Merge pull request #211 from hotosm/feat/unlock-task-if-locked

Feat: add task reset feature for drone operators

src/backend/app/models/enums.py

@@ -161,6 +161,7 @@ class EventType(str, Enum):
     - ``split`` -- Set the state *unlocked done* then generate additional subdivided task areas.
     - ``assign`` -- For a requester user to assign a task to another user. Set the state *locked for mapping* passing in the required user id.
     - ``comment`` -- Keep the state the same, but simply add a comment.
+    - ``unlock`` -- Unlock a task state by unlocking it if it's locked.
 
     Note that ``task_id`` must be specified in the endpoint too.
     """
@@ -175,3 +176,4 @@ class EventType(str, Enum):
     SPLIT = "split"
     ASSIGN = "assign"
     COMMENT = "comment"
+    UNLOCK = "unlock"

src/backend/app/tasks/task_logic.py

@@ -128,3 +128,41 @@ async def request_mapping(
         )
         result = await cur.fetchone()
         return result
+
+
+async def get_task_state(
+    db: Connection, project_id: uuid.UUID, task_id: uuid.UUID
+) -> dict:
+    """
+    Retrieve the latest state of a task by querying the task_events table.
+
+    Args:
+        db (Connection): The database connection.
+        project_id (uuid.UUID): The project ID.
+        task_id (uuid.UUID): The task ID.
+
+    Returns:
+        dict: A dictionary containing the task's state and associated metadata.
+    """
+    try:
+        async with db.cursor(row_factory=dict_row) as cur:
+            await cur.execute(
+                """
+                SELECT state, user_id, created_at, comment
+                FROM task_events
+                WHERE project_id = %(project_id)s AND task_id = %(task_id)s
+                ORDER BY created_at DESC
+                LIMIT 1;
+                """,
+                {
+                    "project_id": str(project_id),
+                    "task_id": str(task_id),
+                },
+            )
+            result = await cur.fetchone()
+            return result
+    except Exception as e:
+        raise HTTPException(
+            status_code=500,
+            detail=f"An error occurred while retrieving the task state: {str(e)}",
+        )

src/backend/app/tasks/task_routes.py

@@ -368,4 +368,36 @@ async def new_event(
                 State.UNFLYABLE_TASK,
             )
 
+        case EventType.UNLOCK:
+            # Fetch the task state
+            current_task_state = await task_logic.get_task_state(
+                db, project_id, task_id
+            )
+
+            state = current_task_state.get("state")
+            locked_user_id = current_task_state.get("user_id")
+
+            # Determine error conditions
+            if state != State.LOCKED_FOR_MAPPING.name:
+                raise HTTPException(
+                    status_code=400,
+                    detail="Task state does not match expected state for unlock operation.",
+                )
+            if user_id != locked_user_id:
+                raise HTTPException(
+                    status_code=403,
+                    detail="You cannot unlock this task as it is locked by another user.",
+                )
+
+            # Proceed with unlocking the task
+            return await task_logic.update_task_state(
+                db,
+                project_id,
+                task_id,
+                user_id,
+                f"Task has been unlock by user {user_data.name}.",
+                State.LOCKED_FOR_MAPPING,
+                State.UNLOCKED_TO_MAP,
+            )
+
     return True