<?php
namespace W3TCL\YuiCssMin;

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);
	}
}
