using Input;
using UnityEngine;
using System;
using System.Collections.Generic;
using UnityEngine.Events;
using System.Threading.Tasks;

namespace Interactions
{
    public enum CharacterToInteract
    {
        None,
        Trafalgar,
        Pulver,
        Both
    }
    
    /// <summary>
    /// Represents an interactable object that can respond to tap input events.
    /// </summary>
    public class Interactable : MonoBehaviour, ITouchInputConsumer
    {
        [Header("Interaction Settings")]
        public bool isOneTime;
        public float cooldown = -1f;
        public CharacterToInteract characterToInteract = CharacterToInteract.Pulver;
        
        [Header("Interaction Events")]
        public UnityEvent<PlayerTouchController, FollowerController> interactionStarted;
        public UnityEvent interactionInterrupted;
        public UnityEvent characterArrived;
        public UnityEvent<bool> interactionComplete;
        
        // Helpers for managing interaction state
        private bool _interactionInProgress;
        private PlayerTouchController _playerRef;
        private FollowerController _followerController;
        private bool _isActive = true;
        private InteractionEventType _currentEventType;
        
        // Action component system
        private List<InteractionActionBase> _registeredActions = new List<InteractionActionBase>();

        private void Awake()
        {
            // Subscribe to interactionComplete event
            interactionComplete.AddListener(OnInteractionComplete);
        }

        /// <summary>
        /// Register an action component with this interactable
        /// </summary>
        public void RegisterAction(InteractionActionBase action)
        {
            if (!_registeredActions.Contains(action))
            {
                _registeredActions.Add(action);
            }
        }

        /// <summary>
        /// Unregister an action component from this interactable
        /// </summary>
        public void UnregisterAction(InteractionActionBase action)
        {
            _registeredActions.Remove(action);
        }
        
        /// <summary>
        /// Dispatch an interaction event to all registered actions and await their completion
        /// </summary>
        private async Task DispatchEventAsync(InteractionEventType eventType)
        {
            _currentEventType = eventType;
            
            // Collect all tasks from actions that want to respond
            List<Task<bool>> tasks = new List<Task<bool>>();
            
            foreach (var action in _registeredActions)
            {
                Task<bool> task = action.OnInteractionEvent(eventType, _playerRef, _followerController);
                if (task != null)
                {
                    tasks.Add(task);
                }
            }
            
            if (tasks.Count > 0)
            {
                // Wait for all tasks to complete
                await Task.WhenAll(tasks);
            }
            // If no tasks were added, the method will complete immediately (no need for await)
        }

        /// <summary>
        /// Handles tap input. Triggers interaction logic.
        /// </summary>
        public void OnTap(Vector2 worldPosition)
        {
            if (!_isActive)
            {
                Debug.Log($"[Interactable] Is disabled!");
                return;
            }
            Debug.Log($"[Interactable] OnTap at {worldPosition} on {gameObject.name}");
            
            // Start the interaction process asynchronously
            _ = TryInteractAsync();
        }

        private async Task TryInteractAsync()
        {
            _interactionInProgress = true;
            
            _playerRef = FindFirstObjectByType<PlayerTouchController>();
            _followerController = FindFirstObjectByType<FollowerController>();
            
            interactionStarted?.Invoke(_playerRef, _followerController);
            
            // Dispatch the InteractionStarted event to action components
            await DispatchEventAsync(InteractionEventType.InteractionStarted);
            
            // After all InteractionStarted actions complete, proceed to player movement
            await StartPlayerMovementAsync();
        }
        
        private async Task StartPlayerMovementAsync()
        {
            if (_playerRef == null)
            {
                Debug.Log($"[Interactable] Player character could not be found. Aborting interaction.");
                interactionInterrupted.Invoke();
                await DispatchEventAsync(InteractionEventType.InteractionInterrupted);
                return;
            }

            // If characterToInteract is None, immediately trigger the characterArrived event
            if (characterToInteract == CharacterToInteract.None)
            {
                await BroadcastCharacterArrivedAsync();
                return;
            }
            
            // Check for a CharacterMoveToTarget component for Trafalgar (player) or Both
            Vector3 stopPoint;
            bool customTargetFound = false;
            
            CharacterMoveToTarget[] moveTargets = GetComponentsInChildren<CharacterMoveToTarget>();
            foreach (var target in moveTargets)
            {
                // Target is valid if it matches Trafalgar specifically or is set to Both
                if (target.characterType == CharacterToInteract.Trafalgar || target.characterType == CharacterToInteract.Both)
                {
                    stopPoint = target.GetTargetPosition();
                    customTargetFound = true;
                    
                    // We need to wait for the player to arrive, so use a TaskCompletionSource
                    var tcs = new TaskCompletionSource<bool>();
                    
                    // Use local functions instead of circular lambda references
                    void OnPlayerArrivedLocal()
                    {
                        // First remove both event handlers to prevent memory leaks
                        if (_playerRef != null)
                        {
                            _playerRef.OnArrivedAtTarget -= OnPlayerArrivedLocal;
                            _playerRef.OnMoveToCancelled -= OnPlayerMoveCancelledLocal;
                        }
                        
                        // Then continue with the interaction flow
                        OnPlayerArrivedAsync().ContinueWith(_ => tcs.TrySetResult(true));
                    }
                    
                    void OnPlayerMoveCancelledLocal()
                    {
                        // First remove both event handlers to prevent memory leaks
                        if (_playerRef != null)
                        {
                            _playerRef.OnArrivedAtTarget -= OnPlayerArrivedLocal;
                            _playerRef.OnMoveToCancelled -= OnPlayerMoveCancelledLocal;
                        }
                        
                        // Then handle the cancellation
                        OnPlayerMoveCancelledAsync().ContinueWith(_ => tcs.TrySetResult(false));
                    }
                    
                    // Unsubscribe previous handlers (if any)
                    _playerRef.OnArrivedAtTarget -= OnPlayerArrived;
                    _playerRef.OnMoveToCancelled -= OnPlayerMoveCancelled;
                    
                    // Subscribe our new handlers
                    _playerRef.OnArrivedAtTarget += OnPlayerArrivedLocal;
                    _playerRef.OnMoveToCancelled += OnPlayerMoveCancelledLocal;
                    
                    // Start the player movement
                    _playerRef.MoveToAndNotify(stopPoint);
                    
                    // Await player arrival
                    await tcs.Task;
                    return;
                }
            }
            
            // If no custom target was found, use the default behavior
            if (!customTargetFound)
            {
                // Compute closest point on the interaction radius
                Vector3 interactablePos = transform.position;
                Vector3 playerPos = _playerRef.transform.position;
                float stopDistance = characterToInteract == CharacterToInteract.Pulver
                    ? GameManager.Instance.PlayerStopDistance
                    : GameManager.Instance.PlayerStopDistanceDirectInteraction;
                Vector3 toPlayer = (playerPos - interactablePos).normalized;
                stopPoint = interactablePos + toPlayer * stopDistance;

                // We need to wait for the player to arrive, so use a TaskCompletionSource
                var tcs = new TaskCompletionSource<bool>();
                
                // Use local functions instead of circular lambda references
                void OnPlayerArrivedLocal()
                {
                    // First remove both event handlers to prevent memory leaks
                    if (_playerRef != null)
                    {
                        _playerRef.OnArrivedAtTarget -= OnPlayerArrivedLocal;
                        _playerRef.OnMoveToCancelled -= OnPlayerMoveCancelledLocal;
                    }
                    
                    // Then continue with the interaction flow
                    OnPlayerArrivedAsync().ContinueWith(_ => tcs.TrySetResult(true));
                }
                
                void OnPlayerMoveCancelledLocal()
                {
                    // First remove both event handlers to prevent memory leaks
                    if (_playerRef != null)
                    {
                        _playerRef.OnArrivedAtTarget -= OnPlayerArrivedLocal;
                        _playerRef.OnMoveToCancelled -= OnPlayerMoveCancelledLocal;
                    }
                    
                    // Then handle the cancellation
                    OnPlayerMoveCancelledAsync().ContinueWith(_ => tcs.TrySetResult(false));
                }
                
                // Unsubscribe previous handlers (if any)
                _playerRef.OnArrivedAtTarget -= OnPlayerArrived;
                _playerRef.OnMoveToCancelled -= OnPlayerMoveCancelled;
                
                // Subscribe our new handlers
                _playerRef.OnArrivedAtTarget += OnPlayerArrivedLocal;
                _playerRef.OnMoveToCancelled += OnPlayerMoveCancelledLocal;
                
                // Start the player movement
                _playerRef.MoveToAndNotify(stopPoint);
                
                // Await player arrival
                await tcs.Task;
            }
        }

        private async Task OnPlayerMoveCancelledAsync()
        {
            _interactionInProgress = false;
            interactionInterrupted?.Invoke();
            await DispatchEventAsync(InteractionEventType.InteractionInterrupted);
        }

        private async Task OnPlayerArrivedAsync()
        {
            if (!_interactionInProgress)
                return;
            
            // Dispatch PlayerArrived event
            await DispatchEventAsync(InteractionEventType.PlayerArrived);
            
            // After all PlayerArrived actions complete, proceed to character interaction
            await HandleCharacterInteractionAsync();
        }
        
        private async Task HandleCharacterInteractionAsync()
        {
            if (characterToInteract == CharacterToInteract.Pulver)
            {
                // We need to wait for the follower to arrive, so use a TaskCompletionSource
                var tcs = new TaskCompletionSource<bool>();
                
                // Create a proper local function for the event handler
                void OnFollowerArrivedLocal()
                {
                    // First remove the event handler to prevent memory leaks
                    if (_followerController != null)
                    {
                        _followerController.OnPickupArrived -= OnFollowerArrivedLocal;
                    }
                    
                    // Then continue with the interaction flow
                    OnFollowerArrivedAsync().ContinueWith(_ => tcs.TrySetResult(true));
                }
                
                // Register our new local function handler
                _followerController.OnPickupArrived += OnFollowerArrivedLocal;
                
                // Check for a CharacterMoveToTarget component for Pulver or Both
                Vector3 targetPosition = transform.position;
                CharacterMoveToTarget[] moveTargets = GetComponentsInChildren<CharacterMoveToTarget>();
                foreach (var target in moveTargets)
                {
                    if (target.characterType == CharacterToInteract.Pulver || target.characterType == CharacterToInteract.Both)
                    {
                        targetPosition = target.GetTargetPosition();
                        break;
                    }
                }
                
                // Use the new GoToPoint method instead of GoToPointAndReturn
                _followerController.GoToPoint(targetPosition);
                
                // Await follower arrival
                await tcs.Task;
            }
            else if (characterToInteract == CharacterToInteract.Trafalgar)
            {
                await BroadcastCharacterArrivedAsync();
            }
            else if (characterToInteract == CharacterToInteract.Both)
            {
                // We need to wait for the follower to arrive, so use a TaskCompletionSource
                var tcs = new TaskCompletionSource<bool>();
                
                // Create a proper local function for the event handler
                void OnFollowerArrivedLocal()
                {
                    // First remove the event handler to prevent memory leaks
                    if (_followerController != null)
                    {
                        _followerController.OnPickupArrived -= OnFollowerArrivedLocal;
                    }
                    
                    // Then continue with the interaction flow
                    OnFollowerArrivedAsync().ContinueWith(_ => tcs.TrySetResult(true));
                }
                
                // Register our new local function handler
                _followerController.OnPickupArrived += OnFollowerArrivedLocal;
                
                // Check for a CharacterMoveToTarget component for Pulver or Both
                Vector3 targetPosition = transform.position;
                CharacterMoveToTarget[] moveTargets = GetComponentsInChildren<CharacterMoveToTarget>();
                foreach (var target in moveTargets)
                {
                    if (target.characterType == CharacterToInteract.Pulver || target.characterType == CharacterToInteract.Both)
                    {
                        targetPosition = target.GetTargetPosition();
                        break;
                    }
                }
                
                // Use the new GoToPoint method instead of GoToPointAndReturn
                _followerController.GoToPoint(targetPosition);
                
                // Await follower arrival
                await tcs.Task;
            }
        }

        private async Task OnFollowerArrivedAsync()
        {
            if (!_interactionInProgress)
                return;
            
            // Dispatch InteractingCharacterArrived event and WAIT for all actions to complete
            // This ensures we wait for any timeline animations to finish before proceeding
            Debug.Log("[Interactable] Follower arrived, dispatching InteractingCharacterArrived event and waiting for completion");
            await DispatchEventAsync(InteractionEventType.InteractingCharacterArrived);
            Debug.Log("[Interactable] All InteractingCharacterArrived actions completed, proceeding with interaction");
            
            // Check if we have any components that might have paused the interaction flow
            bool hasTimelineActions = false;
            foreach (var action in _registeredActions)
            {
                if (action is InteractionTimelineAction timelineAction && 
                    timelineAction.respondToEvents.Contains(InteractionEventType.InteractingCharacterArrived) &&
                    timelineAction.pauseInteractionFlow)
                {
                    hasTimelineActions = true;
                    break;
                }
            }
            
            // Tell the follower to return to the player
            if (_followerController != null && _playerRef != null)
            {
                _followerController.ReturnToPlayer(_playerRef.transform);
            }
            
            // After all InteractingCharacterArrived actions complete, proceed to character arrived
            await BroadcastCharacterArrivedAsync();
        }
        
        // Legacy non-async method to maintain compatibility with existing code
        private void OnPlayerArrived()
        {
            // This is now just a wrapper for the async version
            _ = OnPlayerArrivedAsync();
        }
        
        // Legacy non-async method to maintain compatibility with existing code
        private void OnPlayerMoveCancelled()
        {
            // This is now just a wrapper for the async version
            _ = OnPlayerMoveCancelledAsync();
        }
        
        private async Task BroadcastCharacterArrivedAsync()
        {
            // Check for ObjectiveStepBehaviour and lock state
            var step = GetComponent<PuzzleS.ObjectiveStepBehaviour>();
            if (step != null && !step.IsStepUnlocked())
            {
                DebugUIMessage.Show("This step is locked!", Color.yellow);
                BroadcastInteractionComplete(false);
                // Reset variables for next time
                _interactionInProgress = false;
                _playerRef = null;
                _followerController = null;
                return;
            }

            // Dispatch CharacterArrived event
            // await DispatchEventAsync(InteractionEventType.InteractingCharacterArrived);
            
            // Broadcast appropriate event
            characterArrived?.Invoke();
            
            // Reset variables for next time
            _interactionInProgress = false;
            _playerRef = null;
            _followerController = null;
        }
        
        private async void OnInteractionComplete(bool success)
        {
            // Dispatch InteractionComplete event
            await DispatchEventAsync(InteractionEventType.InteractionComplete);
            
            if (success)
            {
                if (isOneTime)
                {
                    _isActive = false;
                }
                else if (cooldown >= 0f)
                {
                    StartCoroutine(HandleCooldown());
                }
            }
        }

        private System.Collections.IEnumerator HandleCooldown()
        {
            _isActive = false;
            yield return new WaitForSeconds(cooldown);
            _isActive = true;
        }

        public void OnHoldStart(Vector2 position)
        {
            throw new NotImplementedException();
        }

        public void OnHoldMove(Vector2 position)
        {
            throw new NotImplementedException();
        }

        public void OnHoldEnd(Vector2 position)
        {
            throw new NotImplementedException();
        }

        public void BroadcastInteractionComplete(bool success)
        {
            interactionComplete?.Invoke(success);
        }
        
    #if UNITY_EDITOR
        /// <summary>
        /// Draws gizmos for pickup interaction range in the editor.
        /// </summary>
        void OnDrawGizmos()
        {
            float playerStopDistance = characterToInteract == CharacterToInteract.Trafalgar
                ? AppleHills.SettingsAccess.GetPlayerStopDistanceDirectInteraction()
                : AppleHills.SettingsAccess.GetPlayerStopDistance();

            Gizmos.color = Color.yellow;
            Gizmos.DrawWireSphere(transform.position, playerStopDistance);
            GameObject playerObj = GameObject.FindGameObjectWithTag("Player");
            if (playerObj != null)
            {
                Vector3 stopPoint = transform.position +
                                    (playerObj.transform.position - transform.position).normalized * playerStopDistance;
                Gizmos.color = Color.cyan;
                Gizmos.DrawSphere(stopPoint, 0.15f);
            }
        }
    #endif
    }
}