From 51b568f35171f13e6421f06de8bff8fb41021ed7 Mon Sep 17 00:00:00 2001
From: minhnguyen <ntminh611@gmail.com>
Date: Wed, 15 Mar 2023 21:36:13 +0700
Subject: [PATCH] Update node #1

---
 core/broadcast.go |  35 ++++++++++++++
 core/client.go    | 113 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 148 insertions(+)
 create mode 100644 core/broadcast.go
 create mode 100644 core/client.go

diff --git a/core/broadcast.go b/core/broadcast.go
new file mode 100644
index 0000000000..94605b6116
--- /dev/null
+++ b/core/broadcast.go
@@ -0,0 +1,35 @@
+package core
+
+type Broadcast struct {
+	allClient        map[*Client]bool
+	broadcastMessage chan []byte
+	registerClient   chan *Client
+	unregisterClient chan *Client
+}
+
+func NewBroadcast() *Broadcast {
+	return &Broadcast{
+		allClient:        make(map[*Client]bool),
+		broadcastMessage: make(chan []byte),
+		registerClient:   make(chan *Client),
+		unregisterClient: make(chan *Client),
+	}
+}
+func (b *Broadcast) Run() {
+	for {
+		select {
+		case newClient := <-b.registerClient:
+			b.allClient[newClient] = true
+		case clientData := <-b.unregisterClient:
+			_, stateClient := b.allClient[clientData]
+			if stateClient {
+				delete(b.allClient, clientData)
+				close(clientData.sendMessage)
+			}
+		case messageData := <-b.broadcastMessage:
+			for clientData := range b.allClient {
+				clientData.sendMessage <- messageData
+			}
+		}
+	}
+}
diff --git a/core/client.go b/core/client.go
new file mode 100644
index 0000000000..15cec3115b
--- /dev/null
+++ b/core/client.go
@@ -0,0 +1,113 @@
+package core
+
+import (
+	"fmt"
+	"github.com/gorilla/websocket"
+	"log"
+	"net/http"
+	"time"
+)
+
+const (
+	pongWait      = 10 * time.Second
+	pingPeriod    = 5 * time.Second
+	writeDeadline = 10 * time.Second
+)
+
+var upgraderConn = &websocket.Upgrader{}
+
+type Client struct {
+	clientBroadcast *Broadcast
+	websocketConn   *websocket.Conn
+	sendMessage     chan []byte
+}
+
+func (c *Client) readPump() {
+	defer func() {
+		c.clientBroadcast.unregisterClient <- c
+		c.websocketConn.Close()
+	}()
+
+	err := c.websocketConn.SetReadDeadline(time.Now().Add(pongWait))
+	if err != nil {
+		return
+	}
+
+	c.websocketConn.SetPongHandler(func(string) error {
+		fmt.Println("Received Pong")
+		err = c.websocketConn.SetReadDeadline(time.Now().Add(pongWait))
+		return nil
+	})
+
+	for {
+		_, _, err = c.websocketConn.ReadMessage()
+		if err != nil {
+			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
+				log.Println("Error", err)
+			}
+			log.Println("Error", err)
+			break
+		}
+	}
+}
+
+func (c *Client) writePump() {
+	newTicker := time.NewTicker(pingPeriod)
+	defer func() {
+		newTicker.Stop()
+		c.websocketConn.Close()
+	}()
+	for {
+		select {
+		case messageData, stateData := <-c.sendMessage:
+			err := c.websocketConn.SetWriteDeadline(time.Now().Add(pingPeriod))
+			if err != nil {
+				return
+			}
+			if !stateData {
+				log.Println("Close the channel")
+				c.websocketConn.WriteMessage(websocket.CloseMessage, []byte{})
+				return
+			}
+
+			c.websocketConn.WriteMessage(websocket.BinaryMessage, messageData)
+
+			err = c.websocketConn.SetWriteDeadline(time.Time{})
+			if err != nil {
+				return
+			}
+		case <-newTicker.C:
+			log.Println("Send Ping")
+			err := c.websocketConn.SetWriteDeadline(time.Now().Add(writeDeadline))
+			if err != nil {
+				return
+			}
+
+			c.websocketConn.WriteMessage(websocket.PingMessage, nil)
+			err = c.websocketConn.SetWriteDeadline(time.Time{})
+			if err != nil {
+				return
+			}
+		}
+	}
+}
+
+func serveWs(broadcast *Broadcast, w http.ResponseWriter, r *http.Request) {
+	websocketConn, err := upgraderConn.Upgrade(w, r, nil)
+	if err != nil {
+		return
+	}
+
+	newClient := &Client{
+		clientBroadcast: broadcast,
+		websocketConn:   websocketConn,
+		sendMessage:     make(chan []byte, 256),
+	}
+	newClient.clientBroadcast.registerClient <- newClient
+	go newClient.writePump()
+	go newClient.readPump()
+}
+
+func messageHandler(broadcast *Broadcast, b []byte) {
+	broadcast.broadcastMessage <- b
+}