// Artist class with better encapsulation

class Artist {
  const EARLIEST_DATE = 'January 1, 1200';
  
  private static $artistCount = 0;
  private $firstName;
  private $lastName;
  private $birthDate;
  private $deathDate;
  private $birthCity;

  // notice constructor is using setters instead
  // of accessing properties
  function __construct($firstName, $lastName, $birthCity, $birthDate,
                       $deathDate) {
    $this->setFirstName($firstName);
    $this->setLastName($lastName);
    $this->setBirthCity($birthCity);
    $this->setBirthDate($birthDate);
    $this->setDeathDate($deathDate);
    self::$artistCount++;
  }
  // saving book space by putting each getter on single line
  public function getFirstName() { return $this->firstName; }
  public function getLastName() { return $this->lastName; }
  public function getBirthCity() { return $this->birthCity; }
  public function getBirthDate() { return $this->birthDate; }
  public function getDeathDate() { return $this->deathDate; }
  public static function getArtistCount() { return self::$artistCount; }
  public function getEarliestAllowedDate () {
    return date_create(self::EARLIEST_DATE);
  }
  
  public function setLastName($lastName)
  { $this->lastName = $lastName; }
  public function setFirstName($firstName)
  { $this->firstName = $firstName; }
  public function setBirthCity($birthCity)
  { $this->birthCity = $birthCity; }
  public function setBirthDate($birthdate) {
    // set variable only if passed a valid date string
    $date = date_create($birthdate);
    if ( ! $date ) {
      $this->birthDate = $this->getEarliestAllowedDate();
    }
    else {
      
      // if very early date then change it to earliest allowed date
      if ( $date < $this->getEarliestAllowedDate()  ) {
	$date = $this->getEarliestAllowedDate();
      }
      $this->birthDate = $date;
    }
  }
  public function setDeathDate($deathdate)  {
    // set variable only if passed a valid date string
    $date = date_create($deathdate);
    if ( ! $date ) {
      $this->deathDate = $this->getEarliestAllowedDate();
    }
    else {
      // set variable only if later than birth date
      if ($date > $this->getBirthDate()) {
	$this->deathDate = $date;
      }
      else {
	$this->deathDate = $this->getBirthDate();
      }
    }
  }
}