GetDeveloperSettings<DebugSettings>();
            if (debugSettings != null && debugSettings.PauseTimeOnPauseGame)
            {
                Time.timeScale = shouldPause ? 0f : 1f;
            }
            
            // Notify registered components
            foreach (var component in _pausableComponents)
            {
                if (shouldPause)
                    component.Pause();
                else
                    component.DoResume();
            }

            // Fire events
            if (shouldPause)
            {
                // TODO: Stop input here?
                InputManager.Instance.SetInputMode(InputMode.UI);
                OnGamePaused?.Invoke();
            }
            else
            {
                // TODO: Release input here?
                InputManager.Instance.SetInputMode(InputMode.GameAndUI);
                OnGameResumed?.Invoke();
            }
            
            LogDebugMessage($"Game {(shouldPause ? "paused" : "resumed")}. Paused {_pausableComponents.Count} components.");
        }

        private void InitializeSettings()
        {
            LogDebugMessage("Starting settings initialization...", "SettingsInitialization", _settingsLogVerbosity);
        
            // Load settings synchronously
            var playerSettings = SettingsProvider.Instance.LoadSettingsSynchronous<PlayerFollowerSettings>();
            var interactionSettings = SettingsProvider.Instance.LoadSettingsSynchronous<InteractionSettings>();
            var minigameSettings = SettingsProvider.Instance.LoadSettingsSynchronous<DivingMinigameSettings>();
        
            // Register settings with service locator
            if (playerSettings != null)
            {
                ServiceLocator.Register<IPlayerFollowerSettings>(playerSettings);
                LogDebugMessage("PlayerFollowerSettings registered successfully", "SettingsInitialization", _settingsLogVerbosity);
            }
            else
            {
                Debug.LogError("Failed to load PlayerFollowerSettings");
            }
            
            if (interactionSettings != null)
            {
                ServiceLocator.Register<IInteractionSettings>(interactionSettings);
                LogDebugMessage("InteractionSettings registered successfully", "SettingsInitialization", _settingsLogVerbosity);
            }
            else
            {
                Debug.LogError("Failed to load InteractionSettings");
            }
            
            if (minigameSettings != null)
            {
                ServiceLocator.Register<IDivingMinigameSettings>(minigameSettings);
                LogDebugMessage("MinigameSettings registered successfully", "SettingsInitialization", _settingsLogVerbosity);
            }
            else
            {
                Debug.LogError("Failed to load MinigameSettings");
            }

            // Log success
            _settingsLoaded = playerSettings != null && interactionSettings != null && minigameSettings != null;
            if (_settingsLoaded)
            {
                LogDebugMessage("All settings loaded and registered with ServiceLocator", "SettingsInitialization", _settingsLogVerbosity);
            }
            else
            {
                Logging.Warning("Some settings failed to load - check that all settings assets exist and are marked as Addressables");
            }
        }

        /// <summary>
        /// Check for and initialize developer settings.
        /// </summary>
        private void InitializeDeveloperSettings()
        {
            LogDebugMessage("Starting developer settings initialization...", "SettingsInitialization", _settingsLogVerbosity);
        
            // Load developer settings
            var divingDevSettings = DeveloperSettingsProvider.Instance.GetSettings<DivingDeveloperSettings>();
            var debugSettings = DeveloperSettingsProvider.Instance.GetSettings<DebugSettings>();
        
            _developerSettingsLoaded = divingDevSettings != null && debugSettings != null;
        
            if (_developerSettingsLoaded)
            {
                LogDebugMessage("All developer settings loaded successfully", "SettingsInitialization", _settingsLogVerbosity);
            }
            else
            {
                Logging.Warning("Some developer settings failed to load");
            }
        }


        // Helper method to get settings
        private T GetSettings<T>() where T : class
        {
            return ServiceLocator.Get<T>();
        }

        /// <summary>
        /// Returns the entire settings object of specified type.
        /// </summary>
        /// <typeparam name="T">Type of settings to retrieve</typeparam>
        /// <returns>The settings object or null if not found</returns>
        public static T GetSettingsObject<T>() where T : class
        {
            return Instance?.GetSettings<T>();
        }
    
        /// <summary>
        /// Returns the developer settings object of specified type.
        /// </summary>
        /// <typeparam name="T">Type of developer settings to retrieve</typeparam>
        /// <returns>The developer settings object or null if not found</returns>
        public static T GetDeveloperSettings<T>() where T : BaseDeveloperSettings
        {
            return DeveloperSettingsProvider.Instance?.GetSettings<T>();
        }
    
        private void LogDebugMessage(string message, string prefix = "GameManager", LogVerbosity verbosity = LogVerbosity.None)
        {
            if (verbosity == LogVerbosity.None)
            {
                verbosity = _managerLogVerbosity;
            }
            
            if ( verbosity <= LogVerbosity.Debug)
            {
                Logging.Debug($"[{prefix}] {message}");
            }
        }
        
        // LEFTOVER LEGACY SETTINGS
        public float PlayerStopDistance => GetSettings<IInteractionSettings>()?.PlayerStopDistance ?? 6.0f;
        public float PlayerStopDistanceDirectInteraction => GetSettings<IInteractionSettings>()?.PlayerStopDistanceDirectInteraction ?? 2.0f;
        public float DefaultPuzzlePromptRange => GetSettings<IInteractionSettings>()?.DefaultPuzzlePromptRange ?? 3.0f;
    }
}