saveDrawing method

Implementation

Future<void> saveDrawing({
  required File pdfFile,
  required int totalPages,
  required BuildContext context,
  required DrawingController drawingController,
  required ImageController imageController,
  required TextBoxController textBoxController,
  required HighlightController highlightController,
  required UnderlineController underlineController,
  required Function refresh,
}) async {
  if (isSaving) return;

  isSaving = true;
  PdfDocument? pdfDoc;

  try {
    // Early exit if nothing to save
    if (!(drawingController.hasAnyContent() ||
        imageController.hasAnyContent() ||
        textBoxController.hasAnyContent() ||
        highlightController.hasAnyContent() ||
        underlineController.hasAnyContent())) {
      return Navigator.pop(context, pdfFile);
    }

    final output = await getTemporaryDirectory();
    final String originalName = pdfFile.path.split('/').last.split('.').first;
    final String timestamp = DateTime.now().millisecondsSinceEpoch.toString();
    final String savedPath = '${output.path}/${originalName}_$timestamp.pdf';
    final file = File(savedPath);

    // Copy the original file as base
    await pdfFile.copy(savedPath);

    const int batchSize = 5;

    for (
      int batchStart = 0;
      batchStart < totalPages;
      batchStart += batchSize
    ) {
      // final fileBytes = await readFileInChunks(file);
      pdfDoc ??= await Isolate.run(() async {
        return await processPdfDocViaUt(file);
      });

      final int batchEnd =
          (batchStart + batchSize > totalPages)
              ? totalPages
              : batchStart + batchSize;

      dev.log('Processing batch: pages ${batchStart + 1} to $batchEnd');

      /// ✅ Only proceed if something changed
      final bool batchModified = await _processPageBatch(
        pdfDoc!,
        batchStart,
        batchEnd,
        context,
        drawingController,
        imageController,
        textBoxController,
        highlightController,
        underlineController,
      );

      if (batchModified) {
        // Save only if something was added/changed
        await Isolate.run(() async {
          await savePdfDocToFile(pdfDoc!, file);
        });
        pdfDoc.dispose();
        pdfDoc = null;
        dev.log("Batch ${batchStart + 1}–$batchEnd saved");
      } else {
        dev.log("Batch ${batchStart + 1}–$batchEnd skipped (no changes)");
      }
      // Allow UI to refresh
      await Future.delayed(const Duration(milliseconds: 50));
    }
    if (pdfDoc != null) {
      await Isolate.run(() async {
        await savePdfDocToFile(pdfDoc!, file);
      });
    }
    dev.log('All pages processed, PDF saved at $savedPath');
    Navigator.pop(context, file);
  } catch (e) {
    debugPrint('Error while saving drawing and text: $e');
    rethrow;
  } finally {
    pdfDoc?.dispose();
    pdfDoc = null;
    isSaving = false;
  }
}