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

namespace Vanguard.UI
{
    /// <summary>Список колод и быстрый сборщик стартовой колоды из триал-деки.</summary>
    public sealed class DecksView
    {
        private readonly MetaService _meta;
        private readonly PlayerState _player;
        private readonly Action _onBack;
        private readonly Action<DeckDto> _onPlay;

        private readonly RectTransform _root;
        private RectTransform _content;
        private readonly Text _balances;
        private readonly Text _status;
        private readonly Button _createButton;
        private readonly RectTransform _confirm;
        private Text _confirmText;
        private DeckDto _pendingDelete;
        private bool _loading;

        public DecksView(
            Transform parent,
            MetaService meta,
            PlayerState player,
            Action onBack,
            Action<DeckDto> onPlay)
        {
            _meta = meta;
            _player = player;
            _onBack = onBack;
            _onPlay = onPlay;

            _root = UiKit.CreatePanel(parent, "DecksScreen", new Color(0.035f, 0.045f, 0.065f, 1f));

            var top = UiKit.CreatePanel(_root, "TopBar", new Color(0.07f, 0.085f, 0.115f, 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", "Колоды", 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(0.035f, 0.045f, 0.065f, 0f));
            body.anchorMin = Vector2.zero;
            body.anchorMax = Vector2.one;
            body.offsetMin = new Vector2(40f, 28f);
            body.offsetMax = new Vector2(-40f, -110f);
            UiKit.AddVerticalLayout(body, 8, 10);

            var hint = UiKit.CreateText(
                body,
                "Hint",
                "Стартовая колода собирается из выбранной триал-деки: 50 карт, состав уже проверен сервером.",
                17,
                new Color(0.58f, 0.65f, 0.78f),
                TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(hint, 26f);

            var scroll = UiKit.CreateScrollView(body, "DecksScroll", out _content, 8f);
            var scrollElement = scroll.gameObject.AddComponent<LayoutElement>();
            scrollElement.flexibleHeight = 1f;
            scrollElement.minHeight = 180f;

            var actions = UiKit.CreatePanel(body, "Actions", new Color(0.05f, 0.06f, 0.085f, 0f));
            UiKit.SetPreferredHeight(actions, 56f);
            UiKit.AddHorizontalLayout(actions, 0, 12);

            _createButton = UiKit.CreateButton(
                actions,
                "CreateFromTrial",
                "Собрать из триал-деки",
                OnCreateFromTrialClicked,
                19);
            UiKit.SetPreferredHeight(_createButton, 52f);

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

            _confirm = BuildConfirm(parent);
            _confirm.gameObject.SetActive(false);

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

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

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

        private RectTransform BuildConfirm(Transform parent)
        {
            var overlay = UiKit.CreatePanel(parent, "DeleteDeckConfirm", new Color(0f, 0f, 0f, 0.72f));
            var card = UiKit.CreateCenteredCard(
                overlay, "ConfirmCard", new Vector2(620f, 280f),
                new Color(0.08f, 0.10f, 0.14f, 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),
                TextAnchor.MiddleCenter);
            UiKit.SetPreferredHeight(_confirmText, 80f);

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

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

            overlay.gameObject.SetActive(false);
            return overlay;
        }

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

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

            try
            {
                var decks = await _meta.GetDecksAsync();
                Rebuild(decks);
                SetStatus(
                    decks.Count == 0 ? "Колод пока нет." : "Колод: " + decks.Count + ".",
                    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 колоды.", new Color(1f, 0.55f, 0.45f));
            }
            finally
            {
                _loading = false;
            }
        }

        private void Rebuild(IReadOnlyList<DeckDto> decks)
        {
            for (var i = _content.childCount - 1; i >= 0; i--)
                UnityEngine.Object.Destroy(_content.GetChild(i).gameObject);

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

        private void AddRow(DeckDto deck)
        {
            var row = UiKit.CreatePanel(_content, "Deck_" + deck.Id, new Color(0.07f, 0.085f, 0.115f, 1f));
            var rowElement = row.gameObject.AddComponent<LayoutElement>();
            rowElement.preferredHeight = 72f;
            UiKit.AddHorizontalLayout(row, 12, 12);

            var name = UiKit.CreateText(
                row, "Name", deck.Name, 21, Color.white, TextAnchor.MiddleLeft);
            name.fontStyle = FontStyle.Bold;
            var nameElement = name.gameObject.AddComponent<LayoutElement>();
            nameElement.flexibleWidth = 1f;
            nameElement.preferredHeight = 44f;

            var info = UiKit.CreateText(
                row,
                "Info",
                deck.Cards.Count + " карт · " + deck.Format,
                16,
                new Color(0.58f, 0.65f, 0.78f),
                TextAnchor.MiddleLeft);
            var infoElement = info.gameObject.AddComponent<LayoutElement>();
            infoElement.preferredWidth = 230f;
            infoElement.preferredHeight = 40f;

            var play = UiKit.CreateButton(row, "Play", "В бой", () => OnPlayClicked(deck), 17);
            var playElement = play.gameObject.AddComponent<LayoutElement>();
            playElement.preferredWidth = 120f;
            playElement.preferredHeight = 46f;
            playElement.flexibleWidth = 0f;

            var delete = UiKit.CreateButton(row, "Delete", "Удалить", () => ShowConfirm(deck), 16);
            var deleteElement = delete.gameObject.AddComponent<LayoutElement>();
            deleteElement.preferredWidth = 110f;
            deleteElement.preferredHeight = 46f;
            deleteElement.flexibleWidth = 0f;
        }

        private async void OnCreateFromTrialClicked()
        {
            if (_loading)
                return;

            _loading = true;
            _createButton.interactable = false;
            SetStatus("Ищем выбранную триал-деку…", new Color(0.62f, 0.68f, 0.82f));

            try
            {
                var store = await _meta.GetStoreAsync();
                var trial = store.TrialDecks.FirstOrDefault(deck => deck.Owned);

                if (trial == null)
                {
                    SetStatus("Сначала завершите онбординг и выберите триал-деку.", new Color(1f, 0.60f, 0.45f));
                    return;
                }

                var cards = trial.Cards
                    .SelectMany(card => Enumerable.Repeat(card.PrintingId, card.Count))
                    .ToList();

                var created = await _meta.CreateDeckAsync(trial.Name + " (старт)", cards);
                SetStatus("Колода «" + created.Name + "» собрана: " + created.Cards.Count + " карт.", new Color(0.45f, 0.85f, 0.55f));
                _loading = false;
                await LoadAsync();
            }
            catch (ApiException exception)
            {
                SetStatus(exception.Message, new Color(1f, 0.55f, 0.45f));
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetStatus("Не удалось собрать колоду.", new Color(1f, 0.55f, 0.45f));
            }
            finally
            {
                _loading = false;
                _createButton.interactable = true;
            }
        }

        private void OnPlayClicked(DeckDto deck)
        {
            _onPlay(deck);
        }

        private void ShowConfirm(DeckDto deck)
        {
            _pendingDelete = deck;
            _confirmText.text = "«" + deck.Name + "» будет удалена без возможности восстановления.";
            _confirm.SetAsLastSibling();
            _confirm.gameObject.SetActive(true);
        }

        private void HideConfirm()
        {
            _pendingDelete = null;
            _confirm.gameObject.SetActive(false);
        }

        private async void OnConfirmDelete()
        {
            if (_pendingDelete == null)
                return;

            var deck = _pendingDelete;
            _confirm.gameObject.SetActive(false);
            SetStatus("Удаляем «" + deck.Name + "»…", new Color(0.62f, 0.68f, 0.82f));

            try
            {
                await _meta.DeleteDeckAsync(deck.Id);
                SetStatus("Колода удалена.", new Color(0.45f, 0.85f, 0.55f));
                await LoadAsync();
            }
            catch (ApiException exception)
            {
                SetStatus(exception.Message, new Color(1f, 0.55f, 0.45f));
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetStatus("Не удалось удалить колоду.", new Color(1f, 0.55f, 0.45f));
            }
            finally
            {
                _pendingDelete = null;
            }
        }

        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;
        }
    }
}