public ResultOperation Remove(int id)
{
return(SurroundWithTryCatch(() =>
{
string error = string.Empty;
ProductEntry entry = DB.ProductEntries.SingleOrDefault(r => r.Id == id);
if (entry == null)
{
error = "Item was not found.";
}
else
{
if (entry.SaleItems.Any())
{
error = "You cannot remove this product! There are sales related to this item.";
}
else
{
DB.ProductEntries.Remove(entry);
DB.SaveChanges();
}
}
return error;
}
));
}
private void VerifyOtherEntries(ProductEntry entry, PurchaseItem item)
{
List <ProductEntry> entries = GetProductEntriesWithSamePrice(entry.IdProduct, entry.UnitPrice);
int qttAvail = entries.Sum(r => r.QuantityAvailable);
if (qttAvail >= item.Qtd)
{
int qttAux = item.Qtd;
foreach (var ent in entries)
{
if (qttAux == 0)
{
break;
}
if (ent.QuantityAvailable <= qttAux)
{
qttAux -= ent.QuantityAvailable;
ent.QuantityAvailable = 0;
}
else
{
ent.QuantityAvailable -= qttAux;
qttAux = 0;
}
}
}
else
{
errorMessage = $"Product {item.productName} has only {qttAvail} available unities.<br/>";
}
}
public ResultOperation Update(InventoryProduct inventoryProduct)
{
return(SurroundWithTryCatch(() =>
{
string error = string.Empty;
ProductEntry entry = DB.ProductEntries.Include("SaleItems")
.FirstOrDefault(r => r.Id == inventoryProduct.Id);
if (entry == null)
{
error = "Inventory Item was not found.";
}
else if (entry.QuantityAvailable == 0 && entry.QuantityBought > inventoryProduct.Qtd)
{
error = $"This product has sold {entry.QuantityBought } unities. You must specify in quantity bought a number higher than it";
}
else
{
entry.PurchaseDate = inventoryProduct.DatePurchase;
entry.UnitPrice = inventoryProduct.Price;
entry.QuantityAvailable += (inventoryProduct.Qtd - entry.QuantityBought);
entry.QuantityBought = inventoryProduct.Qtd;
entry.UnitPriceAcquisition = inventoryProduct.PriceAcquisition;
DB.SaveChanges();
}
return error;
}));
}
public ResultOperation SavePurchase(DateTime date, PurchaseItem[] items)
{
if (items.Any(r => r.Qtd <= 0))
{
return(new ResultOperation()
{
Success = false, Message = "There are invalid quantities in this request. Please review before saving purchase!"
});
}
using (var transaction = DB.Database.BeginTransaction(System.Data.IsolationLevel.RepeatableRead))
{
try
{
// Creating the header of the sale
Sale sale = new Sale()
{
Date = date
};
// Items that will be worked through loop
SaleItem saleItem = null;
ProductEntry entry = null;
// For each item that came from the client
foreach (var item in items)
{
//Looking for the specific entry and not the product itself that is in a different table
entry = DB.ProductEntries.FirstOrDefault(r => r.Id == item.IdProduct);
//Something must be wrong, the entry was not found
if (entry == null)
{
errorMessage += $"Product {item.productName} was not found!<br/>";
break;
}
else
{
// Something happened and the quantity requested is not available
if (entry.QuantityAvailable < item.Qtd)
{
VerifyOtherEntries(entry, item);
}
else
{
// Here is where the transaction is useful
// if someone else is changing the QuantityAvailable,
// we need to avoid that this transaction override the update in a concurrent environment
entry.QuantityAvailable -= item.Qtd;
}
if (string.IsNullOrEmpty(errorMessage))
{
// Creating one item for the sale
saleItem = new SaleItem()
{
ProductEntry = entry,
UnitPrice = entry.UnitPrice,
Quantity = item.Qtd
};
// You can do this, or just set the property Sale from saleItem with 'sale'
sale.SaleItems.Add(saleItem);
}
}
}
DB.Sales.Add(sale);
}
catch (Exception ex)
{
errorMessage = ex.Message;
}
if (string.IsNullOrEmpty(errorMessage))
{
try
{
// You must call save changes first
DB.SaveChanges();
transaction.Commit();
}
catch (Exception)
{
errorMessage = "The server is busy! Try again, if the problem persists, get in touch with the System Admin";
}
}
else
{
transaction.Rollback();
}
}
return(new ResultOperation()
{
Success = errorMessage == string.Empty, Message = errorMessage
});
}