Implement reconnection logic and improve server connection handling

client/sync.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"time"
 
 	"github.com/getlantern/systray"
 	"github.com/gorilla/websocket"
@@ -15,6 +16,7 @@ var (
 	lastClipboard  []byte
 	identification string
 	isConnected    bool
+	serverURL      string
 )
 
 func onReady() {
@@ -58,7 +60,7 @@ func startClient(statusItem *systray.MenuItem) {
 	identification = EmbeddedIdentification
 	server_ip := EmbeddedServerIP
 	server_port := EmbeddedServerPort
-	server_connection := "ws://" + server_ip + ":" + server_port + "/ws"
+	serverURL = "ws://" + server_ip + ":" + server_port + "/ws"
 
 	if identification == "" || server_ip == "" || server_port == "" {
 		log.Println("Missing configuration")
@@ -66,29 +68,70 @@ func startClient(statusItem *systray.MenuItem) {
 		return
 	}
 
-	// Connect to the server
-	var connectErr error
-	conn, _, connectErr = websocket.DefaultDialer.Dial(server_connection, nil)
-	if connectErr != nil {
-		log.Println("Error connecting to server:", connectErr)
+	// Reconnection loop with exponential backoff
+	backoff := 1 * time.Second
+	maxBackoff := 60 * time.Second
+
+	for {
+		if connectToServer(statusItem) {
+			// Successfully connected, reset backoff
+			backoff = 1 * time.Second
+
+			// Listen for messages until connection drops
+			listenForMessages(statusItem)
+		}
+
+		// Connection failed or dropped, wait before retry
+		isConnected = false
+		statusItem.SetTitle(fmt.Sprintf("Status: Reconnecting in %ds...", int(backoff.Seconds())))
+		log.Printf("Reconnecting in %s...", backoff)
+		time.Sleep(backoff)
+
+		// Increase backoff exponentially
+		backoff *= 2
+		if backoff > maxBackoff {
+			backoff = maxBackoff
+		}
+	}
+}
+
+func connectToServer(statusItem *systray.MenuItem) bool {
+	statusItem.SetTitle("Status: Connecting...")
+
+	var err error
+	conn, _, err = websocket.DefaultDialer.Dial(serverURL, nil)
+	if err != nil {
+		log.Println("Error connecting to server:", err)
 		statusItem.SetTitle("Status: Connection failed")
-		return
+		return false
 	}
 
 	// Send identification to the server
-	sendMessage(conn, websocket.TextMessage, []byte(identification))
+	err = conn.WriteMessage(websocket.TextMessage, []byte(identification))
+	if err != nil {
+		log.Println("Error sending identification:", err)
+		conn.Close()
+		conn = nil
+		return false
+	}
 
 	isConnected = true
 	statusItem.SetTitle(fmt.Sprintf("Status: Connected (%s)", identification))
 	log.Println("Connected to server")
+	return true
+}
 
-	// Listen for messages from the server
+func listenForMessages(statusItem *systray.MenuItem) {
 	for {
 		messageType, message, err := conn.ReadMessage()
 		if err != nil {
 			log.Println("Error reading message:", err)
 			isConnected = false
 			statusItem.SetTitle("Status: Disconnected")
+			if conn != nil {
+				conn.Close()
+				conn = nil
+			}
 			return
 		}
 		handleMessage(messageType, message)
@@ -109,6 +152,7 @@ func sendMessage(conn *websocket.Conn, messageType int, message []byte) {
 	err := conn.WriteMessage(messageType, message)
 	if err != nil {
 		log.Println("Error sending message:", err)
+		isConnected = false
 	}
 }