using System;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.UI;
using Vanguard.Api;
using Vanguard.Auth;
using Vanguard.State;

namespace Vanguard.UI
{
    /// <summary>Главный экран после входа: профиль, балансы и заглушки разделов.</summary>
    public sealed class MetaView : IDisposable
    {
        private readonly AuthService _auth;
        private readonly PlayerState _player;
        private readonly Action _onLoggedOut;
        private readonly Action _onCollection;
        private readonly Action _onDecks;
        private readonly Action _onStore;
        private readonly Action _onPlay;
        private readonly Action _onOnboarding;
        private bool _disposed;

        private readonly RectTransform _root;
        private readonly Text _playerName;
        private readonly Text _onboarding;
        private readonly Text _gold;
        private readonly Text _dust;
        private readonly Text _tokens;
        private readonly Text _ranked;
        private readonly Text _casual;
        private readonly Text _record;
        private readonly Text _status;
        private readonly Button _logout;
        private readonly Button _onboardingButton;
        private bool _refreshing;

        public MetaView(
            Transform parent,
            AuthService auth,
            PlayerState player,
            Action onLoggedOut,
            Action onCollection,
            Action onDecks,
            Action onStore,
            Action onPlay,
            Action onOnboarding)
        {
            _auth = auth;
            _player = player;
            _onLoggedOut = onLoggedOut;
            _onCollection = onCollection;
            _onDecks = onDecks;
            _onStore = onStore;
            _onPlay = onPlay;
            _onOnboarding = onOnboarding;

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

            var top = UiKit.CreatePanel(_root, "TopBar", new Color(0.07f, 0.085f, 0.115f, 1f));
            var topRect = top;
            topRect.anchorMin = new Vector2(0f, 1f);
            topRect.anchorMax = new Vector2(1f, 1f);
            topRect.pivot = new Vector2(0.5f, 1f);
            topRect.anchoredPosition = Vector2.zero;
            topRect.sizeDelta = new Vector2(0f, 92f);
            UiKit.AddHorizontalLayout(top, 22, 16);

            var brand = UiKit.CreateText(
                top, "Brand", "VANGUARD", 34, new Color(0.86f, 0.90f, 1f), TextAnchor.MiddleLeft);
            brand.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(brand, 48f, 0f);

            _playerName = UiKit.CreateText(
                top, "PlayerName", "…", 20, new Color(0.70f, 0.76f, 0.90f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_playerName, 40f);

            _logout = UiKit.CreateButton(top, "Logout", "Выйти", OnLogoutClicked, 18);
            UiKit.SetPreferredHeight(_logout, 42f, 0f);

            var content = UiKit.CreatePanel(_root, "Content", new Color(0.035f, 0.045f, 0.065f, 0f));
            var contentRect = content;
            contentRect.anchorMin = Vector2.zero;
            contentRect.anchorMax = Vector2.one;
            contentRect.offsetMin = new Vector2(48f, 36f);
            contentRect.offsetMax = new Vector2(-48f, -116f);
            UiKit.AddVerticalLayout(contentRect, 12, 16);

            var welcome = UiKit.CreateText(
                content, "Welcome", "Личный кабинет", 38, Color.white, TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(welcome, 56f);

            _onboarding = UiKit.CreateText(
                content, "Onboarding", string.Empty, 18,
                new Color(1f, 0.76f, 0.38f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_onboarding, 28f);

            var stats = UiKit.CreatePanel(content, "Stats", new Color(0.07f, 0.085f, 0.115f, 1f));
            UiKit.SetPreferredHeight(stats, 130f);
            UiKit.AddHorizontalLayout(stats, 18, 14);

            _gold = AddStat(stats, "Gold");
            _dust = AddStat(stats, "Пыль");
            _tokens = AddStat(stats, "Токены");
            _ranked = AddStat(stats, "Ranked MMR");
            _casual = AddStat(stats, "Casual MMR");

            var actions = UiKit.CreatePanel(content, "Actions", new Color(0.07f, 0.085f, 0.115f, 1f));
            UiKit.SetPreferredHeight(actions, 96f);
            UiKit.AddHorizontalLayout(actions, 18, 14);

            AddAction(actions, "Коллекция", _onCollection);
            AddAction(actions, "Колоды", _onDecks);
            AddAction(actions, "Магазин", _onStore);
            AddAction(actions, "В бой", _onPlay);

            var lower = UiKit.CreatePanel(content, "Lower", new Color(0.07f, 0.085f, 0.115f, 1f));
            UiKit.SetPreferredHeight(lower, 220f, 1f);
            UiKit.AddVerticalLayout(lower, 20, 8);

            _record = UiKit.CreateText(
                lower, "Record", string.Empty, 20,
                new Color(0.72f, 0.78f, 0.92f), TextAnchor.MiddleLeft);
            UiKit.SetPreferredHeight(_record, 28f);

            _status = UiKit.CreateText(
                lower, "Status", string.Empty, 18,
                new Color(0.62f, 0.68f, 0.82f), TextAnchor.UpperLeft);
            UiKit.SetPreferredHeight(_status, 70f);

            _onboardingButton = UiKit.CreateButton(
                lower, "OnboardingButton", "Выбрать триал-деку", () => _onOnboarding(), 20);
            UiKit.SetPreferredHeight(_onboardingButton, 46f);

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

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

        public void Hide() => UiKit.SetActive(_root, false);

        public void Dispose()
        {
            if (_disposed)
                return;

            _disposed = true;
            _player.Changed -= UpdateTexts;
        }

        private static Text AddStat(Transform parent, string caption)
        {
            var card = UiKit.CreatePanel(parent, "Stat_" + caption, new Color(0.09f, 0.11f, 0.15f, 1f));
            UiKit.AddVerticalLayout(card, 12, 4);
            var element = card.gameObject.AddComponent<LayoutElement>();
            element.flexibleWidth = 1f;
            element.preferredHeight = 100f;

            var label = UiKit.CreateText(
                card, "Caption", caption, 16, new Color(0.58f, 0.65f, 0.78f));
            UiKit.SetPreferredHeight(label, 22f);

            var value = UiKit.CreateText(
                card, "Value", "—", 30, Color.white);
            value.fontStyle = FontStyle.Bold;
            UiKit.SetPreferredHeight(value, 40f);
            return value;
        }

        private static Button AddAction(Transform parent, string caption, Action onClick)
        {
            var button = UiKit.CreateButton(parent, "Action_" + caption, caption, () => onClick(), 20);
            var element = button.gameObject.AddComponent<LayoutElement>();
            element.flexibleWidth = 1f;
            element.preferredHeight = 56f;
            return button;
        }

        private async Task RefreshAsync()
        {
            if (_refreshing)
                return;

            _refreshing = true;
            SetStatus("Обновляем профиль…", new Color(0.62f, 0.68f, 0.82f));

            try
            {
                await _auth.RefreshMeAsync();
                if (_disposed)
                    return;

                SetStatus("Профиль обновлён.", new Color(0.45f, 0.85f, 0.55f));
            }
            catch (ApiException exception) when (exception.StatusCode == 401)
            {
                if (!_disposed)
                    _onLoggedOut();
            }
            catch (Exception exception)
            {
                Debug.LogException(exception);
                SetStatus("Не удалось обновить профиль. Сервер недоступен?", new Color(1f, 0.60f, 0.45f));
            }
            finally
            {
                _refreshing = false;
            }
        }

        private void UpdateTexts()
        {
            if (_disposed)
                return;
            _playerName.text = string.IsNullOrEmpty(_player.UserName)
                ? "…"
                : _player.UserName;

            _gold.text = _player.Gold.ToString();
            _dust.text = _player.Dust.ToString();
            _tokens.text = _player.Tokens.ToString();
            _ranked.text = _player.RankedMmr.ToString();
            _casual.text = _player.CasualMmr.ToString();

            _record.text = "Матчей: " + _player.Matches + "   ·   побед: " + _player.Wins
                + "   ·   XP: " + _player.Xp;

            _onboarding.text = _player.OnboardingCompleted
                ? "Онбординг завершён: " + (_player.SelectedTrialDeckId ?? "—")
                : "Онбординг не завершён: выберите стартовую триал-деку.";

            _onboardingButton.gameObject.SetActive(!_player.OnboardingCompleted);
        }

        private void SetStatus(string text, Color color)
        {
            if (_disposed || _status == null)
                return;

            _status.text = text ?? string.Empty;
            _status.color = color;
        }

        private async void OnLogoutClicked()
        {
            _logout.interactable = false;
            await _auth.LogoutAsync();
            if (_disposed)
                return;

            _logout.interactable = true;
            _onLoggedOut();
        }
    }
}