chance.js

//  Chance.js 0.5.3
//  http://chancejs.com
//  (c) 2013 Victor Quinn
//  Chance may be freely distributed or modified under the MIT license.

(function () {

    // Constants
    var MAX_INT = 9007199254740992;
    var MIN_INT = -MAX_INT;
    var NUMBERS = '0123456789';
    var CHARS_LOWER = 'abcdefghijklmnopqrstuvwxyz';
    var CHARS_UPPER = CHARS_LOWER.toUpperCase();
    var HEX_POOL  = NUMBERS + "abcdef";

    // Constructor
    var Chance = function (seed) {
        if (seed !== undefined) {
            // If we were passed a generator rather than a seed, use it.
            if (typeof seed === 'function') {
                this.random = seed;
            } else {
                this.seed = seed;
            }
        }

        // If no generator function was provided, use our MT
        if (typeof this.random === 'undefined') {
            this.mt = this.mersenne_twister(seed);
            this.random = function () {
                return this.mt.random(this.seed);
            };
        }
    };

    // Random helper functions
    function initOptions(options, defaults) {
        options || (options = {});
        if (!defaults) {
            return options;
        }
        for (var i in defaults) {
            if (typeof options[i] === 'undefined') {
                options[i] = defaults[i];
            }
        }
        return options;
    }

    function testRange(test, errorMessage) {
        if (test) {
            throw new RangeError(errorMessage);
        }
    }

    // -- Basics --

    Chance.prototype.bool = function (options) {

        // likelihood of success (true)
        options = initOptions(options, {likelihood : 50});

        testRange(
            options.likelihood < 0 || options.likelihood > 100,
            "Chance: Likelihood accepts values from 0 to 100."
        );

        return this.random() * 100 < options.likelihood;
    };

    Chance.prototype.character = function (options) {
        options = initOptions(options);

        var symbols = "!@#$%^&*()[]",
            letters, pool;

        testRange(
            options.alpha && options.symbols,
            "Chance: Cannot specify both alpha and symbols."
        );


        if (options.casing === 'lower') {
            letters = CHARS_LOWER;
        } else if (options.casing === 'upper') {
            letters = CHARS_UPPER;
        } else {
            letters = CHARS_LOWER + CHARS_UPPER;
        }

        if (options.pool) {
            pool = options.pool;
        } else if (options.alpha) {
            pool = letters;
        } else if (options.symbols) {
            pool = symbols;
        } else {
            pool = letters + NUMBERS + symbols;
        }

        return pool.charAt(this.natural({max: (pool.length - 1)}));
    };

    // Note, wanted to use "float" or "double" but those are both JS reserved words.

    // Note, fixed means N OR LESS digits after the decimal. This because
    // It could be 14.9000 but in JavaScript, when this is cast as a number,
    // the trailing zeroes are dropped. Left to the consumer if trailing zeroes are
    // needed
    Chance.prototype.floating = function (options) {
        var num, range;

        options = initOptions(options, {fixed : 4});
        var fixed = Math.pow(10, options.fixed);

        testRange(
            options.fixed && options.precision,
            "Chance: Cannot specify both fixed and precision."
        );

        var max = MAX_INT / fixed;
        var min = -max;

        testRange(
            options.min && options.fixed && options.min < min,
            "Chance: Min specified is out of range with fixed. Min should be, at least, " + min
        );
        testRange(
            options.max && options.fixed && options.max > max,
            "Chance: Max specified is out of range with fixed. Max should be, at most, " + max
        );

        options = initOptions(options, {min : min, max : max});

        // Todo - Make this work!
        // options.precision = (typeof options.precision !== "undefined") ? options.precision : false;

        num = this.integer({min: options.min * fixed, max: options.max * fixed});
        var num_fixed = (num / fixed).toFixed(options.fixed);

        return parseFloat(num_fixed);
    };

    Chance.prototype.integer = function (options) {
        var num, range;

        options = initOptions(options, {min : MIN_INT, max : MAX_INT});

        // Greatest of absolute value of either max or min so we know we're
        // including the entire search domain.
        range = Math.max(Math.abs(options.min), Math.abs(options.max));

        // Probably a better way to do this...
        do {
            num = this.natural({max: range});
            num = this.bool() ? num : num * -1;
        } while (num < options.min || num > options.max);

        return num;
    };

    // NOTE the max and min are INCLUDED in the range. So:
    //
    // chance.natural({min: 1, max: 3});
    //
    // would return either 1, 2, or 3.

    Chance.prototype.natural = function (options) {

        // 9007199254740992 (2^53) is the max integer number in JavaScript
        // See: http://vq.io/132sa2j
        options = initOptions(options, {min: 0, max: MAX_INT});

        testRange(options.min > options.max, "Chance: Min cannot be greater than Max.");

        return Math.floor(this.random() * (options.max - options.min + 1) + options.min);
    };

    Chance.prototype.normal = function (options) {
        options = initOptions(options, {mean : 0, dev : 1});

        // The Marsaglia Polar method
        var s, u, v, norm,
            mean = options.mean,
            dev = options.dev;

        do {
            // U and V are from the uniform distribution on (-1, 1)
            u = this.random() * 2 - 1;
            v = this.random() * 2 - 1;

            s = u * u + v * v;
        } while (s >= 1);

        // Compute the standard normal variate
        norm = u * Math.sqrt(-2 * Math.log(s) / s);

        // Shape and scale
        return dev * norm + mean;
    };

    Chance.prototype.string = function (options) {
        options = initOptions(options);

        var length = options.length || this.natural({min: 5, max: 20}),
            text = '',
            pool = options.pool;

        for (var i = 0; i < length; i++) {
            text += this.character({pool: pool});
        }
        return text;
    };

    // -- End Basics --

    // -- Helpers --

    Chance.prototype.capitalize = function (word) {
        return word.charAt(0).toUpperCase() + word.substr(1);
    };

    Chance.prototype.mixin = function (obj) {
        var chance = this;
        for (var func_name in obj) {
            Chance.prototype[func_name] = obj[func_name];
        }
        return this;
    };

    Chance.prototype.pick = function (arr, count) {
        if (!count || count === 1) {
            return arr[this.natural({max: arr.length - 1})];
        } else {
            return this.shuffle(arr).slice(0, count);
        }
    };

    Chance.prototype.shuffle = function (arr) {
        var old_array = arr.slice(0),
            new_array = [],
            j = 0,
            length = Number(old_array.length);

        for (var i = 0; i < length; i++) {
            // Pick a random index from the array
            j = this.natural({max: old_array.length - 1});
            // Add it to the new array
            new_array[i] = old_array[j];
            // Remove that element from the original array
            old_array.splice(j, 1);
        }

        return new_array;
    };

    // -- End Helpers --

    // -- Text --

    Chance.prototype.paragraph = function (options) {
        options = initOptions(options);

        var sentences = options.sentences || this.natural({min: 3, max: 7}),
            sentence_array = [];

        for (var i = 0; i < sentences; i++) {
            sentence_array.push(this.sentence());
        }

        return sentence_array.join(' ');
    };

    // Could get smarter about this than generating random words and
    // chaining them together. Such as: http://vq.io/1a5ceOh
    Chance.prototype.sentence = function (options) {
        options = initOptions(options);

        var words = options.words || this.natural({min: 12, max: 18}),
            text, word_array = [];

        for (var i = 0; i < words; i++) {
            word_array.push(this.word());
        }

        text = word_array.join(' ');

        // Capitalize first letter of sentence, add period at end
        text = this.capitalize(text) + '.';

        return text;
    };

    Chance.prototype.syllable = function (options) {
        options = initOptions(options);

        var length = options.length || this.natural({min: 2, max: 3}),
            consanants = 'bcdfghjklmnprstvwz', // consonants except hard to speak ones
            vowels = 'aeiou', // vowels
            all = consanants + vowels, // all
            text = '',
            chr;

        // I'm sure there's a more elegant way to do this, but this works
        // decently well.
        for (var i = 0; i < length; i++) {
            if (i === 0) {
                // First character can be anything
                chr = this.character({pool: all});
            } else if (consanants.indexOf(chr) === -1) {
                // Last charcter was a vowel, now we want a consanant
                chr = this.character({pool: consanants});
            } else {
                // Last charcter was a consanant, now we want a vowel
                chr = this.character({pool: vowels});
            }

            text += chr;
        }

        return text;
    };

    Chance.prototype.word = function (options) {
        options = initOptions(options);

        testRange(
            options.syllables && options.length,
            "Chance: Cannot specify both syllables AND length."
        );

        var syllables = options.syllables || this.natural({min: 1, max: 3}),
            text = '';

        if (options.length) {
            // Either bound word by length
            do {
                text += this.syllable();
            } while (text.length < options.length);
            text = text.substring(0, options.length);
        } else {
            // Or by number of syllables
            for (var i = 0; i < syllables; i++) {
                text += this.syllable();
            }
        }
        return text;
    };

    // -- End Text --

    // -- Person --

    Chance.prototype.age = function (options) {
        options = initOptions(options);
        var age;

        switch (options.type) {
        case 'child':
            age = this.natural({min: 1, max: 12});
            break;
        case 'teen':
            age = this.natural({min: 13, max: 19});
            break;
        case 'adult':
            age = this.natural({min: 18, max: 120});
            break;
        case 'senior':
            age = this.natural({min: 65, max: 120});
            break;
        default:
            age = this.natural({min: 1, max: 120});
            break;
        }

        return age;
    };

    Chance.prototype.birthday = function (options) {
        options = initOptions(options, {
            year: (new Date().getFullYear() - this.age(options))
        });

        return this.date(options);
    };

    var firstNames = ['Sophia', 'Emma', 'Isabella', 'Jacob', 'Mason', 'Ethan', 'Noah', 'Olivia', 'William', 'Liam', 'Jayden', 'Michael', 'Ava', 'Alexander', 'Aiden', 'Daniel', 'Matthew', 'Elijah', 'Emily', 'James', 'Anthony', 'Benjamin', 'Abigail', 'Joshua', 'Andrew', 'David', 'Joseph', 'Logan', 'Jackson', 'Mia', 'Christopher', 'Gabriel', 'Madison', 'Samuel', 'Ryan', 'Lucas', 'John', 'Nathan', 'Isaac', 'Dylan', 'Caleb', 'Elizabeth', 'Chloe', 'Christian', 'Landon', 'Jonathan', 'Carter', 'Ella', 'Luke', 'Owen', 'Brayden', 'Avery', 'Gavin', 'Wyatt', 'Addison', 'Isaiah', 'Aubrey', 'Henry', 'Eli', 'Hunter', 'Lily', 'Jack', 'Natalie', 'Evan', 'Sofia', 'Jordan', 'Nicholas', 'Tyler', 'Aaron', 'Charlotte', 'Zoey', 'Jeremiah', 'Julian', 'Cameron', 'Grace', 'Hannah', 'Amelia', 'Harper', 'Levi', 'Lillian', 'Brandon', 'Angel', 'Austin', 'Connor', 'Adrian', 'Robert', 'Samantha', 'Charles', 'Evelyn', 'Victoria', 'Thomas', 'Brooklyn', 'Sebastian', 'Zoe', 'Colton', 'Jaxon', 'Layla', 'Kevin', 'Zachary', 'Ayden', 'Dominic', 'Blake', 'Jose', 'Hailey', 'Oliver', 'Justin', 'Bentley', 'Leah', 'Jason', 'Chase', 'Ian', 'Kaylee', 'Anna', 'Aaliyah', 'Gabriella', 'Josiah', 'Allison', 'Parker', 'Xavier', 'Nevaeh', 'Alexis', 'Adam', 'Audrey', 'Cooper', 'Savannah', 'Sarah', 'Alyssa', 'Claire', 'Taylor', 'Riley', 'Camila', 'Nathaniel', 'Arianna', 'Ashley', 'Grayson', 'Jace', 'Brianna', 'Carson', 'Sophie', 'Peyton', 'Nolan', 'Tristan', 'Luis', 'Brody', 'Bella', 'Khloe', 'Genesis', 'Alexa', 'Juan', 'Hudson', 'Serenity', 'Kylie', 'Aubree', 'Scarlett', 'Bryson', 'Carlos', 'Stella', 'Maya', 'Easton', 'Katherine', 'Julia', 'Damian', 'Alex', 'Kayden', 'Ryder', 'Lucy', 'Madelyn', 'Jesus', 'Cole', 'Autumn', 'Makayla', 'Kayla', 'Mackenzie', 'Micah', 'Vincent', 'Max', 'Lauren', 'Jaxson', 'Gianna', 'Eric', 'Ariana', 'Asher', 'Hayden', 'Faith', 'Alexandra', 'Melanie', 'Sydney', 'Bailey', 'Caroline', 'Naomi', 'Morgan', 'Kennedy', 'Ellie', 'Jasmine', 'Eva', 'Skylar', 'Diego', 'Kimberly', 'Violet', 'Molly', 'Miles', 'Steven', 'Aria', 'Ivan', 'Jocelyn', 'Trinity', 'Elias', 'Aidan', 'Maxwell', 'London', 'Bryce', 'Lydia', 'Madeline', 'Antonio', 'Giovanni', 'Reagan', 'Timothy', 'Bryan', 'Piper', 'Andrea', 'Santiago', 'Annabelle', 'Maria', 'Colin', 'Richard', 'Braxton', 'Kaleb', 'Brooke', 'Kyle', 'Kaden', 'Preston', 'Payton', 'Miguel', 'Jonah', 'Paisley', 'Paige', 'Lincoln', 'Ruby', 'Nora', 'Riley', 'Mariah', 'Leo', 'Victor', 'Brady', 'Jeremy', 'Mateo', 'Brian', 'Jaden', 'Ashton', 'Patrick', 'Rylee', 'Declan', 'Lilly', 'Brielle', 'Sean', 'Joel', 'Gael', 'Sawyer', 'Alejandro', 'Jade', 'Marcus', 'Destiny', 'Leonardo', 'Jesse', 'Caden', 'Jake', 'Kaiden', 'Nicole', 'Mila', 'Wesley', 'Kendall', 'Liliana', 'Camden', 'Kaitlyn', 'Natalia', 'Sadie', 'Edward', 'Brantley', 'Jordyn', 'Roman', 'Vanessa', 'Mary', 'Mya', 'Penelope', 'Isabelle', 'Alice', 'Axel', 'Silas', 'Jude', 'Grant', 'Reese', 'Gabrielle', 'Hadley', 'Katelyn', 'Angelina', 'Rachel', 'Isabel', 'Eleanor', 'Cayden', 'Emmanuel', 'George', 'Clara', 'Brooklynn', 'Jessica', 'Maddox', 'Malachi', 'Bradley', 'Alan', 'Weston', 'Elena', 'Gage', 'Aliyah', 'Vivian', 'Laila', 'Sara', 'Amy', 'Devin', 'Eliana', 'Greyson', 'Lyla', 'Juliana', 'Kenneth', 'Mark', 'Oscar', 'Tanner', 'Rylan', 'Valeria', 'Adriana', 'Nicolas', 'Makenzie', 'Harrison', 'Elise', 'Mckenzie', 'Derek', 'Quinn', 'Delilah', 'Peyton', 'Ezra', 'Cora', 'Kylee', 'Tucker', 'Emmett', 'Avery', 'Cody', 'Rebecca', 'Gracie', 'Izabella', 'Calvin', 'Andres', 'Jorge', 'Abel', 'Paul', 'Abraham', 'Kai', 'Josephine', 'Alaina', 'Michelle', 'Jennifer', 'Collin', 'Theodore', 'Ezekiel', 'Eden', 'Omar', 'Jayce', 'Valentina', 'Conner', 'Bennett', 'Aurora', 'Catherine', 'Stephanie', 'Trevor', 'Valerie', 'Eduardo', 'Peter', 'Maximus', 'Jayla', 'Jaiden', 'Willow', 'Jameson', 'Seth', 'Daisy', 'Alana', 'Melody', 'Hazel', 'Kingston', 'Summer', 'Melissa', 'Javier', 'Margaret', 'Travis', 'Kinsley', 'Kinley', 'Garrett', 'Everett', 'Ariel', 'Lila', 'Graham', 'Giselle', 'Ryleigh', 'Xander', 'Haley', 'Julianna', 'Ivy', 'Alivia', 'Cristian', 'Brynn', 'Damien', 'Ryker', 'Griffin', 'Keira', 'Daniela', 'Aniyah', 'Angela', 'Kate', 'Londyn', 'Corbin', 'Myles', 'Hayden', 'Harmony', 'Adalyn', 'Luca', 'Zane', 'Francisco', 'Ricardo', 'Alexis', 'Stephen', 'Zayden', 'Megan', 'Allie', 'Gabriela', 'Iker', 'Drake', 'Alayna', 'Lukas', 'Presley', 'Charlie', 'Spencer', 'Zion', 'Erick', 'Jenna', 'Josue', 'Alexandria', 'Ashlyn', 'Adrianna', 'Jada', 'Jeffrey', 'Trenton', 'Fiona', 'Chance', 'Norah', 'Paxton', 'Elliot', 'Emery', 'Fernando', 'Maci', 'Miranda', 'Keegan', 'Landen', 'Ximena', 'Amaya', 'Manuel', 'Amir', 'Shane', 'Cecilia', 'Raymond', 'Andre', 'Ana', 'Shelby', 'Katie', 'Hope', 'Callie', 'Jordan', 'Luna', 'Leilani', 'Eliza', 'Mckenna', 'Angel', 'Genevieve', 'Makenna', 'Isla', 'Lola', 'Danielle', 'Chelsea', 'Leila', 'Tessa', 'Adelyn', 'Camille', 'Mikayla', 'Adeline', 'Adalynn', 'Sienna', 'Esther', 'Jacqueline', 'Emerson', 'Arabella', 'Maggie', 'Athena', 'Lucia', 'Lexi', 'Ayla'];

    Chance.prototype.first = function () {
        return this.pick(firstNames);
    };

    Chance.prototype.gender = function () {
        return this.pick(['Male', 'Female']);
    };

    var lastNames = ['Smith', 'Johnson', 'Williams', 'Jones', 'Brown', 'Davis', 'Miller', 'Wilson', 'Moore', 'Taylor', 'Anderson', 'Thomas', 'Jackson', 'White', 'Harris', 'Martin', 'Thompson', 'Garcia', 'Martinez', 'Robinson', 'Clark', 'Rodriguez', 'Lewis', 'Lee', 'Walker', 'Hall', 'Allen', 'Young', 'Hernandez', 'King', 'Wright', 'Lopez', 'Hill', 'Scott', 'Green', 'Adams', 'Baker', 'Gonzalez', 'Nelson', 'Carter', 'Mitchell', 'Perez', 'Roberts', 'Turner', 'Phillips', 'Campbell', 'Parker', 'Evans', 'Edwards', 'Collins', 'Stewart', 'Sanchez', 'Morris', 'Rogers', 'Reed', 'Cook', 'Morgan', 'Bell', 'Murphy', 'Bailey', 'Rivera', 'Cooper', 'Richardson', 'Cox', 'Howard', 'Ward', 'Torres', 'Peterson', 'Gray', 'Ramirez', 'James', 'Watson', 'Brooks', 'Kelly', 'Sanders', 'Price', 'Bennett', 'Wood', 'Barnes', 'Ross', 'Henderson', 'Coleman', 'Jenkins', 'Perry', 'Powell', 'Long', 'Patterson', 'Hughes', 'Flores', 'Washington', 'Butler', 'Simmons', 'Foster', 'Gonzales', 'Bryant', 'Alexander', 'Russell', 'Griffin', 'Diaz', 'Hayes', 'Myers', 'Ford', 'Hamilton', 'Graham', 'Sullivan', 'Wallace', 'Woods', 'Cole', 'West', 'Jordan', 'Owens', 'Reynolds', 'Fisher', 'Ellis', 'Harrison', 'Gibson', 'McDonald', 'Cruz', 'Marshall', 'Ortiz', 'Gomez', 'Murray', 'Freeman', 'Wells', 'Webb', 'Simpson', 'Stevens', 'Tucker', 'Porter', 'Hunter', 'Hicks', 'Crawford', 'Henry', 'Boyd', 'Mason', 'Morales', 'Kennedy', 'Warren', 'Dixon', 'Ramos', 'Reyes', 'Burns', 'Gordon', 'Shaw', 'Holmes', 'Rice', 'Robertson', 'Hunt', 'Black', 'Daniels', 'Palmer', 'Mills', 'Nichols', 'Grant', 'Knight', 'Ferguson', 'Rose', 'Stone', 'Hawkins', 'Dunn', 'Perkins', 'Hudson', 'Spencer', 'Gardner', 'Stephens', 'Payne', 'Pierce', 'Berry', 'Matthews', 'Arnold', 'Wagner', 'Willis', 'Ray', 'Watkins', 'Olson', 'Carroll', 'Duncan', 'Snyder', 'Hart', 'Cunningham', 'Bradley', 'Lane', 'Andrews', 'Ruiz', 'Harper', 'Fox', 'Riley', 'Armstrong', 'Carpenter', 'Weaver', 'Greene', 'Lawrence', 'Elliott', 'Chavez', 'Sims', 'Austin', 'Peters', 'Kelley', 'Franklin', 'Lawson', 'Fields', 'Gutierrez', 'Ryan', 'Schmidt', 'Carr', 'Vasquez', 'Castillo', 'Wheeler', 'Chapman', 'Oliver', 'Montgomery', 'Richards', 'Williamson', 'Johnston', 'Banks', 'Meyer', 'Bishop', 'McCoy', 'Howell', 'Alvarez', 'Morrison', 'Hansen', 'Fernandez', 'Garza', 'Harvey', 'Little', 'Burton', 'Stanley', 'Nguyen', 'George', 'Jacobs', 'Reid', 'Kim', 'Fuller', 'Lynch', 'Dean', 'Gilbert', 'Garrett', 'Romero', 'Welch', 'Larson', 'Frazier', 'Burke', 'Hanson', 'Day', 'Mendoza', 'Moreno', 'Bowman', 'Medina', 'Fowler', 'Brewer', 'Hoffman', 'Carlson', 'Silva', 'Pearson', 'Holland', 'Douglas', 'Fleming', 'Jensen', 'Vargas', 'Byrd', 'Davidson', 'Hopkins', 'May', 'Terry', 'Herrera', 'Wade', 'Soto', 'Walters', 'Curtis', 'Neal', 'Caldwell', 'Lowe', 'Jennings', 'Barnett', 'Graves', 'Jimenez', 'Horton', 'Shelton', 'Barrett', 'Obrien', 'Castro', 'Sutton', 'Gregory', 'McKinney', 'Lucas', 'Miles', 'Craig', 'Rodriquez', 'Chambers', 'Holt', 'Lambert', 'Fletcher', 'Watts', 'Bates', 'Hale', 'Rhodes', 'Pena', 'Beck', 'Newman', 'Haynes', 'McDaniel', 'Mendez', 'Bush', 'Vaughn', 'Parks', 'Dawson', 'Santiago', 'Norris', 'Hardy', 'Love', 'Steele', 'Curry', 'Powers', 'Schultz', 'Barker', 'Guzman', 'Page', 'Munoz', 'Ball', 'Keller', 'Chandler', 'Weber', 'Leonard', 'Walsh', 'Lyons', 'Ramsey', 'Wolfe', 'Schneider', 'Mullins', 'Benson', 'Sharp', 'Bowen', 'Daniel', 'Barber', 'Cummings', 'Hines', 'Baldwin', 'Griffith', 'Valdez', 'Hubbard', 'Salazar', 'Reeves', 'Warner', 'Stevenson', 'Burgess', 'Santos', 'Tate', 'Cross', 'Garner', 'Mann', 'Mack', 'Moss', 'Thornton', 'Dennis', 'McGee', 'Farmer', 'Delgado', 'Aguilar', 'Vega', 'Glover', 'Manning', 'Cohen', 'Harmon', 'Rodgers', 'Robbins', 'Newton', 'Todd', 'Blair', 'Higgins', 'Ingram', 'Reese', 'Cannon', 'Strickland', 'Townsend', 'Potter', 'Goodwin', 'Walton', 'Rowe', 'Hampton', 'Ortega', 'Patton', 'Swanson', 'Joseph', 'Francis', 'Goodman', 'Maldonado', 'Yates', 'Becker', 'Erickson', 'Hodges', 'Rios', 'Conner', 'Adkins', 'Webster', 'Norman', 'Malone', 'Hammond', 'Flowers', 'Cobb', 'Moody', 'Quinn', 'Blake', 'Maxwell', 'Pope', 'Floyd', 'Osborne', 'Paul', 'McCarthy', 'Guerrero', 'Lindsey', 'Estrada', 'Sandoval', 'Gibbs', 'Tyler', 'Gross', 'Fitzgerald', 'Stokes', 'Doyle', 'Sherman', 'Saunders', 'Wise', 'Colon', 'Gill', 'Alvarado', 'Greer', 'Padilla', 'Simon', 'Waters', 'Nunez', 'Ballard', 'Schwartz', 'McBride', 'Houston', 'Christensen', 'Klein', 'Pratt', 'Briggs', 'Parsons', 'McLaughlin', 'Zimmerman', 'French', 'Buchanan', 'Moran', 'Copeland', 'Roy', 'Pittman', 'Brady', 'McCormick', 'Holloway', 'Brock', 'Poole', 'Frank', 'Logan', 'Owen', 'Bass', 'Marsh', 'Drake', 'Wong', 'Jefferson', 'Park', 'Morton', 'Abbott', 'Sparks', 'Patrick', 'Norton', 'Huff', 'Clayton', 'Massey', 'Lloyd', 'Figueroa', 'Carson', 'Bowers', 'Roberson', 'Barton', 'Tran', 'Lamb', 'Harrington', 'Casey', 'Boone', 'Cortez', 'Clarke', 'Mathis', 'Singleton', 'Wilkins', 'Cain', 'Bryan', 'Underwood', 'Hogan', 'McKenzie', 'Collier', 'Luna', 'Phelps', 'McGuire', 'Allison', 'Bridges', 'Wilkerson', 'Nash', 'Summers', 'Atkins'];

    Chance.prototype.last = function () {
        return this.pick(lastNames);
    };

    Chance.prototype.name = function (options) {
        options = initOptions(options);

        var first = this.first(),
            last = this.last(),
            name;

        if (options.middle) {
            name = first + ' ' + this.first() + ' ' + last;
        } else if (options.middle_initial) {
            name = first + ' ' + this.character({alpha: true, casing: 'upper'}) + '. ' + last;
        } else {
            name = first + ' ' + last;
        }

        if (options.prefix) {
            name = this.prefix() + ' ' + name;
        }

        return name;
    };

    Chance.prototype.name_prefixes = function () {
        return [
            {name: 'Doctor', abbreviation: 'Dr.'},
            {name: 'Miss', abbreviation: 'Miss'},
            {name: 'Misses', abbreviation: 'Mrs.'},
            {name: 'Mister', abbreviation: 'Mr.'}
        ];
    };

    // Alias for name_prefix
    Chance.prototype.prefix = function (options) {
        return this.name_prefix(options);
    };

    Chance.prototype.name_prefix = function (options) {
        options = initOptions(options);
        return options.full ?
            this.pick(this.name_prefixes()).name :
            this.pick(this.name_prefixes()).abbreviation;
    };

    // -- End Person --

    // -- Web --

    Chance.prototype.color = function (options) {
        function gray(value, delimiter) {
            return [value, value, value].join(delimiter || '');
        }

        options = initOptions(options, {format: this.pick(['hex', 'shorthex', 'rgb']), grayscale: false});
        var isGrayscale = options.grayscale;

        if (options.format === 'hex') {
            return '#' + (isGrayscale ? gray(this.hash({length: 2})) : this.hash({length: 6}));
        }

        if (options.format === 'shorthex') {
            return '#' + (isGrayscale ? gray(this.hash({length: 1})) : this.hash({length: 3}));
        }

        if (options.format === 'rgb') {
            if (isGrayscale) {
                return 'rgb(' + gray(this.natural({max: 255}), ',') + ')';
            } else {
                return 'rgb(' + this.natural({max: 255}) + ',' + this.natural({max: 255}) + ',' + this.natural({max: 255}) + ')';
            }
        }

        throw new Error('Invalid format provided. Please provide one of "hex", "shorthex", or "rgb"');
    };

    Chance.prototype.domain = function (options) {
        options = initOptions(options);
        return this.word() + '.' + (options.tld || this.tld());
    };

    Chance.prototype.email = function (options) {
        options = initOptions(options);
        return this.word() + '@' + (options.domain || this.domain());
    };

    Chance.prototype.fbid = function () {
        return parseInt('10000' + this.natural({max: 100000000000}), 10);
    };

    Chance.prototype.hashtag = function () {
        return '#' + this.word();
    };

    Chance.prototype.ip = function () {
        // Todo: This could return some reserved IPs. See http://vq.io/137dgYy
        // this should probably be updated to account for that rare as it may be
        return this.natural({max: 255}) + '.' +
               this.natural({max: 255}) + '.' +
               this.natural({max: 255}) + '.' +
               this.natural({max: 255});
    };

    Chance.prototype.ipv6 = function () {
        var ip_addr = "";

        for (var i = 0; i < 8; i++) {
            ip_addr += this.hash({length: 4}) + ':';
        }
        return ip_addr.substr(0, ip_addr.length - 1);
    };

    Chance.prototype.klout = function () {
        return this.natural({min: 1, max: 99});
    };

    Chance.prototype.tlds = function () {
        return ['com', 'org', 'edu', 'gov', 'co.uk', 'net', 'io'];
    };

    Chance.prototype.tld = function () {
        return this.pick(this.tlds());
    };

    Chance.prototype.twitter = function () {
        return '@' + this.word();
    };

    // -- End Web --

    // -- Address --

    Chance.prototype.address = function (options) {
        options = initOptions(options);
        return this.natural({min: 5, max: 2000}) + ' ' + this.street(options);
    };

    Chance.prototype.areacode = function (options) {
        options = initOptions(options, {parens : true});
        // Don't want area codes to start with 1, or have a 9 as the second digit
        var areacode = this.natural({min: 2, max: 9}).toString() + this.natural({min: 0, max: 8}).toString() + this.natural({min: 0, max: 9}).toString();
        return options.parens ? '(' + areacode + ')' : areacode;
    };

    Chance.prototype.city = function () {
        return this.capitalize(this.word({syllables: 3}));
    };

    Chance.prototype.coordinates = function (options) {
        options = initOptions(options);
        return this.latitude(options) + ', ' + this.longitude(options);
    };

    Chance.prototype.latitude = function (options) {
        options = initOptions(options, {fixed : 5});
        return this.floating({min: -90, max: 90, fixed: options.fixed});
    };

    Chance.prototype.longitude = function (options) {
        options = initOptions(options, {fixed : 5});
        return this.floating({min: 0, max: 180, fixed: options.fixed});
    };

    Chance.prototype.phone = function (options) {
        options = initOptions(options, {formatted : true});
        if (!options.formatted) {
            options.parens = false;
        }
        var areacode = this.areacode(options).toString();
        var exchange = this.natural({min: 2, max: 9}).toString() + this.natural({min: 0, max: 9}).toString() + this.natural({min: 0, max: 9}).toString();
        var subscriber = this.natural({min: 1000, max: 9999}).toString(); // this could be random [0-9]{4}
        return options.formatted ? areacode + ' ' + exchange + '-' + subscriber : areacode + exchange + subscriber;
    };

    Chance.prototype.postal = function () {
        // Postal District
        var pd = this.character({pool: "XVTSRPNKLMHJGECBA"});
        // Forward Sortation Area (FSA)
        var fsa = pd + this.natural({max: 9}) + this.character({alpha: true, casing: "upper"});
        // Local Delivery Unut (LDU)
        var ldu = this.natural({max: 9}) + this.character({alpha: true, casing: "upper"}) + this.natural({max: 9});

        return fsa + " " + ldu;
    };

    Chance.prototype.provinces = function () {
        return [
            {name: 'Alberta', abbreviation: 'AB'},
            {name: 'British Columbia', abbreviation: 'BC'},
            {name: 'Manitoba', abbreviation: 'MB'},
            {name: 'New Brunswick', abbreviation: 'NB'},
            {name: 'Newfoundland and Labrador', abbreviation: 'NL'},
            {name: 'Nova Scotia', abbreviation: 'NS'},
            {name: 'Ontario', abbreviation: 'ON'},
            {name: 'Prince Edward Island', abbreviation: 'PE'},
            {name: 'Quebec', abbreviation: 'QC'},
            {name: 'Saskatchewan', abbreviation: 'SK'},

            // The case could be made that the following are not actually provinces
            // since they are technically considered "territories" however they all
            // look the same on an envelope!
            {name: 'Northwest Territories', abbreviation: 'NT'},
            {name: 'Nunavut', abbreviation: 'NU'},
            {name: 'Yukon', abbreviation: 'YT'}
        ];
    };

    Chance.prototype.province = function (options) {
        return (options && options.full) ?
            this.pick(this.provinces()).name :
            this.pick(this.provinces()).abbreviation;
    };

    Chance.prototype.radio = function (options) {
        // Initial Letter (Typically Designated by Side of Mississippi River)
        options = initOptions(options, {side : "?"});
        var fl = "";
        switch (options.side.toLowerCase()) {
        case "east":
        case "e":
            fl = "W";
            break;
        case "west":
        case "w":
            fl = "K";
            break;
        default:
            fl = this.character({pool: "KW"});
            break;
        }

        return fl + this.character({alpha: true, casing: "upper"}) + this.character({alpha: true, casing: "upper"}) + this.character({alpha: true, casing: "upper"});
    };

    Chance.prototype.state = function (options) {
        return (options && options.full) ?
            this.pick(this.states()).name :
            this.pick(this.states()).abbreviation;
    };

    Chance.prototype.states = function () {
        return [
            {name: 'Alabama', abbreviation: 'AL'},
            {name: 'Alaska', abbreviation: 'AK'},
            {name: 'American Samoa', abbreviation: 'AS'},
            {name: 'Arizona', abbreviation: 'AZ'},
            {name: 'Arkansas', abbreviation: 'AR'},
            {name: 'Armed Forces Europe', abbreviation: 'AE'},
            {name: 'Armed Forces Pacific', abbreviation: 'AP'},
            {name: 'Armed Forces the Americas', abbreviation: 'AA'},
            {name: 'California', abbreviation: 'CA'},
            {name: 'Colorado', abbreviation: 'CO'},
            {name: 'Connecticut', abbreviation: 'CT'},
            {name: 'Delaware', abbreviation: 'DE'},
            {name: 'District of Columbia', abbreviation: 'DC'},
            {name: 'Federated States of Micronesia', abbreviation: 'FM'},
            {name: 'Florida', abbreviation: 'FL'},
            {name: 'Georgia', abbreviation: 'GA'},
            {name: 'Guam', abbreviation: 'GU'},
            {name: 'Hawaii', abbreviation: 'HI'},
            {name: 'Idaho', abbreviation: 'ID'},
            {name: 'Illinois', abbreviation: 'IL'},
            {name: 'Indiana', abbreviation: 'IN'},
            {name: 'Iowa', abbreviation: 'IA'},
            {name: 'Kansas', abbreviation: 'KS'},
            {name: 'Kentucky', abbreviation: 'KY'},
            {name: 'Louisiana', abbreviation: 'LA'},
            {name: 'Maine', abbreviation: 'ME'},
            {name: 'Marshall Islands', abbreviation: 'MH'},
            {name: 'Maryland', abbreviation: 'MD'},
            {name: 'Massachusetts', abbreviation: 'MA'},
            {name: 'Michigan', abbreviation: 'MI'},
            {name: 'Minnesota', abbreviation: 'MN'},
            {name: 'Mississippi', abbreviation: 'MS'},
            {name: 'Missouri', abbreviation: 'MO'},
            {name: 'Montana', abbreviation: 'MT'},
            {name: 'Nebraska', abbreviation: 'NE'},
            {name: 'Nevada', abbreviation: 'NV'},
            {name: 'New Hampshire', abbreviation: 'NH'},
            {name: 'New Jersey', abbreviation: 'NJ'},
            {name: 'New Mexico', abbreviation: 'NM'},
            {name: 'New York', abbreviation: 'NY'},
            {name: 'North Carolina', abbreviation: 'NC'},
            {name: 'North Dakota', abbreviation: 'ND'},
            {name: 'Northern Mariana Islands', abbreviation: 'MP'},
            {name: 'Ohio', abbreviation: 'OH'},
            {name: 'Oklahoma', abbreviation: 'OK'},
            {name: 'Oregon', abbreviation: 'OR'},
            {name: 'Pennsylvania', abbreviation: 'PA'},
            {name: 'Puerto Rico', abbreviation: 'PR'},
            {name: 'Rhode Island', abbreviation: 'RI'},
            {name: 'South Carolina', abbreviation: 'SC'},
            {name: 'South Dakota', abbreviation: 'SD'},
            {name: 'Tennessee', abbreviation: 'TN'},
            {name: 'Texas', abbreviation: 'TX'},
            {name: 'Utah', abbreviation: 'UT'},
            {name: 'Vermont', abbreviation: 'VT'},
            {name: 'Virgin Islands, U.S.', abbreviation: 'VI'},
            {name: 'Virginia', abbreviation: 'VA'},
            {name: 'Washington', abbreviation: 'WA'},
            {name: 'West Virginia', abbreviation: 'WV'},
            {name: 'Wisconsin', abbreviation: 'WI'},
            {name: 'Wyoming', abbreviation: 'WY'}
        ];
    };

    Chance.prototype.street = function (options) {
        options = initOptions(options);

        var street = this.word({syllables: 2});
        street = this.capitalize(street);
        street += ' ';
        street += options.short_suffix ?
            this.street_suffix().abbreviation :
            this.street_suffix().name;
        return street;
    };

    Chance.prototype.street_suffix = function () {
        return this.pick(this.street_suffixes());
    };

    Chance.prototype.street_suffixes = function () {
        // These are the most common suffixes.
        return [
            {name: 'Avenue', abbreviation: 'Ave'},
            {name: 'Boulevard', abbreviation: 'Blvd'},
            {name: 'Center', abbreviation: 'Ctr'},
            {name: 'Circle', abbreviation: 'Cir'},
            {name: 'Court', abbreviation: 'Ct'},
            {name: 'Drive', abbreviation: 'Dr'},
            {name: 'Extension', abbreviation: 'Ext'},
            {name: 'Glen', abbreviation: 'Gln'},
            {name: 'Grove', abbreviation: 'Grv'},
            {name: 'Heights', abbreviation: 'Hts'},
            {name: 'Highway', abbreviation: 'Hwy'},
            {name: 'Junction', abbreviation: 'Jct'},
            {name: 'Key', abbreviation: 'Key'},
            {name: 'Lane', abbreviation: 'Ln'},
            {name: 'Loop', abbreviation: 'Loop'},
            {name: 'Manor', abbreviation: 'Mnr'},
            {name: 'Mill', abbreviation: 'Mill'},
            {name: 'Park', abbreviation: 'Park'},
            {name: 'Parkway', abbreviation: 'Pkwy'},
            {name: 'Pass', abbreviation: 'Pass'},
            {name: 'Path', abbreviation: 'Path'},
            {name: 'Pike', abbreviation: 'Pike'},
            {name: 'Place', abbreviation: 'Pl'},
            {name: 'Plaza', abbreviation: 'Plz'},
            {name: 'Point', abbreviation: 'Pt'},
            {name: 'Ridge', abbreviation: 'Rdg'},
            {name: 'River', abbreviation: 'Riv'},
            {name: 'Road', abbreviation: 'Rd'},
            {name: 'Square', abbreviation: 'Sq'},
            {name: 'Street', abbreviation: 'St'},
            {name: 'Terrace', abbreviation: 'Ter'},
            {name: 'Trail', abbreviation: 'Trl'},
            {name: 'Turnpike', abbreviation: 'Tpke'},
            {name: 'View', abbreviation: 'Vw'},
            {name: 'Way', abbreviation: 'Way'}
        ];
    };

    // Note: only returning US zip codes, internationalization will be a whole
    // other beast to tackle at some point.
    Chance.prototype.zip = function (options) {
        var zip = "";

        for (var i = 0; i < 5; i++) {
            zip += this.natural({max: 9}).toString();
        }

        if (options && options.plusfour === true) {
            zip += '-';
            for (i = 0; i < 4; i++) {
                zip += this.natural({max: 9}).toString();
            }
        }

        return zip;
    };

    // -- End Address --

    // -- Time

    Chance.prototype.ampm = function () {
        return this.bool() ? 'am' : 'pm';
    };

    Chance.prototype.date = function (options) {
        var m = this.month({raw: true}),
            date_string;

        options = initOptions(options, {
            year: parseInt(this.year(), 10),
            // Necessary to subtract 1 because Date() 0-indexes month but not day or year
            // for some reason.
            month: m.numeric - 1,
            day: this.natural({min: 1, max: m.days}),
            hour: this.hour(),
            minute: this.minute(),
            second: this.second(),
            millisecond: this.millisecond(),
            american: true,
            string: false
        });

        var date = new Date(options.year, options.month, options.day, options.hour, options.minute, options.second, options.millisecond);

        if (options.american) {
            // Adding 1 to the month is necessary because Date() 0-indexes
            // months but not day for some odd reason.
            date_string = (date.getMonth() + 1) + '/' + date.getDate() + '/' + date.getFullYear();
        } else {
            date_string = date.getDate() + '/' + (date.getMonth() + 1) + '/' + date.getFullYear();
        }

        return options.string ? date_string : date;
    };

    Chance.prototype.hammertime = function (options) {
        return this.date(options).getTime();
    };

    Chance.prototype.hour = function (options) {
        options = initOptions(options);
        var max = options.twentyfour ? 24 : 12;
        return this.natural({min: 1, max: max});
    };

    Chance.prototype.millisecond = function () {
        return this.natural({max: 999});
    };

    Chance.prototype.minute = Chance.prototype.second = function () {
        return this.natural({max: 59});
    };

    Chance.prototype.month = function (options) {
        options = initOptions(options);
        var month = this.pick(this.months());
        return options.raw ? month : month.name;
    };

    Chance.prototype.months = function () {
        return [
            {name: 'January', short_name: 'Jan', numeric: '01', days: 31},
            // Not messing with leap years...
            {name: 'February', short_name: 'Feb', numeric: '02', days: 28},
            {name: 'March', short_name: 'Mar', numeric: '03', days: 31},
            {name: 'April', short_name: 'Apr', numeric: '04', days: 30},
            {name: 'May', short_name: 'May', numeric: '05', days: 31},
            {name: 'June', short_name: 'Jun', numeric: '06', days: 30},
            {name: 'July', short_name: 'Jul', numeric: '07', days: 31},
            {name: 'August', short_name: 'Aug', numeric: '08', days: 31},
            {name: 'September', short_name: 'Sep', numeric: '09', days: 30},
            {name: 'October', short_name: 'Oct', numeric: '10', days: 31},
            {name: 'November', short_name: 'Nov', numeric: '11', days: 30},
            {name: 'December', short_name: 'Dec', numeric: '12', days: 31}
        ];
    };

    Chance.prototype.second = function () {
        return this.natural({max: 59});
    };

    Chance.prototype.timestamp = function () {
        return this.natural({min: 1, max: parseInt(new Date().getTime() / 1000, 10)});
    };

    Chance.prototype.year = function (options) {
        // Default to current year as min if none specified
        options = initOptions(options, {min: new Date().getFullYear()});

        // Default to one century after current year as max if none specified
        options.max = (typeof options.max !== "undefined") ? options.max : options.min + 100;

        return this.natural(options).toString();
    };

    // -- End Time

    // -- Finance --

    Chance.prototype.cc = function (options) {
        options = initOptions(options);

        var type, number, to_generate, type_name;

        type = (options.type) ?
                    this.cc_type({ name: options.type, raw: true }) :
                    this.cc_type({ raw: true });
        number = type.prefix.split("");
        to_generate = type.length - type.prefix.length - 1;

        // Generates n - 1 digits
        for (var i = 0; i < to_generate; i++) {
            number.push(this.integer({min: 0, max: 9}));
        }

        // Generates the last digit according to Luhn algorithm
        number.push(this.luhn_calculate(number.join("")));

        return number.join("");
    };

    Chance.prototype.cc_types = function () {
        // http://en.wikipedia.org/wiki/Bank_card_number#Issuer_identification_number_.28IIN.29
        return [
            {name: "American Express", short_name: 'amex', prefix: '34', length: 15},
            {name: "Bankcard", short_name: 'bankcard', prefix: '5610', length: 16},
            {name: "China UnionPay", short_name: 'chinaunion', prefix: '62', length: 16},
            {name: "Diners Club Carte Blanche", short_name: 'dccarte', prefix: '300', length: 14},
            {name: "Diners Club enRoute", short_name: 'dcenroute', prefix: '2014', length: 15},
            {name: "Diners Club International", short_name: 'dcintl', prefix: '36', length: 14},
            {name: "Diners Club United States & Canada", short_name: 'dcusc', prefix: '54', length: 16},
            {name: "Discover Card", short_name: 'discover', prefix: '6011', length: 16},
            {name: "InstaPayment", short_name: 'instapay', prefix: '637', length: 16},
            {name: "JCB", short_name: 'jcb', prefix: '3528', length: 16},
            {name: "Laser", short_name: 'laser', prefix: '6304', length: 16},
            {name: "Maestro", short_name: 'maestro', prefix: '5018', length: 16},
            {name: "Mastercard", short_name: 'mc', prefix: '51', length: 16},
            {name: "Solo", short_name: 'solo', prefix: '6334', length: 16},
            {name: "Switch", short_name: 'switch', prefix: '4903', length: 16},
            {name: "Visa", short_name: 'visa', prefix: '4', length: 16},
            {name: "Visa Electron", short_name: 'electron', prefix: '4026', length: 16}
        ];
    };

    Chance.prototype.cc_type = function (options) {
        options = initOptions(options);
        var types = this.cc_types(),
            type = null;

        if (options.name) {
            for (var i = 0; i < types.length; i++) {
                // Accept either name or short_name to specify card type
                if (types[i].name === options.name || types[i].short_name === options.name) {
                    type = types[i];
                    break;
                }
            }
            if (type === null) {
                throw new Error("Credit card type '" + options.name + "'' is not suppoted");
            }
        } else {
            type = this.pick(types);
        }

        return options.raw ? type : type.name;
    };

    Chance.prototype.dollar = function (options) {
        // By default, a somewhat more sane max for dollar than all available numbers
        options = initOptions(options, {max : 10000, min : 0});

        var dollar = this.floating({min: options.min, max: options.max, fixed: 2}).toString(),
            cents = dollar.split('.')[1];

        if (cents === undefined) {
            dollar += '.00';
        } else if (cents.length < 2) {
            dollar = dollar + '0';
        }

        return '$' + dollar;
    };

    Chance.prototype.exp = function (options) {
        options = initOptions(options);
        var exp = {};

        exp.year = this.exp_year();

        // If the year is this year, need to ensure month is greater than the
        // current month or this expiration will not be valid
        if (exp.year === (new Date().getFullYear())) {
            exp.month = this.exp_month({future: true});
        } else {
            exp.month = this.exp_month();
        }

        return options.raw ? exp : exp.month + '/' + exp.year;
    };

    Chance.prototype.exp_month = function (options) {
        options = initOptions(options);
        var month, month_int;

        if (options.future) {
            do {
                month = this.month({raw: true}).numeric;
                month_int = parseInt(month, 10);
            } while (month_int < new Date().getMonth());
        } else {
            month = this.month({raw: true}).numeric;
        }

        return month;
    };

    Chance.prototype.exp_year = function () {
        return this.year({max: new Date().getFullYear() + 10});
    };

    // -- End Finance

    // -- Miscellaneous --

    // Dice - For all the board game geeks out there, myself included ;)
    Chance.prototype.d4 = function () { return this.natural({min: 1, max: 4}); };
    Chance.prototype.d6 = function () { return this.natural({min: 1, max: 6}); };
    Chance.prototype.d8 = function () { return this.natural({min: 1, max: 8}); };
    Chance.prototype.d10 = function () { return this.natural({min: 1, max: 10}); };
    Chance.prototype.d12 = function () { return this.natural({min: 1, max: 12}); };
    Chance.prototype.d20 = function () { return this.natural({min: 1, max: 20}); };
    Chance.prototype.d30 = function () { return this.natural({min: 1, max: 30}); };
    Chance.prototype.d100 = function () { return this.natural({min: 1, max: 100}); };
    Chance.prototype.rpg = function (thrown, options) {
        options = initOptions(options);
        if (thrown === null) {
            throw new Error("A type of die roll must be included");
        } else {
            var bits = thrown.toLowerCase().split("d"),
                rolls = [];

            if (bits.length !== 2 || !parseInt(bits[0], 10) || !parseInt(bits[1], 10)) {
                throw new Error("Invalid format provided. Please provide #d# where the first # is the number of dice to roll, the second # is the max of each die");
            }
            for (var i = bits[0]; i > 0; i--) {
                rolls[i - 1] = this.natural({min: 1, max: bits[1]});
            }
            return (typeof options.sum !== 'undefined' && options.sum) ? rolls.reduce(function (p, c) { return p + c; }) : rolls;
        }
    };

    // Guid
    Chance.prototype.guid = function (options) {
        options = options || {version: 5};
        
        var guid_pool = "ABCDEF1234567890",
            variant_pool = "AB89",
            guid = this.string({pool: guid_pool, length: 8}) + '-' +
                   this.string({pool: guid_pool, length: 4}) + '-' +
                   // The Version
                   options.version + 
                   this.string({pool: guid_pool, length: 3}) + '-' +
                   // The Variant
                   this.string({pool: variant_pool, length: 1}) +
                   this.string({pool: guid_pool, length: 3}) + '-' +
                   this.string({pool: guid_pool, length: 12});
        return guid;
    };

    // Hash
    Chance.prototype.hash = function (options) {
        options = initOptions(options, {length : 40, casing: 'lower'});
        var pool = options.casing === 'upper' ? HEX_POOL.toUpperCase() : HEX_POOL;
        return this.string({pool: pool, length: options.length});
    };

    Chance.prototype.luhn_check = function (num) {
        var str = num.toString();
        var checkDigit = +str.substring(str.length - 1);
        return checkDigit === this.luhn_calculate(+str.substring(0, str.length - 1));
    };

    Chance.prototype.luhn_calculate = function (num) {
        var digits = num.toString().split("").reverse();
        var sum = 0;
        for (var i = 0, l = digits.length; l > i; ++i) {
            var digit = +digits[i];
            if (i % 2 === 0) {
                digit *= 2;
                if (digit > 9) {
                    digit -= 9;
                }
            }
            sum += digit;
        }
        return (sum * 9) % 10;
    };

    Chance.prototype.mersenne_twister = function (seed) {
        return new MersenneTwister(seed);
    };

    // -- End Miscellaneous --

    Chance.prototype.VERSION = "0.5.3";

    // Mersenne Twister from https://gist.github.com/banksean/300494
    var MersenneTwister = function (seed) {
        if (seed === undefined) {
            seed = new Date().getTime();
        }
        /* Period parameters */
        this.N = 624;
        this.M = 397;
        this.MATRIX_A = 0x9908b0df;   /* constant vector a */
        this.UPPER_MASK = 0x80000000; /* most significant w-r bits */
        this.LOWER_MASK = 0x7fffffff; /* least significant r bits */

        this.mt = new Array(this.N); /* the array for the state vector */
        this.mti = this.N + 1; /* mti==N + 1 means mt[N] is not initialized */

        this.init_genrand(seed);
    };

    /* initializes mt[N] with a seed */
    MersenneTwister.prototype.init_genrand = function (s) {
        this.mt[0] = s >>> 0;
        for (this.mti = 1; this.mti < this.N; this.mti++) {
            s = this.mt[this.mti - 1] ^ (this.mt[this.mti - 1] >>> 30);
            this.mt[this.mti] = (((((s & 0xffff0000) >>> 16) * 1812433253) << 16) + (s & 0x0000ffff) * 1812433253) + this.mti;
            /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
            /* In the previous versions, MSBs of the seed affect   */
            /* only MSBs of the array mt[].                        */
            /* 2002/01/09 modified by Makoto Matsumoto             */
            this.mt[this.mti] >>>= 0;
            /* for >32 bit machines */
        }
    };

    /* initialize by an array with array-length */
    /* init_key is the array for initializing keys */
    /* key_length is its length */
    /* slight change for C++, 2004/2/26 */
    MersenneTwister.prototype.init_by_array = function (init_key, key_length) {
        var i = 1, j = 0, k, s;
        this.init_genrand(19650218);
        k = (this.N > key_length ? this.N : key_length);
        for (; k; k--) {
            s = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
            this.mt[i] = (this.mt[i] ^ (((((s & 0xffff0000) >>> 16) * 1664525) << 16) + ((s & 0x0000ffff) * 1664525))) + init_key[j] + j; /* non linear */
            this.mt[i] >>>= 0; /* for WORDSIZE > 32 machines */
            i++;
            j++;
            if (i >= this.N) { this.mt[0] = this.mt[this.N - 1]; i = 1; }
            if (j >= key_length) { j = 0; }
        }
        for (k = this.N - 1; k; k--) {
            s = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
            this.mt[i] = (this.mt[i] ^ (((((s & 0xffff0000) >>> 16) * 1566083941) << 16) + (s & 0x0000ffff) * 1566083941)) - i; /* non linear */
            this.mt[i] >>>= 0; /* for WORDSIZE > 32 machines */
            i++;
            if (i >= this.N) { this.mt[0] = this.mt[this.N - 1]; i = 1; }
        }

        this.mt[0] = 0x80000000; /* MSB is 1; assuring non-zero initial array */
    };

    /* generates a random number on [0,0xffffffff]-interval */
    MersenneTwister.prototype.genrand_int32 = function () {
        var y;
        var mag01 = new Array(0x0, this.MATRIX_A);
        /* mag01[x] = x * MATRIX_A  for x=0,1 */

        if (this.mti >= this.N) { /* generate N words at one time */
            var kk;

            if (this.mti === this.N + 1) {   /* if init_genrand() has not been called, */
                this.init_genrand(5489); /* a default initial seed is used */
            }
            for (kk = 0; kk < this.N - this.M; kk++) {
                y = (this.mt[kk]&this.UPPER_MASK)|(this.mt[kk + 1]&this.LOWER_MASK);
                this.mt[kk] = this.mt[kk + this.M] ^ (y >>> 1) ^ mag01[y & 0x1];
            }
            for (;kk < this.N - 1; kk++) {
                y = (this.mt[kk]&this.UPPER_MASK)|(this.mt[kk + 1]&this.LOWER_MASK);
                this.mt[kk] = this.mt[kk + (this.M - this.N)] ^ (y >>> 1) ^ mag01[y & 0x1];
            }
            y = (this.mt[this.N - 1]&this.UPPER_MASK)|(this.mt[0]&this.LOWER_MASK);
            this.mt[this.N - 1] = this.mt[this.M - 1] ^ (y >>> 1) ^ mag01[y & 0x1];

            this.mti = 0;
        }

        y = this.mt[this.mti++];

        /* Tempering */
        y ^= (y >>> 11);
        y ^= (y << 7) & 0x9d2c5680;
        y ^= (y << 15) & 0xefc60000;
        y ^= (y >>> 18);

        return y >>> 0;
    };

    /* generates a random number on [0,0x7fffffff]-interval */
    MersenneTwister.prototype.genrand_int31 = function () {
        return (this.genrand_int32() >>> 1);
    };

    /* generates a random number on [0,1]-real-interval */
    MersenneTwister.prototype.genrand_real1 = function () {
        return this.genrand_int32() * (1.0 / 4294967295.0);
        /* divided by 2^32-1 */
    };

    /* generates a random number on [0,1)-real-interval */
    MersenneTwister.prototype.random = function () {
        return this.genrand_int32() * (1.0 / 4294967296.0);
        /* divided by 2^32 */
    };

    /* generates a random number on (0,1)-real-interval */
    MersenneTwister.prototype.genrand_real3 = function () {
        return (this.genrand_int32() + 0.5) * (1.0 / 4294967296.0);
        /* divided by 2^32 */
    };

    /* generates a random number on [0,1) with 53-bit resolution*/
    MersenneTwister.prototype.genrand_res53 = function () {
        var a = this.genrand_int32()>>>5, b = this.genrand_int32()>>>6;
        return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
    };


    // CommonJS module
    if (typeof exports !== 'undefined') {
        if (typeof module !== 'undefined' && module.exports) {
            exports = module.exports = Chance;
        }
        exports.Chance = Chance;
    }

    // Register as a named AMD module
    if (typeof define === 'function' && define.amd) {
        define('Chance', [], function () {
            return Chance;
        });
    }

    // If there is a window object, that at least has a document property,
    // instantiate and define chance on the window
    if (typeof window === "object" && typeof window.document === "object") {
        window.Chance = Chance;
        window.chance = new Chance();
    }
})();