From d2c429f047a5dd61e8b7073ae2036a2b75f1c331 Mon Sep 17 00:00:00 2001
From: azeeee05 <azeemazm31@gmail.com>
Date: Wed, 10 Jun 2026 19:29:11 +0530
Subject: [PATCH] done React: form field viewing (Widget annotations) with
 saving issues fixed

---
 engine/src/parser/pdfium_document.cpp   | 43 +++++++++++++++++++++++++
 frontend/src/App.tsx                    |  8 +++++
 frontend/src/viewer/AnnotationLayer.tsx |  9 ++++++
 frontend/src/viewer/PDFViewer.tsx       |  3 ++
 gateway/app/routers/documents.py        | 25 ++++++++++++++
 gateway/app/routers/edits.py            | 17 ++++++++--
 6 files changed, 103 insertions(+), 2 deletions(-)

diff --git a/engine/src/parser/pdfium_document.cpp b/engine/src/parser/pdfium_document.cpp
index 5dab1e5..87932a0 100644
--- a/engine/src/parser/pdfium_document.cpp
+++ b/engine/src/parser/pdfium_document.cpp
@@ -1695,6 +1695,49 @@ std::expected<void, EngineError> PdfiumDocument::applyEdits(const std::string& e
                 }
 
                 FPDF_ClosePage(page);
+            } else if (type == "update_field") {
+                if (!op.contains("data") || !op["data"].is_object()) {
+                    spdlog::error("update_field operation missing 'data' object");
+                    return std::unexpected(EngineError::InvalidFormat);
+                }
+                auto data = op["data"];
+                std::string value;
+                if (data["value"].is_boolean()) {
+                    value = data["value"].get<bool>() ? "Yes" : "Off";
+                } else if (data["value"].is_string()) {
+                    value = data["value"].get<std::string>();
+                } else {
+                    spdlog::error("update_field value must be a string or boolean");
+                    return std::unexpected(EngineError::InvalidFormat);
+                }
+
+                std::string id = op.value("id", "");
+                int annotIndex = -1;
+                size_t lastUnderscore = id.find_last_of('_');
+                if (lastUnderscore != std::string::npos) {
+                    try {
+                        annotIndex = std::stoi(id.substr(lastUnderscore + 1));
+                    } catch (...) {
+                        annotIndex = -1;
+                    }
+                }
+
+                if (annotIndex >= 0) {
+                    FPDF_PAGE page = FPDF_LoadPage(doc_, pageIndex);
+                    if (!page) {
+                        spdlog::error("Failed to load page index {} for field update", pageIndex);
+                        return std::unexpected(EngineError::Unknown);
+                    }
+                    FPDF_ANNOTATION annot = FPDFPage_GetAnnot(page, annotIndex);
+                    if (annot) {
+                        auto utf16 = utf8_to_utf16le(value);
+                        FPDFAnnot_SetStringValue(annot, "V", reinterpret_cast<FPDF_WIDESTRING>(utf16.data()));
+                        
+                        FPDFPage_GenerateContent(page);
+                        FPDFPage_CloseAnnot(annot);
+                    }
+                    FPDF_ClosePage(page);
+                }
             } else if (type == "image_overlay") {
                 if (!op.contains("data") || !op["data"].is_object()) {
                     spdlog::error("image_overlay operation missing 'data' object");
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 10b98fc..f755c05 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -480,6 +480,14 @@ function App() {
                 hasSignature={!!pendingSignature}
                 activeStamp={activeStamp?.label ?? null}
                 annotations={annotations}
+                onFieldChange={(id, value, i) => {
+                  applyOps([{
+                    id,
+                    type: 'update_field',
+                    pageIndex: i,
+                    data: { value }
+                  } as any]);
+                }}
                 searchQuery={searchQuery}
                 searchResults={searchResults}
                 searchCurrentMatch={searchCurrentMatch}
diff --git a/frontend/src/viewer/AnnotationLayer.tsx b/frontend/src/viewer/AnnotationLayer.tsx
index a7d572b..f8ca812 100644
--- a/frontend/src/viewer/AnnotationLayer.tsx
+++ b/frontend/src/viewer/AnnotationLayer.tsx
@@ -29,6 +29,7 @@ interface AnnotationLayerProps {
   zoom: number;
   annotations: Annotation[];
   onAnnotationClick?: (annotation: Annotation) => void;
+  onFieldChange?: (id: string, value: string | boolean, pageIndex: number) => void;
 }
 
 export const AnnotationLayer: React.FC<AnnotationLayerProps> = ({
@@ -38,6 +39,7 @@ export const AnnotationLayer: React.FC<AnnotationLayerProps> = ({
   zoom,
   annotations,
   onAnnotationClick,
+  onFieldChange,
 }) => {
   return (
     <div
@@ -101,6 +103,11 @@ export const AnnotationLayer: React.FC<AnnotationLayerProps> = ({
                     <input 
                       type="text" 
                       defaultValue={anno.fieldValue || ''}
+                      onBlur={(e) => {
+                        if (e.target.value !== (anno.fieldValue || '')) {
+                          onFieldChange?.(anno.id, e.target.value, pageIndex);
+                        }
+                      }}
                       className="w-full h-full bg-blue-50/50 border border-blue-400/50 text-sm px-1 focus:outline-none focus:ring-1 focus:ring-blue-500 rounded-sm"
                     />
                   )}
@@ -109,12 +116,14 @@ export const AnnotationLayer: React.FC<AnnotationLayerProps> = ({
                     <input 
                       type={(anno.fieldFlags ?? 0) & 32768 ? 'radio' : 'checkbox'} 
                       defaultChecked={anno.fieldValue === 'Yes' || anno.fieldValue === 'On'}
+                      onChange={(e) => onFieldChange?.(anno.id, e.target.checked, pageIndex)}
                       className="w-4 h-4 text-blue-600 border-gray-300 focus:ring-blue-500"
                     />
                   )}
                   {anno.fieldType === 'Ch' && (
                     <select 
                       defaultValue={anno.fieldValue || ''} 
+                      onChange={(e) => onFieldChange?.(anno.id, e.target.value, pageIndex)}
                       className="w-full h-full bg-blue-50/50 border border-blue-400/50 text-sm px-1 rounded-sm appearance-none"
                     >
                       {anno.fieldOptions?.map((opt: string, i: number) => (
diff --git a/frontend/src/viewer/PDFViewer.tsx b/frontend/src/viewer/PDFViewer.tsx
index e7da437..a8f94da 100644
--- a/frontend/src/viewer/PDFViewer.tsx
+++ b/frontend/src/viewer/PDFViewer.tsx
@@ -33,6 +33,7 @@ interface PDFViewerProps {
   onPlaceText?: (pageIndex: number, rectPts: Rect, text: string) => void;
   onPlaceStamp?: (pageIndex: number, pointPts: { x: number; y: number }) => void;
   onPlaceSignature?: (pageIndex: number, pointPts: { x: number; y: number }) => void;
+  onFieldChange?: (id: string, value: string | boolean, pageIndex: number) => void;
 }
 
 interface PageLayout {
@@ -69,6 +70,7 @@ export const PDFViewer = React.forwardRef<PDFViewerRef, PDFViewerProps>(({
   onPlaceText,
   onPlaceStamp,
   onPlaceSignature,
+  onFieldChange,
 }, ref) => {
   const containerRef = useRef<HTMLDivElement | null>(null);
   const [scrollPosition, setScrollPosition] = useState({ scrollLeft: 0, scrollTop: 0 });
@@ -385,6 +387,7 @@ export const PDFViewer = React.forwardRef<PDFViewerRef, PDFViewerProps>(({
                     height={page.height}
                     zoom={zoom}
                     annotations={annotations}
+                    onFieldChange={onFieldChange}
                   />
 
                   {/* Text Selection Dragging Layer */}
diff --git a/gateway/app/routers/documents.py b/gateway/app/routers/documents.py
index 804ec5d..521e759 100644
--- a/gateway/app/routers/documents.py
+++ b/gateway/app/routers/documents.py
@@ -545,6 +545,31 @@ def export_document(document_id: str):
         filename = d["filename"]
         if not filename.endswith(".pdf"):
             filename += ".pdf"
+            
+        # pyrefly: ignore [missing-import]
+        import sys
+        import os
+        roaming_path = os.path.join(os.environ.get("APPDATA", "C:\\Users\\azeem\\AppData\\Roaming"), "Python", "Python312", "site-packages")
+        if roaming_path not in sys.path:
+            sys.path.append(roaming_path)
+            
+        import pypdf
+        import io
+        
+        # Parse the raw bytes and force NeedAppearances so the viewer 
+        # actually renders the filled values.
+        reader = pypdf.PdfReader(io.BytesIO(bytes_data))
+        writer = pypdf.PdfWriter()
+        writer.append(reader)
+        
+        acro_form = writer.root_object.get("/AcroForm")
+        if acro_form is not None:
+            acro_form_dict = acro_form.get_object()
+            acro_form_dict[pypdf.generic.NameObject("/NeedAppearances")] = pypdf.generic.BooleanObject(True)
+            
+        out_stream = io.BytesIO()
+        writer.write(out_stream)
+        bytes_data = out_stream.getvalue()
 
         return Response(
             content=bytes_data,
diff --git a/gateway/app/routers/edits.py b/gateway/app/routers/edits.py
index aee8952..5601292 100644
--- a/gateway/app/routers/edits.py
+++ b/gateway/app/routers/edits.py
@@ -168,6 +168,17 @@ class PageReorderOperation(BaseModel):
     data: PageReorderData
 
 
+class UpdateFieldData(BaseModel):
+    value: str | bool
+
+
+class UpdateFieldOperation(BaseModel):
+    id: str
+    type: Literal["update_field"]
+    pageIndex: int
+    data: UpdateFieldData
+
+
 EditOperation = Annotated[
     TextOverlayOperation
     | RedactionOperation
@@ -178,7 +189,8 @@ EditOperation = Annotated[
     | FreehandOperation
     | PageRotationOperation
     | PageDeletionOperation
-    | PageReorderOperation,
+    | PageReorderOperation
+    | UpdateFieldOperation,
     Field(discriminator="type"),
 ]
 
@@ -214,7 +226,8 @@ def apply_edits_impl(document_id: str, request: EditsRequest):
                     import os
                     import tempfile
 
-                    from PIL import Image
+                    # pyrefly: ignore [missing-import]
+                    from PIL import Image   
 
                     # Remove data URI header if present
                     if "," in img_data_str: