private async Task HandleSubscribeAsync(ControlMessage subscribeMessage)
{
WSMessage outboundMessage = null;
if (subscribeMessage.ClientId != this.state.ClientId && this.state.ClientId != null)
{
outboundMessage = new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT,
Payload = $"Error: ClientId mismatch ! "
};
outboundQueue.Add(outboundMessage.ToJson());
return;
}
if (await state.redisDB.HashExistsAsync(this.state.ClientId = subscribeMessage.ClientId, subscribeMessage.Channel))
{
outboundMessage = new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT,
Payload = $"Error: ALREADY SUBSCRIBED TO CHANNEL {subscribeMessage.Channel}"
};
outboundQueue.Add(outboundMessage.ToJson());
return;
}
await this.state.subscriber.SubscribeAsync(subscribeMessage.Channel, this.OnRedisMessageHandler);
await state.redisDB.HashSetAsync(subscribeMessage.ClientId, subscribeMessage.Channel, "set");
outboundMessage = new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT,
Payload = $"Subscribed to channel : {subscribeMessage.Channel} SUCCESSFULLY !"
};
outboundQueue.Add(outboundMessage.ToJson());
}
// message handling routine
// SUBSCRIBE- adds channel to redis hashset
// UNSUBSCRIBE- deletes channel from redis hashset
// MESSAGE - publishes redis message to target channel
// GET_CHANNELS - fetches all user subscribed channels from redis hashset
private async Task HandleMessageAsync(WSMessage message)
{
switch (message.Kind)
{
case WSMessage.DISCRIMINATOR.CLIENT__SUBSCRIBE:
ControlMessage subscribeMessage = JsonSerializer.Deserialize <ControlMessage>(message.Payload);
await this.HandleSubscribeAsync(subscribeMessage);
break;
case WSMessage.DISCRIMINATOR.CLIENT_UNSUBSCRIBE:
ControlMessage unsubscribeMessage = JsonSerializer.Deserialize <ControlMessage>(message.Payload);
await this.HandleUnsubscribeAsync(unsubscribeMessage);
break;
case WSMessage.DISCRIMINATOR.CLIENT_MESSAGE:
ChatMessage chatMessage = JsonSerializer.Deserialize <ChatMessage>(message.Payload);
await this.HandleMessageAsync(chatMessage);
break;
case WSMessage.DISCRIMINATOR.CLIENT_GET_CHANNELS:
await this.HandleGetChannelsAsync(message);
break;
}
}
private async Task HandleGetChannelsAsync(WSMessage message)
{
var channels = await this.state.redisDB.HashGetAllAsync(this.state.ClientId);
outboundQueue.Add(new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT,
Payload = channels.ToJson()
}
.ToJson());
}
private async Task HandleMessageAsync(ChatMessage chatMessage)
{
if (!await this.state.redisDB.HashExistsAsync(chatMessage.ClientId, chatMessage.Channel))
{
WSMessage outboundMessage = new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT,
Payload = $"Can not send message. Client : {chatMessage.ClientId} " +
$"does not exist or is not subscribed to channel : {chatMessage.Channel}"
};
outboundQueue.Add(outboundMessage.ToJson());
}
await this.state.subscriber.PublishAsync(chatMessage.Channel, $"Channel : {chatMessage.Channel}, Sender : {chatMessage.ClientId}, Message : {chatMessage.Message}");
}
private async Task HandleUnsubscribeAsync(ControlMessage unsubscribeMessage)
{
WSMessage outboundMessage = null;
bool deleted = await state.redisDB.HashDeleteAsync(this.state.ClientId, unsubscribeMessage.Channel);
if (!deleted)
{
outboundMessage = new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT, Payload = $" UNSUBSCRIBE UNSUCCESSFUL"
};
outboundQueue.Add(outboundMessage.ToJson());
return;
}
await this.state.subscriber.UnsubscribeAsync(unsubscribeMessage.Channel, this.OnRedisMessageHandler);
outboundMessage = new WSMessage {
Kind = WSMessage.DISCRIMINATOR.SERVER__RESULT,
Payload = $" UNSUBSCRIBE SUCCESSFUL"
};
outboundQueue.Add(outboundMessage.ToJson());
}