Add envelope creation functionality

Introduced the ability to create envelopes with documents and receivers via a new `CreateAsync` method in `EnvelopeReceiverService`. Integrated this functionality into `EnvelopeSenderEditorPage.razor` with UI updates, including a save button spinner, validation checks, and a result popup for success or error feedback.

- Added `CreateAsync` method to handle `POST /api/EnvelopeReceiver` API calls.
- Injected `EnvelopeReceiverService` into `EnvelopeSenderEditorPage.razor`.
- Implemented save logic with validation for PDF upload, receivers, and signature fields.
- Added success and error popups for user feedback.
- Improved logging for envelope creation and validation warnings.
- Refactored save logic for better readability and maintainability.

EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Services/EnvelopeReceiverService.cs

@@ -2,6 +2,7 @@ using System.Net;
 using System.Net.Http;
 using System.Net.Http.Json;
 using System.Text.Json;
+using EnvelopeGenerator.Application.EnvelopeReceivers.Commands;
 using EnvelopeGenerator.Server.Client.Models;
 
 namespace EnvelopeGenerator.Server.Client.Services;
@@ -9,6 +10,7 @@ namespace EnvelopeGenerator.Server.Client.Services;
 /// <summary>
 /// Retrieves the <see cref="EnvelopeReceiverDto"/> for the authenticated receiver
 /// from <c>GET /api/EnvelopeReceiver/{envelopeKey}</c>.
+/// Also creates new envelopes via <c>POST /api/EnvelopeReceiver</c>.
 /// </summary>
 public class EnvelopeReceiverService(IHttpClientFactory httpClientFactory)
 {
@@ -37,4 +39,28 @@ public class EnvelopeReceiverService(IHttpClientFactory httpClientFactory)
 
         return await response.Content.ReadFromJsonAsync<EnvelopeReceiverDto>(_jsonOptions, cancel);
     }
+
+    /// <summary>
+    /// Creates a new envelope with document and receivers via <c>POST /api/EnvelopeReceiver</c>.
+    /// Requires sender authentication cookie to be present in the request.
+    /// </summary>
+    /// <exception cref="HttpRequestException">Thrown when the API request fails.</exception>
+    public async Task<CreateEnvelopeReceiverResponse?> CreateAsync(
+        CreateEnvelopeReceiverCommand request,
+        CancellationToken cancel = default)
+    {
+        using var http = httpClientFactory.CreateClient("EnvelopeGenerator.Server");
+        var response   = await http.PostAsJsonAsync("/api/EnvelopeReceiver", request, _jsonOptions, cancel);
+
+        if (!response.IsSuccessStatusCode)
+        {
+            var body = await response.Content.ReadAsStringAsync(cancel);
+            throw new HttpRequestException(
+                $"Fehler beim Erstellen des Umschlags. Status: {(int)response.StatusCode} – {body}",
+                null,
+                response.StatusCode);
+        }
+
+        return await response.Content.ReadFromJsonAsync<CreateEnvelopeReceiverResponse>(_jsonOptions, cancel);
+    }
 }

EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/Pages/EnvelopeSenderEditorPage.razor

@@ -3,6 +3,7 @@
 @using DevExpress.Blazor.PdfViewer
 @using DevExpress.Blazor.Reporting.Models
 @using DevExpress.Blazor
+@using EnvelopeGenerator.Application.EnvelopeReceivers.Commands
 @using EnvelopeGenerator.Server.Client.Services
 @using EnvelopeGenerator.Server.Services
 @using Microsoft.AspNetCore.Components.Forms
@@ -12,6 +13,7 @@
 @inject AppVersionService AppVersion
 @inject ILogger<EnvelopeSenderEditorPage> Logger
 @inject EnvelopeReceiverPageDataService ReceiverPageDataService
+@inject EnvelopeReceiverService EnvelopeReceiverService
 @inject IMemoryCache MemoryCache
 
 <link href="_content/DevExpress.Blazor.Themes/blazing-berry.bs5.min.css" rel="stylesheet" />
@@ -143,11 +145,20 @@
                     @* Save *@
                     <button class="pdf-toolbar__btn pdf-toolbar__btn--success"
                             @onclick="SaveAsync"
+                            disabled="@_isSaving"
                             title="Speichern"
                             style="background: linear-gradient(135deg,#059669,#047857); color:#fff; border-radius:6px; padding:0.3rem 0.75rem; font-size:0.75rem; font-weight:600; border:none;">
+                        @if (_isSaving)
+                        {
+                            <span class="spinner-border spinner-border-sm me-1" role="status"
+                                  style="width:0.8rem;height:0.8rem;border-width:2px;"></span>
+                        }
+                        else
+                        {
                             <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" class="me-1" viewBox="0 0 16 16">
                                 <path d="M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z" />
                             </svg>
+                        }
                         Speichern
                     </button>
                 }
@@ -303,6 +314,79 @@
     </FooterContentTemplate>
 </DxPopup>
 
+@* ── Save result popup (success + error) ── *@
+<DxPopup @bind-Visible="_savePopupVisible"
+         HeaderText="@(_saveErrorMessage is null ? "Umschlag erstellt" : "Fehler")"
+         Width="460px"
+         MaxWidth="95vw"
+         ShowFooter="true"
+         CloseOnOutsideClick="false"
+         ShowCloseButton="false"
+         CloseOnEscape="false">
+    <BodyContentTemplate>
+        @if (_saveErrorMessage is null)
+        {
+            <div style="display:flex;align-items:flex-start;gap:1rem;padding:0.5rem 0;">
+                <div style="flex-shrink:0;width:40px;height:40px;background:#d1fae5;border-radius:50%;
+                            display:flex;align-items:center;justify-content:center;">
+                    <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" fill="#065f46" viewBox="0 0 16 16">
+                        <path d="M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z"/>
+                    </svg>
+                </div>
+                <div>
+                    <p style="margin:0 0 0.4rem;font-weight:600;color:#1f2937;font-size:0.95rem;">
+                        Umschlag wurde erfolgreich erstellt.
+                    </p>
+                    <p style="margin:0;color:#6b7280;font-size:0.85rem;line-height:1.5;">
+                        Der Umschlag wurde gespeichert und die Empfänger wurden benachrichtigt.
+                    </p>
+                </div>
+            </div>
+        }
+        else
+        {
+            <div style="display:flex;align-items:flex-start;gap:1rem;padding:0.5rem 0;">
+                <div style="flex-shrink:0;width:40px;height:40px;background:#fee2e2;border-radius:50%;
+                            display:flex;align-items:center;justify-content:center;">
+                    <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" fill="#991b1b" viewBox="0 0 16 16">
+                        <path d="M8 15A7 7 0 1 1 8 1a7 7 0 0 1 0 14zm0 1A8 8 0 1 0 8 0a8 8 0 0 0 0 16z"/>
+                        <path d="M7.002 11a1 1 0 1 1 2 0 1 1 0 0 1-2 0zM7.1 4.995a.905.905 0 1 1 1.8 0l-.35 3.507a.552.552 0 0 1-1.1 0L7.1 4.995z"/>
+                    </svg>
+                </div>
+                <div>
+                    <p style="margin:0 0 0.4rem;font-weight:600;color:#1f2937;font-size:0.95rem;">
+                        Fehler beim Erstellen des Umschlags
+                    </p>
+                    <p style="margin:0;color:#6b7280;font-size:0.85rem;line-height:1.5;word-break:break-word;">
+                        @_saveErrorMessage
+                    </p>
+                </div>
+            </div>
+        }
+    </BodyContentTemplate>
+    <FooterContentTemplate>
+        <div style="display:flex;gap:0.5rem;justify-content:flex-end;width:100%;padding:0.5rem 0;">
+            @if (_saveErrorMessage is null)
+            {
+                <button class="btn btn-primary"
+                        @onclick="GoToDashboard"
+                        style="background:linear-gradient(135deg,#059669,#047857);border:none;border-radius:6px;
+                               padding:0.5rem 1.5rem;font-weight:600;color:#fff;">
+                    Zur Übersicht
+                </button>
+            }
+            else
+            {
+                <button class="btn btn-outline-secondary"
+                        @onclick="() => _savePopupVisible = false"
+                        style="border-radius:6px;padding:0.5rem 1.25rem;font-weight:500;">
+                    Schließen
+                </button>
+            }
+        </div>
+    </FooterContentTemplate>
+</DxPopup>
+
 @code {
     // ── Session query param — persists across SignalR reconnects ──
     [SupplyParameterFromQuery(Name = "esid")]
@@ -330,6 +414,11 @@
     List<SignatureFieldDraft> _signatureFields = [];
     ReceiverDraft? _pendingReceiverForPlacement; // Set when user clicks "Signatur hinzufügen"
 
+    // ── Save state ──
+    bool    _isSaving          = false;
+    bool    _savePopupVisible  = false;
+    string? _saveErrorMessage  = null;
+
     List<ReceiverDraft> _receivers = [];
     bool   _receiverPopupVisible;
     string _receiverDraftName        = string.Empty;
@@ -523,24 +612,111 @@
 
     void Cancel() => NavigationManager.NavigateTo("/sender");
 
-    // ── Save ──
+    void GoToDashboard()
+    {
+        // Clear session from cache on successful save so it is not restored if user returns
+        if (!string.IsNullOrWhiteSpace(Esid))
+            MemoryCache.Remove(SessionKey);
+
+        NavigationManager.NavigateTo("/sender");
+    }
+
+    // ── Save — POST /api/EnvelopeReceiver ──
     async Task SaveAsync()
     {
+        // ── Validation ──
+        if (!_pdfLoaded || _originalPdfBytes is null)
+        {
+            _saveErrorMessage = "Bitte laden Sie zuerst ein PDF-Dokument hoch.";
+            _savePopupVisible = true;
+            return;
+        }
+        if (_receivers.Count == 0)
+        {
+            _saveErrorMessage = "Bitte fügen Sie mindestens einen Empfänger hinzu.";
+            _savePopupVisible = true;
+            return;
+        }
         if (_signatureFields.Count == 0)
         {
-            await JSRuntime.InvokeVoidAsync("console.log",
-                "[SenderEditor] No signature fields to save.");
+            _saveErrorMessage = "Bitte platzieren Sie mindestens ein Signaturfeld.";
+            _savePopupVisible = true;
             return;
         }
 
-        foreach (var f in _signatureFields)
+        // Warn if any receiver has no signature field, but don't block
+        var receiversWithoutField = _receivers
+            .Where(r => !_signatureFields.Any(f => f.ReceiverName == r.FullName))
+            .ToList();
+        if (receiversWithoutField.Count > 0)
         {
-            await JSRuntime.InvokeVoidAsync("console.log",
-                $"[SenderEditor] Field: Page={f.Page} X={f.XPt:F2}pt ({f.XPt / 72:F3}in) Y={f.YPt:F2}pt ({f.YPt / 72:F3}in) Receiver={f.ReceiverName}");
+            Logger.LogWarning(
+                "[SenderEditor] Receivers without signature field: {Names}",
+                string.Join(", ", receiversWithoutField.Select(r => r.FullName)));
         }
 
-        await JSRuntime.InvokeVoidAsync("console.log",
-            $"[SenderEditor] Total fields: {_signatureFields.Count}");
+        _isSaving         = true;
+        _saveErrorMessage = null;
+        await InvokeAsync(StateHasChanged);
+
+        try
+        {
+            // ── Build request ──
+            // Document: use the ORIGINAL pdf (without placeholder burn-in) as base64
+            var docBase64 = Convert.ToBase64String(_originalPdfBytes);
+
+            // Build receivers list — each receiver gets their own signature fields
+            // Coordinate conversion: PDF points → inches (DB stores inches)
+            var receiversCmd = _receivers.Select(receiver =>
+            {
+                var fields = _signatureFields
+                    .Where(f => f.ReceiverName == receiver.FullName)
+                    .Select(f => new DocReceiverElementCreateDto(
+                        X:    f.XPt / 72.0,
+                        Y:    f.YPt / 72.0,
+                        Page: f.Page))
+                    .ToList();
+
+                return new ReceiverGetOrCreateCommand
+                {
+                    EmailAddress        = receiver.Email,
+                    Salution            = receiver.FullName,
+                    PhoneNumber         = string.IsNullOrWhiteSpace(receiver.PhoneNumber)
+                                            ? null
+                                            : receiver.PhoneNumber,
+                    DocReceiverElements = fields,
+                };
+            }).ToList();
+
+            var command = new CreateEnvelopeReceiverCommand
+            {
+                Title      = "Neuer Umschlag",       // placeholder — dedicated field will be added later
+                Message    = "Bitte unterzeichnen Sie das beigefügte Dokument.",
+                TFAEnabled = false,
+                Document   = new DocumentCreateCommand { DataAsBase64 = docBase64 },
+                Receivers  = receiversCmd,
+            };
+
+            var result = await EnvelopeReceiverService.CreateAsync(command);
+
+            Logger.LogInformation(
+                "[SenderEditor] Envelope created. Id={Id} SentReceivers={Count}",
+                result?.Id, result?.SentReceiver.Count());
+
+            // Success — show popup; GoToDashboard clears cache and navigates
+            _saveErrorMessage = null;
+            _savePopupVisible = true;
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError(ex, "[SenderEditor] Failed to create envelope");
+            _saveErrorMessage = ex.Message;
+            _savePopupVisible = true;
+        }
+        finally
+        {
+            _isSaving = false;
+        }
     }
 
     // ── Cache persistence ──