@page "/envelope/{EnvelopeKey}"
@rendermode InteractiveAuto
@inject IReceiverAuthService ReceiverAuthService
@inject EnvelopeState State
@implements IDisposable

<PageTitle>Dokument</PageTitle>

@switch (State.Status)
{
    case EnvelopePageStatus.Loading:
        <LoadingIndicator Message="Dokument wird geladen..." />
        break;

    case EnvelopePageStatus.NotFound:
        <StatusPage Type="not_found" />
        break;

    case EnvelopePageStatus.AlreadySigned:
        <StatusPage Type="signed"
                    Title="@State.Title"
                    SenderEmail="@State.SenderEmail" />
        break;

    case EnvelopePageStatus.Rejected:
        <StatusPage Type="rejected"
                    Title="@State.Title"
                    SenderEmail="@State.SenderEmail" />
        break;

    case EnvelopePageStatus.Expired:
        <StatusPage Type="expired" />
        break;

    case EnvelopePageStatus.RequiresAccessCode:
        <AccessCodeForm EnvelopeKey="@EnvelopeKey"
                        ErrorMessage="@State.ErrorMessage"
                        SenderEmail="@State.SenderEmail"
                        Title="@State.Title"
                        TfaEnabled="@State.TfaEnabled"
                        HasPhoneNumber="@State.HasPhoneNumber"
                        OnSubmit="HandleAccessCodeSubmit" />
        break;

    case EnvelopePageStatus.RequiresTwoFactor:
        <TfaForm EnvelopeKey="@EnvelopeKey"
                 TfaType="@(State.TfaType ?? "authenticator")"
                 TfaExpiration="@State.TfaExpiration"
                 HasPhoneNumber="@State.HasPhoneNumber"
                 ErrorMessage="@State.ErrorMessage"
                 OnSubmit="HandleTfaSubmit" />
        break;

    case EnvelopePageStatus.ShowDocument:
        @* Phase 4 (PSPDFKit) kommt später — vorerst Platzhalter *@
        <div class="text-center mt-5">
            <div class="status-icon signed">
                <i class="bi bi-file-earmark-check"></i>
            </div>
            <h2>Dokument bereit</h2>
            <p class="text-muted">
                «@State.Title» — PDF-Viewer wird in Phase 4 integriert.
            </p>
            @if (State.ReadOnly)
            {
                <span class="badge bg-secondary">Nur Lesen</span>
            }
        </div>
        break;

    case EnvelopePageStatus.Error:
        <ErrorDisplay Title="Fehler" Message="@State.ErrorMessage" />
        break;
}

@code {
    [Parameter] public string EnvelopeKey { get; set; } = default!;

    protected override async Task OnInitializedAsync()
    {
        State.OnChange += StateHasChanged;
        await LoadStatusAsync();
    }

    /// <summary>
    /// Erster API-Call: Status prüfen.
    /// Entspricht dem GET /Envelope/{key} im Web-Projekt.
    /// Die API entscheidet, was passiert (AccessCode nötig? Bereits signiert? etc.)
    /// </summary>
    private async Task LoadStatusAsync()
    {
        State.SetLoading();

        var result = await ReceiverAuthService.GetStatusAsync(EnvelopeKey);

        if (result.IsSuccess && result.Data is not null)
        {
            State.ApplyApiResponse(result.Data);
        }
        else if (result.StatusCode == 404)
        {
            State.SetNotFound();
        }
        else
        {
            State.SetError(result.ErrorMessage ?? "Verbindung zum Server fehlgeschlagen.");
        }
    }

    /// <summary>
    /// Zweiter API-Call: AccessCode senden.
    /// Wird von AccessCodeForm aufgerufen (OnSubmit-Callback).
    /// Die API prüft den Code und antwortet mit dem nächsten Status.
    /// </summary>
    private async Task HandleAccessCodeSubmit((string Code, bool PreferSms) submission)
    {
        var result = await ReceiverAuthService.SubmitAccessCodeAsync(
            EnvelopeKey, submission.Code, submission.PreferSms);

        if (result.IsSuccess && result.Data is not null)
        {
            State.ApplyApiResponse(result.Data);
        }
        else if (result.Data is not null)
        {
            // 401 mit Body → falscher Code, API gibt trotzdem ReceiverAuthModel zurück
            State.ApplyApiResponse(result.Data);
        }
        else
        {
            State.SetError(result.ErrorMessage ?? "Fehler bei der Code-Prüfung.");
        }
    }

    /// <summary>
    /// Dritter API-Call: TFA-Code senden.
    /// Wird von TfaForm aufgerufen (OnSubmit-Callback).
    /// </summary>
    private async Task HandleTfaSubmit((string Code, string Type) submission)
    {
        var result = await ReceiverAuthService.SubmitTfaCodeAsync(
            EnvelopeKey, submission.Code, submission.Type);

        if (result.IsSuccess && result.Data is not null)
        {
            State.ApplyApiResponse(result.Data);
        }
        else if (result.Data is not null)
        {
            State.ApplyApiResponse(result.Data);
        }
        else
        {
            State.SetError(result.ErrorMessage ?? "Fehler bei der TFA-Prüfung.");
        }
    }

    public void Dispose() => State.OnChange -= StateHasChanged;
}