memory (sqla): add after_uid filter in history_get

libervia/backend/memory/sqla.py

@@ -630,6 +630,18 @@ class Storage:
         if filters is None:
             filters = {}
 
+        # An "after_uid" filter asks for the first messages after a given one, so ASC
+        # order is used and the result is returned as-is. Otherwise DESC+LIMIT keeps the
+        # last messages and the result is reversed.
+        asc = "after_uid" in filters
+        order = (
+            History.timestamp.asc() if asc else History.timestamp.desc(),
+            (
+                History.received_timestamp.asc()
+                if asc
+                else History.received_timestamp.desc()
+            ),
+        )
         stmt = (
             select(History)
             .filter_by(profile_id=self.profiles[profile])
@@ -641,14 +653,7 @@ class Storage:
                 contains_eager(History.subjects),
                 contains_eager(History.thread),
             )
-            .order_by(
-                # timestamp may be identical for 2 close messages (specially when delay is
-                # used) that's why we order ties by received_timestamp. We'll reverse the
-                # order when returning the result. We use DESC here so LIMIT keep the last
-                # messages
-                History.timestamp.desc(),
-                History.received_timestamp.desc(),
-            )
+            .order_by(*order)
         )
 
         if not from_jid and not to_jid:
@@ -689,8 +694,8 @@ class Storage:
             if "timestamp_start" in filters:
                 stmt = stmt.where(History.timestamp >= float(filters["timestamp_start"]))
             if "before_uid" in filters:
-                # orignially this query was using SQLITE's rowid. This has been changed
-                # to use coalesce(received_timestamp, timestamp) to be SQL engine independant
+                # orignially this query was using SQLITE's rowid. This has been changed to
+                # use coalesce(received_timestamp, timestamp) to be SQL engine independant
                 stmt = stmt.where(
                     coalesce(History.received_timestamp, History.timestamp)
                     < (
@@ -699,6 +704,15 @@ class Storage:
                         ).filter_by(uid=filters["before_uid"])
                     ).scalar_subquery()
                 )
+            if "after_uid" in filters:
+                stmt = stmt.where(
+                    coalesce(History.received_timestamp, History.timestamp)
+                    > (
+                        select(
+                            coalesce(History.received_timestamp, History.timestamp)
+                        ).filter_by(uid=filters["after_uid"])
+                    ).scalar_subquery()
+                )
             if "body" in filters:
                 # TODO: use REGEXP (function to be defined) instead of GLOB:
                 #    https://www.sqlite.org/lang_expr.html
@@ -754,7 +768,8 @@ class Storage:
             result = await session.execute(stmt)
 
         result = result.scalars().unique().all()
-        result.reverse()
+        if not asc:
+            result.reverse()
         return [h.as_tuple() for h in result]
 
     @aio