using UnityEngine;

/// <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("Game Settings")]
    public GameSettings gameSettings;

    void Awake()
    {
        _instance = this;
        // DontDestroyOnLoad(gameObject);
    }

    void OnApplicationQuit()
    {
        _isQuitting = true;
    }

    // Accessors for game settings
    public float PlayerStopDistance => gameSettings != null ? gameSettings.playerStopDistance : 1.0f;
    public float FollowerPickupDelay => gameSettings != null ? gameSettings.followerPickupDelay : 0.2f;
    public float FollowDistance => gameSettings != null ? gameSettings.followDistance : 1.5f;
    public float ManualMoveSmooth => gameSettings != null ? gameSettings.manualMoveSmooth : 8f;
    public float ThresholdFar => gameSettings != null ? gameSettings.thresholdFar : 2.5f;
    public float ThresholdNear => gameSettings != null ? gameSettings.thresholdNear : 0.5f;
    public float StopThreshold => gameSettings != null ? gameSettings.stopThreshold : 0.5f;
    public float MoveSpeed => gameSettings != null ? gameSettings.moveSpeed : 5f;
    public float StopDistance => gameSettings != null ? gameSettings.stopDistance : 0.1f;
    public bool UseRigidbody => gameSettings != null ? gameSettings.useRigidbody : true;
    public float FollowUpdateInterval => gameSettings != null ? gameSettings.followUpdateInterval : 0.1f;
    public float FollowerSpeedMultiplier => gameSettings != null ? gameSettings.followerSpeedMultiplier : 1.2f;
    public float HeldIconDisplayHeight => gameSettings != null ? gameSettings.heldIconDisplayHeight : 2.0f;
    public GameObject BasePickupPrefab => gameSettings != null ? gameSettings.basePickupPrefab : null;
    public LayerMask InteractableLayerMask => gameSettings != null ? gameSettings.interactableLayerMask : -1;
    public float PlayerStopDistanceDirectInteraction => gameSettings != null ? gameSettings.playerStopDistanceDirectInteraction : 2.0f;

    /// <summary>
    /// Returns the combination rule for two items, if any.
    /// </summary>
    public GameSettings.CombinationRule GetCombinationRule(PickupItemData item1, PickupItemData item2)
    {
        if (gameSettings == null || gameSettings.combinationRules == null) return null;
        foreach (var rule in gameSettings.combinationRules)
        {
            if ((rule.itemA == item1 && rule.itemB == item2) || (rule.itemA == item2 && 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)
    {
        if (gameSettings == null || gameSettings.slotItemConfigs == null || slotItem == null) return null;
        foreach (var config in gameSettings.slotItemConfigs)
        {
            if (config.slotItem == slotItem)
                return config;
        }
        return null;
    }
    // Add more accessors as needed
    public float EndlessDescenderLerpSpeed => gameSettings != null ? gameSettings.endlessDescenderLerpSpeed : 12f;
    public float EndlessDescenderMaxOffset => gameSettings != null ? gameSettings.endlessDescenderMaxOffset : 3f;
    public float EndlessDescenderClampXMin => gameSettings != null ? gameSettings.endlessDescenderClampXMin : -5f;
    public float EndlessDescenderClampXMax => gameSettings != null ? gameSettings.endlessDescenderClampXMax : 5f;
    public float EndlessDescenderSpeedExponent => gameSettings != null ? gameSettings.endlessDescenderSpeedExponent : 2.5f;
    public GameSettings.HoldMovementMode DefaultHoldMovementMode => gameSettings != null ? gameSettings.defaultHoldMovementMode : GameSettings.HoldMovementMode.Pathfinding;
    public GameObject LevelSwitchMenuPrefab => gameSettings != null ? gameSettings.levelSwitchMenuPrefab : null;
}