<?php
// Thanks to http://www.eval.ca/articles/php-pluralize (MIT license)
//           http://dev.rubyonrails.org/browser/trunk/activesupport/lib/active_support/inflections.rb (MIT license)
//           http://www.fortunecity.com/bally/durrus/153/gramch13.html
//           http://www2.gsu.edu/~wwwesl/egw/crump.htm
//
// Changes (12/17/07)
//   Major changes
//   --
//   Fixed irregular noun algorithm to use regular expressions just like the original Ruby source.
//       (this allows for things like fireman -> firemen
//   Fixed the order of the singular array, which was backwards.
//
//   Minor changes
//   --
//   Removed incorrect pluralization rule for /([^aeiouy]|qu)ies$/ => $1y
//   Expanded on the list of exceptions for *o -> *oes, and removed rule for buffalo -> buffaloes
//   Removed dangerous singularization rule for /([^f])ves$/ => $1fe
//   Added more specific rules for singularizing lives, wives, knives, sheaves, loaves, and leaves and thieves
//   Added exception to /(us)es$/ => $1 rule for houses => house and blouses => blouse
//   Added excpetions for feet, geese and teeth
//   Added rule for deer -> deer
//
//	Changed by Felipe Nascimento de Moura <felipenmoura@gmail.com>
//	added is_singular static method
//
// Changes:
//   Removed rule for virus -> viri
//   Added rule for potato -> potatoes
//   Added rule for *us -> *uses

class Inflect
{
    static $plural = array(
        '/(quiz)$/i'               => "$1zes",
        '/^(ox)$/i'                => "$1en",
        '/([m|l])ouse$/i'          => "$1ice",
        '/(matr|vert|ind)ix|ex$/i' => "$1ices",
        '/(x|ch|ss|sh)$/i'         => "$1es",
        '/([^aeiouy]|qu)y$/i'      => "$1ies",
        '/(hive)$/i'               => "$1s",
        '/(?:([^f])fe|([lr])f)$/i' => "$1$2ves",
        '/(shea|lea|loa|thie)f$/i' => "$1ves",
        '/sis$/i'                  => "ses",
        '/([ti])um$/i'             => "$1a",
        '/(tomat|potat|ech|her|vet)o$/i'=> "$1oes",
        '/(bu)s$/i'                => "$1ses",
        '/(alias)$/i'              => "$1es",
        '/(octop)us$/i'            => "$1i",
        '/(ax|test)is$/i'          => "$1es",
        '/(us)$/i'                 => "$1es",
        '/s$/i'                    => "s"
    );

    static $singular = array(
        '/(quiz)zes$/i'             => "$1",
        '/(matr)ices$/i'            => "$1ix",
        '/(vert|ind)ices$/i'        => "$1ex",
        '/^(ox)en$/i'               => "$1",
        '/(alias)es$/i'             => "$1",
        '/(octop|vir)i$/i'          => "$1us",
        '/(cris|ax|test)es$/i'      => "$1is",
        '/(shoe)s$/i'               => "$1",
        '/(o)es$/i'                 => "$1",
        '/(bus)es$/i'               => "$1",
        '/([m|l])ice$/i'            => "$1ouse",
        '/(x|ch|ss|sh)es$/i'        => "$1",
        '/(m)ovies$/i'              => "$1ovie",
        '/(s)eries$/i'              => "$1eries",
        '/([^aeiouy]|qu)ies$/i'     => "$1y",
        '/([lr])ves$/i'             => "$1f",
        '/(tive)s$/i'               => "$1",
        '/(hive)s$/i'               => "$1",
        '/(li|wi|kni)ves$/i'        => "$1fe",
        '/(shea|loa|lea|thie)ves$/i'=> "$1f",
        '/(^analy)ses$/i'           => "$1sis",
        '/((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$/i'  => "$1$2sis",
        '/([ti])a$/i'               => "$1um",
        '/(n)ews$/i'                => "$1ews",
        '/(h|bl)ouses$/i'           => "$1ouse",
        '/(corpse)s$/i'             => "$1",
        '/(us)es$/i'                => "$1",
        '/s$/i'                     => ""
    );

    static $irregular = array(
        'move'   => 'moves',
        'foot'   => 'feet',
        'goose'  => 'geese',
        'sex'    => 'sexes',
        'child'  => 'children',
        'man'    => 'men',
        'tooth'  => 'teeth',
        'person' => 'people'
    );

    static $uncountable = array(
        'sheep',
        'fish',
        'deer',
        'series',
        'species',
        'money',
        'rice',
        'information',
        'equipment'
    );
    
    public static function is_singular( $string )
    {
    	// if it is uncountable, then, it may be treated as a singular
    	if(in_array($string, Inflect::$uncountable))
    		return true;
    	// let's check for irregular forms
    	if(in_array($string, array_keys(Inflect::$irregular)))
    		return true;
    	// now, let's see if the word isn't the plural from a irregular form
    	// still faster than running all the plural forms, I bet
    	elseif(in_array($string, Inflect::$irregular))
    			return false;
    	// ok, if the word reached here, it diserves some care
    	// let's finally check if it matches with any plural rule
    	foreach(self::$plural as $pattern => $result)
        {
            if(preg_match( $pattern, $string))
            {
            	return false;
            }
		}
		return true;
    }

    public static function pluralize( $string )
    {
        // save some time in the case that singular and plural are the same
        if ( in_array( strtolower( $string ), self::$uncountable ) )
            return $string;

        // check for irregular singular forms
        foreach ( self::$irregular as $pattern => $result )
        {
            $pattern = '/' . $pattern . '$/i';

            if ( preg_match( $pattern, $string ) )
                return preg_replace( $pattern, $result, $string);
        }

        // check for matches using regular expressions
        foreach ( self::$plural as $pattern => $result )
        {
            if ( preg_match( $pattern, $string ) )
                return preg_replace( $pattern, $result, $string );
        }
        return preg_replace('/$/', '$1s', $string);
        return $string;
    }

    public static function singularize( $string )
    {
        // save some time in the case that singular and plural are the same
        if ( in_array( strtolower( $string ), self::$uncountable ) )
            return $string;

        // check for irregular plural forms
        foreach ( self::$irregular as $result => $pattern )
        {
            $pattern = '/' . $pattern . '$/i';

            if ( preg_match( $pattern, $string ) )
                return preg_replace( $pattern, $result, $string);
        }

        // check for matches using regular expressions
        foreach ( self::$singular as $pattern => $result )
        {
            if ( preg_match( $pattern, $string ) )
                return preg_replace( $pattern, $result, $string );
        }

        return $string;
    }

    public static function pluralize_if($count, $string)
    {
        if ($count == 1)
            return "1 $string";
        else
            return $count . " " . self::pluralize($string);
    }
}
