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

class Cashflow {
  async run({ fromDate, toDate, periodicity }) {
    let cashAndBankAccounts = frappe.db
      .knex('Account')
      .select('name')
      .where('accountType', 'in', ['Cash', 'Bank'])
      .andWhere('isGroup', 0);
    let dateAsMonthYear = frappe.db.knex.raw('strftime("%m-%Y", ??)', 'date');
    let res = await frappe.db
      .knex('AccountingLedgerEntry')
      .sum({
        inflow: 'debit',
        outflow: 'credit'
      })
      .select({
        'month-year': dateAsMonthYear
      })
      .where('account', 'in', cashAndBankAccounts)
      .whereBetween('date', [fromDate, toDate])
      .groupBy(dateAsMonthYear);

    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;