path: root/Game.java

import java.util.*;
import card.*;

class Game {
	private List<Card> deck = new ArrayList<>();
	private List<List<Card>> hands = new ArrayList<>();
	private List<Integer> ranks = new ArrayList<>();

	public Game() {
		setDeck();
	}

	public Game(int handsNum) {
		setDeck();
		// preflop
		for (int i = 0; i < handsNum; i++) {
			hands.add(setHand(2));
		}
		for (List<Card> hand : hands) {
			getHand(hand);
			System.out.println();
		}
		// flop, turn, and river
		hands.add(setHand(5));
		List<Card> street = hands.get(hands.size() - 1);
		getHand(hands.get(hands.size() - 1));
		System.out.println();
		for (int i = 0; i < handsNum; i++) {
			for (int j = 0; j < 5; j++) {
				hands.get(i).add(street.get(j));
			}
			hands.set(i, sort(hands.get(i)));
		}
		// TODO: find a better way to calculate combinations for each hand
		for (int i = 0; i < handsNum; i++) {
			List<List<Card>> combinations;
			combinations = generate(hands.get(i));
			List<Integer> combinationRanks = new ArrayList<>();
			for (List<Card> combination : combinations) {
				combinationRanks.add(getRank(combination));
			}
			int winner = getWinner(combinations, combinationRanks);
			hands.set(i, combinations.get(winner));
		}
		for (int i = 0; i < handsNum; i++) {
			ranks.add(getRank(hands.get(i)));
		}
	}

	public void setHands(List<List<Card>> hands) {
		this.hands = hands;
	}

	public void setRanks(List<Integer> ranks) {
		this.ranks = ranks;
	}

	public void setDeck() {
		Suit s = Suit.CLUBS;
		for (int i = 0; i < 4; i++) {
			switch (i) {
				case 0:
					s = Suit.CLUBS;
					break;
				case 1:
					s = Suit.DIAMONDS;
					break;
				case 2:
					s = Suit.HEARTS;
					break;
				case 3:
					s = Suit.SPADES;
					break;
			}
			for (int j = 1; j <= 13; j++) {
				Card card = new Card(j, s);
				deck.add(card);
			}
		}
	}

	public List<Card> sort(List<Card> hand) {
		if (hand.size() <= 1)
			return hand;
		int mid = hand.size() / 2;
		List<Card> left = sort(hand.subList(0, mid));
		List<Card> right = sort(hand.subList(mid, hand.size()));
		return merge(left, right);
	}

	public List<Card> merge(List<Card> left, List<Card> right) {
		List<Card> result = new ArrayList<>();
		int l = 0, r = 0;
		while (l < left.size() || r < right.size()) {
			if (l < left.size() && (r == right.size()
				|| left.get(l).getValue() < right.get(r).getValue() )) {
				result.add(left.get(l));
				l++;
			} else {
				result.add(right.get(r));
				r++;
			}
		}
		return result;
	}

	public List<Card> setHand(int size) {
		List<Card> hand = new ArrayList<>();
		Random rand = new Random();
		for (int i = 0; i < size; i++) {
			int randInt = rand.nextInt(deck.size());
			hand.add(deck.get(randInt));
			deck.remove(randInt);
		}
		return sort(hand);
	}

	public void getHand(List<Card> hand) {
		for (Card c : hand) {
			System.out.println(c.displayCard());
		}
	}

	public List<List<Card>> generate(List<Card> hand) {
		List<List<Card>> combinations = new ArrayList<>();
		helper(hand, new ArrayList<Card>(), combinations);
		return combinations;
	}

	public void helper(List<Card> hand, List<Card> combination, List<List<Card>> combinations) {
		if (combination.size() == 5) {
			combinations.add(new ArrayList<>(sort(combination)));
		} else {
			for (int i = 0; i < 5; i++) {
				if (combination.contains(hand.get(i)))
					continue;
				combination.add(hand.get(i));
				helper(hand, combination, combinations);
				combination.remove(combination.size() - 1);
			}
		}
	}

	public int getRank(List<Card> hand) {
		if (isRoyalFlush(hand)) {
			return 9;
		} else if (isStraightFlush(hand)) {
			return 8;
		} else if (isFourOfKind(hand)) {
			return 7;
		} else if (isFullHouse(hand)) {
			return 6;
		} else if (isFlush(hand)) {
			return 5;
		} else if (isStraight(hand)) {
			return 4;
		} else if (isThreeOfKind(hand)) {
			return 3;
		} else if (isTwoPair(hand)) {
			return 2;
		} else if (isPair(hand)) {
			return 1;
		} else {
			return 0;
		}
	}

	public void displayRank(List<Card> hand, int rank) {
		switch (rank) {
			case 8:
				System.out.println("Straight flush");
				break;
			case 7:
				System.out.println("Four of a kind");
				break;
			case 6:
				System.out.println("Full house");
				break;
			case 5:
				System.out.println("Flush");
				break;
			case 4:
				System.out.println("Straight");
				break;
			case 3:
				System.out.println("Three of a kind");
				break;
			case 2:
				System.out.println("Two pair");
				break;
			case 1:
				System.out.println("Pair");
				break;
			default:
				System.out.println("High card " + highCard(hand));
		}
	}

	public String highCard(List<Card> hand) {
		if (hand.get(0).getValue() == 1)
			return hand.get(0).displayCard();
		return hand.get(hand.size() - 1).displayCard();
	}

	public boolean isPair(List<Card> hand) {
		boolean pair = false;
		for (int i = 0; i < hand.size() - 1; i++)
			pair = pair || (hand.get(i).getValue() == hand.get(i + 1).getValue());
		return pair;
	}

	public boolean isTwoPair(List<Card> hand) {
		int numberOfPairs = 0;
		int i = 0;
		while (i < hand.size() - 1) {
			if (isPair(hand.subList(i, i + 2))) {
				numberOfPairs++;
				i += 2;
			} else {
				i++;
			}
		}
		return numberOfPairs == 2;
	}

	public boolean isThreeOfKind(List<Card> hand) {
		boolean threeOfKind = false;
		for (int i = 0; i < hand.size() - 2; i++)
			threeOfKind = threeOfKind
				|| (hand.get(i).getValue() == hand.get(i + 2).getValue());
		return threeOfKind;
	}

	// TODO: ace high straight
	public boolean isStraight(List<Card> hand) {
		int prev = hand.get(0).getValue();
		int count = 0;
		for (int i = 1; i < hand.size() && count < 4; i++) {
			if (hand.get(i).getValue() - prev == 1) {
				count++;
			} else {
				count = 0;
			}
			prev = hand.get(i).getValue();
		}
		return count == 4;
	}

	public boolean isFlush(List<Card> hand) {
		boolean flush = true;
		Suit suit = hand.get(0).getSuit();
		for (int i = 1; i < hand.size(); i++)
			flush = flush && (hand.get(i).getSuit() == suit);
		return flush;
	}

	public boolean isFullHouse(List<Card> hand) {
		boolean pairThreeOfKind = false;
		boolean threeOfKindPair = false;

		for (int i = 0; i < hand.size() - 4; i++)
			pairThreeOfKind = (hand.get(i).getValue() == hand.get(i + 1).getValue())
				&& (hand.get(i + 2).getValue() == hand.get(i + 4).getValue());

		for (int i = 0; i < hand.size() - 4; i++)
			threeOfKindPair = (hand.get(i).getValue() == hand.get(i + 2).getValue())
				&& (hand.get(i + 3).getValue() == hand.get(i + 4).getValue());

		return pairThreeOfKind || threeOfKindPair;
	}

	public boolean isFourOfKind(List<Card> hand) {
		boolean fourOfKind = false;
		for (int i = 0; i < hand.size() - 3; i++)
			fourOfKind = fourOfKind
				|| (hand.get(i).getValue() == hand.get(i + 3).getValue());
		return fourOfKind;
	}

	public boolean isStraightFlush(List<Card> hand) {
		return isStraight(hand) && isFlush(hand);
	}

	// TODO: check A-10
	public boolean isRoyalFlush(List<Card> hand) {
		return isFlush(hand) && hand.get(0).getValue() == 1
			&& hand.get(1).getValue() == 10 && hand.get(4).getValue() == 13;
	}

	public boolean compareHighCard(List<Card> firstHand, List<Card> secondHand) {
		if (firstHand.get(0).getValue() == 1) {
			return true;
		} else if (secondHand.get(0).getValue() == 1) {
			return false;
		}
		for (int j = firstHand.size() - 1; j > 0; j--) {
			if (firstHand.get(j).getValue()
				> secondHand.get(j).getValue()) {
				return true;
			} else if (secondHand.get(j).getValue()
				> firstHand.get(j).getValue()) {
				return false;
			}
		}
		return false;
	}

	public boolean comparePair(List<Card> firstHand, List<Card> secondHand) {
		Set<Integer> temp = new HashSet<>();
		int high = firstHand.get(0).getValue();
		for (int i = 1; i < firstHand.size(); i++) {
			Card c = firstHand.get(i);
			if (temp.contains(c.getValue())) {
				high = c.getValue();
			} else {
				temp.add(c.getValue());
			}
		}
		temp.clear();
		for (Card c : secondHand) {
			if (temp.contains(c.getValue())) {
				if (high > c.getValue())
					return true;
			} else {
				temp.add(c.getValue());
			}
		}
		return false;
	}

	// TODO: combine with comparePair and compareThreeOfKind
	public boolean compareTwoPair(List<Card> firstHand, List<Card> secondHand) {
		Set<Integer> temp = new HashSet<>();
		int high = firstHand.get(0).getValue();
		for (int i = 1; i < firstHand.size(); i++) {
			Card c = firstHand.get(i);
			if (temp.contains(c.getValue()) && c.getValue() > high) {
				high = c.getValue();
			} else {
				temp.add(c.getValue());
			}
		}
		temp.clear();
		int greater = 0;
		for (Card c : secondHand) {
			if (temp.contains(c.getValue()) && high > c.getValue()) {
				greater++;
			} else {
				temp.add(c.getValue());
			}
		}
		return greater >= 2;
	}

	public int getWinner(List<List<Card>> hands, List<Integer> ranks) {
		int bestHand = 0, bestRank = 0;
		for (int i = 0; i < ranks.size(); i++) {
			if (ranks.get(i) > bestRank) {
				bestHand = i;
				bestRank = ranks.get(i);
			} else if (ranks.get(i) == bestRank) {
				switch (bestRank) {
					case 7:
					case 6:
					case 3:
					case 2:
						if (compareTwoPair(hands.get(i), hands.get(bestHand))) {
							bestHand = i;
							bestRank = ranks.get(i);
						}
						break;
					case 1:
						if (comparePair(hands.get(i), hands.get(bestHand))) {
							bestHand = i;
							bestRank = ranks.get(i);
						}
						break;
					case 5:
					case 4:
					case 0:
						if (compareHighCard(hands.get(i), hands.get(bestHand))) {
							bestHand = i;
							bestRank = ranks.get(i);
						}
				}
			}
		}
		return bestHand;
	}

	public static void main(String[] args) {
		Game g = new Game(8);
		for (int i = 0; i < 8; i++) {
			g.getHand(g.hands.get(i));
			g.displayRank(g.hands.get(i), g.ranks.get(i));
			System.out.println();
		}
		System.out.println(g.getWinner(g.hands, g.ranks));
	}
}