feat: listen for direct messages

tasks.py

@@ -1,18 +1,25 @@
 import asyncio
 import json
-import threading
+from asyncio import Queue
 
 import httpx
 import websocket
 from loguru import logger
+from websocket import WebSocketApp
 
 from lnbits.core.models import Payment
-from lnbits.helpers import url_for
 from lnbits.tasks import register_invoice_listener
 
+from .crud import get_merchant, get_merchant_by_pubkey, get_public_keys_for_merchants
+from .nostr.event import NostrEvent
+from .nostr.nostr_client import connect_to_nostrclient_ws
+
+recieve_event_queue: Queue = Queue()
+send_req_queue: Queue = Queue()
+
 
 async def wait_for_paid_invoices():
-    invoice_queue = asyncio.Queue()
+    invoice_queue = Queue()
     register_invoice_listener(invoice_queue)
 
     while True:
@@ -27,5 +34,61 @@ async def on_invoice_paid(payment: Payment) -> None:
     print("### on_invoice_paid")
 
 
-async def subscribe_nostrclient_ws():
+async def subscribe_nostrclient():
     print("### subscribe_nostrclient_ws")
+
+    def on_open(_):
+        logger.info("Connected to 'nostrclient' websocket")
+
+    def on_message(_, message):
+        print("### on_message", message)
+        recieve_event_queue.put_nowait(message)
+
+    # wait for 'nostrclient' extension to initialize
+    await asyncio.sleep(5)
+    ws: WebSocketApp = None
+    while True:
+        try:
+            req = None
+            if not ws:
+                ws = await connect_to_nostrclient_ws(on_open, on_message)
+                # be sure the connection is open
+                await asyncio.sleep(3)
+            req = await send_req_queue.get()
+            print("### req", req)
+            ws.send(json.dumps(req))
+        except Exception as ex:
+            logger.warning(ex)
+            if req:
+                await send_req_queue.put(req)
+            ws = None  # todo close
+            await asyncio.sleep(5)
+
+
+async def wait_for_nostr_events():
+    public_keys = await get_public_keys_for_merchants()
+    for p in public_keys:
+        await send_req_queue.put(
+            ["REQ", f"direct-messages:{p}", {"kind": 4, "#p": [p]}]
+        )
+
+    while True:
+        message = await recieve_event_queue.get()
+        await handle_message(message)
+
+
+async def handle_message(msg: str):
+    try:
+        type, subscription_id, event = json.loads(msg)
+        _, public_key = subscription_id.split(":")
+        if type.upper() == "EVENT":
+            event = NostrEvent(**event)
+            if event.kind == 4:
+                merchant = await get_merchant_by_pubkey(public_key)
+                if not merchant:
+                    return
+                clear_text_msg = merchant.decrypt_message(event.content, event.pubkey)
+                print("### clear_text_msg", clear_text_msg)
+
+    except Exception as ex:
+        logger.warning(ex)