main.go

package main

import (
	"flag"
	"net/http"
	"strconv"
	"strings"
)

var (
	httpPort = flag.Int("http_port", 80, "HTTP port to serve on (defaults to 80)")
)

func main() {
	// Parse the flags
	flag.Parse()
	mux := http.NewServeMux()
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		query := r.URL.Query()
		host := strings.Split(query.Get("state"), "-")[0]
		state := strings.Split(query.Get("state"), "-")[1]
        usagePointId := query.Get("usage_point_id")
		code := query.Get("code")
		redir := "http://" + host + "?code=" + code + "?state="+ state +"&usage_point_id=" + usagePointId
		http.Redirect(w, r, redir, 302)
	})

	http.ListenAndServe(":"+strconv.Itoa(*httpPort), mux)
}