Chat

talk.php

<?php

$vova = new Man();
$vova->setName('Vova');

$vika = new Woman();
$vika->setName('Vika');

$petr = new Man();
$petr->setName('Petr');

$alex = new Man();
$alex->setName('Alex');

$vova->learn(new Russian());
$vika->learn(new English());
$petr->learn(new English());
$alex->learn(new Russian());

$chat = new Chat();
$chat->add($vova);
$chat->add($vika);
$chat->add($petr);
// $chat->add($alex);

$vova->says('greetings');



interface Speaking
{
    public function greetings();
}

class English implements Speaking
{
    public function greetings()
    {
        return 'Hello';
    }
}

class Russian implements Speaking
{
    public function greetings()
    {
        return 'Привет';
    }
}

abstract class Human
{
    private $name;
    private $language;
    public $chat;

    public function setName($name)
    {
        $this->name = $name;
    }

    public function getName()
    {
        return $this->name;
    }

    public function learn(Speaking $language)
    {
        $this->language = $language;
    }

    public function getLanguage()
    {
        return $this->language;
    }

    public function says($phrase)
    {
        $people = [];
        foreach ($this->chat->getPeople() as $person) {
            if ($this->name === $person->getName()) continue;
            if (get_class($this->language) !== get_class($person->getLanguage())) continue;

            $people[] = $person->getName();
        }

        if (empty($people)) {
            echo 'Nobody understands';
        }
        else {
            $people = implode(', ', $people);
            echo "$this->name says {$this->language->$phrase()} to ($people)";
        }
    }
}

class Man extends Human
{
}

class Woman extends Human
{
}

class Chat
{
    private $people = [];

    public function add(Human $person)
    {
        $this->people[] = $person;
        $person->chat = $this;
    }

    public function getPeople()
    {
        return $this->people;
    }
}