<?php
/**
 * @package     Awf
 * @copyright   2014 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license     GNU GPL version 3 or later
 *
 * The Inflector class is an adaptation of the Akelos PHP Inflector which is a PHP
 * port from a Ruby on Rails project.
 */

namespace Awf\Inflector;

/**
 * An Inflector to pluralize and singularize English nouns.
 */
abstract class Inflector
{
	/**
	 * Rules for pluralizing and singularizing of nouns.
	 *
	 * @var array
	 */
	protected static $_rules = array
	(
		// Pluralization rules. The regex on the left transforms to the regex on the right.
		'pluralization'   => array(
			'/move$/i'                      => 'moves',
			'/sex$/i'                       => 'sexes',
			'/child$/i'                     => 'children',
			'/children$/i'                  => 'children',
			'/man$/i'                       => 'men',
			'/men$/i'                       => 'men',
			'/foot$/i'                      => 'feet',
			'/feet$/i'                      => 'feet',
			'/person$/i'                    => 'people',
			'/people$/i'                    => 'people',
			'/taxon$/i'                     => 'taxa',
			'/taxa$/i'                      => 'taxa',
			'/(quiz)$/i'                    => '$1zes',
			'/^(ox)$/i'                     => '$1en',
			'/oxen$/i'                      => 'oxen',
			'/(m|l)ouse$/i'                 => '$1ice',
			'/(m|l)ice$/i'                  => '$1ice',
			'/(matr|vert|ind|suff)ix|ex$/i' => '$1ices',
			'/(x|ch|ss|sh)$/i'              => '$1es',
			'/([^aeiouy]|qu)y$/i'           => '$1ies',
			'/(?:([^f])fe|([lr])f)$/i'      => '$1$2ves',
			'/sis$/i'                       => 'ses',
			'/([ti]|addend)um$/i'           => '$1a',
			'/([ti]|addend)a$/i'            => '$1a',
			'/(alumn|formul)a$/i'           => '$1ae',
			'/(alumn|formul)ae$/i'          => '$1ae',
			'/(buffal|tomat|her)o$/i'       => '$1oes',
			'/(bu)s$/i'                     => '$1ses',
			'/(alias|status)$/i'            => '$1es',
			'/(octop|vir)us$/i'             => '$1i',
			'/(octop|vir)i$/i'              => '$1i',
			'/(gen)us$/i'                   => '$1era',
			'/(gen)era$/i'                  => '$1era',
			'/(ax|test)is$/i'               => '$1es',
			'/s$/i'                         => 's',
			'/$/'                           => 's',
		),
		// Singularization rules. The regex on the left transforms to the regex on the right.
		'singularization' => array(
			'/cookies$/i'                                                      => 'cookie',
			'/moves$/i'                                                        => 'move',
			'/sexes$/i'                                                        => 'sex',
			'/children$/i'                                                     => 'child',
			'/men$/i'                                                          => 'man',
			'/feet$/i'                                                         => 'foot',
			'/people$/i'                                                       => 'person',
			'/taxa$/i'                                                         => 'taxon',
			'/databases$/i'                                                    => 'database',
			'/menus$/i'                                                        => 'menu',
			'/(quiz)zes$/i'                                                    => '\1',
			'/(matr|suff)ices$/i'                                              => '\1ix',
			'/(vert|ind|cod)ices$/i'                                           => '\1ex',
			'/^(ox)en/i'                                                       => '\1',
			'/(alias|status)es$/i'                                             => '\1',
			'/(tomato|hero|buffalo)es$/i'                                      => '\1',
			'/([octop|vir])i$/i'                                               => '\1us',
			'/(gen)era$/i'                                                     => '\1us',
			'/(cris|^ax|test)es$/i'                                            => '\1is',
			'/is$/i'                                                           => 'is',
			'/us$/i'                                                           => 'us',
			'/ias$/i'                                                          => 'ias',
			'/(shoe)s$/i'                                                      => '\1',
			'/(o)es$/i'                                                        => '\1e',
			'/(bus)es$/i'                                                      => '\1',
			'/([m|l])ice$/i'                                                   => '\1ouse',
			'/(x|ch|ss|sh)es$/i'                                               => '\1',
			'/(m)ovies$/i'                                                     => '\1ovie',
			'/(s)eries$/i'                                                     => '\1eries',
			'/(v)ies$/i'                                                       => '\1ie',
			'/([^aeiouy]|qu)ies$/i'                                            => '\1y',
			'/([lr])ves$/i'                                                    => '\1f',
			'/(tive)s$/i'                                                      => '\1',
			'/(hive)s$/i'                                                      => '\1',
			'/([^f])ves$/i'                                                    => '\1fe',
			'/(^analy)ses$/i'                                                  => '\1sis',
			'/((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$/i' => '\1\2sis',
			'/([ti]|addend)a$/i'                                               => '\1um',
			'/(alumn|formul)ae$/i'                                             => '$1a',
			'/(n)ews$/i'                                                       => '\1ews',
			'/(.*)ss$/i'                                                       => '\1ss',
			'/(.*)s$/i'                                                        => '\1',
		),
		// Uncountable objects are always singular
		'uncountable'       => array(
			'aircraft',
			'cannon',
			'deer',
			'equipment',
			'fish',
			'information',
			'money',
			'moose',
			'news',
			'rice',
			'series',
			'sheep',
			'species',
			'swine',
		)
	);

	/**
	 * Cache of pluralized and singularized nouns.
	 *
	 * @var array
	 */
	protected static $_cache = array(
		'singularized' => array(),
		'pluralized'   => array()
	);

	public static function deleteCache()
	{
		self::$_cache['pluralized'] = array();
		self::$_cache['singularized'] = array();
	}

	/**
	 * Add a word to the cache, useful to make exceptions or to add words in other languages.
	 *
	 * @param   string $singular word.
	 * @param   string $plural   word.
	 *
	 * @return  void
	 */
	public static function addWord($singular, $plural)
	{
		self::$_cache['pluralized'][$singular] = $plural;
		self::$_cache['singularized'][$plural] = $singular;
	}

	/**
	 * Singular English word to plural.
	 *
	 * @param   string $word word to pluralize.
	 *
	 * @return  string Plural noun.
	 */
	public static function pluralize($word)
	{
		// Get the cached noun of it exists
		if (isset(self::$_cache['pluralized'][$word]))
		{
			return self::$_cache['pluralized'][$word];
		}

		// Create the plural noun
		if (in_array($word, self::$_rules['uncountable']))
		{
			$_cache['pluralized'][$word] = $word;

			return $word;
		}

		foreach (self::$_rules['pluralization'] as $regexp => $replacement)
		{
			$matches = null;
			$plural = preg_replace($regexp, $replacement, $word, -1, $matches);

			if ($matches > 0)
			{
				$_cache['pluralized'][$word] = $plural;

				return $plural;
			}
		}

		return $word;
	}

	/**
	 * Plural English word to singular.
	 *
	 * @param   string $word Word to singularize.
	 *
	 * @return  string Singular noun.
	 */
	public static function singularize($word)
	{
		// Get the cached noun of it exists
		if (isset(self::$_cache['singularized'][$word]))
		{
			return self::$_cache['singularized'][$word];
		}

		// Create the singular noun
		if (in_array($word, self::$_rules['uncountable']))
		{
			$_cache['singularized'][$word] = $word;

			return $word;
		}

		foreach (self::$_rules['singularization'] as $regexp => $replacement)
		{
			$matches = null;
			$singular = preg_replace($regexp, $replacement, $word, -1, $matches);

			if ($matches > 0)
			{
				$_cache['singularized'][$word] = $singular;

				return $singular;
			}
		}

		return $word;
	}

	/**
	 * Returns given word as CamelCased.
	 *
	 * Converts a word like "foo_bar" or "foo bar" to "FooBar". It
	 * will remove non alphanumeric characters from the word, so
	 * "who's online" will be converted to "WhoSOnline"
	 *
	 * @param   string $word Word to convert to camel case.
	 *
	 * @return  string  UpperCamelCasedWord
	 */
	public static function camelize($word)
	{
		$word = preg_replace('/[^a-zA-Z0-9\s]/', ' ', $word);
		$word = str_replace(' ', '', ucwords(strtolower(str_replace('_', ' ', $word))));

		return $word;
	}

	/**
	 * Converts a word "into_it_s_underscored_version"
	 *
	 * Convert any "CamelCased" or "ordinary Word" into an "underscored_word".
	 *
	 * @param   string $word Word to underscore
	 *
	 * @return string Underscored word
	 */
	public static function underscore($word)
	{
		$word = preg_replace('/(\s)+/', '_', $word);
		$word = strtolower(preg_replace('/(?<=\\w)([A-Z])/', '_\\1', $word));

		return $word;
	}

	/**
	 * Convert any "CamelCased" word into an array of strings
	 *
	 * Returns an array of strings each of which is a substring of string formed
	 * by splitting it at the camelcased letters.
	 *
	 * @param   string $word Word to explode
	 *
	 * @return  array   Array of strings
	 */
	public static function explode($word)
	{
		$result = explode('_', self::underscore($word));

		return $result;
	}

	/**
	 * Convert  an array of strings into a "CamelCased" word.
	 *
	 * @param   array $words Array to implode
	 *
	 * @return  string UpperCamelCasedWord
	 */
	public static function implode($words)
	{
		$result = self::camelize(implode('_', $words));

		return $result;
	}

	/**
	 * Returns a human-readable string from $word.
	 *
	 * Returns a human-readable string from $word, by replacing
	 * underscores with a space, and by upper-casing the initial
	 * character by default.
	 *
	 * @param   string $word String to "humanize"
	 *
	 * @return string Human-readable word
	 */
	public static function humanize($word)
	{
		$result = ucwords(strtolower(str_replace("_", " ", $word)));

		return $result;
	}

	/**
	 * Converts a class name to its table name according to Koowa
	 * naming conventions.
	 *
	 * Converts "Person" to "people"
	 *
	 * @param   string $className Class name for getting related table_name.
	 *
	 * @return  string  plural_table_name
	 *
	 * @see classify
	 */
	public static function tableize($className)
	{
		$result = self::underscore($className);

		if (!self::isPlural($className))
		{
			$result = self::pluralize($result);
		}

		return $result;
	}

	/**
	 * Converts a table name to its class name according to Koowa naming conventions.
	 *
	 * @param   string $tableName Table name for getting related ClassName.
	 *
	 * @return string SingularClassName
	 *
	 * @example  Converts "people" to "Person"
	 * @see      tableize
	 */
	public static function classify($tableName)
	{
		$result = self::camelize(self::singularize($tableName));

		return $result;
	}

	/**
	 * Returns camelBacked version of a string. Same as camelize but first char is lowercased.
	 *
	 * @param   string $string String to be camelBacked.
	 *
	 * @return string
	 *
	 * @see camelize
	 */
	public static function variablize($string)
	{
		$string = self::camelize(self::underscore($string));
		$result = strtolower(substr($string, 0, 1));
		$variable = preg_replace('/\\w/', $result, $string, 1);

		return $variable;
	}

	/**
	 * Check to see if an English word is singular
	 *
	 * @param   string $string The word to check
	 *
	 * @return boolean
	 */
	public static function isSingular($string)
	{
		// Check cache assuming the string is plural.
		$singular = isset(self::$_cache['singularized'][$string]) ? self::$_cache['singularized'][$string] : null;
		$plural = $singular && isset(self::$_cache['pluralized'][$singular]) ? self::$_cache['pluralized'][$singular] : null;

		if ($singular && $plural)
		{
			return $plural != $string;
		}

		// If string is not in the cache, try to pluralize and singularize it.
		return self::singularize(self::pluralize($string)) == $string;
	}

	/**
	 * Check to see if an Enlish word is plural.
	 *
	 * @param   string $string String to be checked.
	 *
	 * @return boolean
	 */
	public static function isPlural($string)
	{
		// Uncountable objects are always singular (e.g. information)
		if (in_array($string, self::$_rules['uncountable']))
		{
			return false;
		}

		// Check cache assuming the string is singular.
		$plural = isset(self::$_cache['pluralized'][$string]) ? self::$_cache['pluralized'][$string] : null;
		$singular = $plural && isset(self::$_cache['singularized'][$plural]) ? self::$_cache['singularized'][$plural] : null;

		if ($plural && $singular)
		{
			return $singular != $string;
		}

		// If string is not in the cache, try to singularize and pluralize it.
		return self::pluralize(self::singularize($string)) == $string;
	}

	/**
	 * Gets a part of a CamelCased word by index.
	 *
	 * Use a negative index to start at the last part of the word (-1 is the
	 * last part)
	 *
	 * @param   string  $string  Word
	 * @param   integer $index   Index of the part
	 * @param   string  $default Default value
	 *
	 * @return string
	 */
	public static function getPart($string, $index, $default = null)
	{
		$parts = self::explode($string);

		if ($index < 0)
		{
			$index = count($parts) + $index;
		}

		return isset($parts[$index]) ? $parts[$index] : $default;
	}
}
