nano_golang_websocket.go

//nano_golang_websocket.go creates a connection to the beta nano node and logs the hash 
//of confirmed transactions sent from the websocket endpoint.  The hash and subtype
//are printed to the terminal also.

package main

import (
	"encoding/json"
	"log"
	"os"
	"os/signal"
	"strings"

	"github.com/sacOO7/gowebsocket"
)

//WebsocketMessage contains the Topic, Time and Message sent to the websocket client
type WebsocketMessage struct {
	Topic   string      `json:"topic"`
	Time    string      `json:"time"`
	Message NodeMessage `json:"message"`
}

//NodeMessage is the contents of the message sent from the Nano node.
type NodeMessage struct {
	Account string `json:"account"`
	Amount  string `json:"amount"`
	Hash    string `json:"hash"`
	Block   Block  `json:"block"`
}

//Block is the information for the provided block
type Block struct {
	Type           string `json:"state"`
	Account        string `json:"account"`
	Previous       string `json:"previous"`
	Representative string `json:"representative"`
	Balance        string `json:"balance"`
	Link           string `json:"link"`
	LinkAsAccount  string `json:"link_as_account"`
	Work           string `json:"work"`
	Subtype        string `json:"subtype"`
}

func main() {

	workLog := make(map[string]string)
	previousLog := make(map[string]string)
	timeLog := make(map[string]string)
	count := 0

	interrupt := make(chan os.Signal, 1)
	signal.Notify(interrupt, os.Interrupt)

	socket := gowebsocket.New("ws://[::1]:57000/")

	socket.OnConnected = func(socket gowebsocket.Socket) {
		log.Println("Connected to server")
		data := map[string]string{"action": "subscribe", "topic": "confirmation"}
		dataJSON, _ := json.Marshal(data)
		socket.SendBinary(dataJSON)
	}
	socket.OnTextMessage = func(message string, socket gowebsocket.Socket) {
		//log.Println("Recieved message " + message)
		var responseJSON WebsocketMessage

		d := json.NewDecoder(strings.NewReader(message))
		d.Decode(&responseJSON)

		_, wok := workLog[responseJSON.Message.Hash]
		if !wok {
			workLog[responseJSON.Message.Hash] = responseJSON.Message.Block.Work
		}
		_, pok := previousLog[responseJSON.Message.Hash]
		if !pok {
			previousLog[responseJSON.Message.Hash] = responseJSON.Message.Block.Previous
		}
		_, tok := timeLog[responseJSON.Message.Hash]
		if !tok {
			timeLog[responseJSON.Message.Hash] = responseJSON.Time
		}
		count++
		log.Println(count)
	}

	socket.Connect()

	for {
		select {
		case <-interrupt:
			f, err := os.OpenFile("text.log",
				os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
			if err != nil {
				log.Println(err)
			}
			defer f.Close()

			logger := log.New(f, "prefix", log.LstdFlags)
			for k := range workLog {
				logger.Printf(",%v,%v,%v,%v\n", k, workLog[k], previousLog[k], timeLog[k])
			}
			log.Println("Websocket connection closed.")
			socket.Close()
			return
		}
	}
}