refactor: move registering of tasks into app.py (#2290)

* refactor: move registering of tasks into `app.py`

let the app have the responsibility to create the tasks not a helper function inside tasks.py.
makes it way easier to follow on how those background tasks are ran.

lnbits/app.py

@@ -26,12 +26,16 @@ from starlette.responses import JSONResponse
 from lnbits.core.crud import get_dbversions, get_installed_extensions
 from lnbits.core.helpers import migrate_extension_database
 from lnbits.core.services import websocketUpdater
-from lnbits.core.tasks import (  # register_watchdog,; unregister_watchdog,
-    register_killswitch,
-    register_task_listeners,
+from lnbits.core.tasks import (  # watchdog_task
+    killswitch_task,
+    wait_for_paid_invoices,
 )
 from lnbits.settings import settings
-from lnbits.tasks import cancel_all_tasks, create_permanent_task
+from lnbits.tasks import (
+    cancel_all_tasks,
+    create_permanent_task,
+    register_invoice_listener,
+)
 from lnbits.utils.cache import cache
 from lnbits.wallets import get_wallet_class, set_wallet_class
 
@@ -470,9 +474,15 @@ def register_async_tasks(app):
         create_permanent_task(invoice_listener)
         create_permanent_task(internal_invoice_listener)
         create_permanent_task(cache.invalidate_forever)
-        register_task_listeners()
-        register_killswitch()
-        # await run_deferred_async() # calle: doesn't do anyting?
+
+        # core invoice listener
+        invoice_queue = asyncio.Queue(5)
+        register_invoice_listener(invoice_queue, "core")
+        create_permanent_task(lambda: wait_for_paid_invoices(invoice_queue))
+
+        # TODO: implement watchdog properly
+        # create_permanent_task(watchdog_task)
+        create_permanent_task(killswitch_task)
 
 
 def register_exception_handlers(app: FastAPI):

lnbits/core/tasks.py

@@ -17,26 +17,16 @@ from lnbits.core.services import (
     switch_to_voidwallet,
 )
 from lnbits.settings import get_wallet_class, settings
-from lnbits.tasks import (
-    create_permanent_task,
-    create_task,
-    register_invoice_listener,
-    send_push_notification,
-)
+from lnbits.tasks import send_push_notification
 
 api_invoice_listeners: Dict[str, asyncio.Queue] = {}
 
 
-def register_killswitch():
+async def killswitch_task():
     """
-    Registers a killswitch which will check lnbits-status repository for a signal from
+    killswitch will check lnbits-status repository for a signal from
     LNbits and will switch to VoidWallet if the killswitch is triggered.
     """
-    logger.debug("Starting killswitch task")
-    create_permanent_task(killswitch_task)
-
-
-async def killswitch_task():
     while True:
         WALLET = get_wallet_class()
         if settings.lnbits_killswitch and WALLET.__class__.__name__ != "VoidWallet":
@@ -59,17 +49,11 @@ async def killswitch_task():
         await asyncio.sleep(settings.lnbits_killswitch_interval * 60)
 
 
-async def register_watchdog():
+async def watchdog_task():
     """
     Registers a watchdog which will check lnbits balance and nodebalance
     and will switch to VoidWallet if the watchdog delta is reached.
     """
-    # TODO: implement watchdog properly
-    # logger.debug("Starting watchdog task")
-    # create_permanent_task(watchdog_task)
-
-
-async def watchdog_task():
     while True:
         WALLET = get_wallet_class()
         if settings.lnbits_watchdog and WALLET.__class__.__name__ != "VoidWallet":
@@ -84,36 +68,23 @@ async def watchdog_task():
         await asyncio.sleep(settings.lnbits_watchdog_interval * 60)
 
 
-def register_task_listeners():
-    """
-    Registers an invoice listener queue for the core tasks. Incoming payments in this
-    queue will eventually trigger the signals sent to all other extensions
-    and fulfill other core tasks such as dispatching webhooks.
-    """
-    invoice_paid_queue = asyncio.Queue(5)
-    # we register invoice_paid_queue to receive all incoming invoices
-    register_invoice_listener(invoice_paid_queue, "core/tasks.py")
-    # register a worker that will react to invoices
-    create_task(wait_for_paid_invoices(invoice_paid_queue))
-
-
 async def wait_for_paid_invoices(invoice_paid_queue: asyncio.Queue):
     """
-    This worker dispatches events to all extensions,
-    dispatches webhooks and balance notifys.
+    This task dispatches events to all api_invoice_listeners,
+    webhooks, push notifications and balance notifications.
     """
     while True:
         payment = await invoice_paid_queue.get()
         logger.trace("received invoice paid event")
-        # send information to sse channel
+        # dispatch api_invoice_listeners
         await dispatch_api_invoice_listeners(payment)
+        # payment notification
         wallet = await get_wallet(payment.wallet_id)
         if wallet:
             await send_payment_notification(wallet, payment)
         # dispatch webhook
         if payment.webhook and not payment.webhook_status:
             await dispatch_webhook(payment)
-
         # dispatch balance_notify
         url = await get_balance_notify(payment.wallet_id)
         if url:
@@ -136,6 +107,7 @@ async def wait_for_paid_invoices(invoice_paid_queue: asyncio.Queue):
                     logger.warning(f"Could not send balance_notify to {url}")
                     logger.warning(exc)
 
+        # dispatch push notification
         await send_payment_push_notification(payment)
 
 
@@ -145,10 +117,12 @@ async def dispatch_api_invoice_listeners(payment: Payment):
     """
     for chan_name, send_channel in api_invoice_listeners.items():
         try:
-            logger.debug(f"sending invoice paid event to {chan_name}")
+            logger.debug(f"api invoice listener: sending paid event to {chan_name}")
             send_channel.put_nowait(payment)
         except asyncio.QueueFull:
-            logger.error(f"removing sse listener {send_channel}:{chan_name}")
+            logger.error(
+                f"api invoice listener: QueueFull, removing {send_channel}:{chan_name}"
+            )
             api_invoice_listeners.pop(chan_name)