chat.go

package main

import (
	"log"
	"net/http"

	"github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{
	CheckOrigin: func(r *http.Request) bool {
		return true
	},
}

var channels []chan []byte

func chat(w http.ResponseWriter, r *http.Request) {
	c, err := upgrader.Upgrade(w, r, nil)
	defer c.Close()

	myChan := make(chan []byte)
	channels = append(channels, myChan)
	myChanIndex := len(channels) - 1
	defer func() {
		log.Println("Disconnected. Removing channel...")
		channels = append(channels[:myChanIndex], channels[myChanIndex+1:]...)
	}()

	// listen to our myChan for new messages
	go func() {
		for {
			log.Println("waiting to receive from myChan")
			message := <-myChan

			log.Println("message received")
			log.Println(string(message))

			err = c.WriteMessage(websocket.TextMessage, message)

			if err != nil {
				log.Println("write:", err)
				break
			}
		}
	}()

	if err != nil {
		log.Print("upgrade:", err)
		return
	}

	for {
		log.Println("Waiting for message from reader")
		_, message, err := c.ReadMessage()

		if err != nil {
			log.Println("ReadMessage failed")
			return
		} else {
			log.Println("Sending messages")
			for _, channel := range channels {
				if channel != myChan {
					channel <- message
				}
			}
		}
	}
}

func main() {
	http.HandleFunc("/", chat)
	log.Fatal(http.ListenAndServe("localhost:17777", nil))
}