<?php

namespace tubalmartin\CssMin;

class Utils
{
/**
* Clamps a number between a minimum and a maximum value.
* @param int|float $n the number to clamp
* @param int|float $min the lower end number allowed
* @param int|float $max the higher end number allowed
* @return int|float
*/
public static function clampNumber($n, $min, $max)
{
return min(max($n, $min), $max);
}

/**
* Clamps a RGB color number outside the sRGB color space
* @param int|float $n the number to clamp
* @return int|float
*/
public static function clampNumberSrgb($n)
{
return self::clampNumber($n, 0, 255);
}

/**
* Converts a HSL color into a RGB color
* @param array $hslValues
* @return array
*/
public static function hslToRgb($hslValues)
{
$h = floatval($hslValues[0]);
$s = floatval(str_replace('%', '', $hslValues[1]));
$l = floatval(str_replace('%', '', $hslValues[2]));

// Wrap and clamp, then fraction!
$h = ((($h % 360) + 360) % 360) / 360;
$s = self::clampNumber($s, 0, 100) / 100;
$l = self::clampNumber($l, 0, 100) / 100;

if ($s == 0) {
$r = $g = $b = self::roundNumber(255 * $l);
} else {
$v2 = $l < 0.5 ? $l * (1 + $s) : ($l + $s) - ($s * $l);
$v1 = (2 * $l) - $v2;
$r = self::roundNumber(255 * self::hueToRgb($v1, $v2, $h + (1/3)));
$g = self::roundNumber(255 * self::hueToRgb($v1, $v2, $h));
$b = self::roundNumber(255 * self::hueToRgb($v1, $v2, $h - (1/3)));
}

return array($r, $g, $b);
}

/**
* Tests and selects the correct formula for each RGB color channel
* @param $v1
* @param $v2
* @param $vh
* @return mixed
*/
public static function hueToRgb($v1, $v2, $vh)
{
$vh = $vh < 0 ? $vh + 1 : ($vh > 1 ? $vh - 1 : $vh);

if ($vh * 6 < 1) {
return $v1 + ($v2 - $v1) * 6 * $vh;
}

if ($vh * 2 < 1) {
return $v2;
}

if ($vh * 3 < 2) {
return $v1 + ($v2 - $v1) * ((2 / 3) - $vh) * 6;
}

return $v1;
}

/**
* Convert strings like "64M" or "30" to int values
* @param mixed $size
* @return int
*/
public static function normalizeInt($size)
{
if (is_string($size)) {
$letter = substr($size, -1);
$size = intval($size);
switch ($letter) {
case 'M':
case 'm':
return (int) $size * 1048576;
case 'K':
case 'k':
return (int) $size * 1024;
case 'G':
case 'g':
return (int) $size * 1073741824;
}
}
return (int) $size;
}

/**
* Converts a string containing and RGB percentage value into a RGB integer value i.e. '90%' -> 229.5
* @param $rgbPercentage
* @return int
*/
public static function rgbPercentageToRgbInteger($rgbPercentage)
{
if (strpos($rgbPercentage, '%') !== false) {
$rgbPercentage = self::roundNumber(floatval(str_replace('%', '', $rgbPercentage)) * 2.55);
}

return intval($rgbPercentage, 10);
}

/**
* Converts a RGB color into a HEX color
* @param array $rgbColors
* @return array
*/
public static function rgbToHex($rgbColors)
{
$hexColors = array();

// Values outside the sRGB color space should be clipped (0-255)
for ($i = 0, $l = count($rgbColors); $i < $l; $i++) {
$hexColors[$i] = sprintf("%02x", self::clampNumberSrgb(self::rgbPercentageToRgbInteger($rgbColors[$i])));
}

return $hexColors;
}

/**
* Rounds a number to its closest integer
* @param $n
* @return int
*/
public static function roundNumber($n)
{
return intval(round(floatval($n)), 10);
}
}