feat: refactor MailViewer and add utility functions for email handling and attachment processing

2026-02-05 22:25:35 +01:00
parent c0c1fbb08f
commit aef5c317df
6 changed files with 647 additions and 247 deletions
--- a/frontend/src/lib/utils/mail/attachment-handlers.ts
+++ b/frontend/src/lib/utils/mail/attachment-handlers.ts
@@ -0,0 +1,94 @@
+/**
+ * Handlers for opening different attachment types
+ */
+
+import {
+  OpenPDF,
+  OpenPDFWindow,
+  OpenImage,
+  OpenImageWindow,
+  OpenEMLWindow,
+} from '$lib/wailsjs/go/main/App';
+import { settingsStore } from '$lib/stores/settings.svelte';
+import { toast } from 'svelte-sonner';
+import * as m from '$lib/paraglide/messages';
+
+export interface AttachmentHandlerResult {
+  success: boolean;
+  error?: string;
+}
+
+/**
+ * Opens a PDF attachment using either built-in or external viewer
+ * @param base64Data - Base64 encoded PDF data
+ * @param filename - Name of the PDF file
+ */
+export async function openPDFAttachment(
+  base64Data: string,
+  filename: string
+): Promise<AttachmentHandlerResult> {
+  try {
+    if (settingsStore.settings.useBuiltinPDFViewer) {
+      await OpenPDFWindow(base64Data, filename);
+    } else {
+      await OpenPDF(base64Data, filename);
+    }
+    return { success: true };
+  } catch (error: unknown) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+
+    // Check if PDF is already open
+    if (errorMessage.includes(filename) && errorMessage.includes('already open')) {
+      toast.error(m.mail_pdf_already_open());
+      return { success: false, error: 'already_open' };
+    }
+
+    console.error('Failed to open PDF:', error);
+    toast.error(m.mail_error_pdf());
+    return { success: false, error: errorMessage };
+  }
+}
+
+/**
+ * Opens an image attachment using either built-in or external viewer
+ * @param base64Data - Base64 encoded image data
+ * @param filename - Name of the image file
+ */
+export async function openImageAttachment(
+  base64Data: string,
+  filename: string
+): Promise<AttachmentHandlerResult> {
+  try {
+    if (settingsStore.settings.useBuiltinPreview) {
+      await OpenImageWindow(base64Data, filename);
+    } else {
+      await OpenImage(base64Data, filename);
+    }
+    return { success: true };
+  } catch (error: unknown) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    console.error('Failed to open image:', error);
+    toast.error(m.mail_error_image());
+    return { success: false, error: errorMessage };
+  }
+}
+
+/**
+ * Opens an EML attachment in a new EMLy window
+ * @param base64Data - Base64 encoded EML data
+ * @param filename - Name of the EML file
+ */
+export async function openEMLAttachment(
+  base64Data: string,
+  filename: string
+): Promise<AttachmentHandlerResult> {
+  try {
+    await OpenEMLWindow(base64Data, filename);
+    return { success: true };
+  } catch (error: unknown) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    console.error('Failed to open EML:', error);
+    toast.error('Failed to open EML attachment');
+    return { success: false, error: errorMessage };
+  }
+}
--- a/frontend/src/lib/utils/mail/constants.ts
+++ b/frontend/src/lib/utils/mail/constants.ts
@@ -0,0 +1,31 @@
+/**
+ * HTML/CSS injected into the email body iframe for styling and security
+ * - Removes default body margins
+ * - Disables link clicking for security
+ * - Prevents Ctrl+Wheel zoom in iframe
+ */
+export const IFRAME_UTIL_HTML = `<style>body{margin:0;padding:20px;font-family:sans-serif;} a{pointer-events:none!important;cursor:default!important;}</style><script>function handleWheel(event){if(event.ctrlKey){event.preventDefault();}}document.addEventListener('wheel',handleWheel,{passive:false});<\/script>`;
+
+/**
+ * Supported email file extensions
+ */
+export const EMAIL_EXTENSIONS = {
+  EML: '.eml',
+  MSG: '.msg',
+} as const;
+
+/**
+ * Attachment content type prefixes/patterns
+ */
+export const CONTENT_TYPES = {
+  IMAGE: 'image/',
+  PDF: 'application/pdf',
+} as const;
+
+/**
+ * Special PEC (Italian Certified Email) file names
+ */
+export const PEC_FILES = {
+  SIGNATURE: '.p7s',
+  CERTIFICATE: 'daticert.xml',
+} as const;
--- a/frontend/src/lib/utils/mail/data-utils.ts
+++ b/frontend/src/lib/utils/mail/data-utils.ts
@@ -0,0 +1,77 @@
+/**
+ * Utility functions for mail data conversion and processing
+ */
+
+/**
+ * Converts an ArrayBuffer or byte array to a base64 string
+ * @param buffer - The buffer to convert (can be string, array, or ArrayBuffer)
+ * @returns Base64 encoded string
+ */
+export function arrayBufferToBase64(buffer: unknown): string {
+  // Already a base64 string
+  if (typeof buffer === 'string') {
+    return buffer;
+  }
+
+  // Handle array of bytes
+  if (Array.isArray(buffer)) {
+    let binary = '';
+    const bytes = new Uint8Array(buffer);
+    const len = bytes.byteLength;
+    for (let i = 0; i < len; i++) {
+      binary += String.fromCharCode(bytes[i]);
+    }
+    return window.btoa(binary);
+  }
+
+  // Handle ArrayBuffer
+  if (buffer instanceof ArrayBuffer) {
+    let binary = '';
+    const bytes = new Uint8Array(buffer);
+    const len = bytes.byteLength;
+    for (let i = 0; i < len; i++) {
+      binary += String.fromCharCode(bytes[i]);
+    }
+    return window.btoa(binary);
+  }
+
+  return '';
+}
+
+/**
+ * Creates a data URL for downloading attachments
+ * @param contentType - MIME type of the attachment
+ * @param base64Data - Base64 encoded data
+ * @returns Data URL string
+ */
+export function createDataUrl(contentType: string, base64Data: string): string {
+  return `data:${contentType};base64,${base64Data}`;
+}
+
+/**
+ * Checks if a string looks like valid base64 content
+ * @param content - String to check
+ * @returns True if the content appears to be base64 encoded
+ */
+export function looksLikeBase64(content: string): boolean {
+  const clean = content.replace(/[\s\r\n]+/g, '');
+  return (
+    clean.length > 0 &&
+    clean.length % 4 === 0 &&
+    /^[A-Za-z0-9+/]+=*$/.test(clean)
+  );
+}
+
+/**
+ * Attempts to decode base64 content
+ * @param content - Base64 string to decode
+ * @returns Decoded string or null if decoding fails
+ */
+export function tryDecodeBase64(content: string): string | null {
+  try {
+    const clean = content.replace(/[\s\r\n]+/g, '');
+    return window.atob(clean);
+  } catch {
+    return null;
+  }
+}
--- a/frontend/src/lib/utils/mail/email-loader.ts
+++ b/frontend/src/lib/utils/mail/email-loader.ts
@@ -0,0 +1,163 @@
+/**
+ * Email loading and processing utilities
+ */
+
+import {
+  ReadEML,
+  ReadMSG,
+  ReadPEC,
+  ShowOpenFileDialog,
+  SetCurrentMailFilePath,
+  ConvertToUTF8,
+} from '$lib/wailsjs/go/main/App';
+import type { internal } from '$lib/wailsjs/go/models';
+import { isBase64, isHtml } from '$lib/utils';
+import { looksLikeBase64, tryDecodeBase64 } from './data-utils';
+
+export interface LoadEmailResult {
+  success: boolean;
+  email?: internal.EmailData;
+  filePath?: string;
+  error?: string;
+  cancelled?: boolean;
+}
+
+/**
+ * Determines the email file type from the path
+ */
+export function getEmailFileType(filePath: string): 'eml' | 'msg' | null {
+  const lowerPath = filePath.toLowerCase();
+  if (lowerPath.endsWith('.eml')) return 'eml';
+  if (lowerPath.endsWith('.msg')) return 'msg';
+  return null;
+}
+
+/**
+ * Checks if a file path is a valid email file
+ */
+export function isEmailFile(filePath: string): boolean {
+  return getEmailFileType(filePath) !== null;
+}
+
+/**
+ * Loads an email from a file path
+ * @param filePath - Path to the email file
+ * @returns LoadEmailResult with the email data or error
+ */
+export async function loadEmailFromPath(filePath: string): Promise<LoadEmailResult> {
+  const fileType = getEmailFileType(filePath);
+
+  if (!fileType) {
+    return {
+      success: false,
+      error: 'Invalid file type. Only .eml and .msg files are supported.',
+    };
+  }
+
+  try {
+    let email: internal.EmailData;
+
+    if (fileType === 'msg') {
+      email = await ReadMSG(filePath, true);
+    } else {
+      // Try PEC first, fall back to regular EML
+      try {
+        email = await ReadPEC(filePath);
+      } catch {
+        email = await ReadEML(filePath);
+      }
+    }
+
+    // Process body if needed (decode base64)
+    if (email?.body) {
+      const trimmed = email.body.trim();
+      if (looksLikeBase64(trimmed)) {
+        const decoded = tryDecodeBase64(trimmed);
+        if (decoded) {
+          email.body = decoded;
+        }
+      }
+    }
+
+    return {
+      success: true,
+      email,
+      filePath,
+    };
+  } catch (error: unknown) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    console.error('Failed to load email:', error);
+    return {
+      success: false,
+      error: errorMessage,
+    };
+  }
+}
+
+/**
+ * Opens a file dialog and loads the selected email
+ * @returns LoadEmailResult with the email data or error
+ */
+export async function openAndLoadEmail(): Promise<LoadEmailResult> {
+  try {
+    const filePath = await ShowOpenFileDialog();
+
+    if (!filePath || filePath.length === 0) {
+      return { success: false, cancelled: true };
+    }
+
+    const result = await loadEmailFromPath(filePath);
+
+    if (result.success && result.email) {
+      // Track the current mail file path for bug reports
+      await SetCurrentMailFilePath(filePath);
+    }
+
+    return result;
+  } catch (error: unknown) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    console.error('Failed to open email file:', error);
+    return {
+      success: false,
+      error: errorMessage,
+    };
+  }
+}
+
+/**
+ * Processes and fixes the email body content
+ * - Decodes base64 content if needed
+ * - Fixes character encoding issues
+ * @param body - The raw email body
+ * @returns Processed body content
+ */
+export async function processEmailBody(body: string): Promise<string> {
+  if (!body) return body;
+
+  let content = body;
+
+  // 1. Try to decode if not HTML
+  if (!isHtml(content)) {
+    const clean = content.replace(/[\s\r\n]+/g, '');
+    if (isBase64(clean)) {
+      const decoded = tryDecodeBase64(clean);
+      if (decoded) {
+        content = decoded;
+      }
+    }
+  }
+
+  // 2. If it is HTML (original or decoded), try to fix encoding
+  if (isHtml(content)) {
+    try {
+      const fixed = await ConvertToUTF8(content);
+      if (fixed) {
+        content = fixed;
+      }
+    } catch (e) {
+      console.warn('Failed to fix encoding:', e);
+    }
+  }
+
+  return content;
+}
--- a/frontend/src/lib/utils/mail/index.ts
+++ b/frontend/src/lib/utils/mail/index.ts
@@ -0,0 +1,37 @@
+/**
+ * Mail utilities barrel export
+ */
+
+// Constants
+export {
+  IFRAME_UTIL_HTML,
+  EMAIL_EXTENSIONS,
+  CONTENT_TYPES,
+  PEC_FILES,
+} from './constants';
+
+// Data utilities
+export {
+  arrayBufferToBase64,
+  createDataUrl,
+  looksLikeBase64,
+  tryDecodeBase64,
+} from './data-utils';
+
+// Attachment handlers
+export {
+  openPDFAttachment,
+  openImageAttachment,
+  openEMLAttachment,
+  type AttachmentHandlerResult,
+} from './attachment-handlers';
+
+// Email loader
+export {
+  getEmailFileType,
+  isEmailFile,
+  loadEmailFromPath,
+  openAndLoadEmail,
+  processEmailBody,
+  type LoadEmailResult,
+} from './email-loader';