Initial simple client implementation

src/client/Client.js

@@ -0,0 +1,54 @@
+'use strict';
+
+const EventEmitter = require('events');
+const puppeteer = require('puppeteer');
+const Util = require('../util/Util');
+const { WhatsWebURL, UserAgent, DefaultOptions, Events } = require('../util/Constants');
+const { ExposeStore } = require('../util/Injected');
+
+/**
+ * Starting point for interacting with the WhatsApp Web API
+ * @extends {EventEmitter}
+ */
+class Client extends EventEmitter {
+    constructor(options = {}) {
+        super();
+
+        this.options = Util.mergeDefault(DefaultOptions, options);
+
+        this.pupBrowser = null;
+        this.pupPage = null;
+    }
+
+    async initialize() {
+        const browser = await puppeteer.launch(this.options.puppeteer);
+        const page = await browser.newPage();
+        page.setUserAgent(UserAgent);
+
+        await page.goto(WhatsWebURL);
+        await page.evaluate(ExposeStore);
+
+        await page.waitForSelector('._1jjYO');  // Wait for QR Code
+        const qr = await page.$eval('._2EZ_m', node => node.getAttribute('data-ref'));
+        
+        this.emit(Events.QR_RECEIVED, qr);
+
+        // Wait for Auth
+        await page.waitForSelector('._2Uo0Z', {timeout: 0});
+        this.emit(Events.AUTHENTICATED);
+
+        // Check Store Injection
+        await page.waitForFunction('window.Store != undefined');
+
+        this.pupBrowser = browser;
+        this.pupPage = page;
+
+        this.emit(Events.READY);
+    }
+
+    async destroy() {
+        await this.pupBrowser.close();
+    }
+}
+
+module.exports = Client;