[models] extract common fields into mixin

src/teilchensammler_cli/models.py

@@ -1,18 +1,19 @@
-from typing import final
+from datetime import datetime
 
 from tortoise import Model, fields
 
 
-@final
-class Teilchen(Model):
-    name = fields.TextField()
-    description = fields.TextField()
-    number = fields.IntField()  # validate values >= 0
+class TimestampMixin:
+    created_at: fields.Field[datetime] = fields.DatetimeField(auto_now_add=True)
+    modified_at: fields.Field[datetime] = fields.DatetimeField(auto_now=True)
 
-    created_at = fields.DatetimeField(auto_now_add=True)
-    modified_at = fields.DatetimeField(auto_now=True)
 
-    tags = fields.ManyToManyField(
+class Teilchen(TimestampMixin, Model):
+    name: fields.Field[str] = fields.TextField()
+    description: fields.Field[str] = fields.TextField()
+    number: fields.Field[int] = fields.IntField()  # TODO: validate values >= 0
+
+    tags: fields.ManyToManyRelation["Tag"] = fields.ManyToManyField(
         "models.Tag",
         through="models.TeilchenTag",
         related_name="teilchen",
@@ -21,18 +22,13 @@ class Teilchen(Model):
     )
 
 
-@final
-class Tag(Model):
-    name = fields.CharField(max_length=20)
-
-    created_at = fields.DatetimeField(auto_now_add=True)
-    modified_at = fields.DatetimeField(auto_now=True)
+class Tag(TimestampMixin, Model):
+    name: fields.Field[str] = fields.CharField(max_length=20)
 
 
-@final
 class TeilchenTag(Model):
     teilchen: fields.ForeignKeyRelation[Teilchen] = fields.ForeignKeyField(
         "models.Teilchen"
     )
     tag: fields.ForeignKeyRelation[Tag] = fields.ForeignKeyField("models.Tag")
-    weight = fields.IntField()
+    weight: fields.Field[int] = fields.IntField()  # range? percentage?