Allow send with edited link preview

Co-authored-by: Fedor Indutny <79877362+indutny-signal@users.noreply.github.com>

ts/components/CompositionArea.tsx

@@ -51,6 +51,7 @@ import type {
 } from '../state/ducks/conversations';
 import type { EmojiPickDataType } from './emoji/EmojiPicker';
 import type { LinkPreviewType } from '../types/message/LinkPreviews';
+import { isSameLinkPreview } from '../types/message/LinkPreviews';
 
 import { MandatoryProfileSharingActions } from './conversation/MandatoryProfileSharingActions';
 import { MediaQualitySelector } from './MediaQualitySelector';
@@ -366,6 +367,9 @@ export const CompositionArea = memo(function CompositionArea({
     (draftEditMessage != null &&
       dropNull(draftEditMessage.quote?.messageId) !==
         dropNull(quotedMessageId)) ||
+    // Link preview of edited message changed
+    (draftEditMessage != null &&
+      !isSameLinkPreview(linkPreviewResult, draftEditMessage?.preview)) ||
     // Not edit message, but has attachments
     (draftEditMessage == null && draftAttachments.length !== 0);
 

ts/services/LinkPreview.ts

@@ -16,6 +16,7 @@ import * as Errors from '../types/errors';
 import type { StickerPackType as StickerPackDBType } from '../sql/Interface';
 import type { MIMEType } from '../types/MIME';
 import * as Bytes from '../Bytes';
+import { sha256 } from '../Crypto';
 import * as LinkPreview from '../types/LinkPreview';
 import * as Stickers from '../types/Stickers';
 import * as VisualAttachment from '../types/VisualAttachment';
@@ -364,6 +365,7 @@ async function getPreview(
         data,
         size: data.byteLength,
         ...dimensions,
+        plaintextHash: Bytes.toHex(sha256(data)),
         contentType: stringToMIMEType(withBlob.file.type),
         blurHash,
       };

ts/types/message/LinkPreviews.ts

@@ -17,3 +17,28 @@ type GenericLinkPreviewType<Image> = {
 export type LinkPreviewType = GenericLinkPreviewType<AttachmentType>;
 export type LinkPreviewWithHydratedData =
   GenericLinkPreviewType<AttachmentWithHydratedData>;
+
+export function isSameLinkPreview(
+  prev: LinkPreviewType | undefined | null,
+  next: LinkPreviewType | undefined | null
+): boolean {
+  // Both has to be absent or present
+  if (prev == null || next == null) {
+    return prev == null && next == null;
+  }
+
+  if (prev.url !== next.url) {
+    return false;
+  }
+  if (prev.title !== next.title) {
+    return false;
+  }
+  if (prev.description !== next.description) {
+    return false;
+  }
+  if (prev.image?.plaintextHash !== next.image?.plaintextHash) {
+    return false;
+  }
+
+  return true;
+}