public NumberPlateTrigger FunctionHandler(NumberPlateTrigger payload, ILambdaContext context)
{
context.Logger.LogLine($"Process NOOP: process has started. Request={JsonConvert.SerializeObject(payload)}");
string msg = "";
if (payload.numberPlate.detected == true)
{
/////////////////////////////////////////////////////////////
//
// TODO: Read the credit value from the database and decrement it
//
/////////////////////////////////////////////////////////////
msg = "Number plate " + payload.numberPlate.numberPlateString + " was charged $$" + payload.charge + ".";
}
else
{
msg = "Number plate " + payload.numberPlate.numberPlateString + " was not found. This will require manual resolution.";
/////////////////////////////////////////////////////////////
//
// TODO: Return 'errorUnknownNumberPlate' error
//
/////////////////////////////////////////////////////////////
}
context.Logger.LogLine(msg);
return(payload);
}
public async Task <NumberPlateTrigger> FunctionHandler(NumberPlateTrigger payload, ILambdaContext context)
{
Random rand = new Random((Int32)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds);
if (rand.NextDouble() > double.Parse(Environment.GetEnvironmentVariable("RandomProcessingErrorProbability")))
{
string message = "Congratulations! A random processing error occurred!";
context.Logger.LogLine(message);
////////////////////////////////////////////////////////////
//
// TODO: Return 'RandomProcessingError' error
///
/////////////////////////////////////////////////////////////
}
Table table;
Document document;
try
{
table = Table.LoadTable(dbClient, Environment.GetEnvironmentVariable("DDBTableName"));
document = await table.GetItemAsync(payload.numberPlate.numberPlateString);
if (document != null)
{
if (float.Parse(document["credit"]) > payload.charge)
{
var item = document;
item["credit"] = float.Parse(document["credit"]) - payload.charge;
Expression expr = new Expression();
expr.ExpressionStatement = "credit >= :charge";
expr.ExpressionAttributeValues[":charge"] = payload.charge;
// Optional parameters.
UpdateItemOperationConfig config = new UpdateItemOperationConfig
{
ConditionalExpression = expr,
ReturnValues = ReturnValues.AllNewAttributes
};
Document updatedRecord = await table.UpdateItemAsync(item, config);
//
// Success!
//
context.Logger.LogLine("Charge of $$" + payload.charge + " deducted from credit for " + payload.numberPlate.numberPlateString);
}
else
{
string message = "Driver for number plate " + payload.numberPlate.numberPlateString + "(" + document["ownerFirstName"] + ")" + document["ownerLastName"] + ") has insufficient credit (" + document["credit"] + ") for a charge of " + payload.charge;
context.Logger.LogLine(message);
/////////////////////////////////////////////////////////////
//
// TODO: Return 'InsufficientCreditError' error
//
/////////////////////////////////////////////////////////////
}
}
else
{
string message = "Number plate " + payload.numberPlate.numberPlateString + "was not found. This will require manual resolution.";
context.Logger.LogLine(message);
/////////////////////////////////////////////////////////////
//
// TODO: Return 'UnknownNumberPlateError' error
//
/////////////////////////////////////////////////////////////
}
}
catch (AmazonDynamoDBException e)
{
context.Logger.LogLine(e.StackTrace);
////////////////////////////////////////////////////////////
//
// TODO: Return 'DatabaseAccessError' error
///
/////////////////////////////////////////////////////////////
}
catch (Exception e)
{
context.Logger.LogLine(e.StackTrace);
////////////////////////////////////////////////////////////
//
// TODO: Return 'GenericError' error
///
/////////////////////////////////////////////////////////////
}
return(payload);
}