handranker-latest/lib/card.js

poker hand ranking program

'use strict';

var _ = require('underscore');

var TWO = '2', THREE = '3', FOUR = '4', FIVE = '5',
    SIX = '6', SEVEN = '7', EIGHT = '8', NINE = '9',
    TEN = 'T', JACK = 'J', QUEEN = 'Q', KING = 'K',
    ACE = 'A';

var SPADES = 's', HEARTS = 'h', DIAMONDS = 'd', CLUBS = 'c';

var RANKS = [TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, TEN, JACK, QUEEN, KING, ACE];
var ACE_LOW_RANKS = [ACE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, TEN, JACK, QUEEN, KING];
var SUITS = [SPADES, HEARTS, DIAMONDS, CLUBS];

var RANK_NAME_MAP = {
    2   : {singular: 'two',     plural: 'twos'},
    3   : {singular: 'three',   plural: 'threes'},
    4   : {singular: 'four',    plural: 'fours'},
    5   : {singular: 'five',    plural: 'fives'},
    6   : {singular: 'six',     plural: 'sixes'},
    7   : {singular: 'seven',   plural: 'sevens'},
    8   : {singular: 'eight',   plural: 'eights'},
    9   : {singular: 'nine',    plural: 'nines'},
    T   : {singular: 'ten',     plural: 'tens'},
    J   : {singular: 'jack',    plural: 'jacks'},
    Q   : {singular: 'queen',   plural: 'queens'},
    K   : {singular: 'king',    plural: 'kings'},
    A   : {singular: 'ace',     plural: 'aces'}
};

var SUIT_NAME_MAP = {
    s   : {singular: "spade",   plural: "spades"},
    h   : {singular: "heart",   plural: "hearts"},
    d   : {singular: "diamond", plural: "diamonds"},
    c   : {singular: "club",    plural: "clubs"}
};

function getDistance(card1, card2){
    var index1 = _.indexOf(RANKS, card1.rank);
    var index2 = _.indexOf(RANKS, card2.rank);
    return index2 - index1;
}

function compareCards(card1, card2){
    var distance = getDistance(card1, card2);
    if(distance > 0) return -1;
    else if(distance < 0) return 1;
    else return 0;
}

function compareCardsAceLow(card1, card2){
    var index1 = _.indexOf(ACE_LOW_RANKS, card1.rank);
    var index2 = _.indexOf(ACE_LOW_RANKS, card2.rank);
    var distance = index2 - index1;
    if(distance > 0) return -1;
    else if(distance < 0) return 1;
    else return 0;
}


var Card = function()
{

    var constructor = function Card(rank, suit)
    {
        if(arguments.length === 1){
            if(_.isString(arguments[0])){
                this.rank = arguments[0].substring(0,1);
                this.suit = arguments[0].substring(1,2);
            }
            else if(_.isArray(arguments[0])){
                this.rank = arguments[0][0];
                this.suit = arguments[0][1];
            }
            else{
                var card = _.extend({}, rank);
                this.rank = card.rank;
                this.suit = card.suit;
            }
        }
        else if(arguments.length === 2){
            this.rank = rank;
            this.suit = suit;
        }
        else throw 'invalid number of arguments';

        if(!_.contains(RANKS, this.rank)) throw 'invalid rank';
        if(!_.contains(SUITS, this.suit)) throw 'invalid suit';
    };

    constructor.RANKS = RANKS;
    constructor.ACE_LOW_RANKS = ACE_LOW_RANKS;
    constructor.SUITS = SUITS;

    constructor.SUIT_SPADE = SPADES;
    constructor.SUIT_HEART = HEARTS;
    constructor.SUIT_DIAMOND = DIAMONDS;
    constructor.SUIT_CLUB = CLUBS;

    constructor.RANK_TWO = TWO;
    constructor.RANK_THREE = THREE;
    constructor.RANK_FOUR = FOUR;
    constructor.RANK_FIVE = FIVE;
    constructor.RANK_SIX = SIX;
    constructor.RANK_SEVEN = SEVEN;
    constructor.RANK_EIGHT = EIGHT;
    constructor.RANK_NINE = NINE;
    constructor.RANK_TEN = TEN;
    constructor.RANK_JACK = JACK;
    constructor.RANK_QUEEN = QUEEN;
    constructor.RANK_KING = KING;
    constructor.RANK_ACE = ACE;

    constructor.sortCards = function (cards, aceHigh) {
        if(aceHigh === undefined) aceHigh = true;
        var sorted = _.extend([], cards);
        if(aceHigh) sorted.sort(compareCards);
        else sorted.sort(compareCardsAceLow);
        return sorted;
    };

    constructor.compare = function(card1, card2){
        return compareCards(card1, card2);
    };

    constructor.compareAceLow = function(card1, card2){
        return compareCardsAceLow(card1, card2);
    };

    constructor.greaterThan = function(card1, card2){
        return compareCards(card1, card2) === 1;
    };

    constructor.lessThan = function(card1, card2){
        return compareCards(card1, card2) === -1;
    };

    constructor.distance = function(card1, card2){
        return getDistance(card1, card2);
    };

    constructor.singularRankName = function(card){
        return RANK_NAME_MAP[card.rank].singular;
    };
    constructor.pluralRankName = function(card){
        return RANK_NAME_MAP[card.rank].plural;
    };
    constructor.singularSuitName = function(card){
        return SUIT_NAME_MAP[card.suit].singular;
    };
    constructor.pluralSuitName = function(card){
        return SUIT_NAME_MAP[card.suit].plural;
    };

    constructor.objectifyCards = function(cards){
        return _.map(cards, function(card){ return new Card(card) });
    };

    return constructor;
}();

// exports
module.exports = Card;