From c066bfa46e52e4870269aed285cc357e09aea864 Mon Sep 17 00:00:00 2001
From: Nasar Eddaoui <nasar165@hotmail.com>
Date: Sat, 4 May 2024 11:23:32 +0700
Subject: [PATCH] add reconnection strategy

---
 app/components/socket.tsx      | 17 +++-----
 app/hook/socketHook.tsx        | 16 ++++++++
 app/lib/websocket/socket.ts    | 51 ++---------------------
 app/lib/websocket/websocket.ts | 75 ++++++++++++++++++++++++++++++++++
 app/model/websocket.ts         | 22 ++++++++--
 5 files changed, 119 insertions(+), 62 deletions(-)
 create mode 100644 app/hook/socketHook.tsx
 create mode 100644 app/lib/websocket/websocket.ts

diff --git a/app/components/socket.tsx b/app/components/socket.tsx
index 897a49d..29f5b87 100644
--- a/app/components/socket.tsx
+++ b/app/components/socket.tsx
@@ -1,29 +1,24 @@
 'use client';
 
-import React, { useEffect, useState } from 'react';
-import { Websocket } from '../lib/websocket/socket';
-import { ConState, ISocket } from '../model/websocket';
+import React from 'react';
+import { CloseEvent, ConState } from '../model/websocket';
+import WebSocketHook from '../hook/socketHook';
 
 type Url = { url: string; online: boolean; state: ConState };
 
 export default function Socket({ url, online, state }: Url): React.JSX.Element {
-  const [socket, setSocket] = useState<ISocket>();
+  const [socket] = WebSocketHook({ state: state });
 
   const start = () => {
     try {
       if (!socket?.Alive()) {
-        socket?.Start(url, state);
-        setSocket(socket);
-      } else socket?.Stop(1000);
+        socket?.Connect(url, state);
+      } else socket?.Disconnect(CloseEvent.NORMAL);
     } catch (err) {
       console.error(err);
     }
   };
 
-  useEffect(() => {
-    setSocket(new Websocket(state));
-  }, []);
-
   return (
     <div>
       <button
diff --git a/app/hook/socketHook.tsx b/app/hook/socketHook.tsx
new file mode 100644
index 0000000..7fa6d63
--- /dev/null
+++ b/app/hook/socketHook.tsx
@@ -0,0 +1,16 @@
+import { useEffect, useRef, useState } from 'react';
+import { ConState, IWebSocket } from '../model/websocket';
+import { Websocket } from '../lib/websocket/websocket';
+
+type Url = { state: ConState };
+
+export default function WebSocketHook({ state }: Url): [IWebSocket] {
+  const [socket, setSocket] = useState<IWebSocket>();
+  const ref = useRef(state);
+
+  useEffect(() => {
+    setSocket(new Websocket(ref.current));
+  }, []);
+
+  return [socket!];
+}
diff --git a/app/lib/websocket/socket.ts b/app/lib/websocket/socket.ts
index a54807c..ffbdd9d 100644
--- a/app/lib/websocket/socket.ts
+++ b/app/lib/websocket/socket.ts
@@ -1,12 +1,7 @@
-import { ConState, DEAD, ISocket, LIVE } from '@/app/model/websocket';
+import { CloseEvent, DEAD, ISocket, LIVE } from '@/app/model/websocket';
 
-export class Websocket implements ISocket {
-  private socket?: WebSocket;
-  private stateChange: ConState;
-
-  constructor(event: ConState) {
-    this.stateChange = event;
-  }
+export class Socket implements ISocket {
+  protected socket?: WebSocket;
 
   Alive(): boolean {
     return this.socket != null && this.socket.readyState == this.socket.OPEN;
@@ -14,54 +9,16 @@ export class Websocket implements ISocket {
 
   Start(url: string): void {
     if (this.Alive()) throw Error(LIVE);
-
     this.socket = new WebSocket(url, ['ocpp1.6']);
-    this.stateChange(true);
-    this.setEventListeners();
-
     console.info('Websocket connection was successful');
   }
 
   Stop(code?: number): void {
     if (this.socket == null) throw new Error(DEAD);
-
-    try {
-      this.stateChange(false);
-      this.socket!.close(code ?? 1000);
-    } catch (err) {
-      throw err;
-    } finally {
-      this.removeEventListeners();
-    }
-
+    this.socket!.close(code ?? CloseEvent.NORMAL);
     console.info('socket closed');
   }
 
-  protected setEventListeners(): void {
-    this.socket!.addEventListener('close', this.close.bind(this));
-    this.socket!.addEventListener('error', this.error.bind(this));
-    this.socket!.addEventListener('open', this.open.bind(this));
-  }
-
-  protected removeEventListeners(): void {
-    this.socket!.removeEventListener('close', this.close.bind(this));
-    this.socket!.removeEventListener('error', this.error.bind(this));
-    this.socket!.addEventListener('open', this.open.bind(this));
-  }
-
-  protected close(reason: CloseEvent): void {
-    console.info(reason);
-    this.Stop(1000);
-  }
-
-  protected error(ev: Event): void {
-    console.error('an error has occurred', ev);
-  }
-
-  protected open(): void {
-    this.stateChange(true);
-  }
-
   Send(message: string) {
     if (!this.Alive()) throw new Error(DEAD);
     this.socket!.send(message);
diff --git a/app/lib/websocket/websocket.ts b/app/lib/websocket/websocket.ts
new file mode 100644
index 0000000..bcc3cc6
--- /dev/null
+++ b/app/lib/websocket/websocket.ts
@@ -0,0 +1,75 @@
+import { CloseEvent, ConState, DEFAULT_TIMER } from '@/app/model/websocket';
+import { Socket } from './socket';
+
+let id: ReturnType<typeof setTimeout>;
+
+export class Websocket extends Socket {
+  private url: string = '';
+  private timer = 0;
+  private stateChange: ConState;
+
+  constructor(event: ConState) {
+    super();
+    this.timer = DEFAULT_TIMER;
+    this.stateChange = event;
+  }
+
+  Connect(url: string): void {
+    this.stateChange(true);
+    this.url = url;
+    this.Start(url);
+    this.setEventListeners();
+  }
+
+  Disconnect(code: number): void {
+    try {
+      this.stateChange(false);
+      this.Stop(code);
+    } catch (error) {
+      throw error;
+    } finally {
+      this.removeEventListeners();
+    }
+  }
+
+  protected setEventListeners(): void {
+    this.socket!.addEventListener('close', this.close.bind(this));
+    this.socket!.addEventListener('error', this.error.bind(this));
+    this.socket!.addEventListener('open', this.open.bind(this));
+  }
+
+  protected removeEventListeners(): void {
+    this.socket!.removeEventListener('close', this.close.bind(this));
+    this.socket!.removeEventListener('error', this.error.bind(this));
+    this.socket!.addEventListener('open', this.open.bind(this));
+  }
+
+  protected retry(): void {
+    clearTimeout(id);
+    console.log('connection lost retrying');
+    id = setTimeout(() => {
+      this.Start(this.url);
+    }, this.timer);
+  }
+
+  protected error(ev: Event): void {
+    console.error('websocket an error has occurred', ev);
+    const socket = ev.currentTarget as WebSocket;
+
+    if (socket.readyState == socket.CLOSED) {
+      this.stateChange(false);
+      this.removeEventListeners();
+      this.retry();
+    }
+  }
+
+  protected close(reason: CloseEvent): void {
+    if (this.socket?.readyState != this.socket?.OPEN) return;
+    console.info(reason);
+    this.Stop(CloseEvent.NORMAL);
+  }
+
+  protected open(): void {
+    this.stateChange(true);
+  }
+}
diff --git a/app/model/websocket.ts b/app/model/websocket.ts
index 995ee43..ab1527f 100644
--- a/app/model/websocket.ts
+++ b/app/model/websocket.ts
@@ -1,13 +1,27 @@
+const CloseEvent = Object.freeze({
+  NORMAL: 1000,
+  INTERNALERROR: 1011,
+});
+
+const DEFAULT_TIMER = 3600;
 const LIVE = 'web socket client is already initialized';
 const DEAD = 'web socket client is dead, open a new connection';
 
 type ConState = (connected: boolean) => void;
 
-interface ISocket {
-  Alive(): boolean;
+interface ISocket extends IAlive {
   Start(url: string, event: ConState): void;
   Stop(code: number): void;
 }
 
-export type { ISocket, ConState };
-export { LIVE, DEAD };
+interface IWebSocket extends IAlive {
+  Connect(url: string, event: ConState): void;
+  Disconnect(code: number): void;
+}
+
+interface IAlive {
+  Alive(): boolean;
+}
+
+export type { IWebSocket, ISocket, ConState };
+export { LIVE, DEAD, DEFAULT_TIMER, CloseEvent };