<?php
/**
 * The string wrapper class. 
 *
 * @package    phpMyFAQ
 * @subpackage PMF_String
 * @license    MPL
 * @author     Anatoliy Belsky <ab@php.net>
 * @since      2009-04-06
 * @version    SVN: $Id: String.php 4743 2009-08-18 17:38:24Z anatoliy $
 * @copyright  2009 phpMyFAQ Team
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 */

/**
 * PMF_String
 * 
 * The class uses mbstring extension if available. It's strongly recommended
 * to use and extend this class instead of using direct string functions. Doing so
 * you garantee your code is upwards compatible with UTF-8 improvements. All
 * the string methods behaviour is identical to that of the same named 
 * single byte string functions.
 *
 * @package    phpMyFAQ
 * @subpackage PMF_String
 * @license    MPL
 * @author     Anatoliy Belsky <ab@php.net>
 * @since      2009-04-06
 * @version    SVN: $Id: String.php 4743 2009-08-18 17:38:24Z anatoliy $
 * @copyright  2009 phpMyFAQ Team
 */
class PMF_String
{
    /**
     * Instance
     * 
     * @var PMF_String
     */
    private static $instance;
    
    
    /**
     * Constructor
     *
     * @return void
     */
    private final function __construct()
    {
    }
    
    
    /** 
     * Initalize myself
     * 
     * @return void
     */ 
    public static function init($encoding = null, $language = 'en')
    {
        if (!self::$instance) {
            $encoding = 'utf8' == strtolower($encoding) ? 'utf-8' : $encoding;
            if (extension_loaded('mbstring') && function_exists('mb_regex_encoding') && 
                in_array($encoding, mb_list_encodings())) {
                self::$instance = PMF_String_Mbstring::getInstance($encoding, $language);
            } else if($encoding == 'utf-8' && self::isLangUTF8ToLatinConvertable($language)) {
                self::$instance = PMF_String_UTF8ToLatinConvertable::getInstance($encoding, $language);
            } else {
                self::$instance = PMF_String_Basic::getInstance($encoding, $language);
            }
        }
    }
    
    
    /**
     * Get current encoding
     * 
     * @return string
     */
    public static function getEncoding()
    {
        return self::$instance->getEncoding();
    }    
    
    
    /**
     * Get string character count
     * 
     * @param string $str String
     * 
     * @return int
     */
    public static function strlen($str)
    {
        return self::$instance->strlen($str);
    }
    

    /**
     * Get a part of string
     * 
     * @param string  $str    String
     * @param integer $start  Start
     * @param integer $length Length
     * 
     * @return string
     */
    public static function substr($str, $start, $length = null)
    {
        return self::$instance->substr($str, $start, $length);
    }    
    
    
    /**
     * Get position of the first occurence of a string
     * 
     * @param string $haystack Haystack
     * @param string $needle   Needle
     * @param string $offset   Offset
     * 
     * @return int
     */
    public static function strpos($haystack, $needle, $offset = 0)
    {
        return self::$instance->strpos($haystack, $needle, $offset);
    }    
    
    
    /**
     * Make a string lower case
     * 
     * @param string $str String
     * 
     * @return string
     */
    public static function strtolower($str)
    {
        return self::$instance->strtolower($str);
    }    
    
    
    /**
     * Make a string upper case
     * 
     * @param string $str String
     * 
     * @return string
     */
    public static function strtoupper($str)
    {
        return self::$instance->strtoupper($str);
    }

    
    /**
     * Get occurence of a string within another
     * 
     * @param string  $haystack Haystack
     * @param string  $needle   Needle
     * @param boolean $part     Part
     * 
     * @return string|false
     */
    public static function strstr($haystack, $needle, $part = false)
    {
        return self::$instance->strstr($haystack, $needle, $part);
    }

    
    /**
     * Set current encoding
     * 
     * @return string
     */
    public static function setEncoding($encoding)
    {
        self::$instance->setEncoding($encoding);
    }
    
    
    /**
	 * Check if a language could be converted to iso-8859-1
	 * @param string $language
	 * 
	 * @return boolean
     */
    public static function isLangUTF8ToLatinConvertable($language)
    {
        $iso_languages = array('af', 'sq', 'br', 'ca', 'da', 'en', 'fo', 'gl', 'de', 'is', 'it',
                               'ku', 'la', 'lb', 'nb', 'oc', 'pt', 'es', 'sw', 'sv', 'wa', 'eu',
                               // NOTE this languages are not fully supported by latin1 
                               'nl', 'fr', 'et', 'fi', 'cy'
        );
        
        return in_array($language, $iso_languages);
    }
    
    
    /**
	 * Get last occurence of a string within another
	 * @param string $haystack
	 * @param string $needle
	 * 
	 * @return string
     */
    public static function strrchr($haystack, $needle)
    {
        return self::$instance->strrchr($haystack, $needle);
    }
    
    
    /**
     * 
     * Count substring occurences
     * @param string $haystack
     * @param string $needle
     * 
     * @return int
     */
    public static function substr_count($haystack, $needle)
    {
        return self::$instance->substr_count($haystack, $needle);
    }
    
    
    /**
	 * Find position of last occurrence of a char in a string
	 * @param string $haystack
	 * @param string $needle
	 * @param int $offset
	 * 
	 * @return int
     */
    public static function strrpos($haystack, $needle, $offset = 0)
    {
        return self::$instance->strrpos($haystack, $needle, $offset);
    }
    
    
    /**
     * 
     * Match a regexp
     * @param string $pattern
     * @param string $subject
     * @param array &$matches
     * @param int $flags
     * @param int $offset
     * 
     * @return int
     */
    public static function preg_match($pattern, $subject, $matches = null, $flags = 0, $offset = 0)
    {
        return self::$instance->preg_match($pattern, $subject, $matches, $flags, $offset);
    }
    
    
    /**
     * 
     * Match a regexp globally
     * @param string $pattern
     * @param string $subject
     * @param array &$matches
     * @param int $flags
     * @param int $offset
     * 
     * @return int
     */
    public static function preg_match_all($pattern, $subject, $matches, $flags = 0, $offset = 0)
    {
        return self::$instance->preg_match_all($pattern, $subject, $matches, $flags, $offset);
    }
    
    
    /**
     * Split string by a regexp
     * @param string $pattern
     * @param string $subject
     * @param int $limit
     * @param int $flags
     * 
     * @return array
     */
    public static function preg_split($pattern, $subject, $limit = -1, $flags = 0)
    {
        return self::$instance->preg_split($pattern, $subject, $limit = -1, $flags = 0);
    }
    
    
    /**
     * Search and replace by a regexp using a callback
     * @param string|array $pattern
     * @param function $callback
     * @param string|array $subject
     * @param int $limit
     * @param int &$count
     * 
     * @return array|string
     */
    public static function preg_replace_callback($pattern, $callback, $subject, $limit= -1, &$count = 0)
    {
        return self::$instance->preg_replace_callback($pattern, $callback, $subject, $limit, $count);
    }
    
    
    /**
     * Search and replace by a regexp
     * @param string|array $pattern
     * @param string|array $replacement
     * @param string|array $subject
     * @param int $limit
     * @param int &$count
     * 
     * @return array|string|null
     */
    public static function preg_replace($pattern, $replacement, $subject, $limit= -1, &$count = 0)
    {
        return self::$instance->preg_replace($pattern, $replacement, $subject, $limit, $count);
    }
    
    /**
     * Check if the string is a unicode string
     * 
     * @param string $str String
     * 
     * @return boolean
     */
    public static function isUTF8($str)
    {
        return PMF_String_Basic::isUTF8($str);
    }
}
