Added pulling notifications from new backend-pull-notifications service

src/main.py

@@ -3,7 +3,7 @@ from fastapi.responses import JSONResponse
 from fastapi.security.api_key import APIKeyHeader
 from starlette.exceptions import HTTPException as StarletteHTTPException
 from typing import Dict
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 from validator import verify_api_key
 from db_module import get_db, create_connection_pool, close_connection_pool, start_healthcheck_thread
 from simple_logger_handler import setup_logger, LOG_LEVEL
@@ -14,15 +14,29 @@ from metrics_server import REQUEST_COUNTER
 import asyncio
 from uvicorn_logger_config import LOGGING_CONFIG
 from secret_manager import cleanup_secret_files
+import httpx
+import os
+
 
 logger = setup_logger(__name__)
 api_key_header_internal = APIKeyHeader(name="X-API-Key-Internal")
+PULL_SERVICE_URL = os.getenv(
+	"BACKEND_PULL_NOTIFICATIONS_URL",
+	"http://backend-pull-notifications.app-notifications.svc.cluster.local:8101",
+)
+MAX_PAGES = 5
 
 class Notification(BaseModel):
-	receipent_user_id : int
+	receipent_user_id : int = Field(gt=0) #ToDo fix among all services
 	message : Dict
 
+class PullResponse(BaseModel):
+	messages: list[dict]
+	count: int
+	has_more: bool
 
+class PullRequest(BaseModel):
+	user_id: int = Field(gt=0)
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
@@ -41,6 +55,12 @@ async def lifespan(app: FastAPI):
 		app.state.rmq_producer = producer
 		logger.info("[FastAPI] RabbitMQ producer initialized.")
 
+		app.state.http_client = httpx.AsyncClient (
+			base_url=PULL_SERVICE_URL,
+			timeout=httpx.Timeout(10.0,connect=3.0)
+		)
+		logger.info("[FastAPI] HTTP client initialized.")
+
 		SECRET_PATHS = frozenset({
 			"/etc/secrets/db_username",
 			"/etc/secrets/db_password",
@@ -57,6 +77,9 @@ async def lifespan(app: FastAPI):
 		logger.info("Closing MySQL connection pool...")
 		close_connection_pool()
 
+		await app.state.http_client.aclose()
+		logger.info("[FastAPI] Closing Http client")
+
 api = FastAPI(
 		title="Internal Notifier API",
 		description="API to forward messages to RabbitMQ",
@@ -104,7 +127,7 @@ async def custom_http_exception_handler(request,exc):
 		content={"detail": exc.detail}
 	)
 
-@api.post("/internal/receive-notifications")
+@api.post("/internal/receive-notifications") #ToDo fix among all services
 async def receive_notifications(
 	notification_data: Notification,
 	request: Request,
@@ -121,6 +144,37 @@ async def receive_notifications(
 	logger.info("Successfully queued for delivery to RMQ")
 	return {"status": "queued"}
 
+@api.post("/internal/pull-notifications", response_model=PullResponse)
+async def pull_notifications(
+	pull_request: PullRequest,
+	request: Request,
+	program_name: str = Depends(verify_api_key_dependency_internal),
+):
+	user_id = pull_request.user_id
+	logger.debug(f"[FastAPI] User id {user_id} is requesting messages")
+	client: httpx.AsyncClient = request.app.state.http_client
+
+	messages: list[dict] = []
+	has_more = False
+
+	try:
+		for _ in range(MAX_PAGES):
+			resp = await client.post("/internal/pull-notifications", json={"user_id": user_id})
+			resp.raise_for_status()
+			data = PullResponse.model_validate(resp.json())
+
+			messages.extend(data.messages)
+			has_more = data.has_more
+			if not has_more:
+				break
+	except (httpx.HTTPError, ValueError) as e:
+		logger.error(f"[FastAPI] Pull service failed for user_id={user_id}: {e!r}")
+		status = 504 if isinstance(e, httpx.TimeoutException) else 502
+		raise HTTPException(status_code=status, detail="Notification service unavailable")
+
+	logger.info(f"[FastAPI] Returning {len(messages)} message(s) for user_id={user_id}, has_more={has_more}")
+	return PullResponse(messages=messages, count=len(messages), has_more=has_more)
+
 async def start_servers():
 	logger.debug("Starting FastAPI and metrics servers")
 	config_main = uvicorn.Config("main:api", host="0.0.0.0", port=8101, log_level=LOG_LEVEL.lower(), log_config=LOGGING_CONFIG)