Farm Animals version2

animals.php

<?php

namespace App;

/**
 * Interface iGenericUtilities to be implemented by any Concrete Utility Class
 * @package App
 */
interface iGenericUtilities {
    public function saveToFile($filename, $data);
    public function generateSerialNumbers($start, $end, $limit);

}

/**
 * Base Class Animal
 * @package App
 */
class Animal
{
    protected $serialNumber;

    public function getSerialNumber()
    {
        return $this->serialNumber;
    }

    public function setSerialNumber($serialNumber)
    {
        $this->serialNumber = $serialNumber;
    }

}

/**
 * Class Goat
 * @package App
 */
class Goat extends Animal
{

}

/**
 * Class Sheep
 * @package App
 */
class Sheep extends Animal
{

}

/**
 * Class AnimalFactory for creating Animal objects
 * @package App
 */
class AnimalFactory
{

    /**
     * Creates an Animal Object. An exception will be thrown if object cannot be created
     * @param $animal
     * @return Goat|Sheep
     * @throws \Exception
     */
    public static function create($animal)
    {

        switch ($animal) {
            case 'goat':
                return new Goat();
            case 'sheep':
                return new Sheep();
            default:
                throw new \Exception("cant create object of class $animal");
        }
    }
}

/**
 * Class Utilities: generic utilities.
 * @package App
 */
class Utilities implements iGenericUtilities
{

    /**
     * Saves given data in a given file
     * @param $filename
     * @param $data
     */
    public function saveToFile($filename, $data)
    {
        file_put_contents($filename, $data);
    }

    /**
     * Generates $limit unique prime numbers between $start and $end. The result is returned in an array
     * @param $start
     * @param $end
     * @param $limit
     * @return array
     */
    public function generateSerialNumbers($start, $end, $limit)
    {
        $uniqueNumbers = [];

        do {
            $randomNumber = rand($start, $end); //generate random number
            if (!$this->isPrime($randomNumber) || in_array($randomNumber, $uniqueNumbers)) {
                //if its not prime number or unique then try again
                continue;
            }
            $uniqueNumbers[] = $randomNumber;
        } while (count($uniqueNumbers) < $limit);

        return $uniqueNumbers; //return an array of unique prime numbers

    }

    /**
     * Checks if a given number is Even.
     * @param $number
     * @return bool
     */
    public function isEven($number)
    {
        if ($number % 2 == 0) {
            return true;
        }
        return false;
    }

    /**
     * Checks if a given number is prime
     * @param $prime
     * @return bool
     */
    private function isPrime($prime)
    {
        for ($i = 2; $i < $prime; $i++) {
            if ($prime % $i == 0) {
                return false;
            }
        }
        return true;
    }
}

class App
{

    protected $utilities; //property to be used for dependency injection. It'll hold a object of a Utility class.
    protected $animalsIds; //this property is meant to save animals ids, ['goat'] => [1,3,5,7], ['sheep'] => [3,5,7]

    /**
     * App constructor.
     * I'm casting the first argument so that in the future we can inject a new Utility Class and at the same time make
     * sure this dependency complies with the contract defined in the iGenericUtilities interface.
     *
     * @param iGenericUtilities $utilities
     */
    public function __construct(iGenericUtilities $utilities)
    {
        $this->utilities = $utilities; //dependency injection of an Utility class
    }

    /**
     * Main method
     * @param array $animals
     */
    public function run($animals = [])
    {

        foreach ($animals as $animal) {
            $dataForFile = "";
            $uniqueSerialNumbers = $this->utilities->generateSerialNumbers(0, 10000, 100);
            foreach ($uniqueSerialNumbers as $uniqueSerialNumber) {
                $currentAnimal = AnimalFactory::create($animal); //instantiate animal
                $currentAnimal->setSerialNumber($uniqueSerialNumber); //set serial number to animal
                $dataForFile .= $uniqueSerialNumber . " \n"; //prepares data to be saved in file
                $this->animalsIds[$animal][] = $uniqueSerialNumber; //keeping track of ids used.
            }
            $this->utilities->saveToFile($animal . '.txt', $dataForFile); //here so we write to disk once per animal
        }
        $this->findSoulMates();
        $this->getFacts();

    }

    /**
     * Find duplicates ids between animals.
     */
    private function findSoulMates()
    {
        $soulMates = call_user_func_array('array_intersect', $this->animalsIds);
        $ids = "";
        foreach ($soulMates as $soulMate) {
            $ids .= $soulMate . "  \n";
        }
        $this->utilities->saveToFile('soulmates.txt', $ids);
    }

    /**
     * Prints facts (count of even/odd numbers and sum) about animals ids
     */
    private function getFacts()
    {
        $facts = [];
        foreach ($this->animalsIds as $animal => $ids) {
            foreach ($ids as $id) {
                $facts[$animal]['sum'] += $id;
                $lastDigit = substr($id, -1);
                $facts[$animal]['lastDigit'.$lastDigit]++;

            }
            echo "</br>" . "The sum of $animal ids is " . $facts[$animal]['sum'] . " </br>";

            for ($i = 0; $i <=9; $i ++) {
                if ($facts[$animal]['lastDigit'.$i]) {
                    echo "$animal had " . $facts[$animal]['lastDigit'.$i] . " times the number $i as the last digit in their serial numbers </br>";
                }
            }

        }
    }
}


try {
    $utilities = new Utilities();
    $app = new App($utilities);
    $app->run(['goat', 'sheep']);
} catch (\Exception $e) {
    echo "Exception found " . $e->getMessage();
}