refactor: extract NostrEvent

relay/event.py

@@ -0,0 +1,105 @@
+import hashlib
+import json
+from enum import Enum
+from sqlite3 import Row
+from typing import List
+
+from pydantic import BaseModel
+from secp256k1 import PublicKey
+
+
+
+class NostrEventType(str, Enum):
+    EVENT = "EVENT"
+    REQ = "REQ"
+    CLOSE = "CLOSE"
+    AUTH = "AUTH"
+
+
+class NostrEvent(BaseModel):
+    id: str
+    pubkey: str
+    created_at: int
+    kind: int
+    tags: List[List[str]] = []
+    content: str = ""
+    sig: str
+
+    def serialize(self) -> List:
+        return [0, self.pubkey, self.created_at, self.kind, self.tags, self.content]
+
+    def serialize_json(self) -> str:
+        e = self.serialize()
+        return json.dumps(e, separators=(",", ":"), ensure_ascii=False)
+
+    @property
+    def event_id(self) -> str:
+        data = self.serialize_json()
+        id = hashlib.sha256(data.encode()).hexdigest()
+        return id
+
+    @property
+    def size_bytes(self) -> int:
+        s = json.dumps(dict(self), separators=(",", ":"), ensure_ascii=False)
+        return len(s.encode())
+
+    @property
+    def is_replaceable_event(self) -> bool:
+        return self.kind in [0, 3, 41] or (self.kind >= 10000 and self.kind < 20000)
+
+    @property
+    def is_auth_response_event(self) -> bool:
+        return self.kind == 22242
+
+    @property
+    def is_direct_message(self) -> bool:
+        return self.kind == 4
+
+    @property
+    def is_delete_event(self) -> bool:
+        return self.kind == 5
+
+    @property
+    def is_regular_event(self) -> bool:
+        return self.kind >= 1000 and self.kind < 10000
+
+    @property
+    def is_ephemeral_event(self) -> bool:
+        return self.kind >= 20000 and self.kind < 30000
+        
+
+    def check_signature(self):
+        event_id = self.event_id
+        if self.id != event_id:
+            raise ValueError(
+                f"Invalid event id. Expected: '{event_id}' got '{self.id}'"
+            )
+        try:
+            pub_key = PublicKey(bytes.fromhex("02" + self.pubkey), True)
+        except Exception:
+            raise ValueError(
+                f"Invalid public key: '{self.pubkey}' for event '{self.id}'"
+            )
+
+        valid_signature = pub_key.schnorr_verify(
+            bytes.fromhex(event_id), bytes.fromhex(self.sig), None, raw=True
+        )
+        if not valid_signature:
+            raise ValueError(f"Invalid signature: '{self.sig}' for event '{self.id}'")
+
+    def serialize_response(self, subscription_id):
+        return [NostrEventType.EVENT, subscription_id, dict(self)]
+
+    def tag_values(self, tag_name: str) -> List[str]:
+        return [t[1] for t in self.tags if t[0] == tag_name]
+
+    def has_tag_value(self, tag_name: str, tag_value: str) -> bool:
+        return tag_value in self.tag_values(tag_name)
+
+    def is_direct_message_for_pubkey(self, pubkey: str) -> bool:
+        return self.is_direct_message and self.has_tag_value("p", pubkey)
+
+    @classmethod
+    def from_row(cls, row: Row) -> "NostrEvent":
+        return cls(**dict(row))
+