<?php
class VowelFinder extends Model
{

	// This function prints unique vowels (A, E, I, O, U)
	// from a given string in the order they appear.
	// A 'Y' is considered a consonant if it begins a string and this string is greater than 1 character.
	// Otherwise, a 'Y' is considered a vowel.

	public function findVowels($string = '') {

		$string = $this->removeFirstY($string);
		$string = $this->leaveOnlyVowels($string);
		$string = $this->removeDublicateCharacters($string);

		return $string;
	}


	private function removeFirstY($string) {
		if(strlen($string) > 1) {
			string = preg_replace("/^y?/i", "", $string);
		}

		return $string;
	}


	private function leaveOnlyVowels($string) {
		$pattern = "/[^aeiouy]?/i";
		$string = preg_replace($pattern, '', $string);

		return $string;
	}

	private function removeDublicateCharacters($string){
		return implode(array_unique(str_split($string)));
	}
}