apply discussed changes in one go

src/blueapi/service/handler.py

@@ -115,6 +115,9 @@ def begin_task(self, task: WorkerTask) -> WorkerTask:
             self._worker.begin_task(task.task_id)
         return task
 
+    def get_tasks_by_status(self, status:str) -> list[TrackableTask[Task]]:
+       return self._worker.get_tasks_by_status(status) 
+
     @property
     def active_task(self) -> TrackableTask | None:
         return self._worker.get_active_task()

src/blueapi/service/handler_base.py

@@ -49,6 +49,16 @@ def clear_task(self, task_id: str) -> str:
     def begin_task(self, task: WorkerTask) -> WorkerTask:
         """Trigger a task. Will fail if the worker is busy"""
 
+    @abstractmethod
+    def get_tasks_by_status(self, status: str) -> list[TrackableTask[Task]]:
+        """
+        Retrieve a list of tasks based on their status.
+        Args:
+           str: The status to filter tasks by.
+        Returns:
+          list[TrackableTask[T]]: A list of tasks that match the given status.
+        """
+
     @property
     @abstractmethod
     def active_task(self) -> TrackableTask | None:

src/blueapi/service/main.py

@@ -6,6 +6,7 @@
     Depends,
     FastAPI,
     HTTPException,
+    Query,
     Request,
     Response,
     status,
@@ -154,6 +155,21 @@ def submit_task(
         ) from e
 
 
+@app.get("/tasks")
+def get_tasks(
+    status: str = Query("unstarted", description="The status of the tasks to retrieve"),
+    handler: BlueskyHandler = Depends(get_handler),
+) -> list[TrackableTask]:
+    """
+    Retrieve tasks based on their status. The default status is 'unstarted'.
+    """
+    try:
+        tasks = handler.get_tasks_by_status(status)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))  # noqa: B904
+    return tasks
+
+
 @app.delete("/tasks/{task_id}", status_code=status.HTTP_200_OK)
 def delete_submitted_task(
     task_id: str,

src/blueapi/worker/reworker.py

@@ -28,7 +28,7 @@
 )
 from .multithread import run_worker_in_own_thread
 from .task import Task
-from .worker import TrackableTask, Worker
+from .worker import TaskStatusEnum, TrackableTask, Worker
 from .worker_errors import WorkerAlreadyStartedError, WorkerBusyError
 
 LOGGER = logging.getLogger(__name__)
@@ -136,6 +136,20 @@ def submit_task(self, task: Task) -> str:
         self._tasks[task_id] = trackable_task
         return task_id
 
+    def get_tasks_by_status(self, status: TaskStatusEnum) -> list[TrackableTask[Task]]:
+        if status == TaskStatusEnum.UNDERWAY:
+            return [
+                task
+                for task in self._tasks.values()
+                if not task.is_complete and not task.is_pending
+            ]
+        elif status == TaskStatusEnum.PENDING:
+            return [task for task in self._tasks.values() if task.is_pending]
+        elif status == TaskStatusEnum.COMPLETE:
+            return [task for task in self._tasks.values() if task.is_complete]
+        else:
+            raise ValueError("Unknown status")
+
     def _submit_trackable_task(self, trackable_task: TrackableTask) -> None:
         if self.state is not WorkerState.IDLE:
             raise WorkerBusyError(f"Worker is in state {self.state}")

src/blueapi/worker/worker.py

@@ -1,4 +1,5 @@
 from abc import ABC, abstractmethod
+from enum import Enum
 from typing import Generic, TypeVar
 
 from pydantic import Field
@@ -11,6 +12,13 @@
 T = TypeVar("T")
 
 
+class TaskStatusEnum(str, Enum):
+    PENDING = "PENDING"
+    COMPLETE = "COMPLETE"
+    ERROR = "ERROR"
+    UNDERWAY = "UNDERWAY"
+
+
 class TrackableTask(BlueapiBaseModel, Generic[T]):
     """
     A representation of a task that the worker recognizes
@@ -107,6 +115,16 @@ def submit_task(self, task: T) -> str:
             str: A unique ID to refer to this task
         """
 
+    @abstractmethod
+    def get_tasks_by_status(self, status: str) -> list[TrackableTask[T]]:
+        """
+        Retrieve a list of tasks based on their status.
+        Args:
+           str: The status to filter tasks by.
+        Returns:
+          list[TrackableTask[T]]: A list of tasks that match the given status.
+        """
+
     @abstractmethod
     def start(self) -> None:
         """

tests/service/test_rest_api.py

@@ -14,6 +14,7 @@
 from blueapi.service.model import WorkerTask
 from blueapi.worker import WorkerState
 from blueapi.worker.task import Task
+from blueapi.worker.worker import TrackableTask
 
 _TASK = Task(name="count", params={"detectors": ["x"]})
 
@@ -223,6 +224,38 @@ def test_put_plan_begins_task(handler: Handler, client: TestClient) -> None:
     handler.stop()
 
 
+tasks_data = [
+    TrackableTask(
+        task_id="1", task=Task(name="first_task"), is_complete=False, is_pending=False
+    ),
+    TrackableTask(
+        task_id="2", task=Task(name="first_task"), is_complete=False, is_pending=True
+    ),
+]
+
+
+def test_get_unstarted_tasks(handler: Handler, client: TestClient):
+    handler.start()
+    # handler.tasks = tasks_data  # overriding the property
+    handler._worker.get_tasks_by_status = Mock(return_value=tasks_data)
+    response = client.get("/tasks?status=unstarted")
+    assert response.status_code == 200
+    assert (
+        len(response.json()) == 1
+    )  # As per our mock data, only 1 task should be 'unstarted'
+    assert (
+        response.json()[0]["task_id"] == "1"
+    )  # Check that the correct task ID is returned
+
+
+def test_get_tasks_bad_status(handler: Handler, client: TestClient):
+    handler.start()
+    # handler.tasks = tasks_data
+    handler._worker.get_tasks_by_status = Mock(return_value=tasks_data)
+    response = client.get("/tasks?status=invalid")
+    assert response.status_code == 400
+    assert "Unsupported status" in response.json()["detail"]
+
 def test_worker_task_is_none_on_startup(handler: Handler, client: TestClient) -> None:
     handler.start()
     resp = client.get("/worker/task")