Auto-Generate Dunning Emails by Aging Bucket (SuiteScript 2.1)

/**
 * @NApiVersion 2.1
 * @NScriptType MapReduceScript
 * Title: MR | Auto-Dunning Emails by Aging Bucket
 * Author: The NetSuite Pro
 */
define(['N/search','N/email','N/runtime','N/render','N/record','N/log'], (search, email, runtime, render, record, log) => {

  const SEARCH_ID = 'customsearch_overdue_invoices_aging';
  const PARAM_SENDER = 'custscript_dunning_sender_id';

  const getInputData = () => search.load({ id: SEARCH_ID });

  const map = (ctx) => {
    const r = JSON.parse(ctx.value);
    const custId = r.values['internalid.CUSTENTITY_CUSTOMER'] || r.values.entity?.value || null;
    const emailAddr = r.values.email || '';
    const invoiceId = r.id;
    const aging = Number(r.values.formulanumeric || r.values.daysoverdue || 0);
    ctx.write({
      key: custId,
      value: { invoiceId, emailAddr, aging }
    });
  };

  const reduce = (ctx) => {
    const custId = ctx.key;
    const data = ctx.values.map(JSON.parse);
    const recipient = data[0].emailAddr;

    if (!recipient) return;
    const agingMax = Math.max(...data.map(d => d.aging));
    const bucket = getBucket(agingMax);
    const subject = buildSubject(bucket);
    const body = buildBody(bucket, data.length);

    try {
      const sender = Number(runtime.getCurrentScript().getParameter({ name: PARAM_SENDER })) || runtime.getCurrentUser().id;

      const attachments = data.map(d => render.transaction({ entityId: d.invoiceId, printMode: render.PrintMode.PDF }));

      email.send({
        author: sender,
        recipients: recipient,
        subject,
        body,
        attachments
      });

      record.submitFields({
        type: 'customer',
        id: custId,
        values: { custentity_last_dunning_date: new Date() },
        options: { enableSourcing: false, ignoreMandatoryFields: true }
      });

      log.audit(`Dunning sent to Customer ${custId}`, { bucket, recipient });

    } catch (e) {
      log.error('Reduce Error', { custId, e });
    }
  };

  const summarize = (summary) => {
    log.audit('Dunning Summary', {
      usage: summary.usage,
      yields: summary.yields,
      concurrency: summary.concurrency
    });
  };

  // ---------- Helpers ----------
  function getBucket(days) {
    if (days <= 30) return '1-30';
    if (days <= 60) return '31-60';
    if (days <= 90) return '61-90';
    return '90+';
  }

  function buildSubject(bucket) {
    return `Payment Reminder (${bucket} Days Overdue)`;
  }

  function buildBody(bucket, count) {
    const tone = {
      '1-30': 'friendly',
      '31-60': 'gentle',
      '61-90': 'firm',
      '90+': 'urgent'
    }[bucket] || 'friendly';

    return `
      <p>Dear Customer,</p>
      <p>This is a ${tone} reminder that you have <b>${count}</b> outstanding invoice(s) now ${bucket} days past due.</p>
      <p>Please find the invoices attached and remit payment at your earliest convenience.</p>
      <p>Thank you for your prompt attention to this matter.<br/>Accounts Receivable</p>
    `;
  }

  return { getInputData, map, reduce, summarize };
});