Feature/v2/watermark (#4215)

Add watermark feature

Auto scroll on review

---------

Co-authored-by: Connor Yoh <[email protected]>

frontend/src/hooks/tools/addWatermark/useAddWatermarkOperation.ts

@@ -0,0 +1,46 @@
+import { useTranslation } from 'react-i18next';
+import { useToolOperation } from '../shared/useToolOperation';
+import { createStandardErrorHandler } from '../../../utils/toolErrorHandler';
+import { AddWatermarkParameters } from './useAddWatermarkParameters';
+
+const buildFormData = (parameters: AddWatermarkParameters, file: File): FormData => {
+  const formData = new FormData();
+  formData.append("fileInput", file);
+
+  // Required: watermarkType as string
+  formData.append("watermarkType", parameters.watermarkType || "text");
+
+  // Add watermark content based on type
+  if (parameters.watermarkType === 'text') {
+    formData.append("watermarkText", parameters.watermarkText);
+  } else if (parameters.watermarkType === 'image' && parameters.watermarkImage) {
+    formData.append("watermarkImage", parameters.watermarkImage);
+  }
+
+  // Required parameters with correct formatting
+  formData.append("fontSize", parameters.fontSize.toString());
+  formData.append("rotation", parameters.rotation.toString());
+  formData.append("opacity", (parameters.opacity / 100).toString()); // Convert percentage to decimal
+  formData.append("widthSpacer", parameters.widthSpacer.toString());
+  formData.append("heightSpacer", parameters.heightSpacer.toString());
+
+  // Backend-expected parameters from user input
+  formData.append("alphabet", parameters.alphabet);
+  formData.append("customColor", parameters.customColor);
+  formData.append("convertPDFToImage", parameters.convertPDFToImage.toString());
+
+  return formData;
+};
+
+export const useAddWatermarkOperation = () => {
+  const { t } = useTranslation();
+
+  return useToolOperation<AddWatermarkParameters>({
+    operationType: 'watermark',
+    endpoint: '/api/v1/security/add-watermark',
+    buildFormData,
+    filePrefix: t('watermark.filenamePrefix', 'watermarked') + '_',
+    multiFileEndpoint: false, // Individual API calls per file
+    getErrorMessage: createStandardErrorHandler(t('watermark.error.failed', 'An error occurred while adding watermark to the PDF.'))
+  });
+};

frontend/src/hooks/tools/addWatermark/useAddWatermarkParameters.ts

@@ -0,0 +1,50 @@
+import { useState, useCallback } from 'react';
+import { defaultWatermarkParameters } from '../../../constants/addWatermarkConstants';
+
+export interface AddWatermarkParameters {
+  watermarkType?: 'text' | 'image';
+  watermarkText: string;
+  watermarkImage?: File;
+  fontSize: number; // Used for both text size and image size
+  rotation: number;
+  opacity: number;
+  widthSpacer: number;
+  heightSpacer: number;
+  alphabet: string;
+  customColor: string;
+  convertPDFToImage: boolean;
+}
+
+
+export const useAddWatermarkParameters = () => {
+  const [parameters, setParameters] = useState<AddWatermarkParameters>(defaultWatermarkParameters);
+
+  const updateParameter = useCallback(<K extends keyof AddWatermarkParameters>(
+    key: K,
+    value: AddWatermarkParameters[K]
+  ) => {
+    setParameters(prev => ({ ...prev, [key]: value }));
+  }, []);
+
+  const resetParameters = useCallback(() => {
+    setParameters(defaultWatermarkParameters);
+  }, []);
+
+  const validateParameters = useCallback((): boolean => {
+    if (!parameters.watermarkType) {
+      return false;
+    }
+    if (parameters.watermarkType === 'text') {
+      return parameters.watermarkText.trim().length > 0;
+    } else {
+      return parameters.watermarkImage !== undefined;
+    }
+  }, [parameters]);
+
+  return {
+    parameters,
+    updateParameter,
+    resetParameters,
+    validateParameters
+  };
+};