/
chat.go
210 lines (177 loc) · 4.19 KB
/
chat.go
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package main
import (
"flag"
"log"
"net/http"
"net/url"
"strconv"
"strings"
"github.com/gorilla/websocket"
)
// Message 'go-enforced' comment -_-
type Message struct {
Email string `json:"email"`
Username string `json:"username"`
Message string `json:"message"`
}
// Server holds information about connected servers
type Server struct {
Address string `json:"address"`
}
var mode = flag.String("mode", "default", "Server mode: Central/Regular")
var address = flag.String("addr", "default", "Central Server Address")
var clients = make(map[*websocket.Conn]bool)
var servers = make(map[*websocket.Conn]bool)
var broadcast = make(chan Message)
var connect = make(chan Server)
var upgrader = websocket.Upgrader{}
// holds websocket of newly joined server(only used by central server)
var newlyJoinedServer *websocket.Conn
func listenForServers() {
if *address == "default" {
log.Printf("No argument provided: Not connecting to central server...\n Enjoy as a standalone chat!")
return
}
centralServerURL := url.URL{Scheme: "ws", Host: *address, Path: "/ws"}
ws, _, err := websocket.DefaultDialer.Dial(centralServerURL.String(), nil)
if err != nil {
log.Fatal("dial:", err)
}
defer ws.Close()
for {
var server Server
err := ws.ReadJSON(&server)
if err != nil {
log.Printf("error: %v", err)
}
connect <- server
}
}
func handleServers() {
for {
server := <-connect
newServerURL := url.URL{Scheme: "ws", Host: server.Address, Path: "/ws/servers"}
ws, _, err := websocket.DefaultDialer.Dial(newServerURL.String(), nil)
if err != nil {
log.Printf("error: %v", err)
}
defer ws.Close()
servers[ws] = true
}
}
func handleConnections(w http.ResponseWriter, r *http.Request) {
ws, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Fatal(err)
}
defer ws.Close()
clients[ws] = true
for {
var msg Message
err := ws.ReadJSON(&msg)
if err != nil {
log.Printf("error: %v", err)
delete(clients, ws)
break
}
broadcast <- msg
}
}
func handleServerConnections(w http.ResponseWriter, r *http.Request) {
ws, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Fatal(err)
}
defer ws.Close()
servers[ws] = true
for {
var msg Message
err := ws.ReadJSON(&msg)
if err != nil {
log.Printf("error: %v", err)
delete(servers, ws)
break
}
broadcast <- msg
}
}
func handleMessages() {
for {
msg := <-broadcast
for client := range clients {
err := client.WriteJSON(msg)
if err != nil {
log.Printf("error: %v", err)
client.Close()
delete(clients, client)
}
}
for server := range servers {
err := server.WriteJSON(msg)
if err != nil {
log.Printf("error: %v", err)
server.Close()
delete(servers, server)
}
}
}
}
func handleCentralConnections(w http.ResponseWriter, r *http.Request) {
ws, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Printf("error: %v", err)
}
servers[ws] = true
newlyJoinedServer = ws
remoteAddr := strings.Split(r.RemoteAddr, ":")[0] + ":8080"
log.Println(remoteAddr + " joined as server...")
server := Server{Address: remoteAddr}
connect <- server
}
func emitServers() {
for {
newServer := <-connect
log.Println("Emitting " + newServer.Address + " to connected servers...")
for server := range servers {
if server == newlyJoinedServer {
continue
}
err := server.WriteJSON(newServer)
if err != nil {
log.Printf("error: %v", err)
}
}
log.Printf("Done: Emitted")
}
}
// Serve clients: central server
func Serve() {
http.HandleFunc("/ws", handleConnections)
go emitServers()
}
func main() {
flag.Parse()
if *mode == "central" {
log.Println("Starting central server...")
http.HandleFunc("/ws", handleCentralConnections)
go emitServers()
startServer(8090)
return
}
fs := http.FileServer(http.Dir("../public"))
http.Handle("/", fs)
http.HandleFunc("/ws", handleConnections)
http.HandleFunc("/ws/servers", handleServerConnections)
go listenForServers()
go handleServers()
go handleMessages()
startServer(8080)
}
func startServer(port int) {
log.Printf("Listening at port %d", port)
portString := ":" + strconv.Itoa(port)
err := http.ListenAndServe(portString, nil)
if err != nil {
log.Fatal("ListenAndServe: ", err)
}
}