//Get Field Objects
const billingStateField = ZDK.Page.getField('Billing_State');
const billingCodeField = ZDK.Page.getField('Billing_Code');
//Get Field Values
const billingState = billingStateField.getValue();
const billingCode = billingCodeField.getValue();
//Get API Key from CRM Variables
if (billingState && billingCode) {
    //Check the postcode is 4 numbers with a RegEx
    const postcodeRegex = /^\d{4}$/;
    if (postcodeRegex.test(billingCode))
    {
        const fetchApiKey = ZDK.Apps.CRM.Settings.fetchVariablesById('6040139000001156675');
        let apiKey = fetchApiKey.value;
        //Call Auspost API
        auspostQuery = ZDK.HTTP.request({
            url: 'https://digitalapi.auspost.com.au/postcode/search.json',
            method: 'GET',
            parameters: {
                'q': billingCode,
                'state': billingState
            },
            headers: {
                'auth-key': apiKey
            }
        });
        //Get the API Response Status
        let auspostStatus = auspostQuery.getStatusCode();;
        //Get the API Response
        let auspostResponse = auspostQuery.getResponse();
        //Only continue if a 200 status is returned
        if (auspostStatus === 200) {
            let auspostData = JSON.parse(auspostResponse);
            let suburbList = auspostData.localities.locality;
            //API returns either null/undefined || Object || Array based on number of suburbs.
            //null / undefined
            if (suburbList && suburbList !== null) {
                //If object create Array
                if (!Array.isArray(suburbList)) {
                    suburbList = [suburbList];
                }
                //Check there is at least 1 object in the Array
                if (suburbList.length > 0) {
                    //check for a match
                    const matchFound = suburbList.some(suburb => suburb.state === billingState && suburb.postcode == billingCode);
                    if (matchFound) {
                        return true;
                    }
                }
                else {
                    billingCodeField.showError('Postcode does not belong to this State.');
                    return false;
                }
            }
            else {
                billingCodeField.showError('Postcode does not belong to this State.');
                return false;
            }
        }
        else {
            let errorMessage = JSON.parse(auspostResponse).error.errorMessage
            ZDK.Client.showAlert('An Error Occured: ' + errorMessage, 'Notice', 'Got it!');
        }
    }
    else
    {
        billingCodeField.showError('Postcode must be a 4 digit number.');
        return false;
    }
}
else if (!billingState && billingCode)
{
    billingStateField.showError('Please Enter a State Value in the format: NSW, VIC, SA');
    return false;
}
else if (billingState && !billingCode)
{
    billingCodeField.showError('Please Enter a Postcode.');
    return false;
}
return true