using System;
using System.Collections;
using Core;
using Input;
using Interactions;
using UnityEngine;
using UnityEngine.Events;

namespace Items
{
    /// <summary>
    /// Saveable data for ControllerSwitchItem state
    /// </summary>
    [Serializable]
    public class ControllerSwitchItemSaveData
    {
        public bool hasBeenUsed;
    }


    /// <summary>
    /// Base interactable item that switches control from one character controller to another.
    /// Level-agnostic - handles only controller switching logic.
    /// Derive from this class for level-specific behavior (camera switching, teleportation, etc.)
    /// </summary>
    public class ControllerSwitchItem : SaveableInteractable
    {
        [Header("Controller Switch Settings")]
        [Tooltip("Name of the controller to switch to (must match registration name in InputManager)")]
        [SerializeField] protected string targetControllerName;

        [Header("Visual Feedback")]
        [Tooltip("Visual representation to hide after use (optional)")]
        [SerializeField] protected GameObject visualRepresentation;

        public UnityEvent OnCharacterSwitch;

        // State
        protected bool _hasBeenUsed;
        protected bool _isSwitching;

        public override string SaveId => $"{gameObject.scene.name}/ControllerSwitchItem/{gameObject.name}";

        internal override void OnManagedAwake()
        {
            base.OnManagedAwake();

            if (string.IsNullOrEmpty(targetControllerName))
            {
                Debug.LogError($"[ControllerSwitchItem] {gameObject.name} has no target controller name specified!");
            }
        }

        internal override void OnManagedStart()
        {
            base.OnManagedStart();

            // Apply state after restoration
            if (_hasBeenUsed && isOneTime)
            {
                DisableVisual();
            }
        }

        protected override bool CanBeClicked()
        {
            // Cannot be clicked if already used (one-time) or if currently switching
            if (_isSwitching)
                return false;

            if (isOneTime && _hasBeenUsed)
                return false;

            // Check if target controller is registered
            if (!InputManager.Instance.IsControllerRegistered(targetControllerName))
            {
                Debug.LogWarning($"[ControllerSwitchItem] Target controller '{targetControllerName}' is not registered with InputManager.");
                return false;
            }

            return base.CanBeClicked();
        }

        protected override bool DoInteraction()
        {
            if (_isSwitching)
                return false;

            Logging.Debug("[ControllerSwitchItem] Starting controller switch sequence");
            
            StartCoroutine(SwitchControllerSequence());
            
            return true;
        }

        protected virtual IEnumerator SwitchControllerSequence()
        {
            _isSwitching = true;

            // Step 1: Get controllers
            var currentController = InputManager.Instance.GetActiveController();
            var targetController = InputManager.Instance.GetController(targetControllerName);
            
            if (currentController == null || targetController == null)
            {
                Debug.LogError($"[ControllerSwitchItem] Failed to get controllers! Current: {currentController}, Target: {targetController} (name: {targetControllerName})");
                _isSwitching = false;
                yield break;
            }
            
            GameObject currentGameObject = (currentController as MonoBehaviour)?.gameObject;
            GameObject targetGameObject = (targetController as MonoBehaviour)?.gameObject;
            
            Logging.Debug($"[ControllerSwitchItem] Switching from {currentGameObject?.name} to {targetGameObject?.name}");

            // Step 2: Deactivate current controller
            DeactivateCurrentController(currentController, currentGameObject);

            // Step 3: Activate target controller
            ActivateTargetController(targetController, targetGameObject);

            // Step 4: Switch InputManager to target controller
            bool switchSuccess = InputManager.Instance.SwitchToController(targetControllerName);
            
            if (switchSuccess)
            {
                Logging.Debug($"[ControllerSwitchItem] Successfully switched input to controller: {targetControllerName}");
                OnCharacterSwitch.Invoke();
            }
            else
            {
                Debug.LogError($"[ControllerSwitchItem] Failed to switch to controller: {targetControllerName}");
            }

            // Step 5: Mark as used if one-time use
            if (isOneTime)
            {
                _hasBeenUsed = true;
                DisableVisual();
            }

            _isSwitching = false;
        }

        protected virtual void DeactivateCurrentController(ITouchInputConsumer currentController, GameObject currentGameObject)
        {
            // If current is a player controller, deactivate it
            if (currentController is BasePlayerMovementController currentPlayerController)
            {
                currentPlayerController.DeactivateController();
            }
            
            // If switching FROM follower mode, deactivate follower
            if (currentGameObject != null)
            {
                var currentFollower = currentGameObject.GetComponent<FollowerController>();
                if (currentFollower != null && currentFollower.IsFollowerActive)
                {
                    currentFollower.DeactivateFollower();
                }
            }
        }

        protected virtual void ActivateTargetController(ITouchInputConsumer targetController, GameObject targetGameObject)
        {
            // Check if target GameObject has FollowerController component
            FollowerController targetFollower = null;
            if (targetGameObject != null)
            {
                targetFollower = targetGameObject.GetComponent<FollowerController>();
            }
            
            // If switching TO a GameObject with FollowerController, we need special handling
            if (targetFollower != null)
            {
                // Switching TO Pulver player control (Pulver has both FollowerController and PulverController)
                // Deactivate follower mode, activate player control
                targetFollower.DeactivateFollower();
                
                if (targetController is BasePlayerMovementController targetPlayerController)
                {
                    targetPlayerController.ActivateController();
                }
            }
            else
            {
                // Switching TO Trafalgar (no FollowerController on Trafalgar)
                // If there's a Pulver in the scene, activate its follower mode
                var pulverFollower = FindFirstObjectByType<FollowerController>();
                if (pulverFollower != null)
                {
                    pulverFollower.ActivateFollower();
                }
                
                // Activate the target player controller
                if (targetController is BasePlayerMovementController targetPlayerController)
                {
                    targetPlayerController.ActivateController();
                }
            }
        }

        protected void DisableVisual()
        {
            if (visualRepresentation != null)
            {
                visualRepresentation.SetActive(false);
            }
        }

        #region Save/Load

        protected override object GetSerializableState()
        {
            return new ControllerSwitchItemSaveData
            {
                hasBeenUsed = _hasBeenUsed
            };
        }

        protected override void ApplySerializableState(string serializedData)
        {
            try
            {
                var data = JsonUtility.FromJson<ControllerSwitchItemSaveData>(serializedData);
                _hasBeenUsed = data.hasBeenUsed;
                Logging.Debug($"[ControllerSwitchItem] Restored state: hasBeenUsed={_hasBeenUsed}");
            }
            catch (Exception e)
            {
                Debug.LogError($"[ControllerSwitchItem] Failed to deserialize save data: {e.Message}");
            }
        }

        #endregion

#if UNITY_EDITOR
        private void OnValidate()
        {
            // Visual feedback in editor
            if (string.IsNullOrEmpty(targetControllerName))
            {
                name = "ControllerSwitchItem (UNCONFIGURED)";
            }
            else
            {
                name = $"ControllerSwitchItem_To_{targetControllerName}";
            }
        }
#endif
    }
}