internal async static Task <EnterResult> EnterAsync(ParkContext db, string licensePlate, ParkArea parkArea, DateTime time)
{
//检查是否有空位
bool hasEmpty = await db.ParkingSpaces.AnyAsync(p => p.ParkArea == parkArea && !p.HasCar);
//select from parkingspace join parkarea on parkingspace.parkareaid=parkarea.id and not parkingspace.hascar
if (!hasEmpty)
{
return(new EnterResult(false, "停车场已满"));
}
//获取汽车
Car car = await GetCarAsync(db, licensePlate, true);
if (car != null && !car.Enabled)//是否被禁止进入
{
return(new EnterResult(false, "该车辆禁止进入"));
}
//新增进出记录
ParkRecord parkRecord = new ParkRecord()
{
Car = car,
EnterTime = time,
ParkArea = parkArea
};
db.ParkRecords.Add(parkRecord);
await db.SaveChangesAsync();
return(new EnterResult(true));;
}
internal async static Task <LeaveResult> LeaveAsync(ParkContext db, string licensePlate, ParkArea parkArea, DateTime time)
{
ParkRecord parkRecord = null;
try
{
LeaveResult leave = new LeaveResult()
{
CanLeave = true
};
Car car = await GetCarAsync(db, licensePlate, false);
if (car == null)
{
//找不到车，就直接放行，省得麻烦
return(leave);
}
//获取停车记录
parkRecord = await db.ParkRecords
.OrderByDescending(p => p.EnterTime)
.FirstOrDefaultAsync(p => p.Car == car);
if (parkRecord == null)
{
//找不到记录，就直接放行，省得麻烦
return(leave);
}
leave.ParkRecord = parkRecord;
//补全进出记录
parkRecord.LeaveTime = time;
db.Entry(parkRecord).State = EntityState.Modified;
CarOwner owner = car.CarOwner;
//获取价格策略
var priceStrategy = parkArea.PriceStrategy;
if (priceStrategy == null)
{
//免费停车场
return(leave);
}
switch (owner)
{
case CarOwner _ when owner.IsFree:
//免费用户
break;
case CarOwner _:
if (await IsMonthlyCardValidAsync(db, owner.ID))
{
//月租用户，放行
break;
}
else
{
goto needPay;
}
case null:
//没有注册
needPay:
//非会员或普通用户
double price = GetPrice(priceStrategy, parkRecord.EnterTime, time);
double balance = owner == null ? 0 : await GetBalanceAsync(db, owner.ID);
//计算价格
if (balance - price < 0)
{
//拒绝驶离，要求付费
leave.CanLeave = false;
leave.NeedToPay = balance - price;
return(leave);
}
//新增扣费记录
TransactionRecord transaction = new TransactionRecord()
{
Time = time,
Type = TransactionType.Park,
Balance = balance - price,
Value = -price,
CarOwner = owner,
};
db.TransactionRecords.Add(transaction);
parkRecord.TransactionRecord = transaction; //停车记录绑定交易记录
break;
}
return(leave);
}
finally
{
await db.SaveChangesAsync();
}
}
