Added link previews for outgoing messages.

Refactoring.
Moved link preview generation to messages.

SignalServiceKit/src/Messages/Interactions/TSMessage.h

@@ -98,6 +98,10 @@ typedef NS_ENUM(NSInteger, LKMessageFriendRequestStatus) {
 
 - (void)saveGroupChatMessageID:(uint64_t)serverMessageID in:(YapDatabaseReadWriteTransaction *_Nullable)transaction;
 
+#pragma mark - Link preview
+
+- (void)generateLinkPreviewIfNeededFromURL:(NSString *)url;
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Messages/Interactions/TSMessage.m

@@ -512,6 +512,56 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
     }
 }
 
+#pragma mark - Link preview
+
+
+- (void)generateLinkPreviewIfNeededFromURL:(NSString *)url {
+    // If we already have previews or attachments then don't bother making link previews
+    if (self.linkPreview != nil || self.hasAttachments) { return; }
+    
+    [OWSLinkPreview tryToBuildPreviewInfoObjcWithPreviewUrl:url]
+    .thenOn(dispatch_get_main_queue(), ^(OWSLinkPreviewDraft *linkPreviewDraft) {
+        [self.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+            OWSLinkPreview *linkPreview = [OWSLinkPreview buildValidatedLinkPreviewFromInfo:linkPreviewDraft transaction:transaction error:nil];
+            self.linkPreview = linkPreview;
+            [self saveWithTransaction:transaction];
+        }];
+    })
+    .catchOn(dispatch_get_main_queue(), ^(NSError *error) {
+        // If we failed to get link preview due to invalid content then maybe it's a link to a direct image?
+        if ([OWSLinkPreview isInvalidContentError:error]) {
+            __block AnyPromise *promise;
+            [self.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+                promise = [OWSLinkPreview getImagePreviewFromUrl:url transaction:transaction];
+            }];
+            return promise;
+        }
+        
+        // Return the error
+        return [AnyPromise promiseWithValue:error];
+    })
+    .thenOn(dispatch_get_main_queue(), ^(OWSLinkPreview *linkPreview) {
+        // If we managed to get direct previews then render them
+        [self.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+            if (linkPreview.isDirectAttachment) {
+                if (!self.hasAttachments) {
+                    [self addAttachmentId:linkPreview.imageAttachmentId transaction:transaction];
+                    
+                    // Set the message id in attachment
+                    TSAttachmentStream *linkPreviewAttachment = [TSAttachmentStream fetchObjectWithUniqueID:linkPreview.imageAttachmentId transaction:transaction];
+                    linkPreviewAttachment.albumMessageId = self.uniqueId;
+                    linkPreviewAttachment.isUploaded = true;
+                    [linkPreviewAttachment saveWithTransaction:transaction];
+                }
+            } else {
+                self.linkPreview = linkPreview;
+                [self saveWithTransaction:transaction];
+            }
+            
+        }];
+    });
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -1409,7 +1409,7 @@ NS_ASSUME_NONNULL_BEGIN
                 dispatch_async(dispatch_get_main_queue(), ^{
                     NSString *url = [OWSLinkPreview previewURLForRawBodyText:incomingMessage.body];
                     if (url != nil) {
-                        [self handleLinkPreviewsIfNeededWithUrl:url message:incomingMessage];
+                        [incomingMessage generateLinkPreviewIfNeededFromURL:url];
                     }
                 });
 
@@ -1511,7 +1511,7 @@ NS_ASSUME_NONNULL_BEGIN
                 linkPreviewURL = [OWSLinkPreview previewURLForRawBodyText:incomingMessage.body];
             }
             if (linkPreviewURL != nil) {
-                [self handleLinkPreviewsIfNeededWithUrl:linkPreviewURL message:incomingMessage];
+                [incomingMessage generateLinkPreviewIfNeededFromURL:linkPreviewURL];
             }
         });
         
@@ -1519,49 +1519,6 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
-- (void)handleLinkPreviewsIfNeededWithUrl:(NSString *)linkPreviewURL message:(TSMessage *)message {
-    [OWSLinkPreview tryToBuildPreviewInfoObjcWithPreviewUrl:linkPreviewURL]
-    .thenOn(dispatch_get_main_queue(), ^(OWSLinkPreviewDraft *linkPreviewDraft) {
-        [OWSPrimaryStorage.sharedManager.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-            OWSLinkPreview *linkPreview = [OWSLinkPreview buildValidatedLinkPreviewFromInfo:linkPreviewDraft transaction:transaction error:nil];
-            message.linkPreview = linkPreview;
-            [message saveWithTransaction:transaction];
-        }];
-    })
-    .catchOn(dispatch_get_main_queue(), ^(NSError *error) {
-        // If we failed to get link preview due to invalid content then maybe it's a link to a direct image?
-        if ([OWSLinkPreview isInvalidContentError:error]) {
-            __block AnyPromise *promise;
-            [OWSPrimaryStorage.sharedManager.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-                promise = [OWSLinkPreview getImagePreviewFromUrl:linkPreviewURL transaction:transaction];
-            }];
-            return promise;
-        }
-        
-        // Return the error
-        return [AnyPromise promiseWithValue:error];
-    })
-    .thenOn(dispatch_get_main_queue(), ^(OWSLinkPreview *linkPreview) {
-        // If we managed to get direct previews then render them
-        [OWSPrimaryStorage.sharedManager.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-            if (linkPreview.isDirectAttachment) {
-                if (!message.hasAttachments) {
-                    [message addAttachmentId:linkPreview.imageAttachmentId transaction:transaction];
-                    
-                    // Set the message id in attachment
-                    TSAttachment *linkPreviewAttachment = [TSAttachment fetchObjectWithUniqueID:linkPreview.imageAttachmentId transaction:transaction];
-                    linkPreviewAttachment.albumMessageId = message.uniqueId;
-                    [linkPreviewAttachment saveWithTransaction:transaction];
-                }
-            } else {
-                message.linkPreview = linkPreview;
-                [message saveWithTransaction:transaction];
-            }
-            
-        }];
-    });
-}
-
 // The difference between this function and `handleFriendRequestAcceptIfNeededWithEnvelope:` is that this will setup the incoming message for display to the user
 // While `handleFriendRequestAcceptIfNeededWithEnvelope:` handles friend request accepting logic and doesn't need a message
 - (void)handleFriendRequestMessageIfNeededWithEnvelope:(SSKProtoEnvelope *)envelope message:(TSIncomingMessage *)message thread:(TSThread *)thread transaction:(YapDatabaseReadWriteTransaction *)transaction {

SignalServiceKit/src/Messages/OWSMessageSender.m

@@ -1239,6 +1239,15 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
             // have a valid Signal account.
             [SignalRecipient markRecipientAsRegisteredAndGet:recipient.recipientId transaction:transaction];
         }];
+        
+        // Check if we need to generate link previews
+        TSMessage *message = messageSend.message;
+        if (message.linkPreview == nil && !message.hasAttachments) {
+            dispatch_async(dispatch_get_main_queue(), ^{
+                NSString *url = [OWSLinkPreview previewURLForRawBodyText:message.body];
+                if (url) { [message generateLinkPreviewIfNeededFromURL:url]; }
+            });
+        }
 
         messageSend.success();
     });