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

namespace Vanguard.UI
{
    /// <summary>Магазин в Lobby: бустеры и вторая триал-дека.</summary>
    public sealed class StoreView
    {
        private readonly MetaService _meta;
        private readonly AuthService _auth;
        private readonly PlayerState _player;
        private readonly Action _onBack;

        private readonly RectTransform _root;
        private readonly Text _balances;
        private readonly Text _status;
        private readonly Button _goldButton;
        private readonly Button _tokenButton;
        private readonly RectTransform _trialContent;
        private readonly RectTransform _confirm;
        private Text _confirmText;
        private readonly RectTransform _result;
        private Text _resultTitle;
        private RectTransform _resultCards;

        private StoreResponse _store;
        private Func<Task> _confirmAction;
        private bool _busy;
        private bool _loading;

        public StoreView(
            Transform parent,
            MetaService meta,
            AuthService auth,
            PlayerState player,
            Action onBack)
        {
            _meta = meta;
            _auth = auth;
            _player = player;
            _onBack = onBack;

            _root = UiKit.CreatePanel(parent, "StoreScreen", new Color(0.018f, 0.03f, 0.06f, 0.94f));

            var top = UiKit.CreatePanel(_root, "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, 22, 16);

            var back = UiKit.CreateButton(top, "Back", "← Назад", () => _onBack(), 18);
            UiKit.SetPreferredHeight(back, 44f, 0f);

            var title = UiKit.CreateText(top, "Title", "Магазин", 32, Color.white, TextAnchor.MiddleLeft);
            title.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(title, 46f);

            _balances = UiKit.CreateText(
                top, "Balances", string.Empty, 18,
                new Color(0.70f, 0.76f, 0.90f), TextAnchor.MiddleRight);
            UiKit.SetPreferredHeight(_balances, 36f);

            var body = UiKit.CreatePanel(_root, "Body", new Color(0.02f, 0.03f, 0.06f, 0f));
            body.anchorMin = Vector2.zero;
            body.anchorMax = Vector2.one;
            body.offsetMin = new Vector2(44f, 30f);
            body.offsetMax = new Vector2(-44f, -110f);
            UiKit.AddVerticalLayout(body, 8, 12);

            var booster = UiKit.CreatePanel(body, "Booster", new Color(0.07f, 0.10f, 0.17f, 1f));
            UiKit.SetPreferredHeight(booster, 180f);
            UiKit.AddVerticalLayout(booster, 20, 8);

            var boosterTitle = UiKit.CreateText(
                booster, "Title", "Бустер BT01", 26, new Color(0.88f, 0.94f, 1f), TextAnchor.MiddleLeft);
            boosterTitle.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(boosterTitle, 34f);

            var boosterHint = UiKit.CreateText(
                booster,
                "Hint",
                "5 карт: 4 C + 1 R+ · duplicate protection · 100 Gold или 1 токен.",
                18,
                new Color(0.60f, 0.68f, 0.84f),
                TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(boosterHint, 28f);

            var buttons = UiKit.CreatePanel(booster, "Buttons", new Color(0f, 0f, 0f, 0f));
            UiKit.SetPreferredHeight(buttons, 54f);
            UiKit.AddHorizontalLayout(buttons, 0, 12);

            _goldButton = UiKit.CreateButton(
                buttons, "BuyGold", "Купить за 100 Gold", () => AskBooster("gold"), 19);
            UiKit.SetPreferredHeight(_goldButton, 52f);

            _tokenButton = UiKit.CreateButton(
                buttons, "BuyToken", "Купить за 1 токен", () => AskBooster("token"), 19);
            UiKit.SetPreferredHeight(_tokenButton, 52f);

            var trialTitle = UiKit.CreateText(
                body, "TrialTitle", "Триал-деки", 24, Color.white, TextAnchor.MiddleLeft);
            trialTitle.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(trialTitle, 34f);

            var scroll = UiKit.CreateScrollView(body, "TrialScroll", out _trialContent, 8f);
            var scrollElement = scroll.gameObject.AddComponent<LayoutElement>();
            scrollElement.flexibleHeight = 1f;
            scrollElement.minHeight = 160f;

            _status = UiKit.CreateText(
                body, "Status", string.Empty, 18,
                new Color(0.62f, 0.68f, 0.82f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_status, 34f);

            _confirm = BuildConfirm(_root);
            _result = BuildResult(_root);
            _confirm.gameObject.SetActive(false);
            _result.gameObject.SetActive(false);

            _root.gameObject.SetActive(false);
            _player.Changed += OnPlayerChanged;
        }

        public void Show()
        {
            UiKit.SetActive(_root, true);
            _confirm.gameObject.SetActive(false);
            _result.gameObject.SetActive(false);
            OnPlayerChanged();
            _ = LoadAsync();
        }

        public void Hide()
        {
            _confirm.gameObject.SetActive(false);
            _result.gameObject.SetActive(false);
            UiKit.SetActive(_root, false);
        }

        public void Tick()
        {
        }

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

            _loading = true;
            SetStatus("Загружаем магазин…", new Color(0.62f, 0.68f, 0.82f));
            SetButtons(false);

            try
            {
                await _auth.EnsureAccessAsync();
                _store = await _meta.GetStoreAsync();
                RebuildTrials(_store.TrialDecks);
                _goldButton.GetComponentInChildren<Text>().text =
                    "Купить за " + _store.BoosterPriceGold + " Gold";
                SetStatus("Выберите покупку.", new Color(0.62f, 0.68f, 0.82f));
            }
            catch (ApiException exception)
            {
                SetStatus(exception.Message, new Color(1f, 0.55f, 0.45f));
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetStatus("Не удалось загрузить магазин.", new Color(1f, 0.55f, 0.45f));
            }
            finally
            {
                _loading = false;
                SetButtons(true);
            }
        }

        private void RebuildTrials(IReadOnlyList<StoreTrialDeckDto> decks)
        {
            ClearChildren(_trialContent);
            if (decks == null || decks.Count == 0)
            {
                var empty = UiKit.CreateText(_trialContent, "Empty", "Триал-деки недоступны.", 18,
                    new Color(0.62f, 0.68f, 0.82f));
                UiKit.SetPreferredHeight(empty, 80f);
                return;
            }

            foreach (var deck in decks)
                AddTrialRow(deck);
        }

        private void AddTrialRow(StoreTrialDeckDto deck)
        {
            var row = UiKit.CreatePanel(_trialContent, "Trial_" + deck.Id, new Color(0.07f, 0.09f, 0.14f, 1f));
            var rowElement = row.gameObject.AddComponent<LayoutElement>();
            rowElement.preferredHeight = 92f;
            UiKit.AddHorizontalLayout(row, 16, 14);

            var info = UiKit.CreatePanel(row, "Info", new Color(0f, 0f, 0f, 0f));
            var infoElement = info.gameObject.AddComponent<LayoutElement>();
            infoElement.flexibleWidth = 1f;
            infoElement.preferredHeight = 60f;
            UiKit.AddVerticalLayout(info, 0, 2);

            var name = UiKit.CreateText(
                info, "Name", deck.Name, 21, Color.white, TextAnchor.MiddleLeft);
            name.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(name, 28f);

            var details = UiKit.CreateText(
                info,
                "Details",
                (string.IsNullOrEmpty(deck.Clan) ? "—" : deck.Clan)
                + "   ·   " + deck.CardCount + " карт   ·   "
                + (deck.Owned ? "в коллекции" : "цена " + deck.PriceGold + " Gold"),
                16,
                new Color(0.60f, 0.68f, 0.84f),
                TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(details, 24f);

            if (deck.Owned)
            {
                var owned = UiKit.CreateText(
                    row, "Owned", "Уже есть", 17,
                    new Color(0.45f, 0.85f, 0.55f));
                var ownedElement = owned.gameObject.AddComponent<LayoutElement>();
                ownedElement.preferredWidth = 120f;
                ownedElement.preferredHeight = 40f;
            }
            else
            {
                var buy = UiKit.CreateButton(
                    row,
                    "Buy",
                    "Купить за " + deck.PriceGold + " Gold",
                    () => AskTrial(deck),
                    17);
                var buyElement = buy.gameObject.AddComponent<LayoutElement>();
                buyElement.preferredWidth = 240f;
                buyElement.preferredHeight = 46f;
                buyElement.flexibleWidth = 0f;
            }
        }

        private void AskBooster(string payment)
        {
            if (_store == null || _busy)
                return;

            var price = payment == "gold"
                ? _store.BoosterPriceGold + " Gold"
                : "1 токен";
            AskConfirm(
                "Открыть бустер BT01 за " + price + "?",
                () => BuyBoosterAsync(payment));
        }

        private void AskTrial(StoreTrialDeckDto deck)
        {
            if (_busy)
                return;

            AskConfirm(
                "Купить «" + deck.Name + "» за " + deck.PriceGold + " Gold?",
                () => BuyTrialAsync(deck));
        }

        private void AskConfirm(string text, Func<Task> action)
        {
            _confirmText.text = text;
            _confirmAction = action;
            _confirm.SetAsLastSibling();
            _confirm.gameObject.SetActive(true);
        }

        private async void OnConfirmYes()
        {
            if (_confirmAction == null)
                return;

            var action = _confirmAction;
            _confirmAction = null;
            _confirm.gameObject.SetActive(false);
            _busy = true;
            SetButtons(false);
            SetStatus("Выполняем покупку…", new Color(0.62f, 0.68f, 0.82f));

            try
            {
                await action();
            }
            catch (ApiException exception)
            {
                SetStatus(exception.Message, new Color(1f, 0.55f, 0.45f));
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetStatus("Покупка не удалась.", new Color(1f, 0.55f, 0.45f));
            }
            finally
            {
                _busy = false;
                SetButtons(true);
            }
        }

        private async Task BuyBoosterAsync(string payment)
        {
            var result = await _meta.BuyBoosterAsync(payment);
            SetStatus("Бустер открыт!", new Color(0.45f, 0.85f, 0.55f));
            ShowResult(result);
        }

        private async Task BuyTrialAsync(StoreTrialDeckDto deck)
        {
            await _meta.BuyTrialDeckAsync(deck.Id);
            SetStatus("«" + deck.Name + "» добавлена в коллекцию.", new Color(0.45f, 0.85f, 0.55f));
            await LoadAsync();
        }

        private void ShowResult(BoosterResultDto result)
        {
            ClearChildren(_resultCards);
            _resultTitle.text = "Бустер открыт · " + result.Cards.Count + " карт";

            foreach (var card in result.Cards)
            {
                var panel = UiKit.CreatePanel(_resultCards, "Card_" + card.PrintingId, new Color(0.09f, 0.12f, 0.20f, 1f));
                var element = panel.gameObject.AddComponent<LayoutElement>();
                element.preferredWidth = 210f;
                element.preferredHeight = 280f;
                element.flexibleWidth = 0f;
                UiKit.AddVerticalLayout(panel, 14, 8);

                var printing = UiKit.CreateText(
                    panel, "Printing", card.PrintingId, 18, Color.white);
                printing.horizontalOverflow = HorizontalWrapMode.Wrap;
                UiKit.SetPreferredHeight(printing, 50f);

                var name = UiKit.CreateText(
                    panel, "Name", card.NameId, 16,
                    new Color(0.70f, 0.78f, 0.94f));
                name.horizontalOverflow = HorizontalWrapMode.Wrap;
                UiKit.SetPreferredHeight(name, 60f);

                var rarity = UiKit.CreateText(
                    panel, "Rarity", card.Rarity, 20,
                    new Color(0.45f, 0.80f, 1f));
                UiKit.SetPreferredHeight(rarity, 30f);

                if (card.IsNew)
                {
                    var isNew = UiKit.CreateText(
                        panel, "New", "NEW", 18,
                        new Color(1f, 0.78f, 0.32f));
                    isNew.fontStyle = FontStyle.Bold;
                    UiKit.SetPreferredHeight(isNew, 30f);
                }
            }

            _result.SetAsLastSibling();
            _result.gameObject.SetActive(true);
        }

        private void OnResultClosed()
        {
            _result.gameObject.SetActive(false);
            _ = LoadAsync();
        }

        private RectTransform BuildConfirm(Transform parent)
        {
            var overlay = UiKit.CreatePanel(parent, "StoreConfirm", new Color(0f, 0f, 0f, 0.75f));
            var card = UiKit.CreateCenteredCard(
                overlay, "ConfirmCard", new Vector2(620f, 280f),
                new Color(0.08f, 0.10f, 0.16f, 1f));
            UiKit.AddVerticalLayout(card, 30, 14);

            var title = UiKit.CreateText(card, "Title", "Подтвердите покупку", 27, Color.white);
            title.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(title, 40f);

            _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", "Купить", OnConfirmYes, 20);
            UiKit.SetPreferredHeight(yes, 48f);

            var no = UiKit.CreateButton(
                card, "No", "Отмена",
                () => { _confirmAction = null; _confirm.gameObject.SetActive(false); },
                20);
            UiKit.SetPreferredHeight(no, 44f);

            return overlay;
        }

        private RectTransform BuildResult(Transform parent)
        {
            var overlay = UiKit.CreatePanel(parent, "BoosterResult", new Color(0f, 0f, 0f, 0.82f));
            var card = UiKit.CreateCenteredCard(
                overlay, "ResultCard", new Vector2(1400f, 520f),
                new Color(0.06f, 0.08f, 0.14f, 1f));
            UiKit.AddVerticalLayout(card, 28, 14);

            _resultTitle = UiKit.CreateText(
                card, "Title", "Бустер открыт", 28, Color.white);
            _resultTitle.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(_resultTitle, 40f);

            var row = UiKit.CreatePanel(card, "Cards", new Color(0f, 0f, 0f, 0f));
            var rowElement = row.gameObject.AddComponent<LayoutElement>();
            rowElement.flexibleHeight = 1f;
            rowElement.minHeight = 300f;
            UiKit.AddHorizontalLayout(row, 0, 14);
            _resultCards = row;

            var close = UiKit.CreateButton(card, "Close", "Забрать", OnResultClosed, 21);
            UiKit.SetPreferredHeight(close, 52f);

            return overlay;
        }

        private void SetButtons(bool interactable)
        {
            if (_goldButton != null)
                _goldButton.interactable = interactable;
            if (_tokenButton != null)
                _tokenButton.interactable = interactable;
        }

        private void OnPlayerChanged()
        {
            _balances.text = "Gold " + _player.Gold + "   ·   Пыль " + _player.Dust
                + "   ·   Токены " + _player.Tokens;
        }

        private void SetStatus(string text, Color color)
        {
            _status.text = text ?? string.Empty;
            _status.color = color;
        }

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