EnvelopeGenerator/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/Pages/ReceiverReadOnlyPage.razor

@page "/envelope/readonly/{ReadOnlyKey}"
@rendermode InteractiveServer
@using DevExpress.Blazor.Reporting
@using DevExpress.XtraReports.UI
@using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiverReadOnly
@using EnvelopeGenerator.Application.Common.Extensions
@using EnvelopeGenerator.Application.Common.Interfaces.Services
@using EnvelopeGenerator.Domain.Constants
@inject EnvelopeGenerator.Server.Client.Services.AppVersionService AppVersion
@inject ILogger<ReceiverReadOnlyPage> Logger
@inject IEnvelopeReceiverReadOnlyService ReadOnlyService
@inject IEnvelopeReceiverService EnvelopeReceiverService
@inject IEnvelopeHistoryService HistoryService
@implements IDisposable

<link href="_content/DevExpress.Blazor.Themes/blazing-berry.bs5.min.css" rel="stylesheet" />
<link href="_content/DevExpress.Blazor.Reporting.Viewer/css/dx-blazor-reporting-components.bs5.css" rel="stylesheet" />
<link href="@AppVersion.GetVersionedUrl("css/envelope-viewer.css")" rel="stylesheet" />

<div class="envelope-viewer-layout">
    <div class="envelope-action-bar">
        <div class="envelope-action-bar__inner" style="padding: 0.5rem 1.25rem;">
            <div style="display:flex; align-items:center; justify-content:space-between; gap:1rem;">
                <div style="font-weight:600; color:#1f2937;">Dokumentansicht (Nur Lesen)</div>
                @if (_readOnly is not null)
                {
                    <div style="font-size:0.8rem; color:#6b7280;">Gultig bis: @_readOnly.DateValid.ToString("dd.MM.yyyy")</div>
                }
            </div>
        </div>
    </div>

    <div class="envelope-content" style="padding:0; overflow:hidden;">
        @if (_isLoading)
        {
            <div class="d-flex justify-content-center align-items-center h-100">
                <div class="text-center">
                    <div class="spinner-border text-white mb-3" style="width:3.5rem; height:3.5rem;" role="status"></div>
                    <p class="text-white fw-semibold">Dokument wird geladen...</p>
                </div>
            </div>
        }
        else if (!string.IsNullOrWhiteSpace(_errorMessage))
        {
            <div class="error-container">
                <div class="alert alert-danger shadow-lg mb-0">
                    <h5 class="mb-2">Dokument nicht verfugbar</h5>
                    <p class="mb-0">@_errorMessage</p>
                </div>
            </div>
        }
        else if (_isExpired)
        {
            <div class="error-container">
                <div class="alert alert-warning shadow-lg mb-0">
                    <h5 class="mb-2">Freigabe abgelaufen</h5>
                    <p class="mb-0">Der Zeitraum fur diese Nur-Lesen-Freigabe ist abgelaufen.</p>
                </div>
            </div>
        }
        else if (_report is not null)
        {
            <DxReportViewer @ref="_reportViewer"
                            Report="_report"
                            RootCssClasses="w-100 h-100" />
        }
    </div>
</div>

@code {
    [Parameter] public string? ReadOnlyKey { get; set; }

    bool _isLoading = true;
    bool _isExpired = false;
    string? _errorMessage;
    EnvelopeReceiverReadOnlyDto? _readOnly;

    DxReportViewer? _reportViewer;
    XtraReport? _report;

    protected override async Task OnInitializedAsync()
    {
        if (string.IsNullOrWhiteSpace(ReadOnlyKey))
        {
            _errorMessage = "Freigabe-Schlussel fehlt.";
            _isLoading = false;
            return;
        }

        if (!ReadOnlyKey.TryDecode(out var decodedKeys) || decodedKeys.GetEncodeType() != EncodeType.EnvelopeReceiverReadOnly)
        {
            _errorMessage = "Ungultiger Freigabe-Link.";
            _isLoading = false;
            return;
        }

        try
        {
            var readOnlyId = decodedKeys.ParseReadOnlyId();
            var readOnlyRes = await ReadOnlyService.ReadByIdAsync(readOnlyId);
            if (readOnlyRes.IsFailed)
            {
                _errorMessage = "Freigabe konnte nicht geladen werden.";
                _isLoading = false;
                return;
            }

            _readOnly = readOnlyRes.Data;

            if (DateTime.Now > _readOnly.DateValid)
            {
                _isExpired = true;
                _isLoading = false;
                return;
            }

            if (_readOnly.Envelope is null || _readOnly.Receiver is null)
            {
                _errorMessage = "Freigabe ist unvollstandig.";
                _isLoading = false;
                return;
            }

            var erRes = await EnvelopeReceiverService.ReadByUuidSignatureAsync(_readOnly.Envelope.Uuid, _readOnly.Receiver.Signature);
            if (erRes.IsFailed)
            {
                _errorMessage = "Dokument wurde nicht gefunden.";
                _isLoading = false;
                return;
            }

            var envelopeReceiver = erRes.Data;
            var documentBytes = envelopeReceiver.Envelope?.Documents?.FirstOrDefault()?.ByteData;
            if (documentBytes is not { Length: > 0 })
            {
                _errorMessage = "Dokumentdaten konnten nicht geladen werden.";
                _isLoading = false;
                return;
            }

            _report = BuildReport(documentBytes);

            try
            {
                var historyResult = await HistoryService.RecordAsync((int)_readOnly.EnvelopeId, _readOnly.AddedWho, EnvelopeStatus.EnvelopeViewed);
                if (historyResult.IsFailed)
                    Logger.LogWarning("Failed to record EnvelopeViewed history for read-only key {ReadOnlyKey}", ReadOnlyKey);
            }
            catch (Exception ex)
            {
                Logger.LogWarning(ex, "Failed to record read-only history for {ReadOnlyKey}", ReadOnlyKey);
            }
        }
        catch (Exception ex)
        {
            Logger.LogError(ex, "Unexpected error in read-only page for {ReadOnlyKey}", ReadOnlyKey);
            _errorMessage = "Beim Laden ist ein unerwarteter Fehler aufgetreten.";
        }

        _isLoading = false;
    }

    static XtraReport BuildReport(byte[] pdfBytes)
    {
        var report = new XtraReport
        {
            PaperKind = DevExpress.Drawing.Printing.DXPaperKind.A4,
            Landscape = false,
            Margins = new System.Drawing.Printing.Margins(0, 0, 0, 0)
        };

        var detail = new DetailBand { HeightF = 0f };
        report.Bands.Add(detail);

        detail.Controls.Add(new XRPdfContent
        {
            Source = pdfBytes,
            GenerateOwnPages = true
        });

        return report;
    }

    public void Dispose()
    {
        _report?.Dispose();
    }
}