public async Task <object> AddUserBoook(User_BookVM book)
{
try
{
if (book != null)
{
var newBook = new Borrowed_Book()
{
BookId = book.BookId,
UserId = book.UserId,
};
var saveAsync = await context.Borrowed_Books.AddAsync(newBook);
if (saveAsync != null)
{
await context.SaveChangesAsync();
}
return(saveAsync);
}
return(null);
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
private bool PerformRentOperation(ObjectId userId, ObjectId bookId, bool rent)
{
using (var session = MongoClient.StartSession())
{
var cancellationToken = CancellationToken.None;
var bookToRent = new Borrowed_Book {
Book = bookId, User = userId
};
var builder = Builders <Book> .Filter.Where(x => x.Id == bookId);
int copies_available = 0;
int copies_on_rent = 0;
var updateTime = DateTime.UtcNow;
if (rent)
{
copies_available = -1;
copies_on_rent = 1;
}
else
{
copies_available = 1;
copies_on_rent = -1;
}
var result = session.WithTransaction((s, ct) =>
{
try
{
var ObjectToUpdate = new BsonDocument {
{ "$inc", new BsonDocument {
{ "Total_Copies_Available", copies_available },
{ "Copies_on_Rent", copies_on_rent },
{ "UpdatedAt", updateTime.ToTimestamp() }
} }
};
if (rent)
{
_bookRentalCollection.InsertOne(bookToRent, new InsertOneOptions {
BypassDocumentValidation = false
}, cancellationToken: cancellationToken);
}
else
{
var rentalBuilder = Builders <Borrowed_Book> .Filter.Where(x => x.Book == bookId && x.User == userId);
var ObjForUpdate = new BsonDocument
{
{ "Returned", true },
{ "UpdatedAt", updateTime.ToTimestamp() }
};
}
_bookCollection.UpdateOne(builder, ObjectToUpdate, cancellationToken: ct);
return(true);
}
catch (Exception ex)
{
_logger.LogError("could not process rental service for user", ex);
return(false);
}
}, cancellationToken: cancellationToken);
if (result)
{
return(true);
}
}
return(false);
}
