public static async Task <HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Anonymous, "post")] string data,
[Table("transactions", "AzureWebJobsStorage")] CloudTable table, HttpRequestMessage req, TraceWriter log)
{
if (string.IsNullOrWhiteSpace(data))
{
log.Error("Webhook content empty.");
return(req.CreateResponse(HttpStatusCode.OK));
}
// #if !DEBUG
req.Headers.TryGetValues("X-Hook-Signature", out var headers);
var sign = headers?.FirstOrDefault();
var secret = EnvironmentExtensions.GetEnvString("STARLING_WEBHOOK_SECRET");
var(_, valid) = WebhookPayloadValidator.Validate(sign, secret, data);
if (!valid)
{
log.Error("Webhook signature mismatch. Rejected.");
return(req.CreateResponse(HttpStatusCode.OK));
}
// #endif
var payload = StarlingDeserialiser.WebhookPayload(data);
var existing = await table.GetExistingTransaction(payload.AccountHolderUid, payload.Content.TransactionUid);
if (existing != null)
{
log.Warning($"Transaction {existing.RowKey} already processed on {existing.Timestamp}.");
return(req.CreateResponse(HttpStatusCode.OK));
}
var goalId = EnvironmentExtensions.GetEnvString("STARLING_GOAL_ID");
var remainder = (long)(Math.Abs(payload.Content.Amount) * 100 % 100);
var difference = 100 - remainder;
var threshold = EnvironmentExtensions.GetEnvInt("ROUND_UP_THRESHOLD");
if (remainder >= threshold)
{
await _httpClient.SavingsGoalsAddMoney(goalId, difference);
}
await table.SaveTransaction(payload.AccountHolderUid, payload.Content.TransactionUid, difference);
return(req.CreateResponse(HttpStatusCode.OK));
}
private static HttpClient InitHttpClient()
{
var baseAddress = EnvironmentExtensions.GetEnvString("STARLING_BASE_URL");
var accessToken = EnvironmentExtensions.GetEnvString("STARLING_ACCESS_TOKEN");
Guard.AgainstNullOrWhitespaceArgument(nameof(baseAddress), baseAddress);
Guard.AgainstNullOrWhitespaceArgument(nameof(accessToken), accessToken);
return(new HttpClient
{
BaseAddress = new Uri($"{baseAddress}"),
DefaultRequestHeaders =
{
Authorization = new AuthenticationHeaderValue("Bearer", $"{accessToken}"),
Accept =
{
new MediaTypeWithQualityHeaderValue("application/json")
}
}
});
}
public void GetEnvString_KeyNullEmptyWhitespace_ThrowsException(string val, Type exception)
{
Assert.Throws(exception, () => EnvironmentExtensions.GetEnvString(val));
}