using System.Collections.Generic;
using System.Linq;
using AppleHills.Data.CardSystem;
using Bootstrap;
using Data.CardSystem;
using Pixelplacement;
using UI.Core;
using UI.DragAndDrop.Core;
using UnityEngine;
using UnityEngine.UI;

namespace UI.CardSystem
{
    /// <summary>
    /// UI page for viewing the player's card collection in an album.
    /// Manages booster pack button visibility and opening flow.
    /// </summary>
    public class AlbumViewPage : UIPage
    {
        [Header("UI References")]
        [SerializeField] private CanvasGroup canvasGroup;
        [SerializeField] private Button exitButton;
        [SerializeField] private BookCurlPro.BookPro book;
        
        [Header("Zone Navigation")]
        [SerializeField] private BookTabButton[] zoneTabs; // All zone tab buttons
        
        [Header("Album Card Reveal")]
        [SerializeField] private SlotContainer bottomRightSlots;
        [SerializeField] private GameObject albumCardPlacementPrefab; // The wrapper prefab with flip/drag (AlbumPlacementCard)
        
        [Header("Card Enlarge System")]
        [SerializeField] private GameObject cardEnlargedBackdrop; // Backdrop to block interactions
        [SerializeField] private Transform cardEnlargedContainer; // Container for enlarged cards (sits above backdrop)
        
        [Header("Booster Pack UI")]
        [SerializeField] private GameObject[] boosterPackButtons;
        [SerializeField] private BoosterOpeningPage boosterOpeningPage;
        
        private Input.InputMode _previousInputMode;
        private List<AlbumCardPlacementDraggable> _activeCards = new List<AlbumCardPlacementDraggable>();
        private const int MAX_VISIBLE_CARDS = 3;

        private void Awake()
        {
            // Make sure we have a CanvasGroup for transitions
            if (canvasGroup == null)
                canvasGroup = GetComponent<CanvasGroup>();
            if (canvasGroup == null)
                canvasGroup = gameObject.AddComponent<CanvasGroup>();
            
            // Hide backdrop initially
            if (cardEnlargedBackdrop != null)
            {
                cardEnlargedBackdrop.SetActive(false);
            }
            
            // Set up exit button
            if (exitButton != null)
            {
                exitButton.onClick.AddListener(OnExitButtonClicked);
            }
            
            // Set up booster pack button listeners
            SetupBoosterButtonListeners();
            
            // Register for post-boot initialization
            BootCompletionService.RegisterInitAction(InitializePostBoot);
            
            // UI pages should start disabled
            gameObject.SetActive(false);
        }
        
        private void InitializePostBoot()
        {
            // Subscribe to CardSystemManager events
            if (CardSystemManager.Instance != null)
            {
                CardSystemManager.Instance.OnBoosterCountChanged += OnBoosterCountChanged;
                // NOTE: OnPendingCardAdded is subscribed in TransitionIn, not here
                // This prevents spawning cards when page is not active
                
                // Update initial button visibility
                int initialCount = CardSystemManager.Instance.GetBoosterPackCount();
                UpdateBoosterButtons(initialCount);
            }
        }
        
        private void SetupBoosterButtonListeners()
        {
            if (boosterPackButtons == null) return;
            
            for (int i = 0; i < boosterPackButtons.Length; i++)
            {
                if (boosterPackButtons[i] == null) continue;
                
                Button button = boosterPackButtons[i].GetComponent<Button>();
                if (button != null)
                {
                    button.onClick.AddListener(OnBoosterButtonClicked);
                }
            }
        }

        private void OnDestroy()
        {
            // Unsubscribe from CardSystemManager
            if (CardSystemManager.Instance != null)
            {
                CardSystemManager.Instance.OnBoosterCountChanged -= OnBoosterCountChanged;
                // NOTE: OnPendingCardAdded is unsubscribed in TransitionOut
            }
            
            // Clean up exit button
            if (exitButton != null)
            {
                exitButton.onClick.RemoveListener(OnExitButtonClicked);
            }
            
            // Clean up booster button listeners
            if (boosterPackButtons != null)
            {
                foreach (var buttonObj in boosterPackButtons)
                {
                    if (buttonObj == null) continue;
                    
                    Button button = buttonObj.GetComponent<Button>();
                    if (button != null)
                    {
                        button.onClick.RemoveListener(OnBoosterButtonClicked);
                    }
                }
            }
            
            // Clean up active cards
            CleanupActiveCards();
        }

        private void OnExitButtonClicked()
        {
            if (book != null && book.CurrentPaper != 1)
            {
                // Not on page 0, flip to page 0 first
                BookCurlPro.AutoFlip autoFlip = book.GetComponent<BookCurlPro.AutoFlip>();
                if (autoFlip == null)
                {
                    autoFlip = book.gameObject.AddComponent<BookCurlPro.AutoFlip>();
                }
                
                autoFlip.enabled = true;
                autoFlip.StartFlipping(1);
            }
            else
            {
                // Already on page 0 or no book reference, exit
                // Restore input mode before popping
                if (Input.InputManager.Instance != null)
                {
                    Input.InputManager.Instance.SetInputMode(_previousInputMode);
                    Debug.Log($"[AlbumViewPage] Restored input mode to {_previousInputMode} on exit");
                }
                
                if (UIPageController.Instance != null)
                {
                    UIPageController.Instance.PopPage();
                }
            }
        }
        
        private void OnBoosterCountChanged(int newCount)
        {
            UpdateBoosterButtons(newCount);
        }
        
        private void UpdateBoosterButtons(int boosterCount)
        {
            if (boosterPackButtons == null || boosterPackButtons.Length == 0) return;
            
            int visibleCount = Mathf.Min(boosterCount, boosterPackButtons.Length);
            
            for (int i = 0; i < boosterPackButtons.Length; i++)
            {
                if (boosterPackButtons[i] != null)
                {
                    boosterPackButtons[i].SetActive(i < visibleCount);
                }
            }
        }
        
        private void OnBoosterButtonClicked()
        {
            if (boosterOpeningPage != null && UIPageController.Instance != null)
            {
                // Pass current booster count to the opening page
                int boosterCount = CardSystemManager.Instance?.GetBoosterPackCount() ?? 0;
                boosterOpeningPage.SetAvailableBoosterCount(boosterCount);
                
                UIPageController.Instance.PushPage(boosterOpeningPage);
            }
        }
        
        public override void TransitionIn()
        {
            // Only store and switch input mode if this is the first time entering
            // (when _previousInputMode hasn't been set yet)
            if (Input.InputManager.Instance != null)
            {
                // Store the current input mode before switching
                _previousInputMode = Input.InputMode.GameAndUI;
                Input.InputManager.Instance.SetInputMode(Input.InputMode.UI);
                Debug.Log("[AlbumViewPage] Switched to UI-only input mode on first entry");
            }
            
            // Subscribe to pending card events while page is active
            if (CardSystemManager.Instance != null)
            {
                CardSystemManager.Instance.OnPendingCardAdded += OnPendingCardAdded;
            }
            
            // Spawn pending cards when opening album
            SpawnPendingCards();
            
            base.TransitionIn();
        }
        
        public override void TransitionOut()
        {
            // Unsubscribe from pending card events when page closes
            if (CardSystemManager.Instance != null)
            {
                CardSystemManager.Instance.OnPendingCardAdded -= OnPendingCardAdded;
            }
            
            // Don't restore input mode here - only restore when actually exiting (in OnExitButtonClicked)
            base.TransitionOut();
        }

        protected override void DoTransitionIn(System.Action onComplete)
        {
            // Simple fade in animation
            if (canvasGroup != null)
            {
                canvasGroup.alpha = 0f;
                Tween.Value(0f, 1f, (value) => canvasGroup.alpha = value, transitionDuration, 0f, Tween.EaseInOut, Tween.LoopType.None, null, onComplete, obeyTimescale: false);
            }
            else
            {
                // Fallback if no CanvasGroup
                onComplete?.Invoke();
            }
        }

        protected override void DoTransitionOut(System.Action onComplete)
        {
            // Clean up any enlarged card state before closing
            CleanupEnlargedCardState();
            
            // Simple fade out animation
            if (canvasGroup != null)
            {
                Tween.Value(canvasGroup.alpha, 0f, (value) => canvasGroup.alpha = value, transitionDuration, 0f, Tween.EaseInOut, Tween.LoopType.None, null, onComplete, obeyTimescale: false);
            }
            else
            {
                // Fallback if no CanvasGroup
                onComplete?.Invoke();
            }
        }
        
        /// <summary>
        /// Clean up enlarged card state when closing the album
        /// </summary>
        private void CleanupEnlargedCardState()
        {
            // Hide backdrop if visible
            if (cardEnlargedBackdrop != null && cardEnlargedBackdrop.activeSelf)
            {
                cardEnlargedBackdrop.SetActive(false);
            }
            
            // If there's an enlarged card in the container, return it to its slot
            if (cardEnlargedContainer != null && cardEnlargedContainer.childCount > 0)
            {
                // Get all enlarged cards (should only be one, but just in case)
                for (int i = cardEnlargedContainer.childCount - 1; i >= 0; i--)
                {
                    Transform cardTransform = cardEnlargedContainer.GetChild(i);
                    AlbumCard albumCard = cardTransform.GetComponent<AlbumCard>();
                    
                    if (albumCard != null && albumCard.IsEnlarged)
                    {
                        // Force reset state and return to slot
                        Transform originalParent = albumCard.GetOriginalParent();
                        if (originalParent != null)
                        {
                            cardTransform.SetParent(originalParent, true);
                            cardTransform.localPosition = albumCard.GetOriginalLocalPosition();
                            cardTransform.localRotation = albumCard.GetOriginalLocalRotation();
                        }
                        
                        albumCard.ForceResetEnlargedState();
                    }
                }
            }
        }
        
        #region Album Card Reveal System
        
        /// <summary>
        /// Spawn pending cards from CardSystemManager
        /// Only spawns unique cards (one per definition+rarity, not one per copy)
        /// </summary>
        private void SpawnPendingCards()
        {
            if (CardSystemManager.Instance == null || bottomRightSlots == null || albumCardPlacementPrefab == null)
                return;
            
            var pending = CardSystemManager.Instance.GetPendingRevealCards();
            
            // Get unique cards only (by DefinitionId + Rarity)
            // Filter out cards with CopiesOwned = 0 (shouldn't happen but guard against it)
            var uniquePending = pending
                .Where(c => c.CopiesOwned > 0) // Guard: exclude zero-count cards
                .GroupBy(c => new { c.DefinitionId, c.Rarity })
                .Select(g => g.First()) // Take first instance of each unique card
                .ToList();
            
            int spawnCount = Mathf.Min(uniquePending.Count, MAX_VISIBLE_CARDS);
            
            Debug.Log($"[AlbumViewPage] Spawning {spawnCount} unique pending cards (total pending: {pending.Count})");
            
            for (int i = 0; i < spawnCount; i++)
            {
                SpawnCardInSlot(i, uniquePending[i]);
            }
        }
        
        /// <summary>
        /// Spawn a card in a specific slot
        /// </summary>
        private void SpawnCardInSlot(int slotIndex, CardData cardData)
        {
            // Guard: Don't spawn cards with zero copies
            if (cardData.CopiesOwned <= 0)
            {
                Debug.LogWarning($"[AlbumViewPage] Skipping spawn of card '{cardData.Name}' with {cardData.CopiesOwned} copies");
                return;
            }
            
            DraggableSlot slot = FindSlotByIndex(slotIndex);
            if (slot == null)
            {
                Debug.LogWarning($"[AlbumViewPage] Could not find slot with SlotIndex {slotIndex}");
                return;
            }
            
            // Instantiate card directly as child of the slot container (not the slot itself, not canvas root)
            // This keeps it in the correct UI hierarchy
            GameObject cardObj = Instantiate(albumCardPlacementPrefab, bottomRightSlots.transform);
            AlbumCardPlacementDraggable cardPlacement = cardObj.GetComponent<AlbumCardPlacementDraggable>();
            
            if (cardPlacement != null)
            {
                // Setup card data
                cardPlacement.SetupCard(cardData);
                
                // Subscribe to events
                cardPlacement.OnCardRevealed += OnCardRevealed;
                cardPlacement.OnCardPlacedInAlbum += OnCardPlacedInAlbum;
                
                // NOW assign to slot - this will:
                // 1. Reparent to slot
                // 2. Apply slot's occupantSizeMode scaling
                // 3. Animate to slot position
                cardPlacement.AssignToSlot(slot, true);
                
                // Track it
                _activeCards.Add(cardPlacement);
                
                Debug.Log($"[AlbumViewPage] Spawned card '{cardData.Name}' (CopiesOwned: {cardData.CopiesOwned}) in slot {slotIndex}");
            }
            else
            {
                Debug.LogWarning($"[AlbumViewPage] Spawned card has no AlbumCardDraggable component!");
                Destroy(cardObj);
            }
        }
        
        /// <summary>
        /// Handle when a new card is added to pending queue
        /// Only spawn if this unique card isn't already visualized
        /// </summary>
        private void OnPendingCardAdded(CardData card)
        {
            // Guard: Don't spawn cards with zero copies
            if (card.CopiesOwned <= 0)
            {
                Debug.LogWarning($"[AlbumViewPage] Ignoring pending card '{card.Name}' with {card.CopiesOwned} copies");
                return;
            }
            
            // Check if we already have a card with this definition + rarity spawned
            bool alreadySpawned = _activeCards.Any(c => 
                c.CardData.DefinitionId == card.DefinitionId && 
                c.CardData.Rarity == card.Rarity);
            
            if (alreadySpawned)
            {
                Debug.Log($"[AlbumViewPage] Card '{card.Name}' already spawned, skipping duplicate spawn");
                return; // Don't spawn duplicates
            }
            
            // Try to spawn if we have space
            if (_activeCards.Count < MAX_VISIBLE_CARDS)
            {
                int nextSlotIndex = _activeCards.Count;
                SpawnCardInSlot(nextSlotIndex, card);
            }
        }
        
        /// <summary>
        /// Handle when a card is revealed (flipped)
        /// </summary>
        private void OnCardRevealed(AlbumCardPlacementDraggable cardPlacement, CardData cardData)
        {
            Debug.Log($"[AlbumViewPage] Card revealed: {cardData.Name} (Zone: {cardData.Zone}, CopiesOwned: {cardData.CopiesOwned})");
            
            // IMMEDIATELY move card from pending to inventory upon reveal
            if (CardSystemManager.Instance != null)
            {
                CardSystemManager.Instance.MarkCardAsPlaced(cardData);
                Debug.Log($"[AlbumViewPage] Moved card '{cardData.Name}' from pending to inventory on reveal");
            }
            
            // Remove this card from active cards list
            _activeCards.Remove(cardPlacement);
            
            // Check if we're currently viewing the correct zone for this card
            CardZone currentZone = GetCurrentZone();
            
            if (currentZone != cardData.Zone)
            {
                // Card is from a different zone - navigate to its zone
                Debug.Log($"[AlbumViewPage] Card zone ({cardData.Zone}) doesn't match current zone ({currentZone}). Navigating to card's zone...");
                NavigateToZone(cardData.Zone);
            }
            else
            {
                Debug.Log($"[AlbumViewPage] Card zone ({cardData.Zone}) matches current zone - no navigation needed.");
            }
            
            // Shuffle remaining cards to front and spawn next unique card
            ShuffleCardsToFront();
            TrySpawnNextCard();
        }
        
        /// <summary>
        /// Handle when a card is placed in the album (from AlbumCardDraggable)
        /// Card data already moved to inventory in OnCardRevealed
        /// This just handles cleanup
        /// </summary>
        private void OnCardPlacedInAlbum(AlbumCardPlacementDraggable cardPlacement, CardData cardData)
        {
            Debug.Log($"[AlbumViewPage] Card placed in album slot: {cardData.Name}");
            
            // Unsubscribe from events (card is now static in album)
            cardPlacement.OnCardRevealed -= OnCardRevealed;
            cardPlacement.OnCardPlacedInAlbum -= OnCardPlacedInAlbum;
            
            // Note: Card already removed from _activeCards in OnCardRevealed
            // Note: Shuffle and spawn already done in OnCardRevealed
        }
        
        /// <summary>
        /// Shuffle active cards to occupy front slots
        /// </summary>
        private void ShuffleCardsToFront()
        {
            if (bottomRightSlots == null || _activeCards.Count == 0)
                return;
            
            // Convert to base DraggableObject list for helper method
            List<DraggableObject> draggableList = _activeCards.Cast<DraggableObject>().ToList();
            SlotContainerHelper.ShuffleToFront(bottomRightSlots, draggableList, animate: true);
        }
        
        /// <summary>
        /// Try to spawn the next pending card
        /// Only spawns unique cards (not duplicates)
        /// </summary>
        private void TrySpawnNextCard()
        {
            if (CardSystemManager.Instance == null)
                return;
            
            if (_activeCards.Count >= MAX_VISIBLE_CARDS)
                return; // Already at max
            
            var pending = CardSystemManager.Instance.GetPendingRevealCards();
            
            // Get unique pending cards, excluding zero-count cards
            var uniquePending = pending
                .Where(c => c.CopiesOwned > 0) // Guard: exclude zero-count cards
                .GroupBy(c => new { c.DefinitionId, c.Rarity })
                .Select(g => g.First())
                .ToList();
            
            // Find first unique card that's not already spawned
            foreach (var cardData in uniquePending)
            {
                bool alreadySpawned = _activeCards.Any(c => 
                    c.CardData.DefinitionId == cardData.DefinitionId && 
                    c.CardData.Rarity == cardData.Rarity);
                
                if (!alreadySpawned)
                {
                    int nextSlotIndex = _activeCards.Count;
                    SpawnCardInSlot(nextSlotIndex, cardData);
                    break;
                }
            }
        }
        
        /// <summary>
        /// Find a slot by its SlotIndex property
        /// </summary>
        private DraggableSlot FindSlotByIndex(int slotIndex)
        {
            if (bottomRightSlots == null)
                return null;
            
            foreach (var slot in bottomRightSlots.Slots)
            {
                if (slot.SlotIndex == slotIndex)
                {
                    return slot;
                }
            }
            return null;
        }
        
        /// <summary>
        /// Get the current zone based on book page
        /// </summary>
        public CardZone GetCurrentZone()
        {
            if (book == null || zoneTabs == null || zoneTabs.Length == 0)
                return CardZone.AppleHills; // Default
            
            int currentPage = book.CurrentPaper;
            
            // Find tab with matching target page
            foreach (var tab in zoneTabs)
            {
                if (tab.TargetPage == currentPage)
                {
                    return tab.Zone;
                }
            }
            
            // Fallback to first zone
            return zoneTabs[0].Zone;
        }
        
        /// <summary>
        /// Get tab for a specific zone
        /// </summary>
        public BookTabButton GetTabForZone(CardZone zone)
        {
            if (zoneTabs == null)
                return null;
            
            foreach (var tab in zoneTabs)
            {
                if (tab.Zone == zone)
                {
                    return tab;
                }
            }
            return null;
        }
        
        /// <summary>
        /// Navigate to a specific zone
        /// </summary>
        public void NavigateToZone(CardZone zone)
        {
            BookTabButton tab = GetTabForZone(zone);
            if (tab != null)
            {
                tab.ActivateTab();
            }
        }
        
        /// <summary>
        /// Clean up all active cards
        /// </summary>
        private void CleanupActiveCards()
        {
            foreach (var card in _activeCards)
            {
                if (card != null && card.gameObject != null)
                {
                    card.OnCardRevealed -= OnCardRevealed;
                    card.OnCardPlacedInAlbum -= OnCardPlacedInAlbum;
                    Destroy(card.gameObject);
                }
            }
            _activeCards.Clear();
        }
        
        #endregion
        
        #region Card Enlarge System
        
        /// <summary>
        /// Subscribe to album card events when a card is spawned in a slot
        /// Call this when AlbumCardSlot spawns a card
        /// </summary>
        public void RegisterAlbumCard(AlbumCard albumCard)
        {
            if (albumCard == null) return;
            
            albumCard.OnEnlargeRequested += OnCardEnlargeRequested;
            albumCard.OnShrinkRequested += OnCardShrinkRequested;
        }
        
        /// <summary>
        /// Unsubscribe from album card events
        /// </summary>
        public void UnregisterAlbumCard(AlbumCard albumCard)
        {
            if (albumCard == null) return;
            
            albumCard.OnEnlargeRequested -= OnCardEnlargeRequested;
            albumCard.OnShrinkRequested -= OnCardShrinkRequested;
        }
        
        /// <summary>
        /// Handle card enlarge request - show backdrop and reparent card
        /// </summary>
        private void OnCardEnlargeRequested(AlbumCard card)
        {
            if (card == null) return;
            
            Debug.Log($"[AlbumViewPage] OnCardEnlargeRequested called for card: {card.name}, current parent: {card.transform.parent.name}");
            
            // IMPORTANT: Call EnlargeCard FIRST to store original parent (the slot)
            // BEFORE reparenting to the enlarged container
            card.EnlargeCard();
            
            // Show backdrop
            if (cardEnlargedBackdrop != null)
            {
                cardEnlargedBackdrop.SetActive(true);
                Debug.Log($"[AlbumViewPage] Backdrop shown");
            }
            
            // NOW reparent card to enlarged container (above backdrop)
            if (cardEnlargedContainer != null)
            {
                card.transform.SetParent(cardEnlargedContainer, true);
                card.transform.SetAsLastSibling(); // Ensure on top
                Debug.Log($"[AlbumViewPage] Card reparented to enlarged container");
            }
            
            Debug.Log($"[AlbumViewPage] Card enlarged: {card.GetCardData()?.Name}");
        }
        
        /// <summary>
        /// Handle card shrink request - hide backdrop and reparent card back to slot
        /// </summary>
        private void OnCardShrinkRequested(AlbumCard card)
        {
            if (card == null) return;
            
            // Trigger shrink animation
            card.ShrinkCard();
            
            // Hide backdrop
            if (cardEnlargedBackdrop != null)
            {
                cardEnlargedBackdrop.SetActive(false);
            }
            
            // Reparent back to original parent (the slot)
            Transform originalParent = card.GetOriginalParent();
            if (originalParent != null)
            {
                card.transform.SetParent(originalParent, true);
                card.transform.localPosition = card.GetOriginalLocalPosition();
                card.transform.localRotation = card.GetOriginalLocalRotation();
            }

            Debug.Log($"[AlbumViewPage] Card shrunk: {card.GetCardData()?.Name}");
        }
        
        /// <summary>
        /// Show backdrop and reparent slot preview card for enlargement
        /// </summary>
        public void ShowSlotPreview(AlbumCardSlot slot, Transform previewCardTransform)
        {
            if (previewCardTransform == null)
                return;
            
            Debug.Log($"[AlbumViewPage] ShowSlotPreview called for slot: {slot.name}");
            
            // Show backdrop
            if (cardEnlargedBackdrop != null)
            {
                cardEnlargedBackdrop.SetActive(true);
            }
            
            // Reparent preview card to enlarged container (above backdrop)
            if (cardEnlargedContainer != null)
            {
                previewCardTransform.SetParent(cardEnlargedContainer, true);
                previewCardTransform.SetAsLastSibling();
            }
        }
        
        /// <summary>
        /// Hide backdrop and trigger shrink animation for slot preview
        /// </summary>
        public void HideSlotPreview(AlbumCardSlot slot, Transform previewCardTransform, System.Action onComplete)
        {
            if (previewCardTransform == null)
                return;
            
            Debug.Log($"[AlbumViewPage] HideSlotPreview called for slot: {slot.name}");
            
            // Hide backdrop
            if (cardEnlargedBackdrop != null)
            {
                cardEnlargedBackdrop.SetActive(false);
            }
            
            // Shrink preview card
            Vector3 originalScale = previewCardTransform.localScale / 2.5f; // Assuming 2.5x is enlarged scale
            Pixelplacement.Tween.LocalScale(previewCardTransform, originalScale, 0.3f, 0f, Pixelplacement.Tween.EaseInBack,
                completeCallback: () => onComplete?.Invoke());
        }
        
        #endregion
    }
}