<?php
  /*
   * Copyright 2010-2012 Amazon.com, Inc. or its affiliates. All Rights Reserved.
   *
   * Licensed under the Apache License, Version 2.0 (the "License").
   * You may not use this file except in compliance with the License.
   * A copy of the License is located at
   *
   *  http://aws.amazon.com/apache2.0
   *
   * or in the "license" file accompanying this file. This file is distributed
   * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
   * express or implied. See the License for the specific language governing
   * permissions and limitations under the License.
   */
  
  
  /*%******************************************************************************************%*/
  // CLASS
  
  /**
   * Contains a set of utility methods for connecting to, and working with, AWS.
   *
   * @version 2010.09.30
   * @license See the included NOTICE.md file for more information.
   * @copyright See the included NOTICE.md file for more information.
   * @link http://aws.amazon.com/php/ PHP Developer Center
   */
  class CFUtilities
  {
  
  	/*%******************************************************************************************%*/
  	// CONSTANTS
  
  	/**
  	 * Define the RFC 2616-compliant date format.
  	 */
  	const DATE_FORMAT_RFC2616 = 'D, d M Y H:i:s \G\M\T';
  
  	/**
  	 * Define the ISO-8601-compliant date format.
  	 */
  	const DATE_FORMAT_ISO8601 = 'Y-m-d\TH:i:s\Z';
  
  	/**
  	 * Define the MySQL-compliant date format.
  	 */
  	const DATE_FORMAT_MYSQL = 'Y-m-d H:i:s';
  
  	/**
  	 * Define the Signature v4 date format.
  	 */
  	const DATE_FORMAT_SIGV4 = 'Ymd\THis\Z';
  
  
  	/*%******************************************************************************************%*/
  	// METHODS
  
  	/**
  	 * Constructs a new instance of this class.
  	 *
  	 * @return $this A reference to the current instance.
  	 */
  	public function __construct()
  	{
  		return $this;
  	}
  
  	/**
  	 * Retrieves the value of a class constant, while avoiding the `T_PAAMAYIM_NEKUDOTAYIM` error. Misspelled because `const` is a reserved word.
  	 *
  	 * @param object $class (Required) An instance of the class containing the constant.
  	 * @param string $const (Required) The name of the constant to retrieve.
  	 * @return mixed The value of the class constant.
  	 */
  	public function konst($class, $const)
  	{
  		if (is_string($class))
  		{
  			$ref = new ReflectionClass($class);
  		}
  		else
  		{
  			$ref = new ReflectionObject($class);
  		}
  
  		return $ref->getConstant($const);
  	}
  
  	/**
  	 * Convert a HEX value to Base64.
  	 *
  	 * @param string $str (Required) Value to convert.
  	 * @return string Base64-encoded string.
  	 */
  	public function hex_to_base64($str)
  	{
  		$raw = '';
  
  		for ($i = 0; $i < strlen($str); $i += 2)
  		{
  			$raw .= chr(hexdec(substr($str, $i, 2)));
  		}
  
  		return base64_encode($raw);
  	}
  
  	/**
  	 * Convert an associative array into a query string.
  	 *
  	 * @param array $array (Required) Array to convert.
  	 * @return string URL-friendly query string.
  	 */
  	public function to_query_string($array)
  	{
  		$temp = array();
  
  		foreach ($array as $key => $value)
  		{
  			if (is_string($key) && !is_array($value))
  			{
  				$temp[] = rawurlencode($key) . '=' . rawurlencode($value);
  			}
  		}
  
  		return implode('&', $temp);
  	}
  
  	/**
  	 * Convert an associative array into a sign-able string.
  	 *
  	 * @param array $array (Required) Array to convert.
  	 * @return string URL-friendly sign-able string.
  	 */
  	public function to_signable_string($array)
  	{
  		$t = array();
  
  		foreach ($array as $k => $v)
  		{
  			$t[] = $this->encode_signature2($k) . '=' . $this->encode_signature2($v);
  		}
  
  		return implode('&', $t);
  	}
  
  	/**
  	 * Encode the value according to RFC 3986.
  	 *
  	 * @param string $string (Required) String to convert.
  	 * @return string URL-friendly sign-able string.
  	 */
  	public function encode_signature2($string)
  	{
  		$string = rawurlencode($string);
  		return str_replace('%7E', '~', $string);
  	}
  
  	/**
  	 * Convert a query string into an associative array. Multiple, identical keys will become an indexed array.
  	 *
  	 * @param string $qs (Required) Query string to convert.
  	 * @return array Associative array of keys and values.
  	 */
  	public function query_to_array($qs)
  	{
  		$query = explode('&', $qs);
  		$data = array();
  
  		foreach ($query as $q)
  		{
  			$q = explode('=', $q);
  
  			if (isset($data[$q[0]]) && is_array($data[$q[0]]))
  			{
  				$data[$q[0]][] = urldecode($q[1]);
  			}
  			else if (isset($data[$q[0]]) && !is_array($data[$q[0]]))
  			{
  				$data[$q[0]] = array($data[$q[0]]);
  				$data[$q[0]][] = urldecode($q[1]);
  			}
  			else
  			{
  				$data[urldecode($q[0])] = urldecode($q[1]);
  			}
  		}
  		return $data;
  	}
  
  	/**
  	 * Return human readable file sizes.
  	 *
  	 * @author Aidan Lister <aidan@php.net>
  	 * @author Ryan Parman <ryan@getcloudfusion.com>
  	 * @license http://www.php.net/license/3_01.txt PHP License
  	 * @param integer $size (Required) Filesize in bytes.
  	 * @param string $unit (Optional) The maximum unit to use. Defaults to the largest appropriate unit.
  	 * @param string $default (Optional) The format for the return string. Defaults to `%01.2f %s`.
  	 * @return string The human-readable file size.
  	 * @link http://aidanlister.com/repos/v/function.size_readable.php Original Function
  	 */
  	public function size_readable($size, $unit = null, $default = null)
  	{
  		// Units
  		$sizes = array('B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB');
  		$mod = 1024;
  		$ii = count($sizes) - 1;
  
  		// Max unit
  		$unit = array_search((string) $unit, $sizes);
  		if ($unit === null || $unit === false)
  		{
  			$unit = $ii;
  		}
  
  		// Return string
  		if ($default === null)
  		{
  			$default = '%01.2f %s';
  		}
  
  		// Loop
  		$i = 0;
  		while ($unit != $i && $size >= 1024 && $i < $ii)
  		{
  			$size /= $mod;
  			$i++;
  		}
  
  		return sprintf($default, $size, $sizes[$i]);
  	}
  
  	/**
  	 * Convert a number of seconds into Hours:Minutes:Seconds.
  	 *
  	 * @param integer $seconds (Required) The number of seconds to convert.
  	 * @return string The formatted time.
  	 */
  	public function time_hms($seconds)
  	{
  		$time = '';
  
  		// First pass
  		$hours = (int) ($seconds / 3600);
  		$seconds = $seconds % 3600;
  		$minutes = (int) ($seconds / 60);
  		$seconds = $seconds % 60;
  
  		// Cleanup
  		$time .= ($hours) ? $hours . ':' : '';
  		$time .= ($minutes < 10 && $hours > 0) ? '0' . $minutes : $minutes;
  		$time .= ':';
  		$time .= ($seconds < 10) ? '0' . $seconds : $seconds;
  
  		return $time;
  	}
  
  	/**
  	 * Returns the first value that is set. Based on [Try.these()](http://api.prototypejs.org/language/Try/these/) from [Prototype](http://prototypejs.org).
  	 *
  	 * @param array $attrs (Required) The attributes to test, as strings. Intended for testing properties of the $base object, but also works with variables if you place an @ symbol at the beginning of the command.
  	 * @param object $base (Optional) The base object to use, if any.
  	 * @param mixed $default (Optional) What to return if there are no matches. Defaults to `null`.
  	 * @return mixed Either a matching property of a given object, boolean `false`, or any other data type you might choose.
  	 */
  	public function try_these($attrs, $base = null, $default = null)
  	{
  		if ($base)
  		{
  			foreach ($attrs as $attr)
  			{
  				if (isset($base->$attr))
  				{
  					return $base->$attr;
  				}
  			}
  		}
  		else
  		{
  			foreach ($attrs as $attr)
  			{
  				if (isset($attr))
  				{
  					return $attr;
  				}
  			}
  		}
  
  		return $default;
  	}
  
  	/**
  	 * Can be removed once all calls are updated.
  	 *
  	 * @deprecated Use <php:json_encode()> instead.
  	 * @param mixed $obj (Required) The PHP object to convert into a JSON string.
  	 * @return string A JSON string.
  	 */
  	public function json_encode($obj)
  	{
  		return json_encode($obj);
  	}
  
  	/**
  	 * Converts a SimpleXML response to an array structure.
  	 *
  	 * @param ResponseCore $response (Required) A response value.
  	 * @return array The response value as a standard, multi-dimensional array.
  	 */
  	public function convert_response_to_array(ResponseCore $response)
  	{
  		return json_decode(json_encode($response), true);
  	}
  
  	/**
  	 * Checks to see if a date stamp is ISO-8601 formatted, and if not, makes it so.
  	 *
  	 * @param string $datestamp (Required) A date stamp, or a string that can be parsed into a date stamp.
  	 * @return string An ISO-8601 formatted date stamp.
  	 */
  	public function convert_date_to_iso8601($datestamp)
  	{
  		if (!preg_match('/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}((\+|-)\d{2}:\d{2}|Z)/m', $datestamp))
  		{
  			return gmdate(self::DATE_FORMAT_ISO8601, strtotime($datestamp));
  		}
  
  		return $datestamp;
  	}
  
  	/**
  	 * Determines whether the data is Base64 encoded or not.
  	 *
  	 * @license http://us.php.net/manual/en/function.base64-decode.php#81425 PHP License
  	 * @param string $s (Required) The string to test.
  	 * @return boolean Whether the string is Base64 encoded or not.
  	 */
  	public function is_base64($s)
  	{
  		return (bool) preg_match('/^[a-zA-Z0-9\/\r
  +]*={0,2}$/', $s);
  	}
  
  	/**
  	 * Determines whether the data is a JSON string or not.
  	 *
  	 * @param string $s (Required) The string to test.
  	 * @return boolean Whether the string is a valid JSON object or not.
  	 */
  	public function is_json($s)
  	{
  		return !!(json_decode($s) instanceof stdClass);
  	}
  
  	/**
  	 * Decodes `\uXXXX` entities into their real unicode character equivalents.
  	 *
  	 * @param string $s (Required) The string to decode.
  	 * @return string The decoded string.
  	 */
  	public function decode_uhex($s)
  	{
  		preg_match_all('/\\\u([0-9a-f]{4})/i', $s, $matches);
  		$matches = $matches[count($matches) - 1];
  		$map = array();
  
  		foreach ($matches as $match)
  		{
  			if (!isset($map[$match]))
  			{
  				$map['\u' . $match] = html_entity_decode('&#' . hexdec($match) . ';', ENT_NOQUOTES, 'UTF-8');
  			}
  		}
  
  		return str_replace(array_keys($map), $map, $s);
  	}
  
  	/**
  	 * Generates a random GUID.
  	 *
  	 * @author Alix Axel <http://www.php.net/manual/en/function.com-create-guid.php#99425>
  	 * @license http://www.php.net/license/3_01.txt PHP License
  	 * @return string A random GUID.
  	 */
  	public function generate_guid()
  	{
  	    return sprintf(
  			'%04X%04X-%04X-%04X-%04X-%04X%04X%04X',
  			mt_rand(0, 65535),
  			mt_rand(0, 65535),
  			mt_rand(0, 65535),
  			mt_rand(16384, 20479),
  			mt_rand(32768, 49151),
  			mt_rand(0, 65535),
  			mt_rand(0, 65535),
  			mt_rand(0, 65535)
  		);
  	}
  }