private async Task UpdateReminderAsync(StoredReminder reminder)
{
//add a small threshold to prevent off by one errors
var futureTime = Math.Max(MinReminderFuture.TotalMinutes, reminder.Minutes) + EventDiscoveryOverlap;
var evts = (await calendarService.Get(reminder.UserId, DateTimeOffset.Now,
DateTimeOffset.Now.AddMinutes(futureTime))) ?? new Event[0];
var events = (evts).Where(v => v.Start >= DateTimeOffset.Now);
var existingInstances = new List <ReminderInstance>(reminder.Instances);
foreach (var e in events)
{
var instance = reminder.Instances.Where(v => v.EventId == e.Id && v.FeedId == e.FeedId).FirstOrDefault();
var shouldFire = e.Start.AddMinutes(-reminder.Minutes) <= DateTimeOffset.Now;
var eventHash = e.GenerateHash();
if (null != instance)
{
existingInstances.Remove(instance);
if (instance.Hash != eventHash)
{
instance = await reminderRepository.UpdateInstanceAsync(instance.Id, eventHash);
await FireOrInstallAsync(reminder, e, instance, shouldFire, eventHash);
}
}
else
{
instance = new ReminderInstance()
{
Id = Guid.NewGuid().ToString(),
EventId = e.Id,
FeedId = e.FeedId,
Hash = eventHash
};
await reminderRepository.AddInstanceAsync(reminder.Id, instance);
await FireOrInstallAsync(reminder, e, instance, shouldFire, eventHash);
}
}
foreach (var instance in existingInstances)
{
if (instance.RemindRemovalUntil.HasValue && instance.RemindRemovalUntil > DateTimeOffset.Now.UtcDateTime)
{
await PostReminder(reminder, new ReminderDelivery
{
ReminderId = reminder.Id,
ClientState = reminder.ClientState,
Event = null,
EventId = instance.EventId,
FeedId = instance.FeedId,
Removed = true
});
}
await reminderRepository.RemoveInstanceAsync(instance.Id);
}
}