⚗️ Implement bot v2 MVP (#194)

Closes #190

packages/js/src/lib/gtag.ts

@@ -0,0 +1,45 @@
+import { GoogleAnalyticsOptions } from 'models'
+
+declare const gtag: (
+  type: string,
+  action: string | undefined,
+  options: {
+    event_category: string | undefined
+    event_label: string | undefined
+    value: number | undefined
+  }
+) => void
+
+const initGoogleAnalytics = (id: string): Promise<void> =>
+  new Promise((resolve) => {
+    const existingScript = document.getElementById('gtag')
+    if (!existingScript) {
+      const script = document.createElement('script')
+      script.src = `https://www.googletagmanager.com/gtag/js?id=${id}`
+      script.id = 'gtag'
+      const initScript = document.createElement('script')
+      initScript.innerHTML = `window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+    
+      gtag('config', '${id}');
+      `
+      document.body.appendChild(script)
+      document.body.appendChild(initScript)
+      script.onload = () => {
+        resolve()
+      }
+    }
+    if (existingScript) resolve()
+  })
+
+export const sendGaEvent = (options: GoogleAnalyticsOptions) => {
+  if (!options) return
+  gtag('event', options.action, {
+    event_category: options.category,
+    event_label: options.label,
+    value: options.value,
+  })
+}
+
+export default initGoogleAnalytics