kraken.go

package main

import (
	"encoding/json"
	"log"
	"net/http"
	"strconv"
	"time"
)

func getStream(pair string, delay time.Duration) chan map[string]interface{} {
	ch := make(chan map[string]interface{}, 32)
	go func() {
		for {
			resp, err := http.Get("https://api.kraken.com/0/public/Ticker?pair=" + pair)
			if err != nil {
				log.Print(err)
				close(ch)
				return
			}
			decoder := json.NewDecoder(resp.Body)
			res := make(map[string]interface{})
			err = decoder.Decode(&res)
			if err != nil {
				log.Print(err)
				close(ch)
				return
			}
			pairs := res["result"].(map[string]interface{})
			val := pairs[pair].(map[string]interface{})
			ch <- val
			time.Sleep(delay)
		}
	}()
	return ch
}

func getLastTrades(pair string, delay time.Duration) chan float64 {
	ch := make(chan float64, 32)
	go func() {
		for tick := range getStream(pair, delay) {
			v, err := strconv.ParseFloat(tick["c"].([]interface{})[0].(string), 64)
			if err != nil {
				log.Print(err)
				close(ch)
				return
			}
			ch <- v
		}
		close(ch)
	}()
	return ch
}

func main() {
	stream := getLastTrades("XETHZEUR", 5*time.Second)
	for tick := range stream {
		log.Print(tick)
	}
}