public async Task <PushSubscription> SubscribeAsync(string clientId, PushSubscription subscription)
{
Subscription stored = null;
var client = await _db.ClientSet.FindAsync(clientId);
if (client == null)
{
return(null);
}
// retrieve existing, if any
stored = await _db.SubscriptionSet
.Include(s => s.Client)
.Where(i => i.ClientId == clientId &&
((!string.IsNullOrEmpty(subscription.UserId) && i.UserId == subscription.UserId) ||
(string.IsNullOrEmpty(subscription.UserId) && i.P256Dh == subscription.P256Dh()))
)
.FirstOrDefaultAsync();
// expired or disabled client?
if (stored != null &&
(
!client.IsEnabled ||
(stored.Expires.HasValue == true && DateTimeOffset.FromUnixTimeMilliseconds(stored.Expires.Value) < DateTimeOffset.UtcNow)
)
)
{
// tidy up
_db.Remove(stored);
stored = null;
}
// client isn't enabled?
if (!client.IsEnabled)
{
// tidy up already done, exit
return(null);
}
// (re)new
if (stored == null)
{
stored = _mapper.Map <Subscription>(subscription);
stored.ClientId = clientId;
await _db.AddAsync(stored);
await _db.SaveChangesAsync(true);
}
// update (userId, basically)
_mapper.Map(stored, subscription);
return(subscription);
}
