public static async Task <Tuple <string, bool> > AccrueInterestForSpecificAccount
([ActivityTrigger] IDurableActivityContext accrueInterestContext)
{
const decimal DEBIT_INTEREST_RATE = 0.001M;
const decimal CREDIT_INTEREST_RATE = 0.0005M;
string accountNumber = accrueInterestContext.GetInput <string>();
#region Tracing telemetry
Activity.Current.AddTag("Account Number", accountNumber);
#endregion
if (!string.IsNullOrEmpty(accountNumber))
{
EventStream bankAccountEvents = new EventStream(new EventStreamAttribute("Bank", "Account", accountNumber));
if (await bankAccountEvents.Exists())
{
// Has the accrual been done today for this account?
Classification clsAccruedToday = new Classification(new ClassificationAttribute("Bank", "Account", accountNumber, nameof(InterestAccruedToday)));
ClassificationResponse isAccrued = await clsAccruedToday.Classify <InterestAccruedToday>();
if (isAccrued.Result != ClassificationResponse.ClassificationResults.Include)
{
// Get the account balance
Projection prjBankAccountBalance = new Projection(new ProjectionAttribute("Bank", "Account", accountNumber, nameof(Balance)));
// Get the current account balance, as at midnight
Balance projectedBalance = await prjBankAccountBalance.Process <Balance>(DateTime.Today);
if (null != projectedBalance)
{
Account.Events.InterestAccrued evAccrued = new Account.Events.InterestAccrued()
{
Commentary = $"Daily scheduled interest accrual",
AccrualEffectiveDate = DateTime.Today // set the accrual to midnight today
};
// calculate the accrual amount
if (projectedBalance.CurrentBalance >= 0)
{
// Using the credit rate
evAccrued.AmountAccrued = CREDIT_INTEREST_RATE * projectedBalance.CurrentBalance;
evAccrued.InterestRateInEffect = CREDIT_INTEREST_RATE;
}
else
{
// Use the debit rate
evAccrued.AmountAccrued = DEBIT_INTEREST_RATE * projectedBalance.CurrentBalance;
evAccrued.InterestRateInEffect = DEBIT_INTEREST_RATE;
}
try
{
await bankAccountEvents.AppendEvent(evAccrued, isAccrued.AsOfSequence);
}
catch (EventSourcingOnAzureFunctions.Common.EventSourcing.Exceptions.EventStreamWriteException)
{
// We can't be sure this hasn't already run...
return(new Tuple <string, bool>(accountNumber, false));
}
}
}
}
}
return(new Tuple <string, bool>(accountNumber, true));
}
public static async Task <HttpResponseMessage> AccrueInterestRun(
[HttpTrigger(AuthorizationLevel.Function, "POST", Route = @"AccrueInterest/{accountnumber}")] HttpRequestMessage req,
string accountnumber,
[EventStream("Bank", "Account", "{accountnumber}")] EventStream bankAccountEvents,
[Projection("Bank", "Account", "{accountnumber}", nameof(Balance))] Projection prjBankAccountBalance,
[Classification("Bank", "Account", "{accountnumber}", nameof(InterestAccruedToday))] Classification clsAccruedToday)
{
// Set the start time for how long it took to process the message
DateTime startTime = DateTime.UtcNow;
if (!await bankAccountEvents.Exists())
{
// You cannot accrue interest if the account does not exist
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Account {accountnumber} does not exist",
0)));
}
ClassificationResponse isAccrued = await clsAccruedToday.Classify <InterestAccruedToday>();
if (isAccrued.Result == ClassificationResponse.ClassificationResults.Include)
{
// The accrual for today has been performed for this account
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Interest accrual already done on account {accountnumber} today",
isAccrued.AsOfSequence),
FunctionResponse.MEDIA_TYPE
));
}
// get the request body...
InterestAccrualData data = await req.Content.ReadAsAsync <InterestAccrualData>();
// Get the current account balance, as at midnight
Balance projectedBalance = await prjBankAccountBalance.Process <Balance>(DateTime.Today);
if (null != projectedBalance)
{
Account.Events.InterestAccrued evAccrued = new Account.Events.InterestAccrued()
{
Commentary = data.Commentary,
AccrualEffectiveDate = DateTime.Today // set the accrual to midnight today
};
if (projectedBalance.CurrentBalance >= 0)
{
// Using the credit rate
evAccrued.AmountAccrued = data.CreditInterestRate * projectedBalance.CurrentBalance;
}
else
{
// Use the debit rate
evAccrued.AmountAccrued = data.DebitInterestRate * projectedBalance.CurrentBalance;
}
try
{
await bankAccountEvents.AppendEvent(evAccrued, isAccrued.AsOfSequence);
}
catch (EventSourcingOnAzureFunctions.Common.EventSourcing.Exceptions.EventStreamWriteException exWrite)
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Failed to write interest accrual event {exWrite.Message}",
projectedBalance.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.OK,
ProjectionFunctionResponse.CreateResponse(startTime,
false,
$"Interest accrued for account {accountnumber} is {evAccrued.AmountAccrued}",
projectedBalance.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
else
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Unable to get current balance for account {accountnumber} for interest accrual",
0),
FunctionResponse.MEDIA_TYPE
));
}
}