Visualizes a life calendar in the terminal. Each line is a year, each character is 2 days. Tracks progress and supports leap years.

life-passes.php

#!/usr/bin/env php
<?php

declare(strict_types=1);
/**
 * Life Calendar Visualizer
 *
 * This script prints a visual timeline of a person's life in years and "day pairs",
 * where each line represents a year, and each character represents 2 days.
 * It uses `X` for days already lived and `_` for days yet to come.
 *
 * Usage:
 *   ./life-passes.php <birth-date> [max-years]
 *
 * Examples:
 *   ./life-passes.php 1993-06-15
 *   ./life-passes.php 15-06-1993 90
 *   ./life-passes.php 1993 100
 *
 * Supports birth date formats: YYYY-MM-DD, DD-MM-YYYY, or YYYY
 * Supports leap years and provides life stats at the end.
 */

// ------------------------------------------------------------
// Helpers
// ------------------------------------------------------------

/**
 * Parses a birthdate string into a DateTime object.
 */
function parseBirthDate(string $input): DateTime
{
    $formats = ['Y-m-d', 'd-m-Y', 'Y'];
    foreach ($formats as $format) {
        $d = DateTime::createFromFormat($format, $input);
        if ($d && $d->format($format) === $input) {
            return $d;
        }
    }

    fwrite(STDERR, "❌ Invalid date format. Use YYYY-MM-DD, DD-MM-YYYY, or YYYY.\n");
    exit(1);
}

/**
 * Parses optional max-years argument.
 */
function parseMaxYears(?string $input, int $default = 80): int
{
    if ($input === null) {
        return $default;
    }

    if (!ctype_digit($input) || (int)$input <= 0) {
        fwrite(STDERR, "❌ Invalid max years. Must be a positive integer.\n");
        exit(1);
    }

    return (int)$input;
}

/**
 * Checks if a given year is a leap year.
 */
function isLeapYear(int $year): bool
{
    return ($year % 4 === 0 && $year % 100 !== 0) || ($year % 400 === 0);
}

// ------------------------------------------------------------
// Core Logic
// ------------------------------------------------------------

/**
 * Prints the visual matrix and life stats.
 */
function printLifeMatrix(DateTime $birthDate, int $maxYears): void
{
    $today = new DateTime();
    $birthYear = (int)$birthDate->format('Y');
    $startOfLife = new DateTime("{$birthYear}-01-01");

    $totalExpectedDays = 0;
    $realDaysLived = (int)$birthDate->diff($today)->days;

    echo PHP_EOL;

    for ($y = 0; $y < $maxYears; ++$y) {
        $year = $birthYear + $y;
        $lineIndex = str_pad((string)$y, 2, ' ', STR_PAD_LEFT);
        $line = "{$year}({$lineIndex}): ";

        $daysInYear = isLeapYear($year) ? 366 : 365;
        $charsInLine = (int)floor($daysInYear / 2);

        for ($c = 0; $c < $charsInLine; ++$c) {
            $dayOffset = $c * 2;
            $day = (new DateTime("{$year}-01-01"))->modify("+{$dayOffset} days");

            $char = ($day < $birthDate) ? '_'
                : (($day <= $today) ? 'X' : '_');

            $line .= $char;
        }

        $totalExpectedDays += $daysInYear;
        echo $line . PHP_EOL;
    }

    echo PHP_EOL;
    echo "📈 Life Summary\n";
    echo "---------------------------\n";
    echo "🎂 Days lived:     {$realDaysLived}\n";
    echo "📅 Days expected:  {$totalExpectedDays}\n";
    printf("📊 Life progress:  %.2f%%\n", min(100, ($realDaysLived / $totalExpectedDays) * 100));
}

// ------------------------------------------------------------
// Entry Point
// ------------------------------------------------------------

if ($argc < 2) {
    fwrite(STDERR, "Usage: ./life-passes.php <birth-date> [max-years]\n");
    exit(1);
}

$birthDate = parseBirthDate($argv[1]);
$maxYears = parseMaxYears($argv[2] ?? null);
printLifeMatrix($birthDate, $maxYears);