Fix database migration

backend/migration.py

@@ -104,8 +104,23 @@ def run_migrations():
         
         # Run the upgrade command
         logger.info("Running database migrations...")
+        try:
             command.upgrade(alembic_cfg, "head")
             logger.info("Database migrations completed successfully.")
+        except Exception as upgrade_error:
+            if "Can't locate revision identified by 'direct_creation'" in str(upgrade_error):
+                logger.info("Found 'direct_creation' revision - resetting migration state...")
+                # Clear the alembic_version table and start fresh
+                engine = create_engine(DATABASE_URL)
+                with engine.connect() as connection:
+                    from sqlalchemy import text
+                    connection.execute(text("DELETE FROM alembic_version"))
+                    connection.commit()
+                # Try upgrade again
+                command.upgrade(alembic_cfg, "head")
+                logger.info("Database migrations completed successfully after reset.")
+            else:
+                raise upgrade_error
         
     except Exception as e:
         logger.error(f"Error running database migrations: {e}")
@@ -165,6 +180,16 @@ def _populate_migration_file(migration_path):
     with open(migration_path, 'r') as f:
         content = f.read()
     
+    # Add datetime import if needed
+    if "datetime.now" in migration_content and "from datetime import datetime" not in content:
+        # Insert the import after the existing imports
+        import re
+        content = re.sub(
+            r'(from alembic import op\nimport sqlalchemy as sa\n)',
+            r'\1from datetime import datetime\n',
+            content
+        )
+    
     # Replace the empty upgrade/downgrade functions
     import re
     # More flexible regex to match the actual content
@@ -184,6 +209,7 @@ def _generate_migration_from_models():
     """Generate migration content dynamically from SQLAlchemy models."""
     from models import Base
     import sqlalchemy as sa
+    from datetime import datetime
     
     # Generate migration content using Alembic's op functions
     upgrade_statements = []
@@ -202,15 +228,18 @@ def _generate_migration_from_models():
                     for statement in schema_diff['alter_statements']:
                         upgrade_statements.append(f"    {statement}")
                 else:
-                    # Table exists and is up to date
-                    upgrade_statements.append(f"    # Table {table_name} is already up to date")
+                    # Table exists and is up to date - skip creating it
+                    upgrade_statements.append(f"    # Table {table_name} already exists and is up to date")
             else:
                 # Generate CREATE TABLE for new table
                 table_code = _generate_table_creation_code(table_name, table)
                 upgrade_statements.append(f"    # Create {table_name} table")
                 upgrade_statements.append(table_code)
             
-            # Generate DROP TABLE statement for downgrade
+            # Only add to downgrade if table actually exists
+            if schema_diff['table_exists']:
+                downgrade_statements.append(f"    # op.drop_table('{table_name}')  # Skipped - table exists")
+            else:
                 downgrade_statements.append(f"    op.drop_table('{table_name}')")
     
     # Combine all statements
@@ -294,34 +323,51 @@ def _generate_table_creation_code(table_name, table):
     """Generate op.create_table code for a SQLAlchemy table."""
     lines = [f"    op.create_table('{table_name}',"]
     
+    # Collect all table items (columns + constraints)
+    all_items = []
+    
     # Add columns
     for column in table.columns:
         column_def = f"        sa.Column('{column.name}', {_get_column_type(column)}, nullable={column.nullable}"
         if column.default is not None:
+            # Handle callable defaults properly
+            if hasattr(column.default, 'arg') and callable(column.default.arg):
+                column_def += f", default=datetime.now"
+            else:
                 column_def += f", default={repr(column.default)}"
         column_def += ")"
-        lines.append(column_def)
+        all_items.append(column_def)
     
     # Add constraints
     for constraint in table.constraints:
         if hasattr(constraint, 'columns'):
             if constraint.__class__.__name__ == 'PrimaryKeyConstraint':
-                lines.append(f"        sa.PrimaryKeyConstraint('{constraint.columns.keys()[0]}')")
+                all_items.append(f"        sa.PrimaryKeyConstraint('{constraint.columns.keys()[0]}')")
             elif constraint.__class__.__name__ == 'UniqueConstraint':
                 cols = "', '".join(constraint.columns.keys())
-                lines.append(f"        sa.UniqueConstraint('{cols}')")
+                all_items.append(f"        sa.UniqueConstraint('{cols}')")
     
     # Add foreign key constraints
     for fk in table.foreign_keys:
-        lines.append(f"        sa.ForeignKeyConstraint(['{fk.parent.name}'], ['{fk.column.table.name}.{fk.column.name}'], )")
+        all_items.append(f"        sa.ForeignKeyConstraint(['{fk.parent.name}'], ['{fk.column.table.name}.{fk.column.name}'], )")
+    
+    # Add all items with commas (except the last one)
+    for i, item in enumerate(all_items):
+        if i < len(all_items) - 1:
+            item += ","
+        lines.append(item)
     
     lines.append("    )")
     
-    # Add indexes
+    # Add indexes with IF NOT EXISTS equivalent using try/except
     for index in table.indexes:
         if not index.unique:
             cols = "', '".join([col.name for col in index.columns])
+            lines.append(f"    # Create index for {table_name}")
+            lines.append(f"    try:")
             lines.append(f"        op.create_index(op.f('ix_{table_name}_{index.name}'), '{table_name}', ['{cols}'], unique=False)")
+            lines.append(f"    except Exception:")
+            lines.append(f"        pass  # Index may already exist")
     
     return "\n".join(lines)
 

backend/models.py

@@ -135,7 +135,7 @@ class DMReaction(Base):
     
     # Relationships
     user = relationship("User")
-    dm_envelope = relationship("DMEnvelope")
+    dm_envelope = relationship("DMEnvelope", overlaps="reactions")
     
     # Ensure unique combination of dm_envelope, user, and emoji
     __table_args__ = (UniqueConstraint('dm_envelope_id', 'user_id', 'emoji', name='unique_dm_reaction'),)