From d193bc05f18453a899b2e646c6f4431d89f71cc5 Mon Sep 17 00:00:00 2001
From: Florian <flo@meergans.org>
Date: Mon, 13 Oct 2025 11:35:07 +0200
Subject: [PATCH] First commit

---
 Dockerfile               | 11 +++++
 requirements.txt         | 21 +++++++++
 src/db.py                | 93 ++++++++++++++++++++++++++++++++++++++++
 src/logger_handler.py    | 13 ++++++
 src/rabbitmq_handler.py  | 87 +++++++++++++++++++++++++++++++++++++
 src/secret_handler.py    | 12 ++++++
 src/send_notification.py | 83 +++++++++++++++++++++++++++++++++++
 7 files changed, 320 insertions(+)
 create mode 100644 Dockerfile
 create mode 100644 requirements.txt
 create mode 100644 src/db.py
 create mode 100644 src/logger_handler.py
 create mode 100644 src/rabbitmq_handler.py
 create mode 100644 src/secret_handler.py
 create mode 100644 src/send_notification.py

diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..a54e052
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,11 @@
+FROM python:3.12-slim
+
+COPY requirements.txt .
+
+RUN pip install --no-cache-dir -r requirements.txt
+
+WORKDIR /app
+
+COPY src/ /app/
+
+ENTRYPOINT ["python","main.py"]
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..f5290a2
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,21 @@
+aio-pika==9.5.7
+aiodns==3.5.0
+aiohappyeyeballs==2.6.1
+aiohttp==3.13.0
+aiomysql==0.2.0
+aiormq==6.9.0
+aiosignal==1.4.0
+attrs==25.4.0
+Brotli==1.1.0
+cffi==2.0.0
+frozenlist==1.8.0
+idna==3.11
+multidict==6.7.0
+pamqp==3.3.0
+propcache==0.4.1
+pycares==4.11.0
+pycparser==2.23
+PyMySQL==1.1.2
+typing_extensions==4.15.0
+yarl==1.22.0
+zstandard==0.25.0
diff --git a/src/db.py b/src/db.py
new file mode 100644
index 0000000..8a22a68
--- /dev/null
+++ b/src/db.py
@@ -0,0 +1,93 @@
+import aiomysql
+import asyncio
+from secret_handler import return_credentials
+import os
+from logger_handler import setup_logger
+
+
+db_username = return_credentials("/etc/secrets/db_username")
+db_password = return_credentials("/etc/secrets/db_password")
+db_host = os.getenv("BACKEND_PN_DB_HOST","localhost")
+db_database = os.getenv("BACKEND_PN_DB_DATABASE","app")
+
+logger = setup_logger(__name__)
+
+
+class DBManager:
+	def __init__(self, host, user, password, db, port=3306, pool_size=5, health_interval=60):
+		self.host = host
+		self.user = user
+		self.password = password
+		self.db = db
+		self.port = port
+		self.pool_size = pool_size
+		self._pool: aiomysql.Pool | None = None
+		self._health_interval = health_interval
+		self._health_task: asyncio.Task | None = None
+		self._closing = False
+
+	async def connect(self):
+		self._pool = await aiomysql.create_pool(
+			host=self.host,
+			user=self.user,
+			password=self.password,
+			db=self.db,
+			port=self.port,
+			minsize=1,
+			maxsize=self.pool_size,
+			autocommit=True,
+			cursorclass=aiomysql.DictCursor
+		)
+		logger.info("[DB] Connection pool created")
+		self._health_task = asyncio.create_task(self._healthcheck_loop())
+
+	async def _healthcheck_loop(self):
+		while not self._closing:
+			await asyncio.sleep(self._health_interval)
+			try:
+				async with self.acquire() as conn:
+					async with conn.cursor() as cur:
+						await cur.execute("SELECT 1")
+				logger.debug("[DB] Healthcheck OK")
+			except Exception as e:
+				logger.warning(f"[DB] Healthcheck failed: {e}")
+
+	async def acquire(self):
+		if not self._pool:
+			raise RuntimeError("DB pool not initialized")
+		return await self._pool.acquire()
+
+	async def release(self, conn):
+		if self._pool:
+			self._pool.release(conn)
+
+	async def execute(self, query, *args, retries=3):
+		for attempt in range(1, retries + 1):
+			conn = await self.acquire()
+			try:
+				async with conn.cursor() as cur:
+					await cur.execute(query, args)
+					if cur.description:
+						return await cur.fetchall()
+					return None
+			except aiomysql.OperationalError as e:
+				logger.warning(f"[DB] Query failed (attempt {attempt}/{retries}): {e}")
+				await asyncio.sleep(2 ** (attempt - 1))
+			finally:
+				await self.release(conn)
+		raise RuntimeError("DB query failed after retries")
+
+	async def close(self):
+		self._closing = True
+		if self._health_task and not self._health_task.done():
+			self._health_task.cancel()
+			try:
+				await self._health_task
+			except asyncio.CancelledError:
+				pass
+		if self._pool:
+			self._pool.close()
+			await self._pool.wait_closed()
+			logger.info("[DB] Connection pool closed")
+
+db_manager = DBManager(host=db_host, port=3306, user=db_username, password=db_password, db=db_database)
\ No newline at end of file
diff --git a/src/logger_handler.py b/src/logger_handler.py
new file mode 100644
index 0000000..25c121d
--- /dev/null
+++ b/src/logger_handler.py
@@ -0,0 +1,13 @@
+import logging
+
+def setup_logger(name: str) -> logging.Logger:
+	logger = logging.getLogger(name)
+	if not logger.handlers:
+		handler = logging.StreamHandler()
+		formatter = logging.Formatter(
+			'%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+		)
+		handler.setFormatter(formatter)
+		logger.addHandler(handler)
+		logger.setLevel(logging.DEBUG)
+	return logger
diff --git a/src/rabbitmq_handler.py b/src/rabbitmq_handler.py
new file mode 100644
index 0000000..981d8cf
--- /dev/null
+++ b/src/rabbitmq_handler.py
@@ -0,0 +1,87 @@
+import asyncio
+import aio_pika
+from aio_pika.exceptions import AMQPException
+from secret_handler import return_credentials
+import os
+from logger_handler import setup_logger
+import json
+from db import db_manager
+from send_notification import send_notification
+
+logger = setup_logger(__name__)
+
+
+rmq_username = return_credentials("/etc/secrets/rmq_username")
+rmq_password = return_credentials("/etc/secrets/rmq_password")
+rmq_host = os.getenv("BACKEND_API_INTERNAL_RMQ_HOST", "localhost")
+rmq_vhost = os.getenv("BACKEND_API_INTERNAL_RMQ_VHOST", "app_notifications")
+rmq_exchange = os.getenv("BACKEND_API_INTERNAL_RMQ_EXCHANGE", "app_notifications")
+
+RABBITMQ_URL = f"amqp://{rmq_username}:{rmq_password}@{rmq_host}/{rmq_vhost}"
+
+
+class RabbitMQConsumer:
+	def __init__(self, url=RABBITMQ_URL, db_manager=db_manager, exchange_name=rmq_exchange):
+		self.url = url
+		self.exchange_name = exchange_name
+		self.connection: aio_pika.RobustConnection | None = None
+		self.channel: aio_pika.RobustChannel | None = None
+		self.exchange: aio_pika.Exchange | None = None
+		self.queue: aio_pika.Queue | None = None
+		self._closing = False
+		self.db_manager = db_manager
+
+	async def connect(self):
+		self.connection = await aio_pika.connect_robust(self.url)
+		self.channel = await self.connection.channel()
+		self.exchange = await self.channel.declare_exchange(
+			self.exchange_name, aio_pika.ExchangeType.TOPIC, durable=True
+		)
+		self.queue = await self.channel.declare_queue("backend_push_notifications", durable=True)
+		await self.queue.bind(self.exchange, routing_key="notify.user.*")
+		logger.info("[Consumer] Connected, queue bound to notify.user.*")
+
+	async def handle_message(self, message: aio_pika.IncomingMessage):
+		if self._closing:
+			return
+		async with message.process():
+			try:
+				data = json.loads(message.body.decode())
+				logger.info(f"[Consumer] Received: {data}")
+				await send_notification(routing_key=message.routing_key,message=data,db_manager=self.db_manager)
+			except json.JSONDecodeError as e:
+				logger.error(f"[Consumer] Bad message, discarding: {e}")
+				await message.nack(requeue=False)
+			except AMQPException as e:
+				logger.error(f"[Consumer] RabbitMQ error: {e}")
+				await message.nack(requeue=True)
+			except Exception as e:
+				logger.critical(f"[Consumer] Fatal error: {e}")
+				raise
+
+	async def consume(self):
+		if self._closing:
+			return
+		if not self.queue:
+			raise RuntimeError("Queue not initialized")
+		await self.queue.consume(self.handle_message, no_ack=False)
+		logger.info("[Consumer] Consuming messages...")
+
+	async def close(self):
+		self._closing = True
+		if self.connection:
+			await self.connection.close()
+			logger.info("[aio-pika] Connection closed.")
+
+
+
+async def main():
+	consumer = RabbitMQConsumer(db_manager=db_manager)
+	await consumer.connect()
+	logger.info("Creating MySQL connection pool...")
+	await db_manager.connect()
+
+
+if __name__ == "__main__":
+	asyncio.run(main())
+
diff --git a/src/secret_handler.py b/src/secret_handler.py
new file mode 100644
index 0000000..33d66a5
--- /dev/null
+++ b/src/secret_handler.py
@@ -0,0 +1,12 @@
+import sys
+
+def return_credentials(path: str)->str:
+	try:
+		with open (path) as file:
+			return file.read().strip()
+	except FileNotFoundError:
+		print(f"[FATAL] Secret file not found: {path}")
+		sys.exit(1)
+	except Exception as e:
+		print(f"[FATAL] Failed to read secret file {path}: {e}")
+		sys.exit(1)
diff --git a/src/send_notification.py b/src/send_notification.py
new file mode 100644
index 0000000..90b63cc
--- /dev/null
+++ b/src/send_notification.py
@@ -0,0 +1,83 @@
+import aiohttp
+import asyncio
+from logger_handler import setup_logger
+
+API_ENDPOINT="https://exp.host/fakeUSer/api/v2/push/send"
+logger = setup_logger(__name__)
+
+
+
+
+async def send_notification(
+	routing_key: str,
+	message: dict,
+	db_manager,
+	max_retries: int = 5,
+	timeout: int = 5,
+):
+	push_tokens = await database_lookup(routing_key, db_manager)
+	if not push_tokens:
+		logger.warning(f"No push tokens found for user {routing_key}")
+		return
+
+	results = {}
+	for token, uuid in push_tokens:
+		results[token] = await _send_to_token(token, uuid, message, max_retries, timeout)
+
+	return results
+
+async def _send_to_token(token: str, uuid:str , message: dict, max_retries: int, timeout: int):
+	payload = create_payload(token, message)
+
+	for attempt in range(1, max_retries + 1):
+		try:
+			async with aiohttp.ClientSession() as session:
+				async with session.post(
+					url=API_ENDPOINT,
+					json=payload,
+					headers={"Content-Type": "application/json"},
+					timeout=timeout
+				) as response:
+					await response.raise_for_status()
+					logger.info(f"Notification sent successfully to uuid {uuid}")
+					return {"status": "ok"}
+
+		except (aiohttp.ClientError, asyncio.TimeoutError) as e:
+			logger.warning(f"Attempt {attempt}/{max_retries} failed for uuid {uuid}: {type(e).__name__}")
+			await asyncio.sleep(2 ** (attempt - 1))
+
+		except Exception as e:
+			logger.error(f"Unexpected failure for uuid {uuid}: {e}")
+			return {"status": "error", "exception": str(e)}
+
+	logger.error(f"Failed to send notification to uuid {uuid} after {max_retries} attempts")
+	return {"status": "failed"}
+
+def create_payload(push_token: str, message: dict) -> dict:
+	return {
+		"to": push_token,
+		"title": message.get("title"),
+		"body": message.get("body"),
+		"data": {
+			"link": message.get("link"),
+			"category": message.get("category")
+		},
+		"sound": "default",
+		"priority": "high"
+	}
+
+async def database_lookup(routing_key: str, db_manager):
+	try:
+		user_id = int(routing_key.split('.')[-1])
+	except ValueError:
+		logger.error(f"[DB] Invalid user id supplied:{routing_key}")
+		return []
+	
+	async with db_manager.acquire() as conn:
+		async with conn.cursor() as cur:
+			await cur.execute("SELECT tokend_id AS uuid,token FROM device_tokens WHERE user_id=%s",
+					(user_id,))
+			if cur.description:
+				return await cur.fetchall()
+			return []
+