package btc

import (
	"encoding/hex"
	"fmt"
	"log"

	zmq "github.com/pebbe/zmq4"
)

const (
	TOPIC_RAWTX     = "rawtx"
	TOPIC_RAWBLOCK  = "rawblock"
	TOPIC_HASHBLOCK = "hashblock"
)

type Zmq struct {
	subscriber *zmq.Socket
}

func (q *Zmq) Connect(address string) error {
	subscriber, err := zmq.NewSocket(zmq.SUB)
	if err != nil {
		return fmt.Errorf("error creating ZeroMQ subscriber: %w", err)
	}

	if err := subscriber.Connect("tcp://" + address); err != nil {
		return fmt.Errorf("error connecting to ZeroMQ socket: %w", err)
	}

	if err := subscriber.SetSubscribe(TOPIC_HASHBLOCK); err != nil {
		return fmt.Errorf("subscriber.SetSubscribe: %w", err)
	}

	q.subscriber = subscriber
	log.Println("subsribed to: " + address)
	return nil
}

func (q *Zmq) Close() error {
	return q.subscriber.Close()
}
func (q *Zmq) Listen(blocksChan chan<- string) {
	if q.subscriber == nil {
		log.Fatalln("subscriber cannot be nil")
		return
	}
	log.Println("Listening for new blocks...")
	for {
		msgParts, err := q.subscriber.RecvMessageBytes(0)
		if err != nil {
			log.Println("Error receiving message:", err)
			continue
		}

		if len(msgParts) < 2 {
			log.Println("Received message part is too short:", msgParts)
			continue
		}

		topic := string(msgParts[0])
		switch topic {
		case TOPIC_HASHBLOCK:
			blockHash := hex.EncodeToString(msgParts[1])
			blocksChan <- blockHash
		case TOPIC_RAWTX:
			// TODO: do something with raw tx
			continue
		}
	}
}