<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');

/**
 * Convert ascii characters to hex values
 *
 * @access	public
 * @param	string	string containing ascii characters
 * @return	string
 */	
if (!function_exists('ascii_to_hex'))
{
	function ascii_to_hex($ascii)
	{
		$hex = '';

		for($i = 0; $i < strlen($ascii); $i++)
		{
			$hex .= str_pad(base_convert(ord($ascii[$i]), 10, 16), 2, '0', STR_PAD_LEFT);
		}
		return $hex;
	}
}

// --------------------------------------------------------------------

/**
 * Convert ascii characters to hex values
 *
 * @access	public
 * @param	string	string containing ascii characters
 * @return	string
 */	   
if (!function_exists('hex_to_ascii'))
{
	function hex_to_ascii($hex)
	{
		$ascii = '';

		if (strlen($hex) % 2 == 1)
		{
			$hex = '0'.$hex;
		}

		for($i = 0; $i < strlen($hex); $i += 2)
		{
			$ascii .= chr(base_convert(substr($hex, $i, 2), 16, 10));
		}
		return $ascii;
	}
}

// --------------------------------------------------------------------

/**
 * Convert a string into a safe, encoded uri value
 *
 * @access	public
 * @param	string	string to be converted
 * @param	boolean	convert to hex value 
 * @return	string
 */
if (!function_exists('uri_safe_encode'))
{
	function uri_safe_encode($str, $hexify = TRUE)
	{
		$str = ($hexify) ? ascii_to_hex(base64_encode($str)) : base64_encode($str);
		return $str;
	}
}

// --------------------------------------------------------------------

/**
 * Decode a base64 encoded string
 *
 * @access	public
 * @param	string	string to be converted
 * @param	boolean	value is hexified 
 * @return	string
 */
if (!function_exists('uri_safe_decode'))
{
	function uri_safe_decode($str, $hexify = TRUE)
	{
		$str = ($hexify) ? base64_decode(hex_to_ascii($str)) : base64_decode($str);
		return $str;
	}
}

// --------------------------------------------------------------------

/**
 * Encode a key/value array or string into a URI safe value
 *
 * @access	public
 * @param	string	string to be converted
 * @param	boolean	value is hexified 
 * @return	string
 */
if (!function_exists('uri_safe_batch_encode'))
{
	function uri_safe_batch_encode($uri, $delimiter = '|', $hexify = TRUE)
	{
		$str = '';
		if (!empty($uri))
		{
			if (is_string($uri)) {
				$arr = explode('/', $uri);
				foreach($arr as $val)
				{
					$uri[$val] = next($arr);
				}
			}
			foreach($uri as $key => $val)
			{
				if (!is_string($val))
				{
					$val = '??'.serialize($val);
				}
				$str .= $key.'/'.$val.$delimiter;
			}
			return uri_safe_encode($str, $hexify);
		}
		return $str;
	}
}

// --------------------------------------------------------------------

/**
 * Decode a key/value array or string into a URI safe value
 *
 * @access	public
 * @param	string	string to be converted
 * @param	string	delimiter to split string 
 * @param	boolean	value is hexified 
 * @return	string
 */
if (!function_exists('uri_safe_batch_decode'))
{
	function uri_safe_batch_decode($str, $delimiter = '|', $hexify = TRUE)
	{
		$str = uri_safe_decode($str, $hexify);
		$tmp = explode($delimiter, $str);
		$params = array();
		foreach($tmp as $val)
		{
			$key_val = explode('/', $val);
			if (count($key_val) >= 2)
			{
				if (strncmp($key_val[1], '??', 2) === 0)
				{
					$key_val[1] = unserialize(substr($key_val[1], 2));
				}
				$params[$key_val[0]] = $key_val[1];
			}
		}
		return $params;
	}
}

/* End of file convert_helper.php */