public Subscription AddSubscription(string username)
{
//graph client is used to access graph API (create subscriptions, unpack notifications)
var graphClient = _tokenisedHttpClientFactory.GetGraphResourceClient();
//create subscription payload
var subscriptionPayload = new Subscription
{
Resource = string.Format($"Users('{username}')/events?$filter=contains(subject,'Leave')"),
ChangeType = "updated",
NotificationUrl = _appSetting.AbsentiaNotificationUrl,
ClientState = Guid.NewGuid().ToString(),
ExpirationDateTime = DateTime.UtcNow + _subscriptionLength
};
string contentString = JsonConvert.SerializeObject(subscriptionPayload,
new JsonSerializerSettings {
NullValueHandling = NullValueHandling.Ignore
});
//assemble into subscriptions request
string subscriptionsEndpoint = string.Format($"{_appSetting.MicrosoftGraphResource}/v1.0/subscriptions/");
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, subscriptionsEndpoint);
request.Content = new StringContent(contentString, System.Text.Encoding.UTF8, "application/json");
// Send the request and parse the response.
HttpResponseMessage response = graphClient.SendAsync(request).Result;
if (response.IsSuccessStatusCode)
{
// Parse the JSON response.
string stringResult = response.Content.ReadAsStringAsync().Result;
var createdSubscription = JsonConvert.DeserializeObject <Subscription>(stringResult);
if (createdSubscription != null)
{
return(createdSubscription);
}
throw new ApplicationException(string.Format($"could not deserialize response: {stringResult}"));
}
//log error
var callResult = response.Content.ReadAsStringAsync().Result;
var failureReason =
string.Format($"AddSubscription. HTTP status code:{response.StatusCode}. Error:{callResult}");
throw new ApplicationException(failureReason);
}
public void ProcessNotifications()
{
var notifications = _repository.GetPendingNotifications().ToList();
if (!notifications.Any())
{
return;
}
//graph client is used to access graph API (create subscriptions, unpack notifications)
var graphClient = _tokenisedHttpClientFactory.GetGraphResourceClient();
//outlook client is used to access graph API (update calendars)
var outlookClient = _tokenisedHttpClientFactory.GetOutlookResourceClient();
foreach (var notification in notifications)
{
try
{
var subscription = _repository.GetSubscription(notification.SubscriptionId);
if (subscription == null)
{
//if the subscription doesnt exist in the database then stop further notifications?
_subscriptionService.DeleteSubscription(notification.SubscriptionId);
_repository.SetNotificationProcessingResult(notification.NotificationId, true, "Deleted Orphan Subscription");
continue;
}
string serviceRootUrl = string.Format($"{_setting.MicrosoftGraphResource}/v1.0/");
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, serviceRootUrl + notification.Resource);
// Send the 'GET' request to retreive the event
var response = graphClient.SendAsync(request).Result;
// Get the messages from the JSON response.
if (response.IsSuccessStatusCode)
{
string stringResult = response.Content.ReadAsStringAsync().Result;
Event e = JsonConvert.DeserializeObject <Event>(stringResult);
//Appogee events have leave type in the body but "Approved Leave" in the subject
if (e.BodyPreview.Contains("Leave Type: Working From Home") &&
e.Subject.Contains(": Approved Leave"))
{
var username = _repository.GetUsernameFromSubscription(notification.SubscriptionId);
if (string.IsNullOrEmpty(username))
{
throw new ApplicationException(string.Format($"could not locate subscription '{notification.SubscriptionId}' for notification '{notification.NotificationId}'"));
}
//for Graph PATCH requests supply only those properties to be updated
var update = new
{
Subject = e.Subject.Replace(": Approved Leave", ": Approved WFH"),
ShowAs = "4"
};
string patchUrl =
string.Format($"{_setting.OutlookResource}/api/v1.0/Users('{username}')/events/{e.Id}");
HttpRequestMessage updateRequest = new HttpRequestMessage(new HttpMethod("PATCH"), patchUrl);
string contentString = JsonConvert.SerializeObject(update,
new JsonSerializerSettings {
NullValueHandling = NullValueHandling.Ignore
});
updateRequest.Content = new StringContent(contentString, System.Text.Encoding.UTF8,
"application/json");
HttpResponseMessage updateResponse = outlookClient.SendAsync(updateRequest).Result;
if (!updateResponse.IsSuccessStatusCode)
{
throw new ApplicationException(string.Format($"could not update entity: {e.Id}"));
}
_repository.SetNotificationProcessingResult(notification.NotificationId, true, "processed successfully");
}
else
{
_repository.SetNotificationProcessingResult(notification.NotificationId, true, string.Format($"no record to process, did not match predicate: Subject {e.Subject}, Body {e.BodyPreview}"));
}
}
else
{
throw new ApplicationException(String.Format($"failed processing. status code {response.StatusCode} .message {response.ReasonPhrase}"));
}
}
catch
(Exception ex)
{
_repository.SetNotificationProcessingResult(notification.NotificationId, false, ex.Message);
}
}
}