#!/usr/bin/env node;
/******************************************************************************
 * This program...
 * 
 * Copyright © 2020 Richard Lesh.  All rights reserved.
 *****************************************************************************/

const Utils = require('./Utils');

const main = async () => {
    if (process.argv.length != 5) {
        console.log(Utils.format("Syntax: {0:s} loan_amount rate_per_annum term_in_years", Utils.filename(process.argv[1])));
        process.exit(1);
    }

    let balance = Utils.stoiWithDefault(process.argv[2], 0) * 100;
    let interestRate = Utils.stodWithDefault(process.argv[3], 0.05);
    interestRate /= 12.0;
    let periods = Utils.stoiWithDefault(process.argv[4], 30);
    periods *= 12;
    let payment = Math.trunc(interestRate * balance / (1.0 - Math.pow(1.0 + interestRate, -periods)) + 0.5);

    console.log("Month\tPayment\tPrinciple\tInterest\tBalance");
    console.log(Utils.format("0\t\t\t\t{0:.2f}", balance / 100.0));
    for (let i = 0; i < periods; ++i) {
        const INTEREST = Math.trunc(balance * interestRate + 0.5);
        let principle = payment - INTEREST;
        balance -= principle;
        if (i === periods - 1) {
            payment += balance;
            principle += balance;
            balance = 0;
        }
        console.log(Utils.format("{0:d}\t{1:.2f}\t{2:.2f}\t{3:.2f}\t{4:.2f}", i + 1, payment / 100.0, principle / 100.0, INTEREST / 100.0, balance / 100.0));
    }
}
main().catch( e => { console.error(e) } );