增加计算订单价格的接口

app/api/endpoints/order.py

@@ -7,7 +7,9 @@ from app.models.order import (
     OrderCreate, 
     OrderInfo,
     OrderPackageInfo,
-    generate_order_id
+    generate_order_id,
+    OrderPriceCalculateRequest,
+    OrderPriceInfo
 )
 from app.models.database import get_db
 from app.api.deps import get_current_user
@@ -15,6 +17,7 @@ from app.models.user import UserDB
 from app.core.response import success_response, error_response, ResponseModel
 from app.models.coupon import UserCouponDB, CouponStatus
 from datetime import datetime, timezone
+from app.core.config import settings
 
 router = APIRouter()
 
@@ -133,3 +136,49 @@ async def get_user_orders(
     ).offset(skip).limit(limit).all()
     
     return success_response(data=[OrderInfo.model_validate(o) for o in orders]) 
+
+@router.post("/calculate-price", response_model=ResponseModel)
+async def calculate_order_price(
+    request: OrderPriceCalculateRequest,
+    db: Session = Depends(get_db),
+    current_user: UserDB = Depends(get_current_user)
+):
+    """计算订单价格"""
+    package_count = len(request.packages)
+    
+    # 计算原始金额
+    original_amount = settings.ORDER_BASE_PRICE
+    if package_count > settings.ORDER_EXTRA_PACKAGE_THRESHOLD:
+        extra_packages = package_count - settings.ORDER_EXTRA_PACKAGE_THRESHOLD
+        original_amount += extra_packages * settings.ORDER_EXTRA_PACKAGE_PRICE
+    
+    # 计算优惠券折扣
+    coupon_discount = 0
+    used_coupon_id = None
+    
+    # 查询用户所有可用的优惠券
+    available_coupons = db.query(UserCouponDB).filter(
+        UserCouponDB.user_id == current_user.userid,
+        UserCouponDB.status == CouponStatus.UNUSED
+    ).order_by(
+        UserCouponDB.coupon_amount.desc()  # 优先使用面额大的优惠券
+    ).all()
+    
+    # 选择最优惠的券
+    if available_coupons:
+        user_coupon = available_coupons[0]  # 取面额最大的优惠券
+        coupon_discount = user_coupon.coupon_amount
+        used_coupon_id = user_coupon.id
+    
+    # 计算最终金额
+    final_amount = max(0, original_amount - coupon_discount)
+    
+    price_info = OrderPriceInfo(
+        package_count=package_count,
+        original_amount=original_amount,
+        coupon_discount_amount=coupon_discount,
+        coupon_id=used_coupon_id,
+        final_amount=final_amount
+    )
+    
+    return success_response(data=price_info) 

app/core/config.py

@@ -6,6 +6,10 @@ class Settings(BaseSettings):
     API_V1_STR: str = "/api/v1"
     PROJECT_NAME: str = "FastAPI 项目"
 
+    # 订单价格配置
+    ORDER_BASE_PRICE: float = 3.0  # 基础费用
+    ORDER_EXTRA_PACKAGE_PRICE: float = 0.5  # 额外包裹费用
+    ORDER_EXTRA_PACKAGE_THRESHOLD: int = 5  # 额外收费阈值
 
     # JWT 配置
     SECRET_KEY: str = "your-secret-key-here"

app/models/order.py

@@ -67,6 +67,18 @@ class OrderPackageInfo(BaseModel):
 def generate_order_id() -> str:
     """生成订单号：日期+时间戳"""
     now = datetime.now()
-    date_str = now.strftime('%Y%m%d')
+    # 生成8位日期 + 6位序号，共14位
-    timestamp = int(now.timestamp() * 1000)
+    date_str = now.strftime('%Y%m%d')  # 8位日期
+    # 生成6位序号（毫秒级时间戳后6位）
+    timestamp = str(int(now.timestamp() * 1000))[-6:]
     return f"{date_str}{timestamp}" 
+
+class OrderPriceCalculateRequest(BaseModel):
+    packages: List[OrderPackage]
+
+class OrderPriceInfo(BaseModel):
+    package_count: int
+    original_amount: float
+    coupon_discount_amount: float
+    coupon_id: Optional[int] = None
+    final_amount: float