feat(achievement): support obtain achievements

app/models/achievement.py

@@ -0,0 +1,37 @@
+from __future__ import annotations
+
+from collections.abc import Awaitable, Callable
+from typing import TYPE_CHECKING, NamedTuple
+
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+if TYPE_CHECKING:
+    from app.database import Beatmap, Score
+
+
+class Achievement(NamedTuple):
+    id: int
+    name: str
+    desc: str
+    assets_id: str
+    medal_url: str | None = None
+    medal_url2x: str | None = None
+
+    @property
+    def url(self) -> str:
+        return (
+            self.medal_url
+            or f"https://assets.ppy.sh/medals/client/{self.assets_id}.png"
+        )
+
+    @property
+    def url2x(self) -> str:
+        return (
+            self.medal_url2x
+            or f"https://assets.ppy.sh/medals/client/{self.assets_id}@2x.png"
+        )
+
+
+MedalProcessor = Callable[[AsyncSession, "Score", "Beatmap"], Awaitable[bool]]
+Medals = dict[Achievement, MedalProcessor]
+MEDALS: Medals = {}