package session

import (
	"io"
	"log"

	"badat.dev/maeqtt/v2/mqtt/packets"
	"badat.dev/maeqtt/v2/subscription"
)

func (s *Session) VisitConnect(_ packets.ConnectPacket) {
	// Disconnect, we handle the connect packet in Connect,
	// this means that we have an estabilished connection already
	log.Println("WARN: Got a connect packet on an already estabilished connection")
	s.Disconnect(packets.DisconnectReasonCodeProtocolError)
}

func (s *Session) VisitPublish(p packets.PublishPacket) {
	subNodes := subscription.Subscriptions.GetSubscriptions(p.TopicName)
	for _, subNode := range subNodes {
		subNode.NodeLock.RLock()
		defer subNode.NodeLock.RUnlock()
		if p.QOSLevel == 0 {
			if p.PacketId != nil {
				log.Printf("Client: %v, Got publish with qos 0 and a packet id, ignoring\n", s.ClientID)
				return
			}
		} else if p.QOSLevel == 1 {
			var reason packets.PubackReasonCode = packets.PubackReasonCodeSuccess
			ack := packets.PubackPacket{
				PacketID: *p.PacketId,
				Reason:   reason,
			}
			err := s.Connection.sendPacket(ack)
			if err != nil {
				panic("TODO")
			}
		} else if p.QOSLevel == 2 {
			panic("UNIMPLEMENTED QOS level 2")
		}

		for _, sub := range subNode.Subscriptions {
			if !(sub.NoLocal && sub.SubscriptionChannel == s.SubscriptionChannel) {
				go func(sub subscription.Subscription) { sub.SubscriptionChannel <- p }(sub)
			}
		}
	}
}

func (s *Session) VisitDisconnect(p packets.DisconnectPacket) {
	err := s.Connection.close()
	if err != nil && err != io.ErrClosedPipe {
		log.Println("Error closing connection", err)
	}
	s.onDisconnect()
}

func (s *Session) VisitSubscribe(p packets.SubscribePacket) {
	for _, filter := range p.TopicFilters {
		subscription.Subscriptions.Subscribe(filter, s.SubscriptionChannel)
	}
	err := s.Connection.sendPacket(packets.SubAckPacket{
		PacketID: p.PacketId,
		Reason:   packets.SubackReasonGrantedQoSTwo,
	})
	if err != nil {
		panic("TODO")
	}
}

func (s *Session) VisitUnsubscribe(p packets.UnsubscribePacket) {
	for _, topic := range p.Topics {
		subscription.Subscriptions.Unsubscribe(topic, s.SubscriptionChannel)
	}
	err := s.Connection.sendPacket(packets.UnsubAckPacket{
		PacketID: p.PacketID,
		Reason:   packets.UnsubackReasonSuccess,
	})
	if err != nil {
		panic("TODO")
	}
}

func (s *Session) VisitPing(p packets.PingreqPacket) {
	_ = s.Connection.sendPacket(packets.PingrespPacket{})
}


//TODO implement QoSLevel 2
func (s *Session) VisitPubackPacket(_ packets.PubackPacket) {
	panic("not implemented") 
}

func (s *Session) VisitPubrecPacket(_ packets.PubrecPacket) {
	panic("not implemented") 
}

func (s *Session) VisitPubrelPacket(_ packets.PubrelPacket) {
	panic("not implemented") 
}

func (s *Session) VisitPubcompPacket(_ packets.PubcompPacket) {
	panic("not implemented") 
}