feat(beatmap,beatmapset): get beatmap & beatmapset information by id

app/router/beatmap.py

@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+from app.database import (
+    Beatmap,
+    BeatmapResp,
+    User as DBUser,
+)
+from app.dependencies.database import get_db
+from app.dependencies.user import get_current_user
+
+from .api_router import router
+
+from fastapi import Depends, HTTPException
+from sqlmodel import Session, select
+
+
+@router.get("/beatmaps/{bid}", tags=["beatmap"], response_model=BeatmapResp)
+async def get_beatmap(
+    bid: int,
+    current_user: DBUser = Depends(get_current_user),
+    db: Session = Depends(get_db),
+):
+    beatmap = db.exec(select(Beatmap).where(Beatmap.id == bid)).first()
+    if not beatmap:
+        raise HTTPException(status_code=404, detail="Beatmap not found")
+    return BeatmapResp.from_db(beatmap)