Initial addition of encrypted PDF thumbnail

frontend/src/utils/thumbnailUtils.ts

@@ -1,5 +1,15 @@
 import { getDocument } from "pdfjs-dist";
 
+interface ColorScheme {
+  bgTop: string;
+  bgBottom: string;
+  border: string;
+  icon: string;
+  badge: string;
+  textPrimary: string;
+  textSecondary: string;
+}
+
 /**
  * Calculate thumbnail scale based on file size
  * Smaller files get higher quality, larger files get lower quality
@@ -14,6 +24,54 @@ export function calculateScaleFromFileSize(fileSize: number): number {
   return 0.15;                            // 30MB+: Low quality
 }
 
+/**
+ * Generate encrypted PDF thumbnail with lock icon
+ */
+function generateEncryptedPDFThumbnail(file: File): string {
+  const canvas = document.createElement('canvas');
+  canvas.width = 120;
+  canvas.height = 150;
+  const ctx = canvas.getContext('2d')!;
+
+  // Use PDF color scheme but with encrypted styling
+  const colorScheme = getFileTypeColorScheme('PDF');
+
+  // Create gradient background
+  const gradient = ctx.createLinearGradient(0, 0, 0, canvas.height);
+  gradient.addColorStop(0, colorScheme.bgTop);
+  gradient.addColorStop(1, colorScheme.bgBottom);
+
+  // Rounded rectangle background
+  drawRoundedRect(ctx, 8, 8, canvas.width - 16, canvas.height - 16, 8);
+  ctx.fillStyle = gradient;
+  ctx.fill();
+
+  // Border with dashed pattern for encrypted indicator
+  ctx.strokeStyle = colorScheme.border;
+  ctx.lineWidth = 2;
+  ctx.setLineDash([4, 4]);
+  ctx.stroke();
+  ctx.setLineDash([]); // Reset dash pattern
+
+  // Modern document icon
+  drawModernDocumentIcon(ctx, canvas.width / 2, 35, colorScheme.icon);
+
+  // Large lock icon overlay
+  drawLockIcon(ctx, canvas.width / 2, canvas.height / 2, colorScheme);
+
+  // "ENCRYPTED" badge
+  drawEncryptionBadge(ctx, canvas.width / 2, canvas.height / 2 + 25, colorScheme);
+
+  // File size with subtle styling
+  const sizeText = formatFileSize(file.size);
+  ctx.font = '11px -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif';
+  ctx.fillStyle = colorScheme.textSecondary;
+  ctx.textAlign = 'center';
+  ctx.fillText(sizeText, canvas.width / 2, canvas.height - 15);
+
+  return canvas.toDataURL();
+}
+
 /**
  * Generate modern placeholder thumbnail with file extension
  */
@@ -61,8 +119,8 @@ function generatePlaceholderThumbnail(file: File): string {
 /**
  * Get color scheme based on file extension
  */
-function getFileTypeColorScheme(extension: string) {
-  const schemes: Record<string, any> = {
+function getFileTypeColorScheme(extension: string): ColorScheme {
+  const schemes: Record<string, ColorScheme> = {
     // Documents
     'PDF': { bgTop: '#FF6B6B20', bgBottom: '#FF6B6B10', border: '#FF6B6B40', icon: '#FF6B6B', badge: '#FF6B6B', textPrimary: '#FFFFFF', textSecondary: '#666666' },
     'DOC': { bgTop: '#4ECDC420', bgBottom: '#4ECDC410', border: '#4ECDC440', icon: '#4ECDC4', badge: '#4ECDC4', textPrimary: '#FFFFFF', textSecondary: '#666666' },
@@ -130,10 +188,64 @@ function drawModernDocumentIcon(ctx: CanvasRenderingContext2D, centerX: number,
   ctx.fill();
 }
 
+/**
+ * Draw lock icon for encrypted PDFs
+ */
+function drawLockIcon(ctx: CanvasRenderingContext2D, centerX: number, centerY: number, colorScheme: ColorScheme) {
+  const size = 16;
+  ctx.fillStyle = colorScheme.icon;
+  ctx.strokeStyle = colorScheme.icon;
+  ctx.lineWidth = 2;
+
+  // Lock body (rectangle)
+  const bodyWidth = size;
+  const bodyHeight = size * 0.6;
+  const bodyX = centerX - bodyWidth / 2;
+  const bodyY = centerY - bodyHeight / 4;
+
+  drawRoundedRect(ctx, bodyX, bodyY, bodyWidth, bodyHeight, 2);
+  ctx.fill();
+
+  // Lock shackle (semicircle)
+  const shackleRadius = size * 0.35;
+  const shackleY = centerY - size * 0.4;
+
+  ctx.beginPath();
+  ctx.arc(centerX, shackleY, shackleRadius, Math.PI, 2 * Math.PI);
+  ctx.stroke();
+
+  // Keyhole
+  ctx.fillStyle = colorScheme.textPrimary;
+  ctx.beginPath();
+  ctx.arc(centerX, centerY - 2, 2, 0, 2 * Math.PI);
+  ctx.fill();
+  ctx.fillRect(centerX - 1, centerY - 2, 2, 4);
+}
+
+/**
+ * Draw encryption badge
+ */
+function drawEncryptionBadge(ctx: CanvasRenderingContext2D, centerX: number, centerY: number, colorScheme: ColorScheme) {
+  const extension = "ENCRYPTED";
+  const badgeWidth = extension.length * 6 + 12;
+  const badgeHeight = 18;
+
+  // Badge background
+  drawRoundedRect(ctx, centerX - badgeWidth/2, centerY - badgeHeight/2, badgeWidth, badgeHeight, 9);
+  ctx.fillStyle = colorScheme.badge;
+  ctx.fill();
+
+  // Badge text
+  ctx.font = 'bold 9px -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif';
+  ctx.fillStyle = colorScheme.textPrimary;
+  ctx.textAlign = 'center';
+  ctx.fillText(extension, centerX, centerY + 3);
+}
+
 /**
  * Draw extension badge
  */
-function drawExtensionBadge(ctx: CanvasRenderingContext2D, centerX: number, centerY: number, extension: string, colorScheme: any) {
+function drawExtensionBadge(ctx: CanvasRenderingContext2D, centerX: number, centerY: number, extension: string, colorScheme: ColorScheme) {
   const badgeWidth = Math.max(extension.length * 8 + 16, 40);
   const badgeHeight = 22;
 
@@ -199,6 +311,13 @@ export async function generateThumbnailForFile(file: File): Promise<string | und
       disableStream: true
     }).promise;
 
+    // Check if PDF is encrypted
+    if ((pdf as any).isEncrypted) {
+      console.log('PDF is encrypted, generating encrypted thumbnail:', file.name);
+      pdf.destroy();
+      return generateEncryptedPDFThumbnail(file);
+    }
+
     const page = await pdf.getPage(1);
     const viewport = page.getViewport({ scale }); // Dynamic scale based on file size
     const canvas = document.createElement("canvas");
@@ -220,6 +339,13 @@ export async function generateThumbnailForFile(file: File): Promise<string | und
     return thumbnail;
   } catch (error) {
     if (error instanceof Error) {
+      // Check if error indicates encrypted PDF
+      const errorMessage = error.message.toLowerCase();
+      if (errorMessage.includes('password') || errorMessage.includes('encrypted')) {
+        console.log('PDF appears to be encrypted based on error, generating encrypted thumbnail:', file.name);
+        return generateEncryptedPDFThumbnail(file);
+      }
+      
       if (error.name === 'InvalidPDFException') {
         console.warn(`PDF structure issue for ${file.name} - using fallback thumbnail`);
         // Return a placeholder or try with full file instead of chunk
@@ -232,6 +358,13 @@ export async function generateThumbnailForFile(file: File): Promise<string | und
             verbosity: 0 // Reduce PDF.js warnings
           }).promise;
 
+          // Check if PDF is encrypted in fallback too
+          if ((pdf as any).isEncrypted) {
+            console.log('PDF is encrypted in fallback, generating encrypted thumbnail:', file.name);
+            pdf.destroy();
+            return generateEncryptedPDFThumbnail(file);
+          }
+
           const page = await pdf.getPage(1);
           const viewport = page.getViewport({ scale });
           const canvas = document.createElement("canvas");