Preserve QOutlook HTML EML bodies

src/io/outlookMail.ts

@@ -81,6 +81,7 @@ export async function importEmlFile(file: File): Promise<ImportedMailMessage> {
 
   const raw = await file.text();
   const parsed = parseEmlSource(raw);
+  const bodyHtml = extractMessageHtmlBody(parsed.headers, parsed.body);
 
   return {
     id: `eml-${Date.now()}`,
@@ -94,6 +95,7 @@ export async function importEmlFile(file: File): Promise<ImportedMailMessage> {
     ...mailPriorityHeaders(parsed.headers),
     subject: decodeMimeWords(parsed.headers.subject || "Без темы"),
     body: extractMessageBody(parsed.headers, parsed.body),
+    ...(bodyHtml ? { bodyHtml } : {}),
     time: parsed.headers.date || new Date().toLocaleString("ru-RU"),
     read: false,
     flagged: false,
@@ -121,6 +123,7 @@ export function msgDataToMailMessage(reader: Pick<MsgReaderInstance, "getAttachm
   const cc = msgRecipientList(data.recipients, "cc") || decodeMimeWords(headerFields.cc || "");
   const bcc = msgRecipientList(data.recipients, "bcc") || decodeMimeWords(headerFields.bcc || "");
   const replyTo = decodeMimeWords(headerFields["reply-to"] || "");
+  const bodyHtml = msgBodyHtml(data);
   return {
     id: `msg-${Date.now()}`,
     folder: "inbox",
@@ -133,6 +136,7 @@ export function msgDataToMailMessage(reader: Pick<MsgReaderInstance, "getAttachm
     ...mailPriorityHeaders(headerFields),
     subject: firstText(data.subject, decodeMimeWords(headerFields.subject || ""), "Без темы"),
     body: msgBodyText(data),
+    ...(bodyHtml ? { bodyHtml } : {}),
     time: firstText(data.messageDeliveryTime, data.clientSubmitTime, data.creationTime, data.lastModificationTime, headerFields.date, new Date().toLocaleString("ru-RU")),
     read: false,
     flagged: false,
@@ -229,6 +233,31 @@ export function extractMessageBody(headers: MailHeaders, body: string): string {
   return contentType.mediaType === "text/html" ? htmlToPlainText(decoded) : normalizeMailNewlines(decoded).trim();
 }
 
+export function extractMessageHtmlBody(headers: MailHeaders, body: string): string {
+  const contentType = parseContentType(headers["content-type"]);
+
+  if (contentType.mediaType.startsWith("multipart/")) {
+    const boundary = contentType.parameters.boundary;
+    if (!boundary) {
+      return "";
+    }
+
+    return (
+      parseMultipartBody(body, boundary)
+        .filter((part) => !isAttachmentPart(part.headers))
+        .filter((part) => isMessageBodyPart(part.headers))
+        .map((part) => extractMessageHtmlBody(part.headers, part.body))
+        .find((html) => html.trim()) ?? ""
+    );
+  }
+
+  if (contentType.mediaType !== "text/html") {
+    return "";
+  }
+
+  return decodeTransferBody(body, headers["content-transfer-encoding"], contentType.parameters.charset).trim();
+}
+
 export function extractMessageAttachments(headers: MailHeaders, body: string): MailAttachment[] {
   return collectAttachmentParts(headers, body).map((part, index) => attachmentFromPart(part, index));
 }
@@ -271,6 +300,19 @@ function msgBodyText(data: MsgFileData): string {
   return "";
 }
 
+function msgBodyHtml(data: MsgFileData): string {
+  const htmlBody = firstText(data.bodyHtml);
+  if (htmlBody) {
+    return htmlBody;
+  }
+
+  if (data.html && data.html.byteLength > 0) {
+    return decodeBytes(data.html, msgCharset(data)).trim();
+  }
+
+  return "";
+}
+
 function msgCharset(data: MsgFileData) {
   const headerFields = data.headers ? parseEmlHeaders(data.headers) : {};
   return parseContentType(headerFields["content-type"]).parameters.charset || "utf-8";
@@ -417,8 +459,10 @@ export function parseContentType(value = "text/plain"): ParsedContentType {
 
 export function buildEmlSource(message: MailMessage): string {
   const attachments = message.attachments ?? [];
+  const hasHtmlBody = Boolean(message.bodyHtml?.trim());
   if (attachments.length > 0) {
     const boundary = createMultipartBoundary(message);
+    const alternativeBoundary = createAlternativeBoundary(message);
     const lines = [
       `From: ${sanitizeHeaderValue(message.from)}`,
       `To: ${sanitizeHeaderValue(message.to)}`,
@@ -431,10 +475,7 @@ export function buildEmlSource(message: MailMessage): string {
       `Content-Type: multipart/mixed; boundary="${boundary}"`,
       "",
       `--${boundary}`,
-      "Content-Type: text/plain; charset=utf-8",
-      "Content-Transfer-Encoding: 8bit",
-      "",
-      normalizeMailNewlines(message.body || ""),
+      ...(hasHtmlBody ? buildAlternativePartLines(alternativeBoundary, message) : buildPlainTextPartLines(message)),
       ...attachments.flatMap((attachment) => buildAttachmentPartLines(boundary, attachment)),
       `--${boundary}--`,
       ""
@@ -443,6 +484,30 @@ export function buildEmlSource(message: MailMessage): string {
     return lines.join("\r\n");
   }
 
+  if (hasHtmlBody) {
+    const boundary = createAlternativeBoundary(message);
+    const lines = [
+      `From: ${sanitizeHeaderValue(message.from)}`,
+      `To: ${sanitizeHeaderValue(message.to)}`,
+      ...optionalAddressHeaders(message),
+      `Subject: ${encodeHeaderValue(message.subject || "Без темы")}`,
+      `Date: ${sanitizeHeaderValue(message.time || new Date().toUTCString())}`,
+      ...optionalThreadHeaders(message),
+      ...optionalPriorityHeaders(message),
+      "MIME-Version: 1.0",
+      `Content-Type: multipart/alternative; boundary="${boundary}"`,
+      "",
+      `--${boundary}`,
+      ...buildPlainTextPartLines(message),
+      `--${boundary}`,
+      ...buildHtmlPartLines(message),
+      `--${boundary}--`,
+      ""
+    ];
+
+    return lines.join("\r\n");
+  }
+
   const lines = [
     `From: ${sanitizeHeaderValue(message.from)}`,
     `To: ${sanitizeHeaderValue(message.to)}`,
@@ -461,6 +526,26 @@ export function buildEmlSource(message: MailMessage): string {
   return lines.join("\r\n");
 }
 
+function buildPlainTextPartLines(message: MailMessage): string[] {
+  return ["Content-Type: text/plain; charset=utf-8", "Content-Transfer-Encoding: 8bit", "", normalizeMailNewlines(message.body || "")];
+}
+
+function buildHtmlPartLines(message: MailMessage): string[] {
+  return ["Content-Type: text/html; charset=utf-8", "Content-Transfer-Encoding: 8bit", "", normalizeMailNewlines(message.bodyHtml || "")];
+}
+
+function buildAlternativePartLines(boundary: string, message: MailMessage): string[] {
+  return [
+    `Content-Type: multipart/alternative; boundary="${boundary}"`,
+    "",
+    `--${boundary}`,
+    ...buildPlainTextPartLines(message),
+    `--${boundary}`,
+    ...buildHtmlPartLines(message),
+    `--${boundary}--`
+  ];
+}
+
 function optionalAddressHeaders(message: MailMessage): string[] {
   return [
     ...(message.cc?.trim() ? [`Cc: ${sanitizeHeaderValue(message.cc)}`] : []),
@@ -659,6 +744,10 @@ function createMultipartBoundary(message: MailMessage): string {
   return `qoffice-${normalizedSeed || "message"}`;
 }
 
+function createAlternativeBoundary(message: MailMessage): string {
+  return `${createMultipartBoundary(message)}-alternative`;
+}
+
 function buildAttachmentPartLines(boundary: string, attachment: MailAttachment): string[] {
   const safeContentType = sanitizeMimeType(attachment.contentType);
   const disposition = attachment.disposition === "inline" ? "inline" : "attachment";