client.go

package main

import (
	"log"
	"net/http"
	"time"
	"encoding/json"
	"fmt"

	"github.com/gorilla/websocket"
	"github.com/golang-jwt/jwt"
)

const (
	// Time allowed to write a message to the peer.
	writeWait = 10 * time.Second

	// Time allowed to read the next pong message from the peer.
	pongWait = 60 * time.Second

	// Send pings to peer with this period. Must be less than pongWait.
	pingPeriod = (pongWait * 9) / 10

	// Maximum message size allowed from peer.
	maxMessageSize = 512
)

var (
	newline = []byte{'\n'}
	space   = []byte{' '}
)

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
}

// Client is a middleman between the websocket connection and the hub.
type Client struct {
	hub *Hub

	// The websocket connection.
	conn *websocket.Conn

	// Buffered channel of outbound messages.
	send chan []byte

	// The org the clients wants to receive updates for
	organization string
}

type Event struct {
	Organization string
	Message string
}

// writePump pumps messages from the hub to the websocket connection.
//
// A goroutine running writePump is started for each connection. The
// application ensures that there is at most one writer to a connection by
// executing all writes from this goroutine.
func (c *Client) writePump() {
	ticker := time.NewTicker(pingPeriod)
	defer func() {
		ticker.Stop()
		c.conn.Close()
	}()
	for {
		select {
		case message, ok := <-c.send:
			c.conn.SetWriteDeadline(time.Now().Add(writeWait))
			if !ok {
				// The hub closed the channel.
				c.conn.WriteMessage(websocket.CloseMessage, []byte{})
				return
			}

			w, err := c.conn.NextWriter(websocket.TextMessage)
			if err != nil {
				return
			}
			w.Write(message)

			// Add queued chat messages to the current websocket message.
			n := len(c.send)
			for i := 0; i < n; i++ {
				w.Write(newline)
				w.Write(<-c.send)
			}

			if err := w.Close(); err != nil {
				return
			}
		case <-ticker.C:
			c.conn.SetWriteDeadline(time.Now().Add(writeWait))
			if err := c.conn.WriteMessage(websocket.PingMessage, nil); err != nil {
				return
			}
		}
	}
}

// serveWs handles websocket requests from the peer.
func serveWs(hub *Hub, w http.ResponseWriter, r *http.Request) {
	// read jwt from request
	jwt := r.Header.Get("Authorization")
	if jwt == "" {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}
	jwt = jwt[7:] // remove "Bearer "
	org := extractOrg(jwt)
	fmt.Println(org)

	conn, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		log.Println(err)
		return
	}
	client := &Client{hub: hub, conn: conn, send: make(chan []byte, 256), organization: org}
	client.hub.register <- client

	// Allow collection of memory referenced by the caller by doing all work in
	// new goroutines.
	go client.writePump()
}

func notify(hub *Hub, w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var event Event
	err := json.NewDecoder(r.Body).Decode(&event)
    if err != nil {
        http.Error(w, err.Error(), http.StatusBadRequest)
        return
    }

	hub.broadcast <- []byte(event.Organization + ";" + event.Message)
}

func extractOrg(tokenStr string) (string) {
	token, _ := jwt.Parse(tokenStr, func(token *jwt.Token) (interface{}, error) {
		// Don't forget to validate the alg is what you expect:
		if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
			return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
		}

		// hmacSampleSecret is a []byte containing your secret, e.g. []byte("my_secret_key")
		return "", nil
	})
	
	claims, _ := token.Claims.(jwt.MapClaims)
	session := claims["session"].(map[string]interface{})
	user_id := session["identity"].(map[string]interface{})["id"].(string)

	return getOrganizationId(user_id)
}

func trimQuotes(s string) string {
    if len(s) >= 2 {
        if c := s[len(s)-1]; s[0] == c && (c == '"' || c == '\'') {
            return s[1 : len(s)-1]
        }
    }
    return s
}