<?php
class Converter {
    /*
     * Class for converting miles to kilometers, and vice versa
     */
    var $number = 0, $fromUnit = '', $toUnit = '';
    /*
     * Constructor takes number and unit, then assigns
     * them to corresponding properties
     * @param int $number Number to be converted
     * @param string $unit Conversion unit
     */
    public function __construct($number = 0, $fromUnit = '', $toUnit = '') {
        $this->number = $number;
        $this->toUnit = $toUnit;
        $this->fromUnit = $fromUnit;
    }
    /*
     * Converts number and returns result
     * @return string Result of conversion
     */
    public function convert(): string {
        if (is_numeric($this->number)) {
            $result = $this->number;
            switch ($this->fromUnit) {
                case "KM":
                    switch ($this->toUnit) {
                        case "KM":
                            break;
                        case "Miles":
                            $result = $this->number * 0.621;
                            break;
                        case "Parsec":
                            $result = $this->number / 30856775812800;
                            break;
                    }
                    break;
                case "Miles":
                    switch ($this->toUnit) {
                        case "KM":
                            $result = $this->number * 1.609;
                            break;
                        case "Miles":
                            break;
                        case "Parsec":
                            $result = $this->number / 19173511575400;
                            break;
                    }
                    break;
                case "Parsec":
                    switch ($this->toUnit) {
                        case "KM":
                            $result = $this->number * 30856775812800;
                            break;
                        case "Miles":
                            $result = $this->number * 19173511575400;
                            break;
                        case "Parsec";
                            break;
                    }
                    break;
            }
        }
        else {
            $result = false;
        }
        return $result;
    }
}