@using System.Threading
@using PlaylistShared.Shared.DTO
@using PlaylistShared.Shared.Yandex
@inject HttpClient Http
@inject ISnackbar Snackbar
@inject IJSRuntime JsRuntime

<MudDialog>
    <TitleContent>
        <MudText Typo="Typo.h6">Авторизация Яндекс.Музыки по QR</MudText>
    </TitleContent>
    <DialogContent>
        @if (_qrUrl != null)
        {
            <div style="text-align: center;">
                <MudText Typo="Typo.body2" Class="mb-2">Отсканируйте QR-код приложением Яндекс</MudText>
                <MudImage Src="@_qrUrl" Style="max-width: 250px; border-radius: 12px; background-color: white;" />
                <MudText Typo="Typo.body2" Class="mt-2" Color="Color.Secondary">
                    Статус: @_statusText
                </MudText>
                @if (_isWaiting)
                {
                    <MudProgressCircular Indeterminate Class="mt-2" Size="Size.Small" />
                }
                @if (_isError)
                {
                    <MudAlert Severity="Severity.Error" Class="mt-4">
                        @_errorMessage
                    </MudAlert>
                }
            </div>
        }
        else
        {
            <MudProgressCircular Indeterminate />
        }
    </DialogContent>
    <DialogActions>
        <MudButton Variant="Variant.Text" OnClick="Cancel">Отмена</MudButton>
    </DialogActions>
</MudDialog>

@code {
    [CascadingParameter] IMudDialogInstance MudDialog { get; set; }

    private string _qrUrl;
    private string _sessionId;
    private string _statusText = "Ожидание сканирования";
    private bool _isWaiting = true;
    private bool _isError = false;
    private string _errorMessage = "";
    private CancellationTokenSource _cts;

    protected override async Task OnInitializedAsync()
    {
        await StartQrFlow();
    }

    private async Task StartQrFlow()
    {
        try
        {
            // 1. Получить QR и sessionId
            var response = await Http.GetFromJsonAsync<ApiResponse<YandexAuthQr>>("/api/yandexaccount/qr");
            if (!response.Success || response.Data == null)
            {
                ShowError("Не удалось получить QR-код");
                return;
            }

            _qrUrl = response.Data.QrLink;
            _sessionId = response.Data.SessionId;

            // 2. Начать опрос статуса
            _cts = new CancellationTokenSource();
            _ = PollStatus(_cts.Token);
            StateHasChanged();
        }
        catch (Exception ex)
        {
            ShowError(ex.Message);
        }
    }

    private async Task PollStatus(CancellationToken token)
    {
        while (!token.IsCancellationRequested)
        {
            try
            {
                await Task.Delay(500, token);
                var statusResponse = await Http.GetFromJsonAsync<ApiResponse<YandexAuthQrCheck>>($"/api/yandexaccount/qr/{_sessionId}", token);
                if (statusResponse?.Data != null)
                {
                    switch (statusResponse.Data.Status)
                    {
                        case Shared.Enums.YandexAuthQrStatus.Pending:
                            _statusText = "Ожидание подтверждения...";
                            break;
                        case Shared.Enums.YandexAuthQrStatus.Authorized:
                            _statusText = "Авторизация успешна!";
                            _isWaiting = false;
                            Snackbar.Add("Авторизация выполнена", Severity.Success);
                            _cts?.Cancel();
                            MudDialog.Close(DialogResult.Ok(true));
                            return;
                        case Shared.Enums.YandexAuthQrStatus.Expired:
                            _cts?.Cancel();
                            ShowError("Срок действия QR-кода истёк");
                            return;
                        case Shared.Enums.YandexAuthQrStatus.Error:
                            _cts?.Cancel();
                            ShowError("Ошибка авторизации");
                            return;
                    }
                    StateHasChanged();
                }
            }
            catch (TaskCanceledException) { break; }
            catch (Exception ex)
            {
                ShowError(ex.Message);
                break;
            }
        }
    }

    private void ShowError(string message)
    {
        _isError = true;
        _errorMessage = message;
        _isWaiting = false;
        StateHasChanged();
    }

    private void Cancel()
    {
        _cts?.Cancel();
        MudDialog.Close(DialogResult.Cancel());
    }

    public void Dispose()
    {
        _cts?.Cancel();
        _cts?.Dispose();
    }
}