private List <FeasiblePromotion> GetPromotionScenarios(List <ItemWithCount> selectedItems)
{
List <SalesPromotion> promotionDataBase = salesPromotionRepository.FindAll();
List <FeasiblePromotion> possiblePromotions = new List <FeasiblePromotion>();
List <string> inputItems = new List <string>();
foreach (var item in selectedItems)
{
inputItems.Add(item.Id);
}
foreach (var promotion in promotionDataBase)
{
if (promotion.RelatedItems.Intersect(inputItems).Count() != 0)
{
FeasiblePromotion temp = new FeasiblePromotion();
temp.DiscountedIds = promotion.RelatedItems.Intersect(inputItems);
var discountItems = new List <ItemWithCount>();
foreach (var id in temp.DiscountedIds)
{
foreach (var j in selectedItems)
{
if (id == j.Id)
{
discountItems.Add(j);
}
}
}
temp.DiscountedItems = discountItems;
temp.DisplayName = promotion.DisplayName;
temp.Discount = Convert.ToDouble(promotion.Type.Substring(0, 2)) / 100;
possiblePromotions.Add(temp);
}
}
return(possiblePromotions);
}
public string BestCharge(List <string> inputs)
{
var selectedItems = GetSelectedItems(inputs);
var promotionScenarios = GetPromotionScenarios(selectedItems);
if (promotionScenarios.Count() == 0)
{
StringBuilder output = new StringBuilder();
output.Append("============= Order details =============\n");
double totalCharge = 0;
foreach (var selectedItem in selectedItems)
{
totalCharge += selectedItem.ItemCharge;
output.Append(selectedItem.Name + " x " + selectedItem.Count.ToString() + " = " + selectedItem.ItemCharge.ToString() + " yuan\n");
}
output.Append("-----------------------------------\n");
output.Append("Total：" + totalCharge.ToString() + " yuan\n");
output.Append("===================================");
return(output.ToString());
}
else
{
var bestPromotion = new FeasiblePromotion();
double bestMoneySaved = 0;
foreach (var promotionScenario in promotionScenarios)
{
double moneySaved = 0;
foreach (var discountedItem in promotionScenario.DiscountedItems)
{
moneySaved += discountedItem.ItemCharge * (1 - promotionScenario.Discount);
}
if (moneySaved > bestMoneySaved)
{
bestMoneySaved = moneySaved;
bestPromotion = promotionScenario;
}
}
StringBuilder output = new StringBuilder();
output.Append("============= Order details =============\n");
double totalCharge = 0;
foreach (var selectedItem in selectedItems)
{
totalCharge += selectedItem.ItemCharge;
output.Append(selectedItem.Name + " x " + selectedItem.Count.ToString() + " = " + selectedItem.ItemCharge.ToString() + " yuan\n");
}
StringBuilder discountDishes = new StringBuilder();
discountDishes.Append(" (" + bestPromotion.DiscountedItems[0].Name);
var itemCount = bestPromotion.DiscountedItems.Count();
for (var i = 1; i < itemCount - 1; i++)
{
discountDishes.Append(", " + bestPromotion.DiscountedItems[i].Name);
}
discountDishes.Append(", " + bestPromotion.DiscountedItems[itemCount - 1].Name + "), ");
output.Append("-----------------------------------\n");
output.Append("Promotion used:\n");
output.Append(bestPromotion.DisplayName + discountDishes.ToString() + "saving " + bestMoneySaved.ToString() + " yuan\n");
output.Append("-----------------------------------\n");
output.Append("Total：" + (totalCharge - bestMoneySaved).ToString() + " yuan\n");
output.Append("===================================");
return(output.ToString());
}
}