add promocodes

app/services/promo.py

@@ -0,0 +1,145 @@
+from datetime import datetime
+from fastapi import HTTPException
+from bson import ObjectId
+from pymongo import ReturnDocument
+from app.db.database import db
+from app.services.coins import CoinsService
+
+promo_codes = db["promo_codes"]
+promo_redemptions = db["promo_redemptions"]
+
+class PromoService:
+    def __init__(self):
+        self.coins = CoinsService()
+
+    @staticmethod
+    def _normalize_code(code: str) -> str:
+        return code.strip().upper()
+
+    async def ensure_indexes(self):
+        # уникальность самого кода
+        await promo_codes.create_index("code", unique=True)
+        # одноразовость на пользователя
+        await promo_redemptions.create_index([("code", 1), ("username", 1)], unique=True)
+        await promo_redemptions.create_index("redeemed_at")
+
+    async def create(self, payload):
+        now = datetime.utcnow()
+        doc = {
+            "code": self._normalize_code(payload.code),
+            "reward_coins": payload.reward_coins,
+            "max_uses": payload.max_uses,
+            "uses_count": 0,
+            "is_active": payload.is_active,
+            "starts_at": payload.starts_at,
+            "ends_at": payload.ends_at,
+            "created_at": now,
+            "updated_at": now,
+        }
+        try:
+            r = await promo_codes.insert_one(doc)
+        except Exception:
+            # можно точнее ловить DuplicateKeyError
+            raise HTTPException(status_code=409, detail="Promo code already exists")
+        doc["_id"] = r.inserted_id
+        return doc
+
+    async def list(self, limit: int = 50, skip: int = 0):
+        cursor = promo_codes.find({}).sort("created_at", -1).skip(skip).limit(limit)
+        return await cursor.to_list(length=limit)
+
+    async def update(self, promo_id: str, payload):
+        try:
+            oid = ObjectId(promo_id)
+        except:
+            raise HTTPException(status_code=400, detail="Invalid promo id")
+
+        update_data = {k: v for k, v in payload.dict(exclude_unset=True).items()}
+        if not update_data:
+            doc = await promo_codes.find_one({"_id": oid})
+            if not doc:
+                raise HTTPException(status_code=404, detail="Promo not found")
+            return doc
+
+        update_data["updated_at"] = datetime.utcnow()
+
+        doc = await promo_codes.find_one_and_update(
+            {"_id": oid},
+            {"$set": update_data},
+            return_document=ReturnDocument.AFTER
+        )
+        if not doc:
+            raise HTTPException(status_code=404, detail="Promo not found")
+        return doc
+
+    async def delete(self, promo_id: str):
+        try:
+            oid = ObjectId(promo_id)
+        except:
+            raise HTTPException(status_code=400, detail="Invalid promo id")
+
+        r = await promo_codes.delete_one({"_id": oid})
+        if r.deleted_count == 0:
+            raise HTTPException(status_code=404, detail="Promo not found")
+        return {"status": "success"}
+
+    async def redeem(self, username: str, code: str):
+        username = username.strip()
+        code = self._normalize_code(code)
+        now = datetime.utcnow()
+
+        # 1) Сначала фиксируем, что этот пользователь пытается активировать этот код.
+        # Уникальный индекс (code, username) гарантирует одноразовость.
+        try:
+            await promo_redemptions.insert_one({
+                "code": code,
+                "username": username,
+                "redeemed_at": now,
+            })
+        except Exception:
+            # DuplicateKey -> уже активировал
+            raise HTTPException(status_code=409, detail="Promo code already redeemed by this user")
+
+        # 2) Затем пытаемся “забрать” 1 использование у промокода атомарно.
+        # Если max_uses = None -> ограничение не проверяем.
+        promo = await promo_codes.find_one({"code": code})
+        if not promo:
+            # откатываем redemption запись
+            await promo_redemptions.delete_one({"code": code, "username": username})
+            raise HTTPException(status_code=404, detail="Promo code not found")
+
+        if not promo.get("is_active", True):
+            await promo_redemptions.delete_one({"code": code, "username": username})
+            raise HTTPException(status_code=400, detail="Promo code is inactive")
+
+        starts_at = promo.get("starts_at")
+        ends_at = promo.get("ends_at")
+        if starts_at and now < starts_at:
+            await promo_redemptions.delete_one({"code": code, "username": username})
+            raise HTTPException(status_code=400, detail="Promo code is not started yet")
+        if ends_at and now > ends_at:
+            await promo_redemptions.delete_one({"code": code, "username": username})
+            raise HTTPException(status_code=400, detail="Promo code expired")
+
+        query = {"code": code}
+        if promo.get("max_uses") is not None:
+            query["uses_count"] = {"$lt": promo["max_uses"]}
+
+        updated = await promo_codes.find_one_and_update(
+            query,
+            {"$inc": {"uses_count": 1}, "$set": {"updated_at": now}},
+            return_document=ReturnDocument.AFTER
+        )
+
+        if not updated:
+            # лимит исчерпан — откатываем redemption
+            await promo_redemptions.delete_one({"code": code, "username": username})
+            raise HTTPException(status_code=409, detail="Promo code usage limit reached")
+
+        # 3) Начисляем монеты
+        new_balance = await self.coins.increase_balance(username, promo["reward_coins"])
+        return {
+            "code": code,
+            "reward_coins": promo["reward_coins"],
+            "new_balance": new_balance
+        }