<?php
class Game {

	private static $instance;

	/**
	 * Singleton-pattern.
	 * Returns instance of class or calls constructor
	 * if instance does not exist.
	 * @return instance
	 */
	public static function &getInstance() {
		if (self::$instance === null) {
		self::$instance = new Game();
		}
		return self::$instance;
	}

	/**
	 * Private constructor.
	 * Constructs an instance of the class
	 * and calls buildDeck().
	 */
	private function __construct() {
		$this->buildDeck();
	}

	private function __clone() {}

	var $deck = array();
	var $communitycards = array();
	var $hands = array();
	var $burned = array();

	/**
	 * Private function buildDeck().
	 * Builds a deck of cards, and shuffles it.
	 */
	private function buildDeck() {
		$suits = "SCHD";
		for ($i=0; $i<strlen($suits); $i++) {
			for ($j=1; $j<=13; $j++) {
				array_push($this->deck, $suits[$i].$j);
			}
		}
		shuffle($this->deck);
	}

	/**
	 * Function deal($players).
	 * Deals cards based on number of players.
	 * @return hand
	 */
	function deal($players) {
		for($i=0; $i<$players; $i++) {
			$hand = $this->deck[count($this->deck)-1];
			array_pop($this->deck);
			$hand = $hand.".".$this->deck[count($this->deck)-1];
			array_pop($this->deck);
			array_push($this->hands, $hand);
		}
		return explode(".", $this->hands[0], 2);
	}

	/**
	 * Private function burn().
	 * Burns a card from the deck.
	 * Removes the upper card of the deck,
	 * and places it in $burned (array).
	 */
	function burn() {
		array_push($this->burned, $this->deck[count($this->deck)-1]);
		array_pop($this->deck);
	}

	/**
	 * Function flop().
	 * Deals the first three communitycards (the flop).
	 * Removes the upper card of the deck,
	 * and places it in $communitycards (array).
	 */
	function flop() {
		$this->burn();
		array_push($this->communitycards, $this->deck[count($this->deck)-1]);
		array_pop($this->deck);
		array_push($this->communitycards, $this->deck[count($this->deck)-1]);
		array_pop($this->deck);
		array_push($this->communitycards, $this->deck[count($this->deck)-1]);
		array_pop($this->deck);
	}

	/**
	 * Function turn().
	 * Deals the fourth communitycard (turn).
	 * Removes the upper card of the deck,
	 * and places it in $communitycards (array).
	 */
	function turn() {
		$this->burn();
		$turn = $this->deck[count($this->deck)-1];
		array_push($this->communitycards, $turn);
		array_pop($this->deck);
	}

	/**
	 * Function river().
	 * Deals the fifth communitycard (river).
	 * Removes the upper card of the deck,
	 * and places it in $communitycards (array).
	 */
	function river() {
		$this->burn();
		$river = $this->deck[count($this->deck)-1];
		array_push($this->communitycards, $river);
		array_pop($this->deck);
	}

	/**
	 * Function score().
	 * Calculates the best hand.
	 * @return score
	 */
	function score() {
		$cards = $this->communitycards;
		$hand = explode(".", $this->hands[0], 2);
		array_push($cards, $hand[0]);
		array_push($cards, $hand[1]);
		//$cards = array("D12", "D13", "D10", "D9", "H7", "H11", "H3");		
		natsort($cards);
		
		// for checking pairs and straights
		$faces = array();
		foreach($cards as $card) {
			array_push($faces, ereg_replace("[^0-9]", "", $card));
		}
		
		$flush = $this->isFlush($cards);
		$straight = $this->isStraight($faces);
		$pair = $this->isPair($faces);
		$highCard = $this->highCard($faces);
		
		if($straight && $flush) {
			return "straight flush";
		} else if($flush) {
			return "flush";
		} else if($straight) {
			return "straight";
		} else if($pair) {
			return "pair";
		} else {
			return $highCard;
		}
	}

	/**
	 * Function highCard($cards).
	 * Calculates the highcard/kicker.
	 * @param cards
	 * @return high
	 */
	function highCard($cards) {
		foreach($cards as $card) {
			if($card == 1) {
				return 14;
			} else if($card > $high) {
				$high = $card;
			}
		}
		return $high;
	}

	/**
	 * Function isPair($cards).
	 * Checks for pairs.
	 * @param cards
	 * @return boolean
	 */
	function isPair($cards) {
		if(count($cards) == count(array_unique($cards))) {
			return false;
		} else {
			return true;
		}
	}

	/**
	 * Function isFlush($cards).
	 * Checks for a flush.
	 * @param cards
	 * @return boolean
	 */
	function isFlush($cards) {
		foreach($cards as $card) {
			$seqence = $seqence.$card[0];
		}
		if(preg_match("/[C]{5,}|[D]{5,}|[H]{5,}|[S]{5,}/", $seqence)) {
			$flush = true;
		} else return false;
	}

	/**
	 * Function isStraight($cards).
	 * Checks for a straight.
	 * @param cards
	 * @return boolean
	 */
	function isStraight($cards) {		
		$cards = array_unique($cards);
		natsort($cards);
		foreach($cards as $card) {
			$sequence = $sequence.$card;
		}
		if( strpos($sequence, "12345") === false &&
			strpos($sequence, "23456") === false &&
			strpos($sequence, "34567") === false &&
			strpos($sequence, "45678") === false &&
			strpos($sequence, "56789") === false &&
			strpos($sequence, "678910") === false &&
			strpos($sequence, "7891011") === false &&
			strpos($sequence, "89101112") === false &&
			strpos($sequence, "910111213") === false &&
			strpos($sequence, "110111213") === false &&
			strpos($sequence, "12111213") === false &&
			strpos($sequence, "1231213") === false &&
			strpos($sequence, "123413") === false) {
			return false;
		} else return true;
	}

	/**
	 * Function reset().
	 * Resets the game.
	 * Places cards back in the deck,
	 * and shuffles it.
	 */
	function reset() {
		$this->deck = array_merge_recursive($this->deck, $this->communitycards);
		$this->deck = array_merge_recursive($this->deck, $this->burned);
		foreach($this->hands as $card) {
			$card = explode(".", $card, 2);
			array_push($this->deck, $card[0]);
			array_push($this->deck, $card[1]);
		}
		unset($this->communitycards);
		unset($this->burned);
		unset($this->hands);
		shuffle($this->deck);
	}

}
?>