Send oversize text messages as attachments.

// FREEBIE

Signal/src/ViewControllers/MessagesViewController.m

@@ -1098,28 +1098,15 @@ typedef enum : NSUInteger {
 
     text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
 
-    // Limit outgoing text messages to 64kb.
+    // Limit outgoing text messages to 16kb.
     //
-    // TODO: Convert large text messages to attachments
+    // We convert large text messages to attachments
     // which are presented as normal text messages.
-    const NSUInteger kMaxTextMessageSize = 64 * 1024;
-    if ([text lengthOfBytesUsingEncoding:NSUTF8StringEncoding] > kMaxTextMessageSize) {
-        UIAlertController *controller =
-        [UIAlertController alertControllerWithTitle:NSLocalizedString(@"CONVERSATION_VIEW_TEXT_MESSAGE_TOO_LARGE_ALERT_TITLE",
-                                                                      @"The title of the 'text message too large' alert.")
-                                            message:NSLocalizedString(@"CONVERSATION_VIEW_TEXT_MESSAGE_TOO_LARGE_ALERT_MESSAGE",
-                                                                      @"The message of the 'text message too large' alert.")
-                                     preferredStyle:UIAlertControllerStyleAlert];
-        [controller addAction:[UIAlertAction actionWithTitle:NSLocalizedString(@"OK", nil)
-                                                       style:UIAlertActionStyleDefault
-                                                     handler:nil]];
-        [self presentViewController:controller
-                           animated:YES
-                         completion:nil];
-        return;
-    }
-    
-    if (text.length > 0) {
+    const NSUInteger kOversizeTextMessageSizeThreshold = 16 * 1024;
+    if ([text lengthOfBytesUsingEncoding:NSUTF8StringEncoding] >= kOversizeTextMessageSizeThreshold) {
+        SignalAttachment *attachment = [SignalAttachment oversizeTextAttachmentWithText:text];
+        [ThreadUtil sendMessageWithAttachment:attachment inThread:self.thread messageSender:self.messageSender];
+    } else if (text.length > 0) {
         if ([Environment.preferences soundInForeground]) {
             [JSQSystemSoundPlayer jsq_playMessageSentSound];
         }