Appointment code in dialogflowFirebaseFulfillment function

dialogflowFirebaseFulfillment.js

exports.dialogflowFirebaseFulfillment = functions.https.onRequest((request, response) => {
  const agent = new WebhookClient({ request, response });
  
  function confirmAppointment(agent) {
    // ...
  }

  function makeAppointment(agent) {
    const appointment_type = agent.parameters.AppointmentType;
    const dateTimeStart = new Date(
      Date.parse(agent.parameters.date.split('T')[0] + 'T' + agent.parameters.time.split('T')[1])
    );
    // Calculate appointment start and end datetimes (end = +1hr from start)
    const dateTimeEnd = new Date(new Date(dateTimeStart).setHours(dateTimeStart.getHours() + 1));

    const appointmentTimeString = dateTimeStart.toLocaleString(
      'en-US',
      { weekday: 'short', day: 'numeric', month: 'short', hour: 'numeric', minute: 'numeric', timeZone: 'Asia/Bangkok' }
    );

    // Check the availibility of the time, and make an appointment if there is time on the calendar
    return createCalendarEvent(dateTimeStart, dateTimeEnd, appointment_type).then(() => {
      agent.add(`ลงตาราง ${appointmentTimeString} ให้เรียบร้อยแล้วจ้า`);
    }).catch(() => {
      agent.add(`ขออภัยค่ะ ช่วงเวลานี้ ${appointmentTimeString} ไม่ว่างนะคะ`);
    });
  }

  let intentMap = new Map();
  intentMap.set('Appointment', confirmAppointment);
  intentMap.set('Appointment - yes', makeAppointment);
  agent.handleRequest(intentMap);
});