const { Client } = require('pg');

const client = new Client({
  host: 'localhost',
  user: 'postgres',
  port: 5432,
  password: '123',
  database: 'AltOne',
});

function calculateData(result) {
  let monthCounter = 0;
  let interestDebt = 0;
  let principalDebt = 0;
  let balanceDebt = result.credit_amount;

  const monthlyRate = +(result.bet_amount / (100 * 12));
  const monthlyPaymentDenominator = (1 - ((1 + monthlyRate) ** (-result.credit_term)));
  const monthlyPayment = +(result.credit_amount * (monthlyRate / monthlyPaymentDenominator));

  return () => {
    monthCounter += 1;
    interestDebt = (balanceDebt * monthlyRate);
    principalDebt = (monthlyPayment - interestDebt);
    balanceDebt -= principalDebt;

    return {
      a: monthCounter,
      b: monthlyPayment.toFixed(2),
      d: principalDebt.toFixed(2),
      c: interestDebt.toFixed(2),
      e: balanceDebt.toFixed(2),
    };
  };
}

async function getData(applicationId) {
  const rqst1 = 'select credit_amount, bet_amount, credit_term from applications where id = $1';
  const rqst2 = 'select sum(service_cost)'
    + ' from application_additional_services'
    + ' join additional_services asm on asm.id = application_additional_services.additional_service_id'
    + ' where application_id = $1';

  try {
    client.connect();
    const objectsArray = [];
    const appData = await client.query(rqst1, [applicationId]);
    const serviceCostData = await client.query(rqst2, [applicationId]);
    appData.rows[0].credit_amount = +appData.rows[0].credit_amount + +serviceCostData.rows[0].sum;
    const calculator = calculateData(appData.rows[0]);

    console.log(`Сумма кредита: ${appData.rows[0].credit_amount}`);
    console.log(`Ставка: ${appData.rows[0].bet_amount}`);
    console.log(`Срок: ${appData.rows[0].credit_term}`);
    console.log('Месяц | Ежемесячный платеж | Основной долг | Долг по процентам | Остаток');
    for (let i = 0; i < appData.rows[0].credit_term; i += 1) {
      objectsArray.push(calculator());
      console.log(`${objectsArray[i].a} | ${objectsArray[i].b} | ${objectsArray[i].c} | ${objectsArray[i].d} | ${objectsArray[i].e}`);
    }

    return objectsArray;
  } catch (err) { return err.stack; } finally { client.end(); }
}

getData(5);