package receiver

import (
	"log"

	"git.wntrmute.dev/kyle/sensenet/config"
	"git.wntrmute.dev/kyle/sensenet/pubsub"
	"git.wntrmute.dev/kyle/sensenet/topic"
)

const (
	packetBuffer = 64
	errBuffer    = 64
)

type Receiver struct {
	packets chan *topic.Packet
	errs    chan error
}

func receive(packets chan *topic.Packet, errs chan error, subscriber *pubsub.Subscriber) {
	packet, err := subscriber.Receive()
	if err != nil {
		errs <- err
		return
	}

	packets <- packet
}

func (rcvr *Receiver) Subscribe(addr string, publisher *config.Publisher) error {
	subscriber, err := pubsub.NewSubscriber(addr, publisher.Name, publisher.Topics...)
	if err != nil {
		return err
	}

	go func() {
		for {
			receive(rcvr.packets, rcvr.errs, subscriber)
		}
	}()

	return nil
}

func (rcvr *Receiver) LogErrors() {
	for {
		select {
		case err := <-rcvr.errs:
			log.Println(err)
		}
	}
}

func New() *Receiver {
	return &Receiver{
		packets: make(chan *topic.Packet, packetBuffer),
		errs:    make(chan error, errBuffer),
	}
}