implement fetching messages from group

meshchat.py

@@ -139,6 +139,52 @@ class GroupChatDataProvider(GroupDataProviderInterface):
 
         return members
 
+    # gets messages of a group
+    def get_messages(self, group_destination_hash: bytes, order: str | None, limit: int | None, after_id: int | None):
+
+        # find group
+        group = self.find_group(group_destination_hash)
+        if group is None:
+            raise Exception("Group not found")
+
+        # build group messages database query
+        query = database.GroupMessage.select().where(database.GroupMessage.group_destination_hash == group.destination_hash)
+
+        # limit results
+        if limit is not None:
+            query = query.limit(limit)
+
+        # order results
+        if order == "asc":
+
+            # order asc
+            query = query.order_by(database.GroupMessage.id.asc())
+
+            # only results after provided id
+            if after_id is not None:
+                query = query.where(database.GroupMessage.id > int(after_id))
+
+        elif order == "desc":
+
+            # order desc
+            query = query.order_by(database.GroupMessage.id.desc())
+
+            # only results before provided id
+            if after_id is not None:
+                query = query.where(database.GroupMessage.id < int(after_id))
+
+        # process messages
+        messages = []
+        for message in query:
+            messages.append({
+                "id": message.id,
+                "member_identity_hash": message.member_identity_hash,
+                "content": message.content,
+                "created_at": message.created_at,
+            })
+
+        return messages
+
     # save a message sent to the group by the provided identity
     def on_message_received(self, group_destination_hash: bytes, identity_hash: bytes, data: dict):
 

src/backend/group_chat/group_chat_client.py

@@ -103,6 +103,14 @@ class GroupChatClient:
             "limit": limit,
         }).encode("utf-8"))
 
+    # get group messages
+    async def get_messages(self, order: str, limit: int, after_id: int | None):
+        return await self.request("/api/v1/messages", data=json.dumps({
+            "order": order,
+            "limit": limit,
+            "after_id": after_id,
+        }).encode("utf-8"))
+
     # send message
     async def send_message(self, content: str):
         return await self.request("/api/v1/messages/send", data=json.dumps({
@@ -128,6 +136,7 @@ async def main():
     print(await group_chat_client.get_info())
     print(await group_chat_client.get_members(page=1, limit=10))
     print(await group_chat_client.send_message("hello world!"))
+    print(await group_chat_client.get_messages(order="desc", limit=1, after_id=None))
     print(await group_chat_client.leave())
     print(await group_chat_client.get_info())
 

src/backend/group_chat/group_chat_server.py

@@ -27,6 +27,10 @@ class GroupDataProviderInterface:
     def get_members(self, group_destination_hash: bytes, page: int | None, limit: int | None):
         raise Exception("Not Implemented")
 
+    # gets messages of a group
+    def get_messages(self, group_destination_hash: bytes, order: str | None, limit: int | None, after_id: int | None):
+        raise Exception("Not Implemented")
+
     # save a message sent to the group by the provided identity
     def on_message_received(self, group_destination_hash: bytes, identity_hash: bytes, data: dict):
         raise Exception("Not Implemented")
@@ -58,6 +62,7 @@ class GroupChatServer:
         self.group_destination.register_request_handler(path="/api/v1/join", response_generator=self.on_received_api_v1_join_request, allow=RNS.Destination.ALLOW_ALL)
         self.group_destination.register_request_handler(path="/api/v1/leave", response_generator=self.on_received_api_v1_leave_request, allow=RNS.Destination.ALLOW_ALL)
         self.group_destination.register_request_handler(path="/api/v1/members", response_generator=self.on_received_api_v1_members_request, allow=RNS.Destination.ALLOW_ALL)
+        self.group_destination.register_request_handler(path="/api/v1/messages", response_generator=self.on_received_api_v1_messages_request, allow=RNS.Destination.ALLOW_ALL)
         self.group_destination.register_request_handler(path="/api/v1/messages/send", response_generator=self.on_received_api_v1_messages_send_request, allow=RNS.Destination.ALLOW_ALL)
 
     # announce group destination
@@ -171,6 +176,47 @@ class GroupChatServer:
             "members": group_members,
         }).encode("utf-8")
 
+    # /api/v1/messages
+    def on_received_api_v1_messages_request(self, path, data: bytes | None, request_id, remote_identity: RNS.Identity | None, requested_at):
+
+        # ensure user has identified
+        if remote_identity is None:
+            return self.identity_not_provided_error_response()
+
+        # ensure user is a member
+        if not self.data_provider.is_member(self.group_destination.hash, remote_identity.hash):
+            return self.error_response("You are not a member of this group")
+
+        # attempt to parse data as json
+        order = None
+        limit = None
+        after_id = None
+        if data is not None:
+            try:
+                json_data = json.loads(data.decode("utf-8"))
+                order = json_data["order"]
+                limit = json_data["limit"]
+                after_id = json_data["after_id"]
+            except:
+                return self.request_json_parsing_error_response()
+
+        # get group messages
+        database_group_messages = self.data_provider.get_messages(self.group_destination.hash, order, limit, after_id)
+
+        # process group messages
+        group_messages = []
+        for database_group_message in database_group_messages:
+            group_messages.append({
+                "id": database_group_message["id"],
+                "member_identity_hash": database_group_message["member_identity_hash"],
+                "content": database_group_message["content"],
+                "created_at": database_group_message["created_at"],
+            })
+
+        return json.dumps({
+            "messages": group_messages,
+        }).encode("utf-8")
+
     # /api/v1/messages/send
     def on_received_api_v1_messages_send_request(self, path, data: bytes | None, request_id, remote_identity: RNS.Identity | None, requested_at):