csv.js

const fs = require('fs');
const path = require('path');
const csv = require('csv-parser');

const CPF_RATES = {
    '<55': { employee: 0.2, employer: 0.17 },
    '55-60': { employee: 0.13, employer: 0.13 },
    '60-65': { employee: 0.075, employer: 0.09 },
    '>65': { employee: 0.05, employer: 0.075 },
};

const getAgeGroup = (age) => {
    if (age < 55) return '<55';
    if (age >= 55 && age < 60) return '55-60';
    if (age >= 60 && age < 65) return '60-65';
    return '>65';
};

const calculateCPF = (salary, age, isCitizen = true) => {
    if (!isCitizen) return { employeeCPF: 0, employerCPF: 0, totalCPF: 0 };

    const ageGroup = getAgeGroup(age);
    const rates = CPF_RATES[ageGroup];

    const employeeCPF = salary * rates.employee;
    const employerCPF = salary * rates.employer;
    const totalCPF = employeeCPF + employerCPF;

    return { employeeCPF, employerCPF, totalCPF };
};

const calculatePayroll = (grossSalary, age, isCitizen, additionalPayments = 0) => {
    const totalSalary = grossSalary + additionalPayments;
    const { employeeCPF, employerCPF, totalCPF } = calculateCPF(totalSalary, age, isCitizen);

    const netSalary = totalSalary - employeeCPF;

    return {
        grossSalary,
        additionalPayments,
        totalSalary,
        employeeCPF,
        employerCPF,
        totalCPF,
        netSalary,
    };
};

const processCSV = (filePath) => {
    const results = [];

    fs.createReadStream(filePath)
        .pipe(csv())
        .on('data', (row) => {
            const name = row['Name'];
            const grossSalary = parseFloat(row['Gross Salary']);
            const age = parseInt(row['Age'], 10);
            const isCitizen = row['Citizen'].toLowerCase() === 'yes';
            const additionalPayments = parseFloat(row['Additional Payments']) || 0;

            const payroll = calculatePayroll(grossSalary, age, isCitizen, additionalPayments);
            console.log(`Payroll for ${name}:`, payroll);

            results.push({ name, ...payroll });
        })
        .on('end', () => {
            console.log('CSV file successfully processed.');
        });
};

const filePath = process.argv[2];
if (!filePath) {
    console.error('Please provide the path to the CSV file as a command-line argument.');
    process.exit(1);
}

processCSV(path.resolve(filePath));

module.exports = { calculateCPF, calculatePayroll, processCSV };