static void Main(string[] args)
{
// Search all the implementations
var type = typeof(IDiscountStrategy);
var types = AppDomain.CurrentDomain.GetAssemblies()
.SelectMany(s => s.GetTypes())
.Where(implemetingType => type.IsAssignableFrom(implemetingType) && !implemetingType.IsAbstract);
var collection = new ServiceCollection();
foreach (var implemetingType in types)
{
collection.AddSingleton(type, implemetingType);
}
collection.AddSingleton <IDiscountService, DiscountService>();
var provider = collection.BuildServiceProvider();
var service = provider.GetService <IDiscountService>();
// From database
var rules = new List <DiscountRule>
{
new DiscountRule
{
TypeCode = "PercentageOnCart",
Value = 10,
ValueType = ValueType.Percent
},
new DiscountRule
{
TypeCode = "PercentageOnItem",
Value = 10,
ValueType = ValueType.Percent
}
};
// From API controller
var request = new DiscountRequest
{
Items = new List <DiscountRequestItem> {
new DiscountRequestItem {
SfId = "asas"
},
new DiscountRequestItem {
SfId = "asas"
}
}
};
service.ComputeDiscount(request, rules);
}
// The real business logic
public DiscountResponse ComputeDiscount(DiscountRequest discountRequest, List <DiscountRule> rules)
{
var discountResponse = new DiscountResponse();
foreach (var rule in rules)
{
var strategy = _strategies[rule.TypeCode];
strategy.ComputeDiscountOnCart(rule, discountRequest, discountResponse);
foreach (var item in discountRequest.Items)
{
strategy.ComputeDiscountOnItem(rule, discountRequest, discountResponse, item);
}
}
return(discountResponse);
}