feat/fetch actor

app/actor.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+from loguru import logger
+from app.database import AsyncSession
+from sqlalchemy import select
+from app.models import Actor
+from urllib.parse import urlparse
+
+import app.activitypub as ap
+
+async def fetch_actor(
+        actor_id : str,
+        db_session : AsyncSession,
+) -> Actor:
+    exist_actor = (
+        await db_session.scalars(
+            select(Actor).where(
+                Actor.ap_id == actor_id
+            )
+        )
+    ).one_or_none()
+
+    if not exist_actor:
+        ap_object = await ap.fetch(actor_id)
+        exist_actor = await save_actor(ap_object, db_session)
+        return exist_actor
+
+    return exist_actor
+
+async def save_actor(
+        ap_object : dict,
+        db_session : AsyncSession
+) -> Actor:
+    logger.info("save actor " + ap_object["id"])
+    actor = Actor(
+        ap_id=ap_object["id"],
+        ap_actor=ap_object,
+        ap_type=ap_object["type"],
+        handle=_handle(ap_object),
+    )
+
+    db_session.add(actor)
+    await db_session.flush()
+    await db_session.refresh(actor)
+    return actor
+
+def _handle (
+    ap_object :dict
+) -> str:
+    ap_id = urlparse(ap_object["id"])
+    if not ap_id.hostname:
+        raise ValueError(f"Invalid actor ID {ap_id}")
+
+    handle = '@' + ap_object["preferredUsername"] + '@' + ap_id.hostname
+
+    return handle