Add consent-gated media exchange library

src/services/chat/service.ts

@@ -582,7 +582,7 @@ export class ChatService {
    * `https://chat.reddit.com/room/<roomId>` URL (web UI compatibility) or
    * a raw Matrix room ID like `!abc:reddit.com`.
    */
-  async sendChatMessage(chatUrlOrRoomId: string, message: string): Promise<boolean> {
+  async sendChatMessage(chatUrlOrRoomId: string, message: string, txnId?: string): Promise<boolean> {
     if (!this.accountAuth?.isFullyAuthenticated()) return false;
     const active = this.getInvitationCooldown();
     if (active && this.blocksExistingRoomSends(active)) {
@@ -599,7 +599,7 @@ export class ChatService {
           this.logger.error(`[chat] cannot extract room ID from "${chatUrlOrRoomId}"`);
           return false;
         }
-        const eventId = await this.withAuth(() => this.matrix.sendTextMessage(roomId, message));
+        const eventId = await this.withAuth(() => this.matrix.sendTextMessage(roomId, message, txnId));
         this.logger.info(`[chat] sent message to ${roomId} (event_id=${eventId})`);
         const chat = this.cache.get().find((c) => c.roomId === roomId);
         if (chat) {
@@ -619,6 +619,47 @@ export class ChatService {
     });
   }
 
+  async sendChatImage(
+    chatUrlOrRoomId: string,
+    image: { bytes: Buffer; mimeType: string; fileName: string; width: number; height: number },
+    txnId: string,
+    existingMxcUri?: string | null,
+  ): Promise<{ eventId: string; mxcUri: string } | null> {
+    if (!this.accountAuth?.isFullyAuthenticated()) return null;
+    const active = this.getInvitationCooldown();
+    if (active && this.blocksExistingRoomSends(active)) return null;
+    return this.enqueue(async () => {
+      try {
+        const roomId = ChatService.extractRoomId(chatUrlOrRoomId);
+        if (!roomId) return null;
+        const mxcUri = existingMxcUri
+          ?? await this.withAuth(() => this.matrix.uploadImage(image.bytes, image.mimeType, image.fileName));
+        const eventId = await this.withAuth(() => this.matrix.sendImageMessage(
+          roomId,
+          image.fileName,
+          mxcUri,
+          { mimeType: image.mimeType, size: image.bytes.length, width: image.width, height: image.height },
+          txnId,
+        ));
+        this.logger.info(`[chat] sent image to ${roomId} (event_id=${eventId})`);
+        const chat = this.cache.get().find((item) => item.roomId === roomId);
+        if (chat) {
+          chat.lastMessageSnippet = '[Image]';
+          chat.lastMessageTime = Date.now();
+          chat.isFromUs = true;
+        }
+        return { eventId, mxcUri };
+      } catch (error) {
+        if (error instanceof MatrixRateLimitError) {
+          this.setInvitationCooldown(error, 'all-sends');
+          return null;
+        }
+        this.logger.error('[chat] sendChatImage failed:', error);
+        return null;
+      }
+    });
+  }
+
   /**
    * Start a brand-new DM with the given Reddit user and send the opening
    * line. Returns the new chat (or null on failure).