add job queue :)

Author: Kerushani

backend/python/app/__init__.py

@@ -1,18 +1,22 @@
 from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
 from logging.config import dictConfig
+import asyncio
 
 import firebase_admin
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.dependencies.services import get_scheduler_service
 from app.services.jobs import init_jobs
+from app.workers.job_worker import JobWorker
 
 from .config import settings
 from .models import init_app as init_models
 from .routers import init_app as init_routers
 
+job_worker: JobWorker | None = None
+
 
 def configure_logging() -> None:
     """Configure application logging based on environment"""
@@ -117,6 +121,8 @@ def initialize_firebase() -> None:
 @asynccontextmanager
 async def lifespan(_app: FastAPI) -> AsyncGenerator[None, None]:
     """Application lifespan management"""
+    global job_worker
+    
     # Startup
     configure_logging()
     initialize_firebase()
@@ -126,11 +132,28 @@ async def lifespan(_app: FastAPI) -> AsyncGenerator[None, None]:
     scheduler_service = get_scheduler_service()
     scheduler_service.start()
     init_jobs(scheduler_service)
+    
+    job_worker = JobWorker(
+        poll_interval=5,
+        job_timeout_minutes=30,
+        enable_orphan_recovery=True
+    )
+    
+    worker_task = asyncio.create_task(job_worker.start())
 
     yield
 
-    # Cleanup: stop the scheduler service during application shutdown
     scheduler_service.stop()
+    
+    if job_worker:
+        job_worker.stop()
+    
+    worker_task.cancel()
+    try:
+        await worker_task
+    except asyncio.CancelledError:
+        # Expected during shutdown - task was cancelled gracefully
+        pass
 
 
 def create_app() -> FastAPI:

backend/python/app/models/enum.py

@@ -28,6 +28,7 @@ class RoleEnum(str, Enum):
 
 class ProgressEnum(str, Enum):
     PENDING = "Pending"
+    QUEUED = "Queued"
     RUNNING = "Running"
     COMPLETED = "Completed"
     FAILED = "Failed"

backend/python/app/services/implementations/job_service.py

@@ -47,23 +47,30 @@ async def get_job(self, job_id: UUID) -> Job | None:
         return result.scalar_one_or_none()
 
     async def update_progress(self, job_id: UUID, progress: ProgressEnum) -> None:
+        """Update job progress and set timestamps appropriately"""
         try:
             job = await self.get_job(job_id)
             if not job:
                 self.logger.error("No job with corresponding job ID")
                 return
             job.progress = progress
             job.updated_at = self.utc_now_naive()
+            
+            if progress == ProgressEnum.RUNNING and job.started_at is None:
+                job.started_at = self.utc_now_naive()
+            
             if progress in (ProgressEnum.COMPLETED, ProgressEnum.FAILED):
                 job.finished_at = self.utc_now_naive()
+            
             self.session.add(job)
             await self.session.commit()
         except Exception as error:
-            self.logger.error("Error creating job")
+            self.logger.error("Error updating job progress")
             await self.session.rollback()
             raise error
 
     async def enqueue(self, job_id: UUID) -> None:
+        """Move job from PENDING to QUEUED (ready for worker to pick up)"""
         try:
             job = await self.get_job(job_id)
 
@@ -79,8 +86,8 @@ async def enqueue(self, job_id: UUID) -> None:
                 )
                 return
 
-            job.progress = ProgressEnum.RUNNING
-            job.started_at = self.utc_now_naive()
+            job.progress = ProgressEnum.QUEUED
+            job.updated_at = self.utc_now_naive()
             self.session.add(job)
             await self.session.commit()
         except Exception: