allow editing in/out attachments from messages

lib/controllers/attachment.dart

@@ -29,6 +29,8 @@ class AttachmentController(final String roomId)
     state = (filename, content);
   }
 
+  void set((String, MessageContent?)? attachment) => state = attachment;
+
   static final provider = NotifierProvider.family
       .autoDispose<AttachmentController, (String, MessageContent?)?, String>(
         AttachmentController.new,

lib/controllers/room_chat.dart

@@ -8,6 +8,7 @@ import "package:fluttertagger/fluttertagger.dart";
 import "package:nexus/controllers/attachment.dart";
 import "package:nexus/controllers/client.dart";
 import "package:nexus/controllers/rooms.dart";
+import "package:nexus/helpers/extensions/is_media.dart";
 import "package:nexus/helpers/extensions/send_failed.dart";
 import "package:nexus/models/content/content.dart";
 import "package:nexus/models/content/image_pack.dart";
@@ -231,22 +232,24 @@ class RoomChatController(final ChatParams info)
     required RelationType relationType,
     int? relatedEventRowId,
   }) async {
-    Content? baseContent;
+    final events = ref.read(RoomsController.provider)[info.roomId]?.events;
     final relatedEvent = relatedEventRowId == null
         ? null
-        : ref.read(
-            RoomsController.provider.select(
-              (rooms) => rooms[info.roomId]?.events[relatedEventRowId],
-            ),
-          );
+        : events?[relatedEventRowId];
 
-    if (relationType == .edit && relatedEventRowId != null) {
-      baseContent = relatedEvent?.content;
-    } else {
-      final provider = AttachmentController.provider(info.roomId);
-      baseContent = ref.read(provider)?.$2;
-      ref.invalidate(provider);
-    }
+    final attachmentProvider = AttachmentController.provider(info.roomId);
+    final attachment = ref.read(attachmentProvider)?.$2;
+    ref.invalidate(attachmentProvider);
+
+    // Edits of media use the attachment, which starts as the current media
+    final latestContent = relatedEvent == null
+        ? null
+        : (events?[relatedEvent.lastEditRowId] ?? relatedEvent).content;
+    final baseContent =
+        attachment ??
+        (relationType == .edit && latestContent?.isMedia == false
+            ? latestContent
+            : null);
 
     // Replaces each formatted tag, like "@id#name#", with its ID
     final taggedMessage = tags.fold(

lib/helpers/extensions/is_media.dart

@@ -0,0 +1,12 @@
+import "package:nexus/models/content/content.dart";
+import "package:nexus/models/content/message.dart";
+
+extension IsMedia on Content {
+  bool get isMedia => switch (this) {
+    ImageMessageContent() ||
+    VideoMessageContent() ||
+    AudioMessageContent() ||
+    FileMessageContent() => true,
+    _ => false,
+  };
+}

lib/widgets/composer/composer.dart

@@ -3,6 +3,8 @@ import "dart:io";
 import "package:fast_immutable_collections/fast_immutable_collections.dart";
 import "package:nexus/controllers/rooms.dart";
 import "package:nexus/widgets/emoji_picker.dart";
+import "package:nexus/helpers/extensions/get_filename.dart";
+import "package:nexus/helpers/extensions/is_media.dart";
 import "package:nexus/helpers/extensions/show_adaptive_sheet.dart";
 import "package:nexus/widgets/adaptive_menu_button.dart";
 import "package:material_ui/material_ui.dart";
@@ -111,6 +113,8 @@ class const Composer(
           );
 
     final textBefore = useState<String?>(null);
+    // Wrapped, since no attachment is a draft too
+    final attachmentBefore = useState<((String, MessageContent?)?,)?>(null);
 
     /// The sticker to send, which replaces the text field until it is sent or
     /// removed, as stickers can't have a caption
@@ -132,16 +136,24 @@ class const Composer(
     final isEditing = relationType == .edit && relatedEvent != null;
 
     useEffect(() {
+      final attachmentProvider = AttachmentController.provider(roomId);
+
       if (relationType == .edit && relatedEvent != null) {
         textBefore.value ??= controller.text;
+        attachmentBefore.value ??= (ref.read(attachmentProvider),);
         sticker.value = null;
         poll.value = null;
         location.value = null;
 
+        final content = relatedEvent.content;
         final text =
             relatedEvent.localContent?.editSource ??
-            switch (relatedEvent.content) {
-              TextMessageContent(:final body) => body,
+            switch (content) {
+              TextMessageContent(:final body) ||
+              ImageMessageContent(:final body) ||
+              VideoMessageContent(:final body) ||
+              AudioMessageContent(:final body) ||
+              FileMessageContent(:final body) => body,
               _ => "",
             };
 
@@ -149,12 +161,34 @@ class const Composer(
           text: text,
           selection: .collapsed(offset: text.length),
         );
-      } else if (textBefore.value case final draft?) {
-        controller.value = .new(
-          text: draft,
-          selection: .collapsed(offset: draft.length),
+
+        Future.microtask(
+          () => ref
+              .read(attachmentProvider.notifier)
+              .set(
+                content is MessageContent && content.isMedia
+                    ? (
+                        content.filename ?? content.body ?? "Attachment",
+                        content,
+                      )
+                    : null,
+              ),
         );
-        textBefore.value = null;
+      } else {
+        if (textBefore.value case final draft?) {
+          controller.value = .new(
+            text: draft,
+            selection: .collapsed(offset: draft.length),
+          );
+          textBefore.value = null;
+        }
+
+        if (attachmentBefore.value case (final draft,)) {
+          Future.microtask(
+            () => ref.read(attachmentProvider.notifier).set(draft),
+          );
+          attachmentBefore.value = null;
+        }
       }
 
       return null;