Add created and modified times #11

object_storage_api/models/attachment.py

@@ -1,15 +1,27 @@
 """
-Module for defining the database models for representing attachments
+Module for defining the database models for representing attachments.
 """
 
 from typing import Optional
 
 from pydantic import BaseModel, ConfigDict, Field
 
 from object_storage_api.models.custom_object_id_data_types import CustomObjectIdField, StringObjectIdField
+from object_storage_api.models.mixins import CreatedModifiedTimeInMixin, CreatedModifiedTimeOutMixin
 
 
-class AttachmentIn(BaseModel):
+class AttachmentBase(BaseModel):
+    """
+    Base database model for an attachment.
+    """
+
+    file_name: str
+    object_key: str
+    title: Optional[str] = None
+    description: Optional[str] = None
+
+
+class AttachmentIn(CreatedModifiedTimeInMixin, AttachmentBase):
     """
     Input database model for an attachment.
     """
@@ -18,13 +30,9 @@ class AttachmentIn(BaseModel):
     # `object_key``) we must manually specify the id rather than relying on MongoDB to do it.
     id: CustomObjectIdField = Field(serialization_alias="_id")
     entity_id: CustomObjectIdField
-    file_name: str
-    object_key: str
-    title: Optional[str] = None
-    description: Optional[str] = None
 
 
-class AttachmentOut(AttachmentIn):
+class AttachmentOut(CreatedModifiedTimeOutMixin, AttachmentBase):
     """
     Output database model for an attachment.
     """

object_storage_api/models/mixins.py

@@ -0,0 +1,51 @@
+"""
+Module for defining the database models mixins to be inherited from to provide specific fields
+and functionality.
+"""
+
+# pylint:disable=fixme
+# TODO: This file is identical to the one in inventory-management-system-api - Use common repo?
+
+from datetime import datetime, timezone
+from typing import Optional
+
+from pydantic import AwareDatetime, BaseModel, Field, model_validator
+
+
+class CreatedModifiedTimeInMixin(BaseModel):
+    """
+    Input model mixin that provides creation and modified time fields
+
+    For a create request an instance of the model should be created without supplying the `created_time` field
+    as this will cause it to be assigned as the current time.
+    When updating, the `created_time` time should be given so that it is kept the same. The `modified_time` will be
+    assigned regardless as it is assumed that a new instance will be created only when creating/updating a
+    database entry.
+    """
+
+    created_time: AwareDatetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    modified_time: Optional[AwareDatetime] = None
+
+    @model_validator(mode="after")
+    def validator(self) -> "CreatedModifiedTimeInMixin":
+        """
+        Validator that assigns the created_time and modified_time times.
+
+        When `modified_time` is None, which occurs when not assigning data from an existing database model this
+        assigns the `modified_time` time to be the same as the `created_time` to ensure they are identical. When
+        `modified_time` is defined then it is reassigned as its assumed it already exists and is now being updated.
+        """
+        if self.modified_time is None:
+            self.modified_time = self.created_time
+        else:
+            self.modified_time = datetime.now(timezone.utc)
+        return self
+
+
+class CreatedModifiedTimeOutMixin(BaseModel):
+    """
+    Output model mixin that provides creation and modified time fields
+    """
+
+    created_time: AwareDatetime
+    modified_time: AwareDatetime

object_storage_api/schemas/attachment.py

@@ -6,6 +6,8 @@
 
 from pydantic import BaseModel, Field, HttpUrl
 
+from object_storage_api.schemas.mixins import CreatedModifiedSchemaMixin
+
 
 class AttachmentPostSchema(BaseModel):
     """
@@ -18,7 +20,7 @@ class AttachmentPostSchema(BaseModel):
     description: Optional[str] = Field(default=None, description="Description of the attachment")
 
 
-class AttachmentPostResponseSchema(AttachmentPostSchema):
+class AttachmentPostResponseSchema(CreatedModifiedSchemaMixin, AttachmentPostSchema):
     """
     Schema model for the response to an attachment creation request
     """

object_storage_api/schemas/mixins.py

@@ -0,0 +1,17 @@
+"""
+Module for defining the schema mixins to be inherited from to provide specific fields
+"""
+
+from pydantic import AwareDatetime, BaseModel, Field
+
+# pylint:disable=fixme
+# TODO: This file is identical to the one in inventory-management-system-api - Use common repo?
+
+
+class CreatedModifiedSchemaMixin(BaseModel):
+    """
+    Output schema mixin that provides creation and modified time fields
+    """
+
+    created_time: AwareDatetime = Field(description="The date and time this entity was created")
+    modified_time: AwareDatetime = Field(description="The date and time this entity was last updated")