From 776700b2472ff9a1cd253be2a3e55a57fc932fc4 Mon Sep 17 00:00:00 2001
From: TekH <h.tek@digitaldata.works>
Date: Tue, 29 Sep 2026 19:22:01 +0200
Subject: [PATCH] feat(sender-editor): use rendered page metadata for field
 placement

---
 .../PdfEditor/SenderPdfImageEditor.razor      | 36 +++++++++++--------
 .../Pages/SenderEditorPage.razor              | 31 +++++++++-------
 2 files changed, 39 insertions(+), 28 deletions(-)

diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/PdfEditor/SenderPdfImageEditor.razor b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/PdfEditor/SenderPdfImageEditor.razor
index a140780b..cc3a1555 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/PdfEditor/SenderPdfImageEditor.razor
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/PdfEditor/SenderPdfImageEditor.razor
@@ -1,17 +1,18 @@
 @using EnvelopeGenerator.Application.Resources
+@using EnvelopeGenerator.Application.Common.Dto
 @using Microsoft.Extensions.Localization
 @inject IStringLocalizer<Resource> UiLocalizer
 
 <div class="pdf-editor-wrapper sender-image-editor sender-editor-pdf-viewer"
      style="cursor: @(IsPlacementMode ? "crosshair" : "default");"
      @onclick="HandleClickAsync">
-    @if (PageCount <= 0)
+@if (PageCount <= 0)
     {
         <div class="sender-image-editor__empty">@L("SenderEditor_NoPagesToDisplay", "Keine Seiten zur Anzeige verfügbar.")</div>
     }
     else
     {
-        @if (PageImageDataUrls.Count == 0 && !string.IsNullOrWhiteSpace(PdfDataUrl))
+        @if (Pages.Count == 0 && !string.IsNullOrWhiteSpace(PdfDataUrl))
         {
             <div class="sender-image-editor__native-preview">
                 <iframe class="sender-image-editor__native-frame"
@@ -21,17 +22,22 @@
         }
 
         <div class="sender-image-editor__pages">
-            @for (var pageNumber = 1; pageNumber <= PageCount; pageNumber++)
+            @for (var pageIndex = 0; pageIndex < PageCount; pageIndex++)
             {
+                var pagePreview = pageIndex < Pages.Count ? Pages[pageIndex] : null;
+                var pageNumber = pagePreview?.PageNumber ?? (pageIndex + 1);
+                var widthPt = pagePreview?.WidthPt ?? 595.0;
+                var heightPt = pagePreview?.HeightPt ?? 842.0;
+
                 <div class="sender-image-editor__page-block"
-                     data-editor-page="@pageNumber"
-                     data-page-width-pt="595"
-                     data-page-height-pt="842">
+                      data-editor-page="@pageNumber"
+                     data-page-width-pt="@widthPt"
+                     data-page-height-pt="@heightPt">
                     <div class="sender-image-editor__page-canvas">
-                        @if (PageImageDataUrls.TryGetValue(pageNumber, out var imageDataUrl) && !string.IsNullOrWhiteSpace(imageDataUrl))
+                        @if (!string.IsNullOrWhiteSpace(pagePreview?.ImageDataUrl))
                         {
                             <img class="sender-image-editor__page-image"
-                                 src="@imageDataUrl"
+                                 src="@(pagePreview!.ImageDataUrl)"
                                  alt="PDF Page @pageNumber"
                                  draggable="false" />
                         }
@@ -44,7 +50,7 @@
                         {
                             <button type="button"
                                     class="sender-image-editor__field"
-                                    style="@GetFieldStyle(field)"
+                                    style="@GetFieldStyle(field, widthPt, heightPt)"
                                     title="@field.ReceiverName"
                                     @onclick:stopPropagation="true"
                                     @onclick="() => RemoveField.InvokeAsync(field.Index)">
@@ -66,7 +72,7 @@
     public int PageCount { get; set; }
 
     [Parameter]
-    public IReadOnlyDictionary<int, string> PageImageDataUrls { get; set; } = new Dictionary<int, string>();
+    public IReadOnlyList<PdfPageImageDto> Pages { get; set; } = Array.Empty<PdfPageImageDto>();
 
     [Parameter]
     public string? PdfDataUrl { get; set; }
@@ -80,12 +86,12 @@
     [Parameter]
     public EventCallback<int> RemoveField { get; set; }
 
-    private static string GetFieldStyle(SenderPdfFieldOverlay field)
+    private static string GetFieldStyle(SenderPdfFieldOverlay field, double pageWidthPt, double pageHeightPt)
     {
-        var leftPercent = (field.XPt / 595.0) * 100.0;
-        var topPercent = (field.YPt / 842.0) * 100.0;
-        var widthPercent = (127.44 / 595.0) * 100.0;
-        var heightPercent = (141.12 / 842.0) * 100.0;
+        var leftPercent = (field.XPt / pageWidthPt) * 100.0;
+        var topPercent = (field.YPt / pageHeightPt) * 100.0;
+        var widthPercent = (127.44 / pageWidthPt) * 100.0;
+        var heightPercent = (141.12 / pageHeightPt) * 100.0;
 
         return string.Join(' ',
             $"left:{leftPercent:F4}%;",
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderEditorPage.razor b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderEditorPage.razor
index 57f8d1cd..59f2e6fd 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderEditorPage.razor
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderEditorPage.razor
@@ -14,6 +14,7 @@
 @inject AppVersionService AppVersion
 @inject ILogger<SenderEditorPage> Logger
 @inject DocumentService DocumentService
+@inject PdfRenderService PdfRenderService
 @inject ReceiverService ReceiverService
 @inject EnvelopeService EnvelopeService
 @inject IStringLocalizer<Resource> UiLocalizer
@@ -278,7 +279,7 @@
         {
             <SenderPdfImageEditor IsPlacementMode="@(_pendingReceiverForPlacement is not null)"
                                   PageCount="@_pageCount"
-                                  PageImageDataUrls="@_pageImageDataUrls"
+                                  Pages="@_pagePreviews"
                                   PdfDataUrl="@PdfDataUrl"
                                   Fields="@FieldOverlays"
                                   EditorClick="OnPdfAreaClickAsync"
@@ -471,7 +472,7 @@
     string? _errorMessage;
     byte[]? _originalPdfBytes;  // Pristine upload — never modified, used as base for redraw
     int _pageCount;
-    Dictionary<int, string> _pageImageDataUrls = [];
+    List<PdfPageImageDto> _pagePreviews = [];
     int? _loadedEnvelopeId;
     int? _editingEnvelopeId;
     bool _isLoadingEnvelopeForEdit;
@@ -594,9 +595,11 @@
 
             _originalPdfBytes = document?.ByteData;
             _pdfLoaded = _originalPdfBytes is { Length: > 0 };
-            _pageCount = EstimatePdfPageCount(_originalPdfBytes) ??
-                Math.Max(1, _signatureFields.Select(f => f.Page).DefaultIfEmpty(1).Max());
-            _pageImageDataUrls.Clear();
+            _pagePreviews = [];
+            _pageCount = _pagePreviews.Count > 0
+                ? _pagePreviews.Count
+                : EstimatePdfPageCount(_originalPdfBytes)
+                    ?? Math.Max(1, _signatureFields.Select(f => f.Page).DefaultIfEmpty(1).Max());
             _fileName = $"Envelope-{envelopeId}.pdf";
             _pendingReceiverForPlacement = null;
             _loadedEnvelopeId = envelopeId;
@@ -638,8 +641,12 @@
             _originalPdfBytes = ms.ToArray();
             _fileName = file.Name;
             _pdfLoaded = true;
-            _pageCount = EstimatePdfPageCount(_originalPdfBytes) ?? 1;
-            _pageImageDataUrls.Clear();
+            _pagePreviews = (await PdfRenderService.RenderPagesAsync(_originalPdfBytes))
+                .OrderBy(p => p.PageNumber)
+                .ToList();
+            _pageCount = _pagePreviews.Count > 0
+                ? _pagePreviews.Count
+                : EstimatePdfPageCount(_originalPdfBytes) ?? 1;
             _signatureFields.Clear();
             _pendingReceiverForPlacement = null;
 
@@ -682,10 +689,10 @@
             return;
         }
 
-        // Approximate points based on A4. This is temporary until the image-based viewer
-        // pipeline provides precise per-page dimensions.
-        const double pageWidthPt = 595.0;
-        const double pageHeightPt = 842.0;
+        int page1Based = coords.PageIndex + 1;
+        var pagePreview = _pagePreviews.FirstOrDefault(p => p.PageNumber == page1Based);
+        var pageWidthPt = pagePreview?.WidthPt ?? 595.0;
+        var pageHeightPt = pagePreview?.HeightPt ?? 842.0;
 
         // Convert normalised [0,1] → PDF points; clamp so box stays inside page
         double xPt = coords.NormX * pageWidthPt;
@@ -694,8 +701,6 @@
         xPt = Math.Max(0, Math.Min(xPt, pageWidthPt - SigWidthPt));
         yPt = Math.Max(0, Math.Min(yPt, pageHeightPt - SigHeightPt));
 
-        int page1Based = coords.PageIndex + 1;
-
         var field = new SignatureFieldDraft(
             XPt: xPt,
             YPt: yPt,