books/reports/Cashflow/Cashflow.js

const { getPeriodList } = require('../FinancialStatements/FinancialStatements');
const { DateTime } = require('luxon');

class Cashflow {
  async run({ fromDate, toDate, periodicity }) {
    let res = await frappe.db.sql(
      `
      select sum(debit) as inflow, sum(credit) as outflow, strftime("%m-%Y", date) as "month-year"
        from AccountingLedgerEntry
        where account in (
          select name from Account where accountType in ('Cash', 'Bank') and isGroup = 0
        )
        and date >= $fromDate and date <= $toDate
      group by strftime("%m-%Y", date)
    `,
      { $fromDate: fromDate, $toDate: toDate }
    );

    let periodList = getPeriodList(fromDate, toDate, periodicity);

    let data = periodList.map(periodKey => {
      let monthYear = this.getMonthYear(periodKey, 'MMM yyyy');
      let cashflowForPeriod = res.find(d => d['month-year'] === monthYear);
      if (cashflowForPeriod) {
        cashflowForPeriod.periodKey = periodKey;
        return cashflowForPeriod;
      }
      return {
        inflow: 0,
        outflow: 0,
        periodKey,
        'month-year': monthYear
      };
    });

    return {
      data,
      periodList
    };
  }

  getMonthYear(periodKey, format) {
    return DateTime.fromFormat(periodKey, format).toFormat('MM-yyyy');
  }
}

module.exports = Cashflow;