using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using Vanguard.Api;
using Vanguard.Api.Contracts;
using Vanguard.Auth;
using Vanguard.Meta;

namespace Vanguard.UI
{
    /// <summary>
    /// Декбилдер в духе HS: коллекция в центре, узкая колонка колод/карт справа.
    /// Список колод и редактор используют один и тот же блок коллекции.
    /// </summary>
    public sealed class DeckBuilderView
    {
        private readonly MetaService _meta;
        private readonly AuthService _auth;
        private readonly Action _onBack;
        private readonly Action<DeckDto> _onPlay;
        private readonly RectTransform _root;

        private readonly RectTransform _listView;
        private readonly RectTransform _editorView;
        private RectTransform _deckListContent;
        private RectTransform _listCollectionContent;
        private RectTransform _editorCollectionContent;
        private RectTransform _deckCardContent;
        private InputField _nameInput;
        private Text _listStatus;
        private Text _editorStatus;
        private Text _stats;
        private Text _deckCount;
        private Text _filterSummary;
        private RectTransform _filterOverlay;
        private RectTransform _clanContent;
        private RectTransform _confirmOverlay;
        private Text _confirmText;
        private DeckDto _pendingDelete;

        private RectTransform _cardOverlay;
        private Image _cardArt;
        private Text _cardArtName;
        private Text _cardTitle;
        private Text _cardSubtitle;
        private Text _cardStats;
        private Text _cardAbilities;
        private Text _cardOwned;
        private Text _cardStatus;
        private Button _dismantleButton;
        private Button _craftButton;
        private CollectionItemDto _selectedItem;
        private CardCatalogItemDto _selectedMeta;

        private readonly List<DeckDto> _decks = new List<DeckDto>();
        private readonly List<CollectionItemDto> _collection = new List<CollectionItemDto>();
        private readonly Dictionary<string, CardCatalogItemDto> _catalog =
            new Dictionary<string, CardCatalogItemDto>(StringComparer.Ordinal);
        private readonly List<string> _cards = new List<string>();
        private readonly Dictionary<string, Text> _listCountTexts =
            new Dictionary<string, Text>(StringComparer.Ordinal);
        private readonly Dictionary<string, Text> _editorCountTexts =
            new Dictionary<string, Text>(StringComparer.Ordinal);

        private DeckDto _editing;
        private string _filterClan = "Все";
        private string _filterTrigger = "Все";
        private int _filterGrade = -1;
        private bool _loading;
        private bool _busy;

        public DeckBuilderView(
            Transform parent,
            MetaService meta,
            AuthService auth,
            Action onBack,
            Action<DeckDto> onPlay)
        {
            _meta = meta;
            _auth = auth;
            _onBack = onBack;
            _onPlay = onPlay;

            _root = UiKit.CreatePanel(parent, "DeckBuilderScreen", new Color(0.018f, 0.03f, 0.06f, 0.97f));
            _listView = BuildListView();
            _editorView = BuildEditorView();
            _filterOverlay = BuildFilterOverlay();
            _confirmOverlay = BuildDeleteConfirm();
            _cardOverlay = BuildCardOverlay();

            _listView.gameObject.SetActive(false);
            _editorView.gameObject.SetActive(false);
            _filterOverlay.gameObject.SetActive(false);
            _confirmOverlay.gameObject.SetActive(false);
            _cardOverlay.gameObject.SetActive(false);
            _root.gameObject.SetActive(false);
        }

        public void Show()
        {
            UiKit.SetActive(_root, true);
            ShowList();
            _ = LoadAsync();
        }

        public void Hide()
        {
            _filterOverlay.gameObject.SetActive(false);
            _confirmOverlay.gameObject.SetActive(false);
            _cardOverlay.gameObject.SetActive(false);
            _root.gameObject.SetActive(false);
        }

        private RectTransform BuildListView()
        {
            var view = UiKit.CreatePanel(_root, "DeckList", new Color(0.018f, 0.03f, 0.06f, 0.97f));

            var top = BuildTopBar(view);
            var back = UiKit.CreateButton(top, "Back", "← В лобби", () => _onBack(), 17);
            SetFixedSize(back, 120f, 44f);

            var title = UiKit.CreateText(top, "Title", "Коллекция", 28, Color.white, TextAnchor.MiddleLeft);
            title.fontStyle = FontStyle.Bold;
            SetFixedSize(title, 150f, 44f);

            _filterSummary = UiKit.CreateText(
                top, "FilterSummary", "Все карты", 16,
                new Color(0.60f, 0.68f, 0.84f), TextAnchor.MiddleLeft);
            SetFlexible(_filterSummary, 1f, 44f);

            var filters = UiKit.CreateButton(top, "Filters", "Фильтры", OpenFilters, 17);
            SetFixedSize(filters, 110f, 44f);

            var reset = UiKit.CreateButton(top, "ResetFilters", "Сброс", ResetFilters, 17);
            SetFixedSize(reset, 90f, 44f);

            var create = UiKit.CreateButton(top, "Create", "Создать колоду", NewDeck, 17);
            SetFixedSize(create, 180f, 44f);

            var body = UiKit.CreatePanel(view, "Body", new Color(0f, 0f, 0f, 0f));
            body.anchorMin = Vector2.zero;
            body.anchorMax = Vector2.one;
            body.offsetMin = new Vector2(34f, 28f);
            body.offsetMax = new Vector2(-34f, -108f);
            UiKit.AddHorizontalLayout(body, 0, 14);

            var collectionArea = UiKit.CreatePanel(
                body, "CollectionArea", new Color(0.04f, 0.06f, 0.10f, 0.55f));
            var collectionElement = collectionArea.gameObject.AddComponent<LayoutElement>();
            collectionElement.flexibleWidth = 1f;
            collectionElement.flexibleHeight = 1f;
            collectionElement.minHeight = 300f;
            UiKit.AddVerticalLayout(collectionArea, 8, 6);

            var scroll = UiKit.CreateGridScrollView(
                collectionArea,
                "CollectionGrid",
                new Vector2(174f, 238f),
                new Vector2(10f, 10f),
                out _listCollectionContent);
            var scrollElement = scroll.gameObject.AddComponent<LayoutElement>();
            scrollElement.flexibleHeight = 1f;
            scrollElement.minHeight = 220f;

            _listStatus = UiKit.CreateText(
                collectionArea, "Status", string.Empty, 16,
                new Color(0.62f, 0.68f, 0.82f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_listStatus, 32f);

            var deckArea = UiKit.CreatePanel(
                body, "DeckArea", new Color(0.04f, 0.06f, 0.10f, 0.85f));
            var deckElement = deckArea.gameObject.AddComponent<LayoutElement>();
            deckElement.preferredWidth = 300f;
            deckElement.minWidth = 280f;
            deckElement.flexibleWidth = 0f;
            deckElement.flexibleHeight = 1f;
            deckElement.minHeight = 300f;
            UiKit.AddVerticalLayout(deckArea, 10, 6);

            var deckTitle = UiKit.CreateText(
                deckArea, "Title", "Мои колоды", 20, Color.white, TextAnchor.MiddleLeft);
            deckTitle.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(deckTitle, 30f);

            var deckScroll = UiKit.CreateScrollView(deckArea, "DeckListScroll", out _deckListContent, 8f);
            var deckScrollElement = deckScroll.gameObject.AddComponent<LayoutElement>();
            deckScrollElement.flexibleHeight = 1f;
            deckScrollElement.minHeight = 200f;

            var hint = UiKit.CreateText(
                deckArea, "Hint", "Нажмите на колоду,\nчтобы открыть редактор.", 14,
                new Color(0.58f, 0.66f, 0.80f), TextAnchor.MiddleLeft);
            hint.horizontalOverflow = HorizontalWrapMode.Wrap;
            UiKit.SetPreferredHeight(hint, 46f);

            return view;
        }

        private RectTransform BuildEditorView()
        {
            var view = UiKit.CreatePanel(_root, "DeckEditor", new Color(0.018f, 0.03f, 0.06f, 0.97f));

            var top = BuildTopBar(view);
            var back = UiKit.CreateButton(top, "Back", "← Коллекция", BackToList, 17);
            SetFixedSize(back, 120f, 44f);

            _nameInput = UiKit.CreateInput(top, "Name", "Название колоды");
            SetFlexible(_nameInput, 0.7f, 46f);

            var filters = UiKit.CreateButton(top, "Filters", "Фильтры", OpenFilters, 17);
            SetFixedSize(filters, 110f, 44f);

            var reset = UiKit.CreateButton(top, "ResetFilters", "Сброс", ResetFilters, 17);
            SetFixedSize(reset, 90f, 44f);

            _stats = UiKit.CreateText(
                top, "Stats", string.Empty, 15,
                new Color(0.72f, 0.78f, 0.92f), TextAnchor.MiddleLeft);
            _stats.horizontalOverflow = HorizontalWrapMode.Wrap;
            SetFlexible(_stats, 1.4f, 50f);

            var save = UiKit.CreateButton(top, "Save", "Сохранить", SaveDeck, 17);
            SetFixedSize(save, 120f, 44f);

            var duel = UiKit.CreateButton(top, "Duel", "В бой", PlayDeck, 17);
            SetFixedSize(duel, 90f, 44f);

            var delete = UiKit.CreateButton(top, "Delete", "Удалить", RequestDeleteCurrent, 17);
            SetFixedSize(delete, 100f, 44f);

            var body = UiKit.CreatePanel(view, "Body", new Color(0f, 0f, 0f, 0f));
            body.anchorMin = Vector2.zero;
            body.anchorMax = Vector2.one;
            body.offsetMin = new Vector2(34f, 28f);
            body.offsetMax = new Vector2(-34f, -108f);
            UiKit.AddHorizontalLayout(body, 0, 14);

            var collectionArea = UiKit.CreatePanel(
                body, "CollectionArea", new Color(0.04f, 0.06f, 0.10f, 0.55f));
            var collectionElement = collectionArea.gameObject.AddComponent<LayoutElement>();
            collectionElement.flexibleWidth = 1f;
            collectionElement.flexibleHeight = 1f;
            collectionElement.minHeight = 300f;
            UiKit.AddVerticalLayout(collectionArea, 8, 6);

            var scroll = UiKit.CreateGridScrollView(
                collectionArea,
                "CollectionGrid",
                new Vector2(174f, 238f),
                new Vector2(10f, 10f),
                out _editorCollectionContent);
            var scrollElement = scroll.gameObject.AddComponent<LayoutElement>();
            scrollElement.flexibleHeight = 1f;
            scrollElement.minHeight = 220f;

            _editorStatus = UiKit.CreateText(
                collectionArea, "Status", string.Empty, 16,
                new Color(0.62f, 0.68f, 0.82f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_editorStatus, 32f);

            var deckArea = UiKit.CreatePanel(
                body, "DeckArea", new Color(0.04f, 0.06f, 0.10f, 0.85f));
            var deckElement = deckArea.gameObject.AddComponent<LayoutElement>();
            deckElement.preferredWidth = 300f;
            deckElement.minWidth = 280f;
            deckElement.flexibleWidth = 0f;
            deckElement.flexibleHeight = 1f;
            deckElement.minHeight = 300f;
            UiKit.AddVerticalLayout(deckArea, 10, 6);

            _deckCount = UiKit.CreateText(
                deckArea, "DeckCount", "Колода: 0/50", 19, Color.white, TextAnchor.MiddleLeft);
            _deckCount.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(_deckCount, 28f);

            var deckScroll = UiKit.CreateScrollView(deckArea, "DeckCardScroll", out _deckCardContent, 6f);
            var deckScrollElement = deckScroll.gameObject.AddComponent<LayoutElement>();
            deckScrollElement.flexibleHeight = 1f;
            deckScrollElement.minHeight = 200f;

            var hint = UiKit.CreateText(
                deckArea, "Hint", "ЛКМ — убрать копию,\nПКМ — посмотреть карту.", 14,
                new Color(0.58f, 0.66f, 0.80f), TextAnchor.MiddleLeft);
            hint.horizontalOverflow = HorizontalWrapMode.Wrap;
            UiKit.SetPreferredHeight(hint, 46f);

            return view;
        }

        private RectTransform BuildTopBar(RectTransform view)
        {
            var top = UiKit.CreatePanel(view, "TopBar", new Color(0.06f, 0.08f, 0.13f, 1f));
            top.anchorMin = new Vector2(0f, 1f);
            top.anchorMax = new Vector2(1f, 1f);
            top.pivot = new Vector2(0.5f, 1f);
            top.anchoredPosition = Vector2.zero;
            top.sizeDelta = new Vector2(0f, 88f);
            UiKit.AddHorizontalLayout(top, 18, 12);
            return top;
        }

        private RectTransform BuildFilterOverlay()
        {
            var overlay = UiKit.CreatePanel(_root, "FilterOverlay", new Color(0f, 0f, 0f, 0.78f));

            var card = UiKit.CreateCenteredCard(
                overlay, "FilterCard", new Vector2(860f, 820f),
                new Color(0.06f, 0.08f, 0.13f, 1f));
            UiKit.AddVerticalLayout(card, 26, 10);

            var title = UiKit.CreateText(card, "Title", "Фильтры коллекции", 28, Color.white);
            title.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(title, 40f);

            AddFilterSection(card, "Ранг", new[] { "Все", "0", "1", "2", "3" }, OnGradeFilter);
            AddFilterSection(card, "Триггер", new[] { "Все", "None", "Critical", "Draw", "Stand", "Heal" }, OnTriggerFilter);

            var clanTitle = UiKit.CreateText(
                card, "ClanTitle", "Клан", 17, new Color(0.66f, 0.74f, 0.90f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(clanTitle, 24f);

            var clanScroll = UiKit.CreateScrollView(card, "ClanScroll", out _clanContent, 4f);
            var clanElement = clanScroll.gameObject.AddComponent<LayoutElement>();
            clanElement.flexibleHeight = 1f;
            clanElement.minHeight = 150f;

            var close = UiKit.CreateButton(card, "Close", "Готово", CloseFilters, 20);
            UiKit.SetPreferredHeight(close, 48f);

            return overlay;
        }

        private void RebuildClanFilters()
        {
            ClearChildren(_clanContent);
            AddClanButton(_clanContent, "Все");
            foreach (var clan in _catalog.Values.Select(item => item.Clan).Distinct().OrderBy(item => item))
                AddClanButton(_clanContent, clan);
        }

        private RectTransform BuildDeleteConfirm()
        {
            var overlay = UiKit.CreatePanel(
                _root, "DeleteDeckConfirm", new Color(0f, 0f, 0f, 0.78f));

            var card = UiKit.CreateCenteredCard(
                overlay, "ConfirmCard", new Vector2(640f, 300f),
                new Color(0.06f, 0.08f, 0.13f, 1f));
            UiKit.AddVerticalLayout(card, 30, 12);

            var title = UiKit.CreateText(card, "Title", "Удалить колоду?", 28, Color.white);
            title.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(title, 42f);

            _confirmText = UiKit.CreateText(
                card, "Text", string.Empty, 19,
                new Color(0.72f, 0.78f, 0.92f));
            UiKit.SetPreferredHeight(_confirmText, 70f);

            var yes = UiKit.CreateButton(card, "Yes", "Удалить", ConfirmDelete, 20);
            UiKit.SetPreferredHeight(yes, 48f);

            var no = UiKit.CreateButton(card, "No", "Отмена", CancelDelete, 20);
            UiKit.SetPreferredHeight(no, 44f);

            return overlay;
        }

        private RectTransform BuildCardOverlay()
        {
            var overlay = UiKit.CreatePanel(_root, "CardOverlay", new Color(0f, 0f, 0f, 0.82f));
            var card = UiKit.CreateCenteredCard(
                overlay, "CardView", new Vector2(1040f, 660f),
                new Color(0.05f, 0.07f, 0.11f, 1f));

            var body = UiKit.CreatePanel(card, "Body", new Color(0f, 0f, 0f, 0f));
            body.anchorMin = Vector2.zero;
            body.anchorMax = Vector2.one;
            body.offsetMin = new Vector2(26f, 26f);
            body.offsetMax = new Vector2(-26f, -26f);
            UiKit.AddHorizontalLayout(body, 0, 22);

            var art = UiKit.CreatePanel(body, "Art", new Color(0.2f, 0.3f, 0.5f, 1f));
            SetFixedSize(art, 360f, 540f);
            _cardArt = art.GetComponent<Image>();

            _cardArtName = UiKit.CreateText(
                art, "ArtName", string.Empty, 18,
                new Color(1f, 1f, 1f, 0.92f), TextAnchor.MiddleCenter);
            UiKit.Stretch(_cardArtName.rectTransform);
            _cardArtName.rectTransform.offsetMin = new Vector2(14f, 16f);
            _cardArtName.rectTransform.offsetMax = new Vector2(-14f, -16f);
            _cardArtName.horizontalOverflow = HorizontalWrapMode.Wrap;

            var info = UiKit.CreatePanel(body, "Info", new Color(0f, 0f, 0f, 0f));
            var infoElement = info.gameObject.AddComponent<LayoutElement>();
            infoElement.flexibleWidth = 1f;
            infoElement.flexibleHeight = 1f;
            UiKit.AddVerticalLayout(info, 4, 6);

            _cardTitle = UiKit.CreateText(
                info, "Title", string.Empty, 30, Color.white, TextAnchor.MiddleLeft);
            _cardTitle.fontStyle = FontStyle.Bold;
            _cardTitle.horizontalOverflow = HorizontalWrapMode.Wrap;
            UiKit.SetPreferredHeight(_cardTitle, 44f);

            _cardSubtitle = UiKit.CreateText(
                info, "Subtitle", string.Empty, 16,
                new Color(0.62f, 0.70f, 0.84f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_cardSubtitle, 26f);

            _cardStats = UiKit.CreateText(
                info, "Stats", string.Empty, 15,
                new Color(0.72f, 0.78f, 0.92f), TextAnchor.UpperLeft);
            _cardStats.horizontalOverflow = HorizontalWrapMode.Wrap;
            UiKit.SetPreferredHeight(_cardStats, 88f);

            var abilitiesCaption = UiKit.CreateText(
                info, "AbilitiesCaption", "Способности", 16,
                new Color(0.66f, 0.74f, 0.90f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(abilitiesCaption, 24f);

            _cardAbilities = UiKit.CreateText(
                info, "Abilities", string.Empty, 15,
                new Color(0.82f, 0.86f, 0.96f), TextAnchor.UpperLeft);
            _cardAbilities.horizontalOverflow = HorizontalWrapMode.Wrap;
            var abilitiesElement = _cardAbilities.gameObject.AddComponent<LayoutElement>();
            abilitiesElement.flexibleHeight = 1f;
            abilitiesElement.minHeight = 100f;

            _cardOwned = UiKit.CreateText(
                info, "Owned", string.Empty, 15,
                new Color(0.98f, 0.82f, 0.42f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_cardOwned, 24f);

            _cardStatus = UiKit.CreateText(
                info, "Status", string.Empty, 14,
                new Color(0.62f, 0.68f, 0.82f), TextAnchor.UpperLeft);
            _cardStatus.horizontalOverflow = HorizontalWrapMode.Wrap;
            UiKit.SetPreferredHeight(_cardStatus, 38f);

            var actions = UiKit.CreatePanel(info, "Actions", new Color(0f, 0f, 0f, 0f));
            UiKit.SetPreferredHeight(actions, 50f);
            UiKit.AddHorizontalLayout(actions, 0, 8);

            _dismantleButton = UiKit.CreateButton(
                actions, "Dismantle", "Разобрать", DismantleSelected, 16);
            SetFixedSize(_dismantleButton, 225f, 46f);

            _craftButton = UiKit.CreateButton(
                actions, "Craft", "Скрафтить", CraftSelected, 16);
            SetFixedSize(_craftButton, 225f, 46f);

            var close = UiKit.CreateButton(actions, "Close", "Закрыть", CloseCardOverlay, 16);
            SetFixedSize(close, 110f, 46f);

            return overlay;
        }

        private void AddRightClick(GameObject target, string printingId, CardCatalogItemDto meta)
        {
            var trigger = target.GetComponent<EventTrigger>()
                ?? target.AddComponent<EventTrigger>();
            var entry = new EventTrigger.Entry { eventID = EventTriggerType.PointerClick };
            entry.callback.AddListener(data =>
            {
                if (data is PointerEventData pointer
                    && pointer.button == PointerEventData.InputButton.Right)
                {
                    ShowCardOverlay(printingId, meta);
                }
            });
            trigger.triggers.Add(entry);
        }

        private void ShowCardOverlay(string printingId, CardCatalogItemDto meta)
        {
            if (meta == null)
                return;

            _selectedMeta = meta;
            _selectedItem = _collection.Find(item => item.PrintingId == printingId);
            _cardStatus.text = string.Empty;
            UpdateCardOverlay();
            _cardOverlay.SetAsLastSibling();
            _cardOverlay.gameObject.SetActive(true);
        }

        private void UpdateCardOverlay()
        {
            if (_selectedMeta == null)
                return;

            var meta = _selectedMeta;
            _cardArt.color = ClanColor(meta.Clan);
            _cardArtName.text = meta.NameEn;
            _cardTitle.text = meta.NameEn;
            _cardSubtitle.text = (string.IsNullOrEmpty(meta.NameRu) ? string.Empty : meta.NameRu + " · ")
                + meta.Clan + " · G" + meta.Grade;
            _cardStats.text = "Тип: " + meta.Type + " · Редкость: " + meta.Rarity + "\n"
                + "Power " + meta.Power + " · Shield " + meta.Shield + " · Critical " + meta.Critical + "\n"
                + "Триггер: " + meta.Trigger
                + " · Sentinel: " + (meta.IsSentinel ? "да" : "нет")
                + " · Boost: " + (meta.HasBoost ? "да" : "нет")
                + " · Intercept: " + (meta.HasIntercept ? "да" : "нет") + "\n"
                + "Принт: " + meta.PrintingId;
            _cardAbilities.text = string.IsNullOrWhiteSpace(meta.TextRu)
                ? (string.IsNullOrWhiteSpace(meta.TextEn) ? "Текст способности отсутствует." : meta.TextEn)
                : meta.TextRu;
            _cardOwned.text = "В коллекции: ×" + (_selectedItem != null ? _selectedItem.Count : 0)
                + " · в колоде: " + UsedByName(meta.NameId);

            var canChange = CanChange(meta.Rarity);
            _dismantleButton.interactable = canChange && !_busy
                && _selectedItem != null && _selectedItem.Count > 0;
            _craftButton.interactable = canChange && !_busy;
            SetButtonLabel(
                _dismantleButton,
                canChange ? "Разобрать (+" + DustFor(meta.Rarity) + " пыли)" : "Нельзя разобрать");
            SetButtonLabel(
                _craftButton,
                canChange ? "Скрафтить (−" + CraftCostFor(meta.Rarity) + " пыли)" : "Нельзя скрафтить");
        }

        private static bool CanChange(string rarity) =>
            rarity == "C" || rarity == "R" || rarity == "RR" || rarity == "RRR";

        private async void DismantleSelected()
        {
            if (_busy || _selectedItem == null || _selectedItem.Count <= 0
                || _selectedMeta == null || !CanChange(_selectedMeta.Rarity))
                return;

            var printingId = _selectedItem.PrintingId;
            _busy = true;
            UpdateCardOverlay();
            _cardStatus.text = "Разбираем…";
            _cardStatus.color = new Color(0.62f, 0.68f, 0.82f);
            try
            {
                await _auth.EnsureAccessAsync();
                await _meta.DismantleAsync(printingId, 1);
                await ReloadCollectionAsync(printingId);
                SetCardStatus("Карта разобрана.", false);
            }
            catch (ApiException exception)
            {
                SetCardStatus(exception.Message, true);
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetCardStatus("Не удалось разобрать карту.", true);
            }
            finally
            {
                _busy = false;
                UpdateCardOverlay();
            }
        }

        private async void CraftSelected()
        {
            if (_busy || _selectedMeta == null || !CanChange(_selectedMeta.Rarity))
                return;

            var printingId = _selectedMeta.PrintingId;
            _busy = true;
            UpdateCardOverlay();
            _cardStatus.text = "Крафтим…";
            _cardStatus.color = new Color(0.62f, 0.68f, 0.82f);
            try
            {
                await _auth.EnsureAccessAsync();
                await _meta.CraftAsync(printingId);
                await ReloadCollectionAsync(printingId);
                SetCardStatus("Карта скрафчена.", false);
            }
            catch (ApiException exception)
            {
                SetCardStatus(exception.Message, true);
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetCardStatus("Не удалось скрафтить карту.", true);
            }
            finally
            {
                _busy = false;
                UpdateCardOverlay();
            }
        }

        private async Task ReloadCollectionAsync(string printingId)
        {
            var collection = await _meta.GetCollectionAsync();
            _collection.Clear();
            _collection.AddRange(collection.Items ?? new List<CollectionItemDto>());
            RebuildCollectionGrids();
            _selectedItem = _collection.Find(item => item.PrintingId == printingId);
            if (_selectedItem == null)
            {
                _cardOverlay.gameObject.SetActive(false);
                _listStatus.text = "Карт в коллекции: " + _collection.Count + ".";
            }
            else
            {
                UpdateCardOverlay();
            }
        }

        private void SetCardStatus(string text, bool error)
        {
            _cardStatus.text = text;
            _cardStatus.color = error
                ? new Color(1f, 0.55f, 0.45f)
                : new Color(0.45f, 0.85f, 0.55f);
        }

        private void CloseCardOverlay()
        {
            _selectedItem = null;
            _selectedMeta = null;
            _cardOverlay.gameObject.SetActive(false);
        }

        private void AddFilterSection(Transform parent, string title, string[] labels, Action<string> onSelected)
        {
            var caption = UiKit.CreateText(
                parent, "Caption_" + title, title, 17,
                new Color(0.66f, 0.74f, 0.90f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(caption, 24f);

            var row = UiKit.CreatePanel(parent, "Row_" + title, new Color(0f, 0f, 0f, 0f));
            UiKit.SetPreferredHeight(row, 44f);
            UiKit.AddHorizontalLayout(row, 0, 6);

            foreach (var label in labels)
            {
                var captured = label;
                var button = UiKit.CreateButton(
                    row, "Filter_" + label, label, () => onSelected(captured), 16);
                UiKit.SetPreferredHeight(button, 40f);
            }
        }

        private void AddClanButton(Transform parent, string clan)
        {
            var captured = clan;
            var button = UiKit.CreateButton(
                parent, "Clan_" + clan, clan, () => OnClanFilter(captured), 16);
            UiKit.SetPreferredHeight(button, 40f);
        }

        private async Task LoadAsync()
        {
            if (_loading)
                return;

            _loading = true;
            _listStatus.text = "Загружаем коллекцию и колоды…";
            _listStatus.color = new Color(0.62f, 0.68f, 0.82f);
            ClearChildren(_deckListContent);

            try
            {
                await _auth.EnsureAccessAsync();
                var collection = await _meta.GetCollectionAsync();
                var catalog = await _meta.GetCatalogAsync();
                var decks = await _meta.GetDecksAsync();
                if (!_root.gameObject.activeSelf)
                    return;

                _collection.Clear();
                _collection.AddRange(collection.Items ?? new List<CollectionItemDto>());
                _catalog.Clear();
                foreach (var item in catalog)
                    _catalog[item.PrintingId] = item;
                RebuildClanFilters();

                _decks.Clear();
                _decks.AddRange(decks);
                BuildDeckList();
                RebuildCollectionGrids();
                _listStatus.text = _decks.Count == 0
                    ? "Колод пока нет. Создайте первую. ПКМ по карте — подробности."
                    : "Карт в коллекции: " + _collection.Count + " · ПКМ по карте — подробности.";
            }
            catch (ApiException exception)
            {
                _listStatus.text = exception.Message;
                _listStatus.color = new Color(1f, 0.55f, 0.45f);
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                _listStatus.text = "Не удалось загрузить декбилдер.";
                _listStatus.color = new Color(1f, 0.55f, 0.45f);
            }
            finally
            {
                _loading = false;
            }
        }

        private void BuildDeckList()
        {
            ClearChildren(_deckListContent);

            if (_decks.Count == 0)
            {
                var empty = UiKit.CreateText(
                    _deckListContent, "Empty", "Нет колод", 16,
                    new Color(0.58f, 0.66f, 0.80f));
                UiKit.SetPreferredHeight(empty, 90f);
                return;
            }

            foreach (var deck in _decks)
            {
                var row = UiKit.CreatePanel(
                    _deckListContent, "DeckRow_" + deck.Id, new Color(0.08f, 0.11f, 0.17f, 1f));
                var rowElement = row.gameObject.AddComponent<LayoutElement>();
                rowElement.preferredHeight = 76f;
                UiKit.AddVerticalLayout(row, 10, 2);

                var button = row.gameObject.AddComponent<Button>();
                button.targetGraphic = row.GetComponent<Image>();
                button.onClick.AddListener(() => OpenDeck(deck));

                var name = UiKit.CreateText(
                    row, "Name", deck.Name, 17, Color.white, TextAnchor.MiddleLeft);
                name.fontStyle = FontStyle.Bold;
                name.horizontalOverflow = HorizontalWrapMode.Wrap;
                UiKit.SetPreferredHeight(name, 30f);

                var count = UiKit.CreateText(
                    row, "Count", deck.Cards.Count + "/50 · " + deck.Format, 13,
                    new Color(0.62f, 0.70f, 0.84f), TextAnchor.MiddleLeft);
                UiKit.SetPreferredHeight(count, 20f);
            }
        }

        private void NewDeck()
        {
            _editing = null;
            _cards.Clear();
            _nameInput.text = "Новая колода";
            ShowEditor();
        }

        private void OpenDeck(DeckDto deck)
        {
            _editing = deck;
            _cards.Clear();
            _cards.AddRange(deck.Cards);
            _nameInput.text = deck.Name;
            ShowEditor();
        }

        private void ShowEditor()
        {
            _listView.gameObject.SetActive(false);
            _editorView.gameObject.SetActive(true);
            _filterOverlay.gameObject.SetActive(false);
            _cardOverlay.gameObject.SetActive(false);
            _editorStatus.text = string.Empty;
            RebuildEditor();
        }

        private void BackToList()
        {
            _filterOverlay.gameObject.SetActive(false);
            _cardOverlay.gameObject.SetActive(false);
            _editorView.gameObject.SetActive(false);
            _listView.gameObject.SetActive(true);
            RefreshAllCounts();
        }

        private void ShowList()
        {
            _editorView.gameObject.SetActive(false);
            _filterOverlay.gameObject.SetActive(false);
            _confirmOverlay.gameObject.SetActive(false);
            _cardOverlay.gameObject.SetActive(false);
            _listView.gameObject.SetActive(true);
        }

        private void RebuildEditor()
        {
            UpdateStats();
            RebuildDeckCards();
            RebuildEditorCollection();
            RefreshAllCounts();
        }

        private void RebuildCollectionGrids()
        {
            RebuildListCollection();
            RebuildEditorCollection();
        }

        private void RebuildListCollection()
        {
            BuildCollectionGrid(_listCollectionContent, _listCountTexts, showDeckCount: false, onAdd: null);
        }

        private void RebuildEditorCollection()
        {
            BuildCollectionGrid(_editorCollectionContent, _editorCountTexts, showDeckCount: true, onAdd: AddCard);
        }

        private void BuildCollectionGrid(
            RectTransform content,
            Dictionary<string, Text> countTexts,
            bool showDeckCount,
            Action<CollectionItemDto> onAdd)
        {
            ClearChildren(content);
            countTexts.Clear();

            var items = _collection
                .Select(item => new { Item = item, Meta = MetaOf(item) })
                .Where(pair => pair.Meta != null && MatchesFilter(pair.Meta))
                .OrderBy(pair => pair.Meta.Clan, StringComparer.Ordinal)
                .ThenBy(pair => pair.Meta.Grade)
                .ThenBy(pair => pair.Meta.NameEn, StringComparer.Ordinal);

            foreach (var pair in items)
                AddCollectionCell(content, pair.Item, pair.Meta, countTexts, showDeckCount, onAdd);
        }

        private void AddCollectionCell(
            RectTransform content,
            CollectionItemDto item,
            CardCatalogItemDto meta,
            Dictionary<string, Text> countTexts,
            bool showDeckCount,
            Action<CollectionItemDto> onAdd)
        {
            var cell = UiKit.CreatePanel(
                content, "Owned_" + item.PrintingId, new Color(0.08f, 0.11f, 0.17f, 1f));
            UiKit.AddVerticalLayout(cell, 6, 2);
            AddRightClick(cell.gameObject, item.PrintingId, meta);

            if (onAdd != null)
            {
                var button = cell.gameObject.AddComponent<Button>();
                button.targetGraphic = cell.GetComponent<Image>();
                button.onClick.AddListener(() => onAdd(item));
            }

            var art = UiKit.CreatePanel(cell, "Art", ClanColor(meta.Clan));
            UiKit.SetPreferredHeight(art, 112f);

            var artName = UiKit.CreateText(
                art, "ArtName", meta.NameEn, 12,
                new Color(1f, 1f, 1f, 0.9f), TextAnchor.MiddleCenter);
            UiKit.Stretch(artName.rectTransform);
            artName.rectTransform.offsetMin = new Vector2(6f, 8f);
            artName.rectTransform.offsetMax = new Vector2(-6f, -6f);
            artName.horizontalOverflow = HorizontalWrapMode.Wrap;

            var grade = UiKit.CreateText(
                art, "Grade", "G" + meta.Grade, 14, Color.white, TextAnchor.MiddleCenter);
            grade.fontStyle = FontStyle.Bold;
            var gradeRect = grade.rectTransform;
            gradeRect.anchorMin = new Vector2(1f, 1f);
            gradeRect.anchorMax = new Vector2(1f, 1f);
            gradeRect.pivot = new Vector2(1f, 1f);
            gradeRect.anchoredPosition = new Vector2(-5f, -5f);
            gradeRect.sizeDelta = new Vector2(34f, 22f);

            var trigger = UiKit.CreateText(
                art, "Trigger", TriggerShort(meta.Trigger), 13, Color.white, TextAnchor.MiddleCenter);
            var triggerRect = trigger.rectTransform;
            triggerRect.anchorMin = new Vector2(0f, 0f);
            triggerRect.anchorMax = new Vector2(0f, 0f);
            triggerRect.pivot = new Vector2(0f, 0f);
            triggerRect.anchoredPosition = new Vector2(5f, 5f);
            triggerRect.sizeDelta = new Vector2(34f, 20f);

            var name = UiKit.CreateText(
                cell, "Name", meta.NameEn, 13, Color.white, TextAnchor.UpperLeft);
            name.fontStyle = FontStyle.Bold;
            name.horizontalOverflow = HorizontalWrapMode.Wrap;
            UiKit.SetPreferredHeight(name, 32f);

            var metaLine = UiKit.CreateText(
                cell, "Meta", meta.Clan + " · " + meta.Rarity, 11,
                new Color(0.58f, 0.66f, 0.80f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(metaLine, 16f);

            var counts = UiKit.CreateText(
                cell, "Counts", CountText(item, showDeckCount), 13,
                new Color(0.98f, 0.82f, 0.42f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(counts, 20f);
            countTexts[item.PrintingId] = counts;
        }

        private void RebuildDeckCards()
        {
            ClearChildren(_deckCardContent);

            if (_cards.Count == 0)
            {
                var empty = UiKit.CreateText(
                    _deckCardContent, "Empty", "Колода пуста", 15,
                    new Color(0.58f, 0.66f, 0.80f));
                UiKit.SetPreferredHeight(empty, 90f);
                return;
            }

            foreach (var group in _cards.GroupBy(card => card).OrderBy(group => group.Key))
            {
                var printingId = group.Key;
                var count = group.Count();
                var meta = _catalog.TryGetValue(printingId, out var found) ? found : null;
                var name = meta != null ? meta.NameEn : printingId;

                var row = UiKit.CreatePanel(
                    _deckCardContent, "DeckCard_" + printingId, new Color(0.08f, 0.11f, 0.17f, 1f));
                var rowElement = row.gameObject.AddComponent<LayoutElement>();
                rowElement.preferredHeight = 64f;
                UiKit.AddHorizontalLayout(row, 6, 6);

                var button = row.gameObject.AddComponent<Button>();
                button.targetGraphic = row.GetComponent<Image>();
                button.onClick.AddListener(() => RemoveCard(printingId));
                if (meta != null)
                    AddRightClick(row.gameObject, printingId, meta);

                var art = UiKit.CreatePanel(
                    row, "Art", ClanColor(meta != null ? meta.Clan : "None"));
                SetFixedSize(art, 36f, 50f);

                var artText = UiKit.CreateText(
                    art, "ArtText", meta != null ? "G" + meta.Grade : "?", 13,
                    Color.white, TextAnchor.MiddleCenter);
                UiKit.Stretch(artText.rectTransform);

                var texts = UiKit.CreatePanel(row, "Texts", new Color(0f, 0f, 0f, 0f));
                var textsElement = texts.gameObject.AddComponent<LayoutElement>();
                textsElement.flexibleWidth = 1f;
                textsElement.preferredHeight = 52f;
                UiKit.AddVerticalLayout(texts, 2, 0);

                var nameText = UiKit.CreateText(
                    texts, "Name", name, 13, Color.white, TextAnchor.MiddleLeft);
                nameText.horizontalOverflow = HorizontalWrapMode.Wrap;
                UiKit.SetPreferredHeight(nameText, 30f);

                var info = UiKit.CreateText(
                    texts, "Info",
                    "×" + count + (meta != null ? " · " + TriggerShort(meta.Trigger) : string.Empty),
                    12,
                    new Color(0.62f, 0.70f, 0.84f),
                    TextAnchor.MiddleLeft);
                UiKit.SetPreferredHeight(info, 18f);
            }
        }

        private void AddCard(CollectionItemDto item)
        {
            if (!_catalog.TryGetValue(item.PrintingId, out _))
                return;

            if (_cards.Count >= 50)
            {
                SetEditorStatus("В колоде уже 50 карт.", true);
                return;
            }

            if (UsedByName(item.NameId) >= 4)
            {
                SetEditorStatus("Не больше 4 копий одной карты.", true);
                return;
            }

            if (_cards.Count(card => card == item.PrintingId) >= item.Count)
            {
                SetEditorStatus("В коллекции больше нет свободных копий.", true);
                return;
            }

            _cards.Add(item.PrintingId);
            SetEditorStatus(string.Empty, false);
            RefreshAfterDeckChange();
        }

        private void RemoveCard(string printingId)
        {
            var index = _cards.LastIndexOf(printingId);
            if (index >= 0)
                _cards.RemoveAt(index);

            RefreshAfterDeckChange();
        }

        private void RefreshAfterDeckChange()
        {
            UpdateStats();
            RebuildDeckCards();
            RefreshAllCounts();
        }

        private void RefreshAllCounts()
        {
            RefreshCounts(_listCountTexts, showDeckCount: false);
            RefreshCounts(_editorCountTexts, showDeckCount: true);
        }

        private void RefreshCounts(Dictionary<string, Text> countTexts, bool showDeckCount)
        {
            foreach (var pair in countTexts)
            {
                var item = _collection.Find(candidate => candidate.PrintingId == pair.Key);
                if (item == null)
                    continue;

                pair.Value.text = CountText(item, showDeckCount);
            }
        }

        private string CountText(CollectionItemDto item, bool showDeckCount)
        {
            var text = "×" + item.Count;
            if (showDeckCount)
                text += " · в колоде " + UsedByName(item.NameId);
            return text;
        }

        private void UpdateStats()
        {
            var grades = new int[4];
            foreach (var printingId in _cards)
            {
                if (_catalog.TryGetValue(printingId, out var meta)
                    && meta.Grade >= 0 && meta.Grade < grades.Length)
                {
                    grades[meta.Grade]++;
                }
            }

            _stats.text = "Всего: " + _cards.Count + "/50   G0 " + grades[0]
                + " · G1 " + grades[1] + " · G2 " + grades[2] + " · G3 " + grades[3];
            _deckCount.text = "Колода: " + _cards.Count + "/50";
        }

        private void OpenFilters()
        {
            _filterOverlay.SetAsLastSibling();
            _filterOverlay.gameObject.SetActive(true);
        }

        private void CloseFilters()
        {
            _filterOverlay.gameObject.SetActive(false);
        }

        private void OnGradeFilter(string value)
        {
            _filterGrade = value == "Все" ? -1 : int.Parse(value);
            OnFiltersChanged();
        }

        private void OnTriggerFilter(string value)
        {
            _filterTrigger = value;
            OnFiltersChanged();
        }

        private void OnClanFilter(string value)
        {
            _filterClan = value;
            OnFiltersChanged();
        }

        private void ResetFilters()
        {
            _filterGrade = -1;
            _filterTrigger = "Все";
            _filterClan = "Все";
            OnFiltersChanged();
        }

        private void OnFiltersChanged()
        {
            UpdateFilterSummary();
            RebuildCollectionGrids();
        }

        private void UpdateFilterSummary()
        {
            _filterSummary.text = (_filterClan == "Все" ? "Клан: все" : "Клан: " + _filterClan)
                + " · " + (_filterTrigger == "Все" ? "Триггер: все" : "Триггер: " + _filterTrigger)
                + " · " + (_filterGrade < 0 ? "Ранг: все" : "Ранг: " + _filterGrade);
        }

        private async void SaveDeck()
        {
            if (_busy)
                return;

            _busy = true;
            SetEditorStatus("Сохраняем…", false);
            try
            {
                await _auth.EnsureAccessAsync();
                var name = string.IsNullOrWhiteSpace(_nameInput.text)
                    ? "Новая колода"
                    : _nameInput.text.Trim();

                var result = _editing == null
                    ? await _meta.CreateDeckAsync(name, new List<string>(_cards))
                    : await _meta.UpdateDeckAsync(_editing.Id, name, new List<string>(_cards));

                _editing = result;
                _cards.Clear();
                _cards.AddRange(result.Cards);
                _nameInput.text = result.Name;
                UpsertDeck(result);
                BuildDeckList();
                RebuildEditor();
                SetEditorStatus("Сохранено: " + result.Cards.Count + " карт.", false);
            }
            catch (ApiException exception)
            {
                var details = exception.Violations.Count > 0
                    ? "\n" + string.Join("\n", exception.Violations.Take(3).Select(v => v.Message))
                    : string.Empty;
                SetEditorStatus(exception.Message + details, true);
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetEditorStatus("Не удалось сохранить колоду.", true);
            }
            finally
            {
                _busy = false;
            }
        }

        private void PlayDeck()
        {
            if (_editing == null)
            {
                SetEditorStatus("Сначала сохраните колоду.", true);
                return;
            }

            _onPlay(_editing);
        }

        private void RequestDeleteCurrent()
        {
            if (_editing == null)
            {
                SetEditorStatus("Сначала сохраните колоду.", true);
                return;
            }

            RequestDelete(_editing);
        }

        private async void DeleteDeck(DeckDto deck)
        {
            if (_busy)
                return;

            _busy = true;
            try
            {
                await _meta.DeleteDeckAsync(deck.Id);
                _decks.RemoveAll(item => item.Id == deck.Id);
                if (_editing != null && _editing.Id == deck.Id)
                    _editing = null;
                BuildDeckList();
                if (_editorView.gameObject.activeSelf)
                    BackToList();
                _listStatus.text = "Колода удалена.";
            }
            catch (ApiException exception)
            {
                _listStatus.text = exception.Message;
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                _listStatus.text = "Не удалось удалить колоду.";
            }
            finally
            {
                _busy = false;
            }
        }

        private void RequestDelete(DeckDto deck)
        {
            _pendingDelete = deck;
            _confirmText.text = deck.Name + "\nКолода будет удалена без восстановления.";
            _confirmOverlay.SetAsLastSibling();
            _confirmOverlay.gameObject.SetActive(true);
        }

        private void CancelDelete()
        {
            _pendingDelete = null;
            _confirmOverlay.gameObject.SetActive(false);
        }

        private void ConfirmDelete()
        {
            var deck = _pendingDelete;
            _confirmOverlay.gameObject.SetActive(false);
            _pendingDelete = null;
            if (deck != null)
                DeleteDeck(deck);
        }

        private void SetEditorStatus(string text, bool error)
        {
            if (_editorStatus == null)
                return;

            _editorStatus.text = text;
            _editorStatus.color = error
                ? new Color(1f, 0.55f, 0.45f)
                : new Color(0.62f, 0.68f, 0.82f);
        }

        private void UpsertDeck(DeckDto deck)
        {
            var index = _decks.FindIndex(item => item.Id == deck.Id);
            if (index >= 0)
                _decks[index] = deck;
            else
                _decks.Add(deck);
        }

        private CardCatalogItemDto MetaOf(CollectionItemDto item) =>
            _catalog.TryGetValue(item.PrintingId, out var meta) ? meta : null;

        private bool MatchesFilter(CardCatalogItemDto meta)
        {
            if (_filterGrade >= 0 && meta.Grade != _filterGrade)
                return false;
            if (_filterTrigger != "Все" && meta.Trigger != _filterTrigger)
                return false;
            if (_filterClan != "Все" && meta.Clan != _filterClan)
                return false;
            return true;
        }

        private int UsedByName(string nameId) =>
            _cards.Count(printingId =>
                _catalog.TryGetValue(printingId, out var meta) && meta.NameId == nameId);

        private static string TriggerShort(string trigger) => trigger switch
        {
            "Critical" => "K",
            "Draw" => "D",
            "Stand" => "S",
            "Heal" => "H",
            _ => "—",
        };

        private static int DustFor(string rarity) => rarity switch
        {
            "C" => 5,
            "R" => 10,
            "RR" => 25,
            "RRR" => 100,
            _ => 0,
        };

        private static int CraftCostFor(string rarity) => rarity switch
        {
            "C" => 20,
            "R" => 40,
            "RR" => 100,
            "RRR" => 400,
            _ => 0,
        };

        private static void SetButtonLabel(Button button, string label)
        {
            var text = button.GetComponentInChildren<Text>();
            if (text != null)
                text.text = label;
        }

        private static Color ClanColor(string clan) => clan switch
        {
            "RoyalPaladin" => new Color(0.22f, 0.42f, 0.78f),
            "OracleThinkTank" => new Color(0.72f, 0.58f, 0.22f),
            "Kagero" => new Color(0.66f, 0.18f, 0.18f),
            "Nubatama" => new Color(0.38f, 0.22f, 0.62f),
            "Tachikaze" => new Color(0.22f, 0.56f, 0.34f),
            "NovaGrappler" => new Color(0.78f, 0.40f, 0.16f),
            "SpikeBrothers" => new Color(0.52f, 0.34f, 0.20f),
            "DarkIrregulars" => new Color(0.28f, 0.20f, 0.36f),
            "Granblue" => new Color(0.16f, 0.46f, 0.54f),
            "Megacolony" => new Color(0.40f, 0.48f, 0.18f),
            _ => new Color(0.25f, 0.30f, 0.40f),
        };

        private static void SetFixedSize(Component component, float width, float height)
        {
            var element = component.gameObject.GetComponent<LayoutElement>()
                ?? component.gameObject.AddComponent<LayoutElement>();
            element.preferredWidth = width;
            element.preferredHeight = height;
            element.flexibleWidth = 0f;
            element.flexibleHeight = 0f;
        }

        private static void SetFlexible(Component component, float widthWeight, float height)
        {
            var element = component.gameObject.GetComponent<LayoutElement>()
                ?? component.gameObject.AddComponent<LayoutElement>();
            element.preferredHeight = height;
            element.flexibleWidth = widthWeight;
            element.flexibleHeight = 0f;
        }

        private static void ClearChildren(Transform parent)
        {
            for (var i = parent.childCount - 1; i >= 0; i--)
            {
                var child = parent.GetChild(i).gameObject;
                if (Application.isPlaying)
                    UnityEngine.Object.Destroy(child);
                else
                    UnityEngine.Object.DestroyImmediate(child);
            }
        }
    }
}