using UnityEngine;
using AppleHills.Core.Settings;
using System.Collections;

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

    /// <summary>
    /// Singleton instance of the GameManager.
    /// </summary>
    public static GameManager Instance
    {
        get
        {
            if (_instance == null && Application.isPlaying && !_isQuitting)
            {
                _instance = FindAnyObjectByType<GameManager>();
                if (_instance == null)
                {
                    var go = new GameObject("GameManager");
                    _instance = go.AddComponent<GameManager>();
                    // DontDestroyOnLoad(go);
                }
            }
            return _instance;
        }
    }

    [Header("Legacy Game Settings (Deprecated)")]
    [Tooltip("This is only used for migration to the new settings system")]
    public GameSettings legacyGameSettings;

    [Header("Settings Status")]
    [SerializeField] private bool _settingsLoaded = false;

    void Awake()
    {
        _instance = this;
        
        // Create settings provider if it doesn't exist
        SettingsProvider.Instance.gameObject.name = "Settings Provider";
        
        // Load all settings
        StartCoroutine(InitializeSettings());
        
        // DontDestroyOnLoad(gameObject);
    }

    private IEnumerator InitializeSettings()
    {
        // Initialize the settings provider
        var initComplete = false;
        SettingsProvider.Instance.PreloadAllSettings(() => initComplete = true);
        
        // Wait for settings to be loaded
        while (!initComplete)
        {
            yield return null;
        }

        // Register settings with service locator
        ServiceLocator.Register<IPlayerFollowerSettings>(
            SettingsProvider.Instance.GetSettings<PlayerFollowerSettings>());
            
        ServiceLocator.Register<IInteractionSettings>(
            SettingsProvider.Instance.GetSettings<InteractionSettings>());
            
        ServiceLocator.Register<IMinigameSettings>(
            SettingsProvider.Instance.GetSettings<MinigameSettings>());

        // Log success
        Debug.Log("All settings loaded and registered with ServiceLocator");
        _settingsLoaded = true;
        
        // Migrate settings if needed
        if (legacyGameSettings != null)
        {
            MigrateFromLegacySettings();
        }
    }
    
    private void MigrateFromLegacySettings()
    {
        // This method can be used to copy settings from the old GameSettings to the new system
        // Implement if needed for your production environment
        Debug.Log("Legacy settings migration available but not implemented.");
    }

    void OnApplicationQuit()
    {
        _isQuitting = true;
        ServiceLocator.Clear();
    }

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

    // PLAYER & FOLLOWER SETTINGS
    
    // Player settings
    public float MoveSpeed => GetSettings<IPlayerFollowerSettings>()?.MoveSpeed ?? 5f;
    public float StopDistance => GetSettings<IPlayerFollowerSettings>()?.StopDistance ?? 0.1f;
    public bool UseRigidbody => GetSettings<IPlayerFollowerSettings>()?.UseRigidbody ?? true;
    public GameSettings.HoldMovementMode DefaultHoldMovementMode => 
        GetSettings<IPlayerFollowerSettings>()?.DefaultHoldMovementMode ?? GameSettings.HoldMovementMode.Pathfinding;
    
    // Follower settings
    public float FollowDistance => GetSettings<IPlayerFollowerSettings>()?.FollowDistance ?? 1.5f;
    public float ManualMoveSmooth => GetSettings<IPlayerFollowerSettings>()?.ManualMoveSmooth ?? 8f;
    public float ThresholdFar => GetSettings<IPlayerFollowerSettings>()?.ThresholdFar ?? 2.5f;
    public float ThresholdNear => GetSettings<IPlayerFollowerSettings>()?.ThresholdNear ?? 0.5f;
    public float StopThreshold => GetSettings<IPlayerFollowerSettings>()?.StopThreshold ?? 0.1f;
    public float FollowUpdateInterval => GetSettings<IPlayerFollowerSettings>()?.FollowUpdateInterval ?? 0.1f;
    public float FollowerSpeedMultiplier => GetSettings<IPlayerFollowerSettings>()?.FollowerSpeedMultiplier ?? 1.2f;
    public float HeldIconDisplayHeight => GetSettings<IPlayerFollowerSettings>()?.HeldIconDisplayHeight ?? 2.0f;
    
    // INTERACTION SETTINGS
    
    public float PlayerStopDistance => GetSettings<IInteractionSettings>()?.PlayerStopDistance ?? 6.0f;
    public float PlayerStopDistanceDirectInteraction => GetSettings<IInteractionSettings>()?.PlayerStopDistanceDirectInteraction ?? 2.0f;
    public float FollowerPickupDelay => GetSettings<IInteractionSettings>()?.FollowerPickupDelay ?? 0.2f;
    public LayerMask InteractableLayerMask => GetSettings<IInteractionSettings>()?.InteractableLayerMask ?? -1;
    public GameObject BasePickupPrefab => GetSettings<IInteractionSettings>()?.BasePickupPrefab;
    public GameObject LevelSwitchMenuPrefab => GetSettings<IInteractionSettings>()?.LevelSwitchMenuPrefab;

    /// <summary>
    /// Returns the combination rule for two items, if any.
    /// </summary>
    public GameSettings.CombinationRule GetCombinationRule(PickupItemData item1, PickupItemData item2)
    {
        var settings = GetSettings<IInteractionSettings>();
        if (settings == null || settings.CombinationRules == null) return null;
        
        foreach (var rule in settings.CombinationRules)
        {
            if ((PickupItemData.AreEquivalent(rule.itemA, item1) && PickupItemData.AreEquivalent(rule.itemB, item2)) ||
                (PickupItemData.AreEquivalent(rule.itemA, item2) && PickupItemData.AreEquivalent(rule.itemB, item1)))
            {
                return rule;
            }
        }
        return null;
    }

    /// <summary>
    /// Returns the slot item config for a given slot item.
    /// </summary>
    public GameSettings.SlotItemConfig GetSlotItemConfig(PickupItemData slotItem)
    {
        var settings = GetSettings<IInteractionSettings>();
        if (settings == null || settings.SlotItemConfigs == null || slotItem == null) return null;
        
        foreach (var config in settings.SlotItemConfigs)
        {
            if (PickupItemData.AreEquivalent(slotItem, config.slotItem))
                return config;
        }
        return null;
    }

    // MINIGAME SETTINGS
    
    // Endless Descender settings
    public float EndlessDescenderLerpSpeed => GetSettings<IMinigameSettings>()?.EndlessDescenderLerpSpeed ?? 12f;
    public float EndlessDescenderMaxOffset => GetSettings<IMinigameSettings>()?.EndlessDescenderMaxOffset ?? 3f;
    public float EndlessDescenderClampXMin => GetSettings<IMinigameSettings>()?.EndlessDescenderClampXMin ?? -3.5f;
    public float EndlessDescenderClampXMax => GetSettings<IMinigameSettings>()?.EndlessDescenderClampXMax ?? 3.5f;
    public float EndlessDescenderSpeedExponent => GetSettings<IMinigameSettings>()?.EndlessDescenderSpeedExponent ?? 2.5f;
}