reorganize changes module into overlay and operations

src/c3nav/editor/operations.py

@@ -0,0 +1,74 @@
+import datetime
+from typing import TypeAlias, Any, Annotated, Literal, Union
+
+from django.db import models
+from django.utils import timezone
+from pydantic.config import ConfigDict
+from pydantic.fields import Field
+from pydantic.types import Discriminator
+
+from c3nav.api.schema import BaseSchema
+
+FieldValuesDict: TypeAlias = dict[str, Any]
+
+
+class ObjectReference(BaseSchema):
+    model_config = ConfigDict(frozen=True)
+    model: str
+    id: int
+
+    @classmethod
+    def from_instance(cls, instance: models.Model):
+        """
+        This method will not convert the ID yet!
+        """
+        return cls(model=instance._meta.model_name, id=instance.pk)
+
+
+class BaseOperation(BaseSchema):
+    obj: ObjectReference
+    datetime: Annotated[datetime.datetime, Field(default_factory=timezone.now)]
+
+
+class CreateObjectOperation(BaseOperation):
+    type: Literal["create"] = "create"
+    fields: FieldValuesDict
+
+
+class UpdateObjectOperation(BaseOperation):
+    type: Literal["update"] = "update"
+    fields: FieldValuesDict
+
+
+class DeleteObjectOperation(BaseOperation):
+    type: Literal["delete"] = "delete"
+
+
+class UpdateManyToManyOperation(BaseOperation):
+    type: Literal["m2m_add"] = "m2m_update"
+    field: str
+    add_values: set[int] = set()
+    remove_values: set[int] = set()
+
+
+class ClearManyToManyOperation(BaseOperation):
+    type: Literal["m2m_clear"] = "m2m_clear"
+    field: str
+
+
+DatabaseOperation = Annotated[
+    Union[
+        CreateObjectOperation,
+        UpdateObjectOperation,
+        DeleteObjectOperation,
+        UpdateManyToManyOperation,
+        ClearManyToManyOperation,
+    ],
+    Discriminator("type"),
+]
+
+
+class CollectedChanges(BaseSchema):
+    prev_reprs: dict[ObjectReference, str] = {}
+    prev_values: dict[ObjectReference, FieldValuesDict] = {}
+    operations: list[DatabaseOperation] = []