Allow users to "save" pages?

Figured it out. Thanks @Velo-Ninja for all your help! Here is my code:

On masterpage.js:

import wixLocation from 'wix-location'
import wixUsers from 'wix-users'
import wixSite from 'wix-site'
import wixSeo from 'wix-seo'
import wixData from 'wix-data'
import {session} from 'wix-storage'
import {saveButton} from 'public/saveButton.js'

if(wixUsers.currentUser.loggedIn) {
 $w('#button117').label = 'Profile/Logout'
}

export function button114_click(event) { //button114 is the save button
 if(wixUsers.currentUser.loggedIn) {
 let currentPage = wixSite.currentPage
 let pageName = ''
 if(currentPage.type === 'static') {
 pageName = currentPage.name
 }
 else {
 pageName = wixSeo.title
 }
 saveButton(wixLocation.url, pageName)
 }
 else { //this allows the page to still be saved once the user logs in so that they don't have to go back and click save again
 session.setItem('accountNeeded', 'true')
 session.setItem('previousUrl', wixLocation.url)
 session.setItem('savedUrl', wixLocation.url)
 let currentPage = wixSite.currentPage
 let pageName = ''
 if(currentPage.type === 'static') {
 pageName = currentPage.name
 }
 else {
 pageName = wixSeo.title
 }
 session.setItem('savedPage', pageName)
 wixLocation.to('/login-signup')
 }
}

export function button117_click(event) { //this is the login/signup button. The session storage allows there to be an "X" on the page which directs the user back to the most recent page.
 wixLocation.to('/login-signup')
 session.setItem('previousUrl', wixLocation.url)
}

The saveButton function:

import wixData from 'wix-data'
import wixUsers from 'wix-users'

export function saveButton(url, pageName) {
 let updateLinksArray = []
 let updatePageTitleArray = []

 wixData.query('Members')
 .eq('_id', wixUsers.currentUser.id)
 .find()
 .then( (results) => {
 let items = results.items
 if(items.length > 0) {
 updateLinksArray = items[0].savedPageLinks
 updatePageTitleArray = items[0].savedPageNames
 }
 updateLinksArray.push(url)
 updatePageTitleArray.push(pageName)
 
 let toUpdateLinks = {
 'savedPageLinks': updateLinksArray,
 'savedPageNames': updatePageTitleArray,
 '_id': wixUsers.currentUser.id
 }
 wixData.update("Members", toUpdateLinks)
 .then( (results) => {
 let item = results
 })
 })
}

On Login/Signup/Logout page:

import wixUsers from 'wix-users';
import wixData from 'wix-data';
import wixLocation from 'wix-location';
import {session} from 'wix-storage'
import {saveButton} from 'public/saveButton.js'


$w.onReady(function () {
 $w('#button114').collapse()

 if(wixUsers.currentUser.loggedIn) {
 $w("#loginButton").label = "Logout";
 $w("#profileButton").show();
 wixUsers.currentUser.getRoles()
 .then( (roles) => {
 if (roles.length > 0 && roles[0].name === 'Staff') {
 $w('#button89').expand()
 }
 })
 }
 else {
 $w("#loginButton").label = "Login";
 $w("#profileButton").hide();
 $w('#button89').collapse()
 }
});

export function loginButton_click(event) { 
 // user is logged in
 if(wixUsers.currentUser.loggedIn) {
 // log the user out
 wixUsers.logout()
 .then( () => {
 // update buttons accordingly
 $w("#loginButton").label = "Login";
 $w("#profileButton").hide();
 $w('#button89').collapse()
 } );
 }
 // user is logged out
 else {
 let userId;
 let userEmail;
 
 // prompt the user to log in 
 wixUsers.promptLogin( {"mode": "login"} )
 .then( (user) => {
 userId = user.id;
 return user.getEmail();
 } )
 .then( (email) => {
 // check if there is an item for the user in the collection
 userEmail = email;
 return wixData.query("Members")
 .eq("_id", userId)
 .find();
 } )
 .then( (results) => {
 // if an item for the user is not found
 if (results.items.length === 0) {
 // create an item
 const toInsert = {
 "_id": userId,
 "email": userEmail
 };
 // add the item to the collection
 wixData.insert("Members", toInsert)
 .then( (results) => {
 console.log(results)
 })
 .catch( (err) => {
 console.log(err);
 } );
 }
 // update buttons accordingly
 $w("#loginButton").label = "Logout";
 $w('#button117').label = 'Profile/Logout'
 $w("#profileButton").show();
 wixUsers.currentUser.getRoles()
 .then( (roles) => {
 if (roles.length > 0 && roles[0].name === 'Staff') {
 $w('#button89').expand()
 }
 })
 if(session.getItem('accountNeeded') === 'true') { //this allows the automatic save once the user has signed up
 session.removeItem('accountNeeded')
 saveButton(session.getItem('savedUrl'), session.getItem('savedPage'))
 }
 $w('#text193').collapse()
 })
 }
}

export function image14_click(event) {
 wixLocation.to(session.getItem('previousUrl'))
}

export function profileButton_click(event) {
 let url = '/members/' + wixUsers.currentUser.id
 wixLocation.to(url)
}

Hope this helps someone in the future! Any tips on shortening code greatly appreciated.