public Rate GetTaxRateForLocation(string zip, string country, string state, string city, string street)
{
Rate locationWithRateInfo = null;
bool failedVerification = false;
Response.StatusCode = BadRequest().StatusCode;
if (string.IsNullOrEmpty(zip) || (zip.Length != 5 && zip.Length != 10))
{
Response.HttpContext.Features.Get <IHttpResponseFeature>().ReasonPhrase = "Zip code is invalid.";
failedVerification = true;
}
// Threw in this online checker just in case bogus zip
if (!failedVerification)
{
try
{
using (var client = new WebClient())
{
var s = client.DownloadString($"http://api.zippopotam.us/us/{zip}");
}
// Of course we can extend this to do actual comparison for Country, state, etc...
}
catch (WebException wex)
{
failedVerification = true;
Debug.WriteLine(
$"Exception thrown when calling zip lookup: {wex.Message}. Response: {wex.Response}");
if (wex.Status == WebExceptionStatus.ProtocolError)
{
var zipLookupReturnStatusCode = ((HttpWebResponse)wex.Response).StatusCode;
var errorDescription = ((HttpWebResponse)wex.Response).StatusDescription;
Debug.WriteLine($"Status Code : {zipLookupReturnStatusCode}. Error: {errorDescription}");
Response.HttpContext.Features.Get <IHttpResponseFeature>().ReasonPhrase = "Zip code is invalid.";
}
}
//
}
if (!failedVerification)
{
ITaxApiCaller taxApi = _apiChooser.GetAppropriateApi();
locationWithRateInfo =
((ITaxCalculatorApi)taxApi).GetTaxRateForLocation(zip, country, state, city, street);
Response.StatusCode = Ok().StatusCode;
}
return(locationWithRateInfo);
}
public ITaxApiCaller GetAppropriateApi(string explicitKey = null)
{
ITaxApiCaller apiCaller = null;
var keyOfApiToLoad = string.IsNullOrEmpty(explicitKey) ? _apiSettings.DefaultTaxApi : explicitKey;
try
{
if (!_taxApiLibraries.ContainsKey(keyOfApiToLoad))
{
TaxApiProvider provider = GetExplicitApi(keyOfApiToLoad);
var assemblyTypeNameOfApi = provider.AssemblyFQN;
string assemblyFileName = provider.Name + ".dll";
string assemblyPath = AppDomain.CurrentDomain.BaseDirectory + provider.Name + "Client.dll";
Assembly apiAssembly = AssemblyLoadContext.Default.LoadFromAssemblyPath(assemblyPath);
var exported = apiAssembly.ExportedTypes.FirstOrDefault(t => t.Name == provider.ClrType);
if (exported == null)
{
throw new InvalidOperationException("Configuration of tax api clients is not valid.");
}
Type taxApiType = apiAssembly.GetType(exported.FullName ?? throw new InvalidOperationException());
object taxApiInstance = Activator.CreateInstance(taxApiType);
apiCaller = taxApiInstance as ITaxApiCaller;
if (apiCaller == null)
{
throw new InvalidOperationException($"Could not instantiate tax api library: '{keyOfApiToLoad}'");
}
apiCaller.AuthenticationToken = provider.ApiToken;
_taxApiLibraries.TryAdd(keyOfApiToLoad, apiCaller);
}
else
{
apiCaller = _taxApiLibraries[keyOfApiToLoad];
}
}
catch (Exception e)
{
// Do some logging here
Debug.WriteLine($"Exception thrown when instantiating taxApi libraries: '{keyOfApiToLoad}'. Exception: {e}");
throw;
}
return(apiCaller);
}
public float CalculateSalesTaxForOrder([FromBody] Order order)
{
float totalSalesTaxForOrder = 0;
try
{
if (order.ProductLineItems == null || order.ProductLineItems.Count == 0)
{
// More detailed verification of Order, Customer, Product info can be added here...
Response.StatusCode = 400;
Response.HttpContext.Features.Get <IHttpResponseFeature>().ReasonPhrase =
"Order contains no product line items.";
}
else
{
ITaxApiCaller taxApi = _apiChooser.GetAppropriateApi();
totalSalesTaxForOrder = ((ITaxCalculatorApi)taxApi).CalculateSalesTaxForOrder(order);
}
}
catch (InvalidOperationException iox)
{
// taxApi client did not like something. Let's check further
if (iox.Data.Contains("Response"))
{
HttpResponseMessage apiResponse = (HttpResponseMessage)iox.Data["Response"];
Response.StatusCode = (int)apiResponse.StatusCode;
Response.HttpContext.Features.Get <IHttpResponseFeature>().ReasonPhrase = apiResponse.ReasonPhrase;
}
}
catch (Exception)
{
Response.StatusCode = 500;
}
return(totalSalesTaxForOrder);
}