<?php defined('SYSPATH') or die('No direct script access.');
/**
 * Number helper class. Provides additional formatting methods that for working
 * with numbers.
 *
 * @package    Kohana
 * @category   Helpers
 * @author     Kohana Team
 * @copyright  (c) 2009-2011 Kohana Team
 * @license    http://kohanaframework.org/license
 */
class Kohana_Num {

	const ROUND_HALF_UP		= 1;
	const ROUND_HALF_DOWN	= 2;
	const ROUND_HALF_EVEN	= 3;
	const ROUND_HALF_ODD	= 4;

	/**
	 * @var  array  Valid byte units => power of 2 that defines the unit's size
	 */
	public static $byte_units = array
	(
		'B'   => 0,
		'K'   => 10,
		'Ki'  => 10,
		'KB'  => 10,
		'KiB' => 10,
		'M'   => 20,
		'Mi'  => 20,
		'MB'  => 20,
		'MiB' => 20,
		'G'   => 30,
		'Gi'  => 30,
		'GB'  => 30,
		'GiB' => 30,
		'T'   => 40,
		'Ti'  => 40,
		'TB'  => 40,
		'TiB' => 40,
		'P'   => 50,
		'Pi'  => 50,
		'PB'  => 50,
		'PiB' => 50,
		'E'   => 60,
		'Ei'  => 60,
		'EB'  => 60,
		'EiB' => 60,
		'Z'   => 70,
		'Zi'  => 70,
		'ZB'  => 70,
		'ZiB' => 70,
		'Y'   => 80,
		'Yi'  => 80,
		'YB'  => 80,
		'YiB' => 80,
	);

	/**
	 * Returns the English ordinal suffix (th, st, nd, etc) of a number.
	 *
	 *     echo 2, Num::ordinal(2);   // "2nd"
	 *     echo 10, Num::ordinal(10); // "10th"
	 *     echo 33, Num::ordinal(33); // "33rd"
	 *
	 * @param   integer  number
	 * @return  string
	 */
	public static function ordinal($number)
	{
		if ($number % 100 > 10 AND $number % 100 < 14)
		{
			return 'th';
		}

		switch ($number % 10)
		{
			case 1:
				return 'st';
			case 2:
				return 'nd';
			case 3:
				return 'rd';
			default:
				return 'th';
		}
	}

	/**
	 * Locale-aware number and monetary formatting.
	 *
	 *     // In English, "1,200.05"
	 *     // In Spanish, "1200,05"
	 *     // In Portuguese, "1 200,05"
	 *     echo Num::format(1200.05, 2);
	 *
	 *     // In English, "1,200.05"
	 *     // In Spanish, "1.200,05"
	 *     // In Portuguese, "1.200.05"
	 *     echo Num::format(1200.05, 2, TRUE);
	 *
	 * @param   float    number to format
	 * @param   integer  decimal places
	 * @param   boolean  monetary formatting?
	 * @return  string
	 * @since   3.0.2
	 */
	public static function format($number, $places, $monetary = FALSE)
	{
		$info = localeconv();

		if ($monetary)
		{
			$decimal   = $info['mon_decimal_point'];
			$thousands = $info['mon_thousands_sep'];
		}
		else
		{
			$decimal   = $info['decimal_point'];
			$thousands = $info['thousands_sep'];
		}

		return number_format($number, $places, $decimal, $thousands);
	}

	/**
	 * Round a number to a specified precision, using a specified tie breaking technique
	 *
	 * @param float $value Number to round
	 * @param integer $precision Desired precision
	 * @param integer $mode Tie breaking mode, accepts the PHP_ROUND_HALF_* constants
	 * @param boolean $native Set to false to force use of the userland implementation
	 * @return float Rounded number
	 */
	public static function round($value, $precision = 0, $mode = self::ROUND_HALF_UP, $native = true)
	{
		if (version_compare(PHP_VERSION, '5.3', '>=') AND $native)
		{
			return round($value, $precision, $mode);
		}

		if ($mode === self::ROUND_HALF_UP)
		{
			return round($value, $precision);
		}
		else
		{
			$factor = ($precision === 0) ? 1 : pow(10, $precision);

			switch ($mode)
			{
				case self::ROUND_HALF_DOWN:
				case self::ROUND_HALF_EVEN:
				case self::ROUND_HALF_ODD:
					// Check if we have a rounding tie, otherwise we can just call round()
					if (($value * $factor) - floor($value * $factor) === 0.5)
					{
						if ($mode === self::ROUND_HALF_DOWN)
						{
							// Round down operation, so we round down unless the value
							// is -ve because up is down and down is up down there. ;)
							$up = ($value < 0);
						}
						else
						{
							// Round up if the integer is odd and the round mode is set to even
							// or the integer is even and the round mode is set to odd.
							// Any other instance round down.
							$up = ( ! ( ! (floor($value * $factor) & 1)) === ($mode === self::ROUND_HALF_EVEN));
						}

						if ($up)
						{
							$value = ceil($value * $factor);
						}
						else
						{
							$value = floor($value * $factor);
						}
						return $value / $factor;
					}
					else
					{
						return round($value, $precision);
					}
				break;
			}
		}
	}

	/**
	 * Converts a file size number to a byte value. File sizes are defined in
	 * the format: SB, where S is the size (1, 8.5, 300, etc.) and B is the
	 * byte unit (K, MiB, GB, etc.). All valid byte units are defined in
	 * Num::$byte_units
	 *
	 *     echo Num::bytes('200K');  // 204800
	 *     echo Num::bytes('5MiB');  // 5242880
	 *     echo Num::bytes('1000');  // 1000
	 *     echo Num::bytes('2.5GB'); // 2684354560
	 *
	 * @param   string   file size in SB format
	 * @return  float
	 */
	public static function bytes($size)
	{
		// Prepare the size
		$size = trim( (string) $size);

		// Construct an OR list of byte units for the regex
		$accepted = implode('|', array_keys(Num::$byte_units));

		// Construct the regex pattern for verifying the size format
		$pattern = '/^([0-9]+(?:\.[0-9]+)?)('.$accepted.')?$/Di';

		// Verify the size format and store the matching parts
		if ( ! preg_match($pattern, $size, $matches))
			throw new Kohana_Exception('The byte unit size, ":size", is improperly formatted.', array(
				':size' => $size,
			));

		// Find the float value of the size
		$size = (float) $matches[1];

		// Find the actual unit, assume B if no unit specified
		$unit = Arr::get($matches, 2, 'B');

		// Convert the size into bytes
		$bytes = $size * pow(2, Num::$byte_units[$unit]);

		return $bytes;
	}

} // End num
