feat(migrations): downgrade

Author: janbritz

questionpy_common/api/qtype.py

@@ -68,6 +68,10 @@ def create_question_from_state(self, question_state: str) -> QuestionInterface:
     def upgrade(self, question_state: str) -> str:
         """Upgrade the given question state to the question state version of the main package."""
 
+    @abstractmethod
+    def downgrade(self, question_state: str, to: int) -> str:
+        """Downgrade the given question state to the provided question state version of the main package."""
+
     @abstractmethod
     def sidegrade(self, question_state: str) -> str:
         """Sidegrade the given question state to the version used by the main package."""

questionpy_server/models.py

@@ -89,6 +89,11 @@ class QuestionUpgradeArguments(RequestBaseData):
     question_state: str
 
 
+class QuestionDowngradeArguments(RequestBaseData):
+    question_state: str
+    to: int
+
+
 class QuestionSidegradeArguments(RequestBaseData):
     question_state: str
 

questionpy_server/web/_routes/_packages.py

@@ -7,6 +7,7 @@
 from questionpy_common.api.question import LmsPermissions
 from questionpy_server.models import (
     QuestionCreateArguments,
+    QuestionDowngradeArguments,
     QuestionEditFormResponse,
     QuestionSidegradeArguments,
     QuestionUpgradeArguments,
@@ -91,6 +92,17 @@ async def post_question_upgrade(request: web.Request, package: Package, data: Qu
     return pydantic_json_response(data=new_question_state)
 
 
+@package_routes.post(r"/packages/{package_hash:\w+}/question/downgrade")
+@ensure_required_parts
+async def post_question_downgrade(
+    request: web.Request, package: Package, data: QuestionDowngradeArguments
+) -> web.Response:
+    async with worker_context(request, package, data) as context:
+        new_question_state = await context.worker.downgrade_question(context.request_info, data.question_state, data.to)
+
+    return pydantic_json_response(data=new_question_state)
+
+
 @package_routes.post(r"/packages/{package_hash:\w+}/question/sidegrade")
 @ensure_required_parts
 async def post_question_sidegrade(

questionpy_server/worker/__init__.py

@@ -163,6 +163,20 @@ async def upgrade_question(self, request_info: RequestInfo, question_state: str)
             Migrated question state.
         """
 
+    @abstractmethod
+    async def downgrade_question(self, request_info: RequestInfo, question_state: str, to: int) -> QuestionMigrated:
+        """Downgrade the given question state to the question state version of this package.
+
+        Args:
+            request_info: Information about the current request.
+            question_state: The question state with the same question state version as this package which should be
+                            downgraded.
+            to: The question state version to downgrade to.
+
+        Returns:
+            Migrated question state.
+        """
+
     @abstractmethod
     async def sidegrade_question(self, request_info: RequestInfo, question_state: str) -> QuestionMigrated:
         """Sidegrade the given question state to the question state version of this package.

questionpy_server/worker/impl/_base.py

@@ -34,6 +34,7 @@
 from questionpy_server.worker.runtime.messages import (
     BaseWorkerError,
     CreateQuestionFromOptions,
+    DowngradeQuestion,
     Exit,
     GetOptionsForm,
     GetQPyPackageManifest,
@@ -262,6 +263,16 @@ async def upgrade_question(self, request_info: RequestInfo, question_state: str)
 
         return QuestionMigrated(question_state=ret.question_state)
 
+    async def downgrade_question(self, request_info: RequestInfo, question_state: str, to: int) -> QuestionMigrated:
+        msg = DowngradeQuestion(
+            request_info=request_info,
+            question_state=question_state,
+            target_question_state_version=to,
+        )
+        ret = await self.send_and_wait_for_response(msg, DowngradeQuestion.Response)
+
+        return QuestionMigrated(question_state=ret.question_state)
+
     async def sidegrade_question(self, request_info: RequestInfo, question_state: str) -> QuestionMigrated:
         msg = SidegradeQuestion(
             request_info=request_info,

questionpy_server/worker/runtime/manager.py

@@ -26,6 +26,7 @@
 from questionpy_server.worker.runtime.connection import WorkerToServerConnection
 from questionpy_server.worker.runtime.messages import (
     CreateQuestionFromOptions,
+    DowngradeQuestion,
     Exit,
     GetOptionsForm,
     GetQPyPackageManifest,
@@ -117,6 +118,7 @@ def __init__(self, server_connection: WorkerToServerConnection):
             GetOptionsForm.message_id: self.on_msg_get_options_form_definition,
             CreateQuestionFromOptions.message_id: self.on_msg_create_question_from_options,
             UpgradeQuestion.message_id: self.on_msg_upgrade_question,
+            DowngradeQuestion.message_id: self.on_msg_downgrade_question,
             SidegradeQuestion.message_id: self.on_msg_sidegrade_question,
             StartAttempt.message_id: self.on_msg_start_attempt,
             ViewAttempt.message_id: self.on_msg_view_attempt,
@@ -269,6 +271,18 @@ def on_msg_upgrade_question(self, msg: UpgradeQuestion) -> UpgradeQuestion.Respo
             migrated_question_state = self._question_type.upgrade(msg.question_state)
             return UpgradeQuestion.Response(question_state=migrated_question_state)
 
+    def on_msg_downgrade_question(self, msg: DowngradeQuestion) -> DowngradeQuestion.Response:
+        if not self._env:
+            self._raise_not_initialized(msg)
+        if not self._question_type:
+            self._raise_no_main_package_loaded(msg)
+
+        with self._with_request_info(msg, msg.request_info):
+            migrated_question_state = self._question_type.downgrade(
+                msg.question_state, msg.target_question_state_version
+            )
+            return DowngradeQuestion.Response(question_state=migrated_question_state)
+
     def on_msg_sidegrade_question(self, msg: SidegradeQuestion) -> SidegradeQuestion.Response:
         if not self._env:
             self._raise_not_initialized(msg)

questionpy_server/worker/runtime/messages.py

@@ -38,6 +38,7 @@ class MessageIds(IntEnum):
 
     CREATE_QUESTION = 40
     UPGRADE_QUESTION = 41
+    DOWNGRADE_QUESTION = 42
     SIDEGRADE_QUESTION = 43
 
     START_ATTEMPT = 50
@@ -54,6 +55,7 @@ class MessageIds(IntEnum):
 
     RETURN_CREATE_QUESTION = 1040
     RETURN_UPGRADE_QUESTION = 1041
+    RETURN_DOWNGRADE_QUESTION = 1042
     RETURN_SIDEGRADE_QUESTION = 1043
 
     RETURN_START_ATTEMPT = 1050
@@ -223,6 +225,17 @@ class Response(MessageToServer):
         question_state: str
 
 
+class DowngradeQuestion(MessageToWorker):
+    message_id: ClassVar[MessageIds] = MessageIds.DOWNGRADE_QUESTION
+    request_info: RequestInfo
+    question_state: str
+    target_question_state_version: int
+
+    class Response(MessageToServer):
+        message_id: ClassVar[MessageIds] = MessageIds.RETURN_DOWNGRADE_QUESTION
+        question_state: str
+
+
 class SidegradeQuestion(MessageToWorker):
     message_id: ClassVar[MessageIds] = MessageIds.SIDEGRADE_QUESTION
     request_info: RequestInfo