feat: implement per user pc-rating curve

utils/helpers.py

@@ -0,0 +1,95 @@
+from decimal import Decimal, getcontext
+import hashlib
+
+import orjson as json
+
+getcontext().prec = 28
+
+
+def salted_hash_userid(user_id: int):
+    SALT = b"Lt2N5xgjJOqRsT5qVt7wWYw6SqOPZDI7"
+
+    hash_uid = hashlib.sha256(f"{user_id}".encode("utf-8") + SALT)
+    return hash_uid.hexdigest()[:16]
+
+
+def dx_rating(difficulty: Decimal, achievement: int) -> int:
+    # Constants
+    SSS_PLUS_THRESHOLD = Decimal("100.5")
+    SSS_PLUS_FACTOR = Decimal("0.224")
+    SSS_PRO_THRESHOLD = Decimal("100.4999")
+    SSS_PRO_FACTOR = Decimal("0.222")
+    SSS_THRESHOLD = Decimal("100.0")
+    SSS_FACTOR = Decimal("0.216")
+    SS_PLUS_PRO_THRESHOLD = Decimal("99.9999")
+    SS_PLUS_PRO_FACTOR = Decimal("0.214")
+    SS_PLUS_THRESHOLD = Decimal("99.5")
+    SS_PLUS_FACTOR = Decimal("0.211")
+    SS_THRESHOLD = Decimal("99.0")
+    SS_FACTOR = Decimal("0.208")
+    S_PLUS_PRO_THRESHOLD = Decimal("98.9999")
+    S_PLUS_PRO_FACTOR = Decimal("0.206")
+    S_PLUS_THRESHOLD = Decimal("98.0")
+    S_PLUS_FACTOR = Decimal("0.203")
+    S_THRESHOLD = Decimal("97.0")
+    S_FACTOR = Decimal("0.2")
+    AAA_PRO_THRESHOLD = Decimal("96.9999")
+    AAA_PRO_FACTOR = Decimal("0.176")
+    AAA_THRESHOLD = Decimal("94.0")
+    AAA_FACTOR = Decimal("0.168")
+    AA_THRESHOLD = Decimal("90.0")
+    AA_FACTOR = Decimal("0.152")
+    A_THRESHOLD = Decimal("80.0")
+    A_FACTOR = Decimal("0.136")
+
+    ach = Decimal(achievement) / Decimal("10000")
+    if ach > Decimal("101.0") or ach < A_THRESHOLD:
+        return 0
+    if ach >= SSS_PLUS_THRESHOLD:
+        factor = SSS_PLUS_FACTOR
+        ach = Decimal("100.5")
+    elif ach >= SSS_PRO_THRESHOLD:
+        factor = SSS_PRO_FACTOR
+    elif ach >= SSS_THRESHOLD:
+        factor = SSS_FACTOR
+    elif ach >= SS_PLUS_PRO_THRESHOLD:
+        factor = SS_PLUS_PRO_FACTOR
+    elif ach >= SS_PLUS_THRESHOLD:
+        factor = SS_PLUS_FACTOR
+    elif ach >= SS_THRESHOLD:
+        factor = SS_FACTOR
+    elif ach >= S_PLUS_PRO_THRESHOLD:
+        factor = S_PLUS_PRO_FACTOR
+    elif ach >= S_PLUS_THRESHOLD:
+        factor = S_PLUS_FACTOR
+    elif ach >= S_THRESHOLD:
+        factor = S_FACTOR
+    elif ach >= AAA_PRO_THRESHOLD:
+        factor = AAA_PRO_FACTOR
+    elif ach >= AAA_THRESHOLD:
+        factor = AAA_FACTOR
+    elif ach >= AA_THRESHOLD:
+        factor = AA_FACTOR
+    elif ach >= A_THRESHOLD:
+        factor = A_FACTOR
+    else:
+        return 0
+    result = (factor * difficulty * ach).quantize(Decimal("1."), rounding="ROUND_FLOOR")
+    return int(result)
+
+
+with open("musicDB.json", "r", encoding="utf-8") as f:
+    MUSIC_DB = json.loads(f.read())
+
+MUSIC_DB = {entry["id"]: entry for entry in MUSIC_DB}
+
+
+def query_music_db(music_id: int):
+    music_info = MUSIC_DB.get(music_id)
+    if music_info is None:
+        return
+    return music_info
+
+
+def find_level(music_info: dict, level_id: int):
+    return [level for level in music_info["levels"] if level["level"] == level_id]