forky-client.go

package main

import (
	"bufio"
	"encoding/json"
	"flag"
	"fmt"
	"log"
	"net/url"
	"os"
	"os/signal"
	"time"

	"github.com/gorilla/websocket"
)

var addr = flag.String("addr", "forky.io:8081", "http service address")
var mapID = flag.String("map", "", "map id")
var token = flag.String("token", "", "api token")

type AuthPacket struct {
	Token string `json:"token"`
	Map   string `json:"map"`
}

func main() {
	flag.Parse()
	log.SetFlags(0)

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

	u := url.URL{Scheme: "ws", Host: *addr, Path: "/"}
	log.Printf("connecting to %s", u.String())

	c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
	if err != nil {
		log.Fatal("dial:", err)
	}
	defer c.Close()
	done := make(chan struct{})

	c.WriteJSON(AuthPacket{
		Map:   *mapID,
		Token: *token,
	})

	go func() {
		defer c.Close()
		defer close(done)
		for {
			_, message, err := c.ReadMessage()
			if err != nil {
				log.Println("read:", err)
				return
			}
			log.Printf("recv: %s", message)
		}
	}()

	msgChan := messages()

	ticker := time.NewTicker(time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			if err := c.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
				return
			}
		case <-interrupt:
			log.Println("interrupt")
			// To cleanly close a connection, a client should send a close
			// frame and wait for the server to close the connection.
			err := c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
			if err != nil {
				log.Println("write close:", err)
				return
			}
			select {
			case <-done:
			case <-time.After(time.Second):
			}
			c.Close()
			return
		case msg, ok := <-msgChan:
			if !ok {
				log.Println("No more messages to send.")
				return
			}
			if err := c.WriteJSON(msg); err != nil {
				return
			}
		}
	}
}

type SendMessage struct {
	Type string `json:"type"`
	Data string `json:"data"`
}

type mapOp struct {
	Version   int `json:"v"`
	Operation int `json:"op"`

	// args
	A string `json:"a"`
	B string `json:"b"`
}

type mapChat struct {
	Message string `json:"message"`
}

func messages() <-chan interface{} {
	out := make(chan interface{})
	go func() {
		defer close(out)
		scanner := bufio.NewScanner(os.Stdin)
		for scanner.Scan() {
			data, _ := json.Marshal(mapChat{
				Message: scanner.Text(),
			})
			out <- SendMessage{
				Type: "chat",
				Data: string(data),
			}
		}
		if err := scanner.Err(); err != nil {
			fmt.Fprintln(os.Stderr, "reading standard input:", err)
		}
	}()
	return out
}