Jul 13 - Optimize code

app/models/messaging.py

@@ -5,6 +5,7 @@ The seller is always listing.user; buyer is any other authenticated user.
 Messages are append-only; soft-delete not needed at Phase 3.
 """
 from datetime import datetime
+from app.utils.time import utcnow
 from app.extensions import db
 
 
@@ -23,7 +24,7 @@ class Conversation(db.Model):
     seller_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
                           db.ForeignKey("users.id"), nullable=False, index=True)
     last_message_at = db.Column(db.DateTime, nullable=True, index=True)
-    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
+    created_at = db.Column(db.DateTime, default=utcnow, nullable=False)
 
     listing = db.relationship("Listing",
                               backref=db.backref("conversations", lazy="dynamic"))
@@ -58,7 +59,7 @@ class Message(db.Model):
                           db.ForeignKey("users.id"), nullable=False)
     body = db.Column(db.Text, nullable=False)
     read_at = db.Column(db.DateTime, nullable=True)
-    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
+    created_at = db.Column(db.DateTime, default=utcnow, nullable=False)
 
     conversation = db.relationship("Conversation", back_populates="messages")
     sender = db.relationship("User",
@@ -70,7 +71,7 @@ class Message(db.Model):
 
     def mark_read(self):
         if self.read_at is None:
-            self.read_at = datetime.utcnow()
+            self.read_at = utcnow()
 
     def __repr__(self):
         return f"<Message {self.id} C{self.conversation_id}>"