working_days_calculator.js

Date.prototype.addDays = function(days) {
    var date = new Date(this.valueOf());
    date.setDate(date.getDate() + days);
    return date;
};

const args = process.argv.slice(2);
const fs = require('fs');

const first_working_date = '5/23/2024'; // can just be left usually
let shift_pattern = {
    on: 5,
    off: 3
};
const months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

const preformat_month_array = () => {
    const ret = {};
    months.forEach(month => ret[month] = []);

    return ret;
};

const month_as_string = (month_as_number) => months[month_as_number];

// allow presetting days
if (args.length == 2) {
    if (parseInt(args[0]) && parseInt(args[1])) {
        shift_pattern.on = parseInt(args[0]);
        shift_pattern.off = parseInt(args[1]);
    }
}

console.log(`Calculating work pattern for ${shift_pattern.on}on ${shift_pattern.off}off...\n`);

let working_date_as_date = new Date(first_working_date);

const get_working_days = () => {
    const working_days = preformat_month_array();
    const rest_days = preformat_month_array();
    let working = 1;
    let rest = 0;

    const running_totals = {
        working_: 0,
        resting: 0
    };

    working_date_as_date.setTime(working_date_as_date.getTime() - 1) // stupid bst shit

    for (let i = 0; i < 364; i++) {
        working_date_as_date = working_date_as_date.addDays(1);
        const current_month = month_as_string(working_date_as_date.getMonth());

        if (!rest) {
            if (working === shift_pattern.on) {
                rest = 1;
                working = 0;
            } else {
                working += 1;
            }

            running_totals.working_++;
            working_days[current_month].push(working_date_as_date.toLocaleDateString());;
        } else {
            if (rest === shift_pattern.off) {
                working = 1;
                rest = 0;
            } else {
                rest += 1;
            }

            running_totals.resting++;
            rest_days[current_month].push(working_date_as_date.toLocaleDateString());
        }
    }

    fs.writeFile('./data/rest-days.json', JSON.stringify(rest_days), err => err);
    fs.writeFile('./data/work-days.json', JSON.stringify(working_days), err => err);

    const { working_, resting } = running_totals;
    console.log(`Finished compiling, totals:
        working: ${working_}
        resting: ${resting}
        == ${Math.round((working_ / (working_ + resting)) * 100)}% working`);
};

get_working_days();