index.js

async function meet(options){
    const { google } = require('googleapis');
    const { OAuth2 } = google.auth
    const SCOPES = ['https://www.googleapis.com/auth/calendar'];


    //upper part for api access

        var date1 = options.date + "T" + (options.time).split(":")[0] + ":00" + ":30";
        var date2 = options.date + "T" + (options.time).split(":")[0] + ":45" + ":30";


        var x = new Date(options.date + "T" + (options.time).split(":")[0] + ":00" + ":30");
        var y = new Date(options.date + "T" + (options.time).split(":")[0] + ":45" + ":30");


        var end1 = options.date + "T" + (x.getUTCHours()) + ":" + (x.getUTCMinutes()) + ":00" + ".000Z";
        var end2 = options.date + "T" + (y.getUTCHours()) + ":" + (y.getUTCMinutes()) + ":00" + ".000Z";



        //setting details for teacher
        let oAuth2Client = new OAuth2(
            options.clientId,
            options.clientSecret
        )

        oAuth2Client.setCredentials({
            refresh_token: options.refreshToken,
        });

        // Create a new calender instance.
        let calendar = google.calendar({ version: 'v3', auth: oAuth2Client })


        //checking whether teacher is budy or not
        let result = await calendar.events.list({
            calendarId: 'primary',
            timeMin: end1,
            timeMax: end2,
            maxResults: 1,
            singleEvents: true,
            orderBy: 'startTime',
        });

        

        let events = result.data.items;
        if (events.length) {
            console.log("you are busy for this time slot !");
            return null;
        }

        //checking end



        // Create a new event start date instance for teacher in their calendar.
        const eventStartTime = new Date();
        eventStartTime.setDate((options.date).split("-")[2]);
        const eventEndTime = new Date();
        eventEndTime.setDate((options.date).split("-")[2]);
        eventEndTime.setMinutes(eventStartTime.getMinutes() + 45);



        // Create a dummy event for temp users in our calendar
        const event = {
            summary: options.summary,
            location: options.location,
            description: options.description,
            colorId: 1,
            conferenceData: {
                createRequest: {
                    requestId: "zzz",
                    conferenceSolutionKey: {
                        type: "hangoutsMeet"
                    }
                }
            },
            start: {
                dateTime: date1,
                timeZone: 'Asia/Kolkata',
            },
            end: {
                dateTime: date2,
                timeZone: 'Asia/Kolkata',
            },
        }


       
            let link = await calendar.events.insert({
                calendarId: 'primary', 
                conferenceDataVersion: '1', 
                resource: event 
            })
            return link.data.hangoutLink

}

module.exports.meet = meet;