added CreatedDateTimeBase, renamed column, edited migration

tested migration manually

files/classes/base.py

@@ -1,9 +1,10 @@
 import time
 from datetime import datetime, timedelta, timezone
 
+from sqlalchemy import text
 from sqlalchemy.orm import declarative_base, declared_attr
 from sqlalchemy.schema import Column
-from sqlalchemy.sql.sqltypes import Integer
+from sqlalchemy.sql.sqltypes import Integer, DateTime
 
 from files.helpers.time import format_age, format_datetime
 
@@ -45,3 +46,80 @@ class CreatedBase(Base):
 	@property
 	def age_string(self) -> str:
 		return format_age(self.created_utc)
+
+
+class CreatedDateTimeBase(Base):
+	"""
+	An abstract class extending our default SQLAlchemy's `Base`.
+
+	All classes inherit from this class automatically maps a `created_datetimez` column
+	for the corresponding SQL table. This column will automatically record the created
+	timestamp of rows. Retrieving `created_datetimez` will return a `datetime` object with 
+	`tzinfo` of UTC.
+
+	This class holds various convenience properties to get `created_datetimez` in different
+	formats.
+	"""
+	__abstract__ = True
+
+	def __init__(self, *args, **kwargs):
+		super().__init__(*args, **kwargs)
+	
+	@declared_attr
+	def created_datetimez(self):
+		"""
+		Retrieving `created_datetimez` will return a `datetime` object with `tzinfo` for UTC.
+		"""
+		return Column(DateTime(timezone=True), nullable=False, server_default=text("now()"))
+
+	@property
+	def created_utc(self):
+		"""
+		the created date in UTC seconds. Milliseconds are truncated/rounded down.
+		"""
+		return int(self.created_datetimez.timestamp())
+	
+	@property
+	def created_date(self) -> str:
+		"""
+		the created date in string.
+		See `file.helpers.time.DATETIME_FORMAT` for the exact format
+		Note: should this be using `format_date` and not `format_datetime`?
+		"""
+		return self.created_datetime
+	
+	@property
+	def created_datetime(self) -> str:
+		"""
+		the created datetime in string.
+		See `file.helpers.time.DATETIME_FORMAT` for the exact format.
+		"""
+		return format_datetime(self.created_datetimez)
+	
+	@property
+	def created_datetime_py(self) -> datetime:
+		"""
+		the created datetime as a `datetime` object with `tzinfo` of UTC.
+		"""
+		return self.created_datetimez
+	
+	@property
+	def age_seconds(self) -> int:
+		"""
+		number of seconds since created.
+		"""
+		return time.time() - self.created_utc
+	
+	@property
+	def age_timedelta(self) -> timedelta:
+		"""
+		a `timedelta` object representing time since created.
+		"""
+		return datetime.now(tz=timezone.utc) - self.created_datetimez
+
+	@property
+	def age_string(self) -> str:
+		"""
+		a string representing time since created. Example: "1h ago", "2d ago".
+		"""
+		return format_age(self.created_datetimez)