public TransactionService(
ICollectionInitializer initializer,
ICollectionResolver <TContext> resolver,
IDatabaseTransactionManager <TContext> transactionManager)
{
_initializer = initializer ?? throw new ArgumentNullException(nameof(initializer));
_resolver = resolver ?? throw new ArgumentNullException(nameof(resolver));
_transactionManager = transactionManager ?? throw new ArgumentNullException(nameof(transactionManager));
}
public async Task <BorrowLog> RevertBookAsync(User userId, Book bookId)
{
BorrowLog leaseLog = null;
BorrowLog leaseLogCheck = (await database.SelectAsync <BorrowLog, BorrowLog>(bl => bl.User.Id == userId.Id && bl.Book.Id == bookId.Id && bl.GiveBack == null)).FirstOrDefault();
if (leaseLogCheck == null)
{
throw new Exception("无符合条件的借阅记录");
}
using IDatabaseTransactionManager transaction = database.StartTransaction();
try
{
await database.ForUpdateAsync <BorrowLog, BorrowLog>(bl => bl.Id == leaseLogCheck.Id && bl.User.Id == bl.User.Id && bl.Book.Id == bl.Book.Id, transaction : transaction.GetTransaction());
leaseLog = (await database.SelectAsync <BorrowLog, BorrowLog>(bl => bl.Id == leaseLogCheck.Id && bl.User.Id == bl.User.Id && bl.Book.Id == bl.Book.Id, transaction: transaction.GetTransaction())).FirstOrDefault();
if (leaseLog == null)
{
throw new Exception("无符合条件的借阅记录");
}
leaseLog.GiveBack = DateTime.Now;
int creditChange = credit.GetCreditChange(leaseLog);
if (await database.UpdateAsync <Book, int>(b => b.Margin + 1, b => b.Id == leaseLog.Book.Id, transaction: transaction.GetTransaction()) == 0)
{
throw new Exception("更新书本信息失败");
}
if (await database.UpdateAsync <User, int>(u => u.CreditValue + creditChange, u => u.Id == leaseLog.User.Id, transaction: transaction.GetTransaction()) == 0)
{
throw new Exception("更新会员信息失败");
}
if (await database.UpdateAsync <BorrowLog, bool>(bl => bl.GiveBack == DateTime.Now, bl => bl.Id == leaseLog.Id, transaction: transaction.GetTransaction()) == 0)
{
throw new Exception("更新借阅记录失败");
}
leaseLog = (await database.SelectAsync <BorrowLog, BorrowLog>(bl => bl.Id == leaseLog.Id && bl.Book.Id == bl.Book.Id, transaction: transaction.GetTransaction())).FirstOrDefault();
if (leaseLog == null)
{
throw new Exception("更新借阅记录失败");
}
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
throw;
}
return(leaseLog);
}
public async Task <int> OutStockAsync(IEnumerable <Book> ids)
{
int rows;
using IDatabaseTransactionManager transaction = database.StartTransaction();
try
{
rows = await database.DeleteAsync <Book, Book>(ids : ids, transaction : transaction.GetTransaction());
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
throw;
}
return(rows);
}
public async Task <int> InStockAsync(IEnumerable <Book> books)
{
int rows;
using IDatabaseTransactionManager transaction = database.StartTransaction();
try
{
rows = await database.InsertAsync(books, transaction.GetTransaction());
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
throw;
}
return(rows);
}
public async Task <BorrowLog> BorrowBookAsync(User userId, Book bookId)
{
BorrowLog leaseLog = null;
Book bCheck = (await database.SelectAsync <Book, Book>(b => b.Id == bookId.Id)).FirstOrDefault();
User uCheck = (await database.SelectAsync <User, User>(u => u.Id == userId.Id)).FirstOrDefault();
_ = (await database.SelectAsync <BorrowLog, BorrowLog>(null, pageIndex: 1, pageSize: 1)).FirstOrDefault();
if (bCheck == null || uCheck == null)
{
throw new Exception("借阅人或目标不合法");
}
using IDatabaseTransactionManager transaction = database.StartTransaction();
try
{
await database.ForUpdateAsync <Book, Book>(b => b.Id == bookId.Id, transaction : transaction.GetTransaction());
Book bSnap = (await database.SelectAsync <Book, Book>(b => b.Id == bookId.Id, transaction: transaction.GetTransaction())).FirstOrDefault();
if (bSnap == null)
{
throw new Exception("借阅目标不合法");
}
if (bSnap.Margin <= 0)
{
throw new Exception("借阅目标数量不足");
}
User uSnap = (await database.SelectAsync <User, User>(u => u.Id == userId.Id, transaction: transaction.GetTransaction())).FirstOrDefault();
if (uSnap == null)
{
throw new Exception("借阅人不合法");
}
List <BorrowLog> leaseLogs = await database.SelectAsync <BorrowLog, BorrowLog>(bl => bl.BookId == bookId.Id && bl.UserId == userId.Id && bl.GiveBack == null, transaction : transaction.GetTransaction());
if (leaseLogs.Count > 0)
{
throw new Exception("已有未归还的同名同书借阅记录");
}
int accreditedDays = credit.GetAccreditedDays(uSnap);
if (accreditedDays == 0)
{
throw new Exception("借阅人信誉过低");
}
if (await database.UpdateAsync <Book, int>(book => book.Margin - 1, book => book.Id == bSnap.Id, transaction: transaction.GetTransaction()) == 0)
{
throw new Exception("更新书本库存失败");
}
leaseLog = new BorrowLog {
BookId = bSnap.Id, UserId = uSnap.Id, Deadline = DateTime.Today.AddDays(accreditedDays)
};
if (await database.InsertAsync(new BorrowLog[] { leaseLog }, transaction: transaction.GetTransaction()) == 0)
{
throw new Exception("创建借阅记录失败");
}
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
throw;
}
return(leaseLog);
}
