public Result Purchase(UserDto userDto, IList <ArticleDto> articles)
{
if (!userDto.HasPurchasePermissions)
{
return(Result.Failure($"Insufficient Permissions for User: '******'"));
}
if (articles.All(a => a.IsArticleInValidRange))
{
return(Result.Failure($"{articles.First(a => !a.IsArticleInValidRange)} is not (yet) purchaseable"));
}
var transactionDate = DateTime.UtcNow;
var distinctArticles = articles.Select(a => a.Id).Distinct();
var transactions = distinctArticles
.Select(articleId => new TransactionDto
{
UserId = userDto.Id,
ArticleId = articleId,
Quantity = articles.Count(a => a.Id == articleId),
TransactionDate = transactionDate
})
.ToList();
var transactionResults = transactions
.Select(_cloudShopDal.AddTransaction);
var stockOperationResult = transactions
.Select(t => _cloudShopDal.DecreaseStockCount(t.ArticleId, t.Quantity));
return(Result
.Combine(transactionResults.Concat(stockOperationResult))
.TapIf(userDto.WantsToReceiveBillingMails, () => _cloudShopMailer.SendBill(userDto.Email, articles)));
}
public Result DecreaseStockCount(long articleId, long quantity)
{
return(_cloudShopDal.DecreaseStockCount(articleId, quantity));
}