public static async Task <Tuple <string, bool> > SetOverdraftForInterestForSpecificAccount
([ActivityTrigger] IDurableActivityContext interestOverdraftContext)
{
string accountNumber = interestOverdraftContext.GetInput <string>();
#region Tracing telemetry
Activity.Current.AddTag("Account Number", accountNumber);
#endregion
bool success = true;
Command cmdPayInterest = new Command(
new CommandAttribute("Bank",
"Pay Interest",
interestOverdraftContext.InstanceId)
);
if (!string.IsNullOrWhiteSpace(accountNumber))
{
string result = "No overdraft required";
await cmdPayInterest.InitiateStep(AccountCommands.COMMAND_STEP_OVERDRAFT,
"Bank",
"Account",
accountNumber);
// run the "set overdraft limit for interest" function
// 1- Get interest due...
Projection prjInterestDue = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(InterestDue)
)
);
// get the interest owed / due as now
InterestDue interestDue = await prjInterestDue.Process <InterestDue>();
if (null != interestDue)
{
// if the interest due is negative we need to make sure the account has sufficient balance
if (interestDue.Due < 0.00M)
{
Projection prjBankAccountBalance = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(InterestDue)
)
);
Balance balance = await prjBankAccountBalance.Process <Balance>();
if (null != balance)
{
decimal availableBalance = balance.CurrentBalance;
// is there an overdraft?
Projection prjBankAccountOverdraft = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(OverdraftLimit)
)
);
OverdraftLimit overdraft = await prjBankAccountOverdraft.Process <OverdraftLimit>();
if (null != overdraft)
{
availableBalance += overdraft.CurrentOverdraftLimit;
}
if (availableBalance < interestDue.Due)
{
// Force an overdraft extension
EventStream bankAccountEvents = new EventStream(
new EventStreamAttribute(
"Bank",
"Account",
accountNumber
)
);
decimal newOverdraft = overdraft.CurrentOverdraftLimit;
decimal extension = 10.00M + Math.Abs(interestDue.Due % 10.00M);
OverdraftLimitSet evNewLimit = new OverdraftLimitSet()
{
OverdraftLimit = newOverdraft + extension,
Commentary = $"Overdraft extended to pay interest of {interestDue.Due} ",
Unauthorised = true
};
result = $"Overdraft set to {evNewLimit.OverdraftLimit } ({evNewLimit.Commentary})";
try
{
await bankAccountEvents.AppendEvent(evNewLimit, balance.CurrentSequenceNumber);
}
catch (EventSourcingOnAzureFunctions.Common.EventSourcing.Exceptions.EventStreamWriteException)
{
success = false;
}
}
}
}
}
// Log the step completion if it was successful
if (success)
{
await cmdPayInterest.StepCompleted(AccountCommands.COMMAND_STEP_OVERDRAFT,
result,
"Bank",
"Account",
accountNumber);
}
}
return(new Tuple <string, bool>(accountNumber, success));
}
public static async void SetOverdraftForInterestCommandStep
([EventGridTrigger] EventGridEvent egStepTriggered
)
{
// Get the parameters from the event grid trigger
// (Payload is a Command Step Initiated)
Command cmdApplyAccruedInterest = new Command(egStepTriggered);
if (null != cmdApplyAccruedInterest)
{
string result = $"No overdraft extension required";
if (cmdApplyAccruedInterest.CommandName == COMMAND_STEP_OVERDRAFT)
{
// Get the parameter for account number
string accountNumber = (string)(await cmdApplyAccruedInterest.GetParameterValue("Account Number"));
if (!string.IsNullOrWhiteSpace(accountNumber))
{
// run the "set overdraft limit for interest" function
// 1- Get interest due...
Projection prjInterestDue = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(InterestDue)
)
);
// get the interest owed / due as now
InterestDue interestDue = await prjInterestDue.Process <InterestDue>();
if (null != interestDue)
{
// if the interest due is negative we need to make sure the account has sufficient balance
if (interestDue.Due < 0.00M)
{
Projection prjBankAccountBalance = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(InterestDue)
)
);
Balance balance = await prjBankAccountBalance.Process <Balance>();
if (null != balance)
{
decimal availableBalance = balance.CurrentBalance;
// is there an overdraft?
Projection prjBankAccountOverdraft = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(OverdraftLimit)
)
);
OverdraftLimit overdraft = await prjBankAccountOverdraft.Process <OverdraftLimit>();
if (null != overdraft)
{
availableBalance += overdraft.CurrentOverdraftLimit;
}
if (availableBalance < interestDue.Due)
{
// Force an overdraft extension
EventStream bankAccountEvents = new EventStream(
new EventStreamAttribute(
"Bank",
"Account",
accountNumber
)
);
decimal newOverdraft = overdraft.CurrentOverdraftLimit;
decimal extension = 10.00M + Math.Abs(interestDue.Due % 10.00M);
OverdraftLimitSet evNewLimit = new OverdraftLimitSet()
{
OverdraftLimit = newOverdraft + extension,
Commentary = $"Overdraft extended to pay interest of {interestDue.Due} ",
Unauthorised = true
};
await bankAccountEvents.AppendEvent(evNewLimit);
result = $"{evNewLimit.Commentary} on account {accountNumber }";
}
}
}
}
}
}
// mark this step as complete
await cmdApplyAccruedInterest.StepCompleted(COMMAND_STEP_OVERDRAFT, result);
}
}
public static async Task <int> SetOverdraftForInterestCommandStep
([ActivityTrigger] IDurableActivityContext setOverdraftContext)
{
int overdraftSequenceNumber = 0;
CommandAttribute payload = setOverdraftContext.GetInput <CommandAttribute>();
Command cmdApplyAccruedInterest = null;
if (payload == null)
{
cmdApplyAccruedInterest = new Command(payload);
}
else
{
cmdApplyAccruedInterest = new Command(new CommandAttribute("Bank", "Apply Accrued Interest"));
}
// Set the next step "setting an overdraft if needed"
await cmdApplyAccruedInterest.InitiateStep(COMMAND_STEP_OVERDRAFT);
string accountNumber = (string)(await cmdApplyAccruedInterest.GetParameterValue("Account Number"));
string result = $"No overdraft extension required";
if (!string.IsNullOrWhiteSpace(accountNumber))
{
// run the "set overdraft limit for interest" function
// 1- Get interest due...
Projection prjInterestDue = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(InterestDue)
)
);
// get the interest owed / due as now
InterestDue interestDue = await prjInterestDue.Process <InterestDue>();
if (null != interestDue)
{
// if the interest due is negative we need to make sure the account has sufficient balance
if (interestDue.Due < 0.00M)
{
Projection prjBankAccountBalance = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(InterestDue)
)
);
Balance balance = await prjBankAccountBalance.Process <Balance>();
if (null != balance)
{
decimal availableBalance = balance.CurrentBalance;
// is there an overdraft?
Projection prjBankAccountOverdraft = new Projection(
new ProjectionAttribute(
"Bank",
"Account",
accountNumber,
nameof(OverdraftLimit)
)
);
OverdraftLimit overdraft = await prjBankAccountOverdraft.Process <OverdraftLimit>();
if (null != overdraft)
{
availableBalance += overdraft.CurrentOverdraftLimit;
}
if (availableBalance < interestDue.Due)
{
// Force an overdraft extension
EventStream bankAccountEvents = new EventStream(
new EventStreamAttribute(
"Bank",
"Account",
accountNumber
)
);
decimal newOverdraft = overdraft.CurrentOverdraftLimit;
decimal extension = 10.00M + Math.Abs(interestDue.Due % 10.00M);
OverdraftLimitSet evNewLimit = new OverdraftLimitSet()
{
OverdraftLimit = newOverdraft + extension,
Commentary = $"Overdraft extended to pay interest of {interestDue.Due} ",
Unauthorised = true
};
await bankAccountEvents.AppendEvent(evNewLimit, overdraft.CurrentSequenceNumber);
overdraftSequenceNumber = 1 + overdraft.CurrentSequenceNumber;
await cmdApplyAccruedInterest.SetParameter("Overdraft Extension", extension);
result = $"{evNewLimit.Commentary} on account {accountNumber }";
}
}
}
}
}
await cmdApplyAccruedInterest.SetParameter("Overdraft Event Sequence Number", overdraftSequenceNumber);
// mark this step as complete
await cmdApplyAccruedInterest.StepCompleted(COMMAND_STEP_OVERDRAFT, result);
return(overdraftSequenceNumber);
}
public static async Task <HttpResponseMessage> ExtendOverdraftForInterestRun(
[HttpTrigger(AuthorizationLevel.Function, "POST", Route = @"ExtendOverdraftForInterest/{accountnumber}")] HttpRequestMessage req,
string accountnumber,
[EventStream("Bank", "Account", "{accountnumber}")] EventStream bankAccountEvents,
[Projection("Bank", "Account", "{accountnumber}", nameof(InterestDue))] Projection prjInterestDue,
[Projection("Bank", "Account", "{accountnumber}", nameof(Balance))] Projection prjBankAccountBalance,
[Projection("Bank", "Account", "{accountnumber}", nameof(OverdraftLimit))] Projection prjBankAccountOverdraft
)
{
// Bolierplate: Set the start time for how long it took to process the message
DateTime startTime = DateTime.UtcNow;
// Check the balance is negative
// get the interest owed / due as now
InterestDue interestDue = await prjInterestDue.Process <InterestDue>();
if (null != interestDue)
{
// if the interest due is negative we need to make sure the account has sufficient balance
if (interestDue.Due < 0.00M)
{
Balance balance = await prjBankAccountBalance.Process <Balance>();
if (null != balance)
{
decimal availableBalance = balance.CurrentBalance;
// is there an overdraft?
OverdraftLimit overdraft = await prjBankAccountOverdraft.Process <OverdraftLimit>();
if (null != overdraft)
{
availableBalance += overdraft.CurrentOverdraftLimit;
}
if (availableBalance < interestDue.Due)
{
decimal newOverdraft = overdraft.CurrentOverdraftLimit;
decimal extension = 10.00M + Math.Abs(interestDue.Due % 10.00M);
OverdraftLimitSet evNewLimit = new OverdraftLimitSet()
{
OverdraftLimit = newOverdraft + extension,
Commentary = $"Overdraft extended to pay interest of {interestDue.Due} ",
Unauthorised = true
};
await bankAccountEvents.AppendEvent(evNewLimit);
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.OK,
ProjectionFunctionResponse.CreateResponse(startTime,
false,
$"Extended the overdraft by {extension} for payment of interest {interestDue.Due} for account {accountnumber}",
interestDue.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
}
}
// Not needed
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.OK,
ProjectionFunctionResponse.CreateResponse(startTime,
false,
$"Extending the overdraft for interest not required for account {accountnumber}",
interestDue.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
else
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Unable to extend the overdraft for account {accountnumber} for interest payment",
0),
FunctionResponse.MEDIA_TYPE
));
}
}
public static async Task <HttpResponseMessage> PayInterestRun(
[HttpTrigger(AuthorizationLevel.Function, "POST", Route = @"PayInterest/{accountnumber}")] HttpRequestMessage req,
string accountnumber,
[EventStream("Bank", "Account", "{accountnumber}")] EventStream bankAccountEvents,
[Projection("Bank", "Account", "{accountnumber}", nameof(InterestDue))] Projection prjInterestDue,
[Projection("Bank", "Account", "{accountnumber}", nameof(Balance))] Projection prjBankAccountBalance,
[Projection("Bank", "Account", "{accountnumber}", nameof(OverdraftLimit))] Projection prjBankAccountOverdraft)
{
// Set the start time for how long it took to process the message
DateTime startTime = DateTime.UtcNow;
if (!await bankAccountEvents.Exists())
{
// You cannot pay 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),
FunctionResponse.MEDIA_TYPE));
}
// get the interest owed / due as now
InterestDue interestDue = await prjInterestDue.Process <InterestDue>();
if (null != interestDue)
{
// if the interest due is negative we need to make sure the account has sufficient balance
if (interestDue.Due < 0.00M)
{
Balance balance = await prjBankAccountBalance.Process <Balance>();
if (null != balance)
{
decimal availableBalance = balance.CurrentBalance;
// is there an overdraft?
OverdraftLimit overdraft = await prjBankAccountOverdraft.Process <OverdraftLimit>();
if (null != overdraft)
{
availableBalance += overdraft.CurrentOverdraftLimit;
}
if (availableBalance < interestDue.Due)
{
// can't pay the interest
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Unable to pay interest of {interestDue.Due} as available balance is only {availableBalance}",
interestDue.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
}
}
// pay the interest
decimal amountToPay = decimal.Round(interestDue.Due, 2, MidpointRounding.AwayFromZero);
if (amountToPay != 0.00M)
{
InterestPaid evInterestPaid = new InterestPaid()
{
AmountPaid = decimal.Round(interestDue.Due, 2, MidpointRounding.AwayFromZero),
Commentary = $"Interest due {interestDue.Due} as at {interestDue.CurrentSequenceNumber}"
};
await bankAccountEvents.AppendEvent(evInterestPaid);
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.OK,
ProjectionFunctionResponse.CreateResponse(startTime,
false,
evInterestPaid.Commentary,
interestDue.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
else
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.OK,
ProjectionFunctionResponse.CreateResponse(startTime,
false,
$"No interest due so none was paid out",
interestDue.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
}
else
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Unable to get interest due for account {accountnumber} for interest payment",
0),
FunctionResponse.MEDIA_TYPE
));
}
}
public static async Task <HttpResponseMessage> WithdrawMoneyRun(
[HttpTrigger(AuthorizationLevel.Function, "POST", Route = @"WithdrawMoney/{accountnumber}")] HttpRequestMessage req,
string accountnumber,
[EventStream("Bank", "Account", "{accountnumber}")] EventStream bankAccountEvents,
[Projection("Bank", "Account", "{accountnumber}", nameof(Balance))] Projection prjBankAccountBalance,
[Projection("Bank", "Account", "{accountnumber}", nameof(OverdraftLimit))] Projection prjBankAccountOverdraft)
{
// Set the start time for how long it took to process the message
DateTime startTime = DateTime.UtcNow;
if (!await bankAccountEvents.Exists())
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.NotFound,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Account {accountnumber} does not exist",
0),
FunctionResponse.MEDIA_TYPE));
}
else
{
// get the request body...
MoneyWithdrawnData data = await req.Content.ReadAsAsync <MoneyWithdrawnData>();
// get the current account balance
Balance projectedBalance = await prjBankAccountBalance.Process <Balance>();
if (null != projectedBalance)
{
OverdraftLimit projectedOverdraft = await prjBankAccountOverdraft.Process <OverdraftLimit>();
decimal overdraftSet = 0.00M;
if (null != projectedOverdraft)
{
if (projectedOverdraft.CurrentSequenceNumber != projectedBalance.CurrentSequenceNumber)
{
// The two projections are out of synch. In a real business case we would retry them
// n times to try and get a match but here we will just throw a consistency error
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Unable to get a matching state for the current balance and overdraft for account {accountnumber}",
0),
FunctionResponse.MEDIA_TYPE));
}
else
{
overdraftSet = projectedOverdraft.CurrentOverdraftLimit;
}
}
if ((projectedBalance.CurrentBalance + overdraftSet) >= data.AmountWithdrawn)
{
// attempt the withdrawal
DateTime dateWithdrawn = DateTime.UtcNow;
Account.Events.MoneyWithdrawn evWithdrawn = new Account.Events.MoneyWithdrawn()
{
LoggedWithdrawalDate = dateWithdrawn,
AmountWithdrawn = data.AmountWithdrawn,
Commentary = data.Commentary
};
try
{
await bankAccountEvents.AppendEvent(evWithdrawn, projectedBalance.CurrentSequenceNumber);
}
catch (EventSourcingOnAzureFunctions.Common.EventSourcing.Exceptions.EventStreamWriteException exWrite)
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Failed to write withdrawal event {exWrite.Message}",
0),
FunctionResponse.MEDIA_TYPE));
}
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.OK,
ProjectionFunctionResponse.CreateResponse(startTime,
false,
$"{data.AmountWithdrawn } withdrawn from account {accountnumber} (New balance: {projectedBalance.CurrentBalance - data.AmountWithdrawn}, overdraft: {overdraftSet} )",
projectedBalance.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
else
{
return(req.CreateResponse <ProjectionFunctionResponse>(System.Net.HttpStatusCode.Forbidden,
ProjectionFunctionResponse.CreateResponse(startTime,
true,
$"Account {accountnumber} does not have sufficent funds for the withdrawal of {data.AmountWithdrawn} (Current balance: {projectedBalance.CurrentBalance}, overdraft: {overdraftSet} )",
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}",
projectedBalance.CurrentSequenceNumber),
FunctionResponse.MEDIA_TYPE));
}
}
}