Merge remote-tracking branch 'erdnaxeli/fix_sqlite_timezone'

mautrix_facebook/db/message.py

@@ -16,11 +16,13 @@
 from typing import Optional, Iterable, List
 from datetime import datetime
 
-from sqlalchemy import Column, String, DateTime, SmallInteger, UniqueConstraint, and_
+from sqlalchemy import Column, String, SmallInteger, UniqueConstraint, and_
 
 from mautrix.types import RoomID, EventID
 from mautrix.util.db import Base
 
+from .types import UTCDateTime
+
 
 class Message(Base):
     __tablename__ = "message"
@@ -31,7 +33,7 @@ class Message(Base):
     fb_chat: str = Column(String(127), nullable=True)
     fb_receiver: str = Column(String(127), primary_key=True)
     index: int = Column(SmallInteger, primary_key=True, default=0)
-    date: Optional[datetime] = Column(DateTime(timezone=True), nullable=True)
+    date: Optional[datetime] = Column(UTCDateTime(timezone=True), nullable=True)
 
     __table_args__ = (UniqueConstraint("mxid", "mx_room", name="_mx_id_room"),)
 

mautrix_facebook/db/types/__init__.py

+from datetime import timezone
+
+import sqlalchemy.types as types
+
+
+class UTCDateTime(types.TypeDecorator):
+    """Decorates the SQLAlchemy DateTime type to work with UTC datetimes.
+
+    It supposes we only manipulate UTC datetime. If the timezone is not set when saving or reading
+    a value, the UTC timezone is set. If a timezone is set, it ensures the datetime is converted to
+    UTC before saving it.
+    This is useful when working with SQLite as the SQLalchemy DateTime type loses the timezone
+    information when saving a datetime on this database.
+    """
+    impl = types.DateTime
+
+    def process_bind_param(self, value, dialect):
+        if value is not None:
+            if value.tzinfo is None:
+                value = value.replace(tzinfo=timezone.utc)
+            elif value.tzinfo != timezone.utc:
+                value = value.astimezone(timezone.utc)
+
+        return value
+
+    def process_result_value(self, value, dialect):
+        if value is not None and value.tzinfo is None:
+            return value.replace(tzinfo=timezone.utc)
+        else:
+            return value