[feat] Watchdog and notifications (#2895)

lnbits/core/services/nostr.py

@@ -0,0 +1,73 @@
+import asyncio
+from typing import Tuple
+
+import httpx
+from loguru import logger
+from pynostr.encrypted_dm import EncryptedDirectMessage
+from websocket import WebSocket, create_connection
+
+from lnbits.core.helpers import is_valid_url
+from lnbits.utils.nostr import (
+    validate_identifier,
+    validate_pub_key,
+)
+
+
+async def send_nostr_dm(
+    from_private_key_hex: str,
+    to_pubkey_hex: str,
+    message: str,
+    relays: list[str],
+) -> dict:
+    dm = EncryptedDirectMessage()
+    dm.encrypt(
+        private_key_hex=from_private_key_hex,
+        recipient_pubkey=to_pubkey_hex,
+        cleartext_content=message,
+    )
+
+    dm_event = dm.to_event()
+    dm_event.sign(private_key_hex=from_private_key_hex)
+    notification = dm_event.to_message()
+
+    ws_connections: list[WebSocket] = []
+    for relay in relays:
+        try:
+            ws = create_connection(relay, timeout=2)
+            ws.send(notification)
+            ws_connections.append(ws)
+        except Exception as e:
+            logger.warning(f"Error sending notification to relay {relay}: {e}")
+    await asyncio.sleep(1)
+    for ws in ws_connections:
+        try:
+            ws.close()
+        except Exception as e:
+            logger.debug(f"Failed to close websocket connection: {e}")
+
+    return dm_event.to_dict()
+
+
+async def fetch_nip5_details(identifier: str) -> Tuple[str, list[str]]:
+    identifier, domain = identifier.split("@")
+    if not identifier or not domain:
+        raise ValueError("Invalid NIP5 identifier")
+
+    if not is_valid_url(f"https://{domain}"):
+        raise ValueError("Invalid NIP5 domain")
+
+    validate_identifier(identifier)
+
+    url = f"https://{domain}/.well-known/nostr.json?name={identifier}"
+    async with httpx.AsyncClient() as client:
+        resp = await client.get(url)
+        resp.raise_for_status()
+        data = resp.json()
+        if "names" not in data or identifier not in data["names"]:
+            raise ValueError("NIP5 not name found")
+        pubkey = data["names"][identifier]
+        validate_pub_key(pubkey)
+
+        relays = data["relays"].get(pubkey, []) if "relays" in data else []
+
+        return pubkey, relays