refactor retrieving ICS file

lib/utils.js

@@ -18,9 +18,44 @@ const createParserError = () => {
   return err
 }
 
+// NOTE: Using mobile facebook URL because it usually
+// contains stringified JSON with event information
+const createMobileURL = (originalURL) => {
+  const urlWithProtocol = originalURL.includes('http') ?
+    originalURL :
+    `https://${originalURL}`
+  const url = new URL(urlWithProtocol)
+
+  return `${url.protocol}//mobile.facebook.com${url.port}${url.pathname}${url.hash}`
+}
+
+// NOTE: Detect whether URL parameter contains
+// number or http address
+const createURL = (param) => {
+  if (checkURLFormat(param)) {
+    return param
+  }
+
+  if (checkNumberURLParameter(param)) {
+    return `https://facebook.com/events/${param}`
+  }
+
+  return ''
+}
+
+const getNormalizedUrl = (URLparameter) => {
+  const fbURL = createURL(URLparameter)
+  const mobileUrl = createMobileURL(fbURL)
+
+  return mobileUrl
+}
+
 module.exports = {
   checkValidURL,
   checkURLFormat,
   checkNumberURLParameter,
   createParserError,
+  createMobileURL,
+  createURL,
+  getNormalizedUrl,
 }