using System.Collections.ObjectModel;
using System.IO;
using System.Text.Json;
using System.Windows;
using System.Windows.Threading;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using LeagueAPI;
using LeagueAPI.ARAM;
using LeagueAPI.Models.ChampSelect;
using LeagueAPI.Models.DDragon.Champions;
using LeagueAPI.Models.ReadyCheck;

namespace ARAMUtility.ViewModel;

public partial class MainViewModel : ObservableObject, IDisposable
{
    private const int TEAM_CHAMPIONS_MAX = 5;
    private const int BENCH_CHAMPIONS_MAX = 10;

    private bool _isDisposed;
    private readonly Lock _syncRoot = new();
    private readonly SemaphoreSlim _championUpdateSemaphore = new(1, 1);

    private Dispatcher Dispatcher { get; } = Dispatcher.CurrentDispatcher;

    [ObservableProperty]
    public partial string Title { get; set; } = "ARAM Utility";

    [ObservableProperty]
    public partial ObservableCollection<ChampionViewModel> TeamChampions { get; private set; } = [];

    [ObservableProperty]
    public partial ObservableCollection<ChampionViewModel> BenchChampions { get; private set; } = [];

    [ObservableProperty]
    public partial bool IsDisconnected { get; private set; } = false;

    [ObservableProperty]
    public partial string ConnectionStatus { get; private set; } = "Not connected.";

    private Dictionary<int, ChampionData> _allChampions = [];
    private List<int> _needChampionIds = [];
    private readonly APIClient _client = new();
    private readonly LcuWebsocket _lcuWebsocket = new();
    private Task _lcuWebsocketTask;
    private readonly ARAMBalanceService _aramBalanceService = new();

    public MainViewModel()
    {
        _lcuWebsocket.Connecting += (_, _) => UpdateConnectionStatus(false, "Connecting ...");
        _lcuWebsocket.Connected += (_, _) => UpdateConnectionStatus(false, "Connected.");
        _lcuWebsocket.Disconnected += (_, _) => UpdateConnectionStatus(true, "Disconnected.");

        _lcuWebsocket.LcuApiEvent += OnLcuApiEvent;
#if DEBUG
        _lcuWebsocket.LcuApiException += (sender, e) =>
        {
            File.AppendAllText("socketerror.log", $"[{DateTime.Now:s}] {e.Message}\n{e.StackTrace}\n\n");
        };
#endif
        _lcuWebsocketTask = _lcuWebsocket.Connect();
    }

    internal async void OnInit(object? sender, RoutedEventArgs e)
    {
        ChampionData[] champions = await _client.GetAllChampionsAsync();
        Dictionary<int, ChampionData> championDictionary = champions
            .Where(c => c.Id != -1)
            .ToDictionary(key => key.Id);
        lock (_syncRoot)
        {
            _allChampions = championDictionary;
        }
        await UpdateNeedChampionIdsAsync();
        await FillChampionLists();
    }

    private void UpdateConnectionStatus(bool isConnected, string statusMessage)
    {
        Dispatcher.Invoke(() =>
        {
            IsDisconnected = isConnected;
            ConnectionStatus = statusMessage;
        });
    }

    private async void OnLcuApiEvent(object? sender, LcuApiEvent apiEvent)
    {
        switch (apiEvent.Uri)
        {
            case "/lol-matchmaking/v1/ready-check":
                LolMatchmakingMatchmakingReadyCheckResource? readyCheck = apiEvent.Data.Deserialize<LolMatchmakingMatchmakingReadyCheckResource>();
                if (readyCheck is not null && readyCheck.PlayerResponse == LolMatchmakingMatchmakingReadyCheckResponse.Accepted)
                {
                    await UpdateNeedChampionIdsAsync();
                }
                break;
            case "/lol-champ-select/v1/session":
                ChampSelectSession? session = apiEvent.Data.Deserialize<ChampSelectSession>();
                await ShowChampionsAsync(session);
                break;
            default:
                File.AppendAllText("socket.log", $"{apiEvent.Uri}: {apiEvent.EventType} - {apiEvent.Data?.ToJsonString()}\n");
                break;
        }

    }

    private async Task UpdateNeedChampionIdsAsync()
    {
        IEnumerable<int> completedChampionIds = await _client.GetAllRandomAllChampionsCompletedChampionsAsync();
        IEnumerable<int> needChampionIds = _allChampions.Keys.Except(completedChampionIds);
        lock (_syncRoot)
        {
            _needChampionIds = [.. needChampionIds];
        }
    }

    private async Task FillChampionLists()
    {
        string defaultImagePath = await ResourceService.GetChampionIconPathAsync(-1);
        while (TeamChampions.Count < TEAM_CHAMPIONS_MAX)
        {
            TeamChampions.Add(GetEmptyChampionViewModel());
        }
        while (BenchChampions.Count < BENCH_CHAMPIONS_MAX)
        {
            BenchChampions.Add(GetEmptyChampionViewModel());
        }

        ChampionViewModel GetEmptyChampionViewModel()
        {
            return new ChampionViewModel(new ChampionData()) { ImagePath = defaultImagePath, IsNeededForChallenge = false };
        }
    }

    private async Task ShowChampionsAsync(ChampSelectSession? session)
    {
        await _championUpdateSemaphore.WaitAsync();

        (IEnumerable<int> teamChampions, IEnumerable<int> benchChampions) = APIClient.GetSelectableChampionIds(session);
        if (!teamChampions.Any() && !benchChampions.Any())
        {
            TeamChampions.Clear();
            BenchChampions.Clear();
        }
        else
        {
            await UpdateChampions(TeamChampions, teamChampions);
            await UpdateChampions(BenchChampions, benchChampions);
        }

        await FillChampionLists();
        _championUpdateSemaphore.Release();

        async Task UpdateChampions(ObservableCollection<ChampionViewModel> viewModel, IEnumerable<int> championIds)
        {
            viewModel.Clear();
            await _aramBalanceService.EnsureIsLoadedAsync();

            foreach (int championId in championIds)
            {
                ChampionData? championData = await _client.GetChampionByIdAsync(championId);
                if (championData is null)
                {
                    continue;
                }

                string imagePath = await ResourceService.GetChampionIconPathAsync(championId);
                ChampionViewModel vm = new(championData with { AramBalance = _aramBalanceService.GetAramStats(championData.Id) })
                {
                    IsNeededForChallenge = _needChampionIds.Contains(championData.Id),
                    ImagePath = imagePath,
                };
                viewModel.Add(vm);
            }
        }
    }

    [RelayCommand(AllowConcurrentExecutions = false, CanExecute = nameof(IsDisconnected))]
    private async Task Connect()
    {
        if (_lcuWebsocketTask is null || _lcuWebsocketTask.IsCompleted)
        {
            _lcuWebsocketTask?.Dispose();
            _lcuWebsocketTask = _lcuWebsocket.Connect();
        }
    }

    [RelayCommand(AllowConcurrentExecutions = false)]
    private async Task OpenLobby()
    {
        await _client.CreateMayhemLobbyAsync();
    }

    [RelayCommand(AllowConcurrentExecutions = false)]
    private async Task StartQueueing()
    {
        await _client.StartMatchmakingQueueAsync();
    }

    [RelayCommand(AllowConcurrentExecutions = false)]
    private async Task ReloadARAMBalance()
    {
        await _aramBalanceService.ReloadAsync(force: true);
        MessageBox.Show("Reloaded ARAM balance data.", "Info", MessageBoxButton.OK, MessageBoxImage.Exclamation);
    }
    
    [RelayCommand]
    private async Task Quit()
    {
        Application.Current.Shutdown();
    }

    #region IDisposable
    protected virtual void Dispose(bool disposing)
    {
        if (!_isDisposed)
        {
            if (disposing)
            {
                _allChampions = [];
                _client.Dispose();
                _lcuWebsocket.Dispose();
            }

            _isDisposed = true;
        }
    }

    public void Dispose()
    {
        // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
        Dispose(disposing: true);
        GC.SuppressFinalize(this);
    }
    #endregion
}