<?php
/* SVN FILE: $Id$ */
/**
 * SassColour class file.
 * @author      Chris Yates <chris.l.yates@gmail.com>
 * @copyright   Copyright (c) 2010 PBM Web Development
 * @license      http://phamlp.googlecode.com/files/license.txt
 * @package      PHamlP
 * @subpackage  Sass.script.literals
 */

require_once 'SassLiteral.php';

/**
 * SassColour class.
 * A SassScript object representing a CSS colour.
 *
 * A colour may be represented internally as RGBA, HSLA, or both. It is
 * originally represented as whatever its input is; if it’s created with RGB
 * values, it’s represented as RGBA, and if it’s created with HSL values, it’s
 * represented as HSLA. Once a property is accessed that requires the other
 * representation – for example, SassColour::red for an HSL color – that
 * component is calculated and cached.
 *
 * The alpha channel of a color is independent of its RGB or HSL representation.
 * It’s always stored, as 1 if nothing else is specified. If only the alpha
 * channel is modified using SassColour::with(), the cached RGB and HSL values
 * are retained.
 *
 * Colour operations are all piecewise, e.g. when adding two colours each
 * component is added independantly; Rr = R1 + R2, Gr = G1 + G2, Br = B1 + B2.
 *
 * Colours are returned as a named colour if possible or #rrggbb.
 *
 * @package      PHamlP
 * @subpackage  Sass.script.literals
 */
class SassColour extends SassLiteral
{
  /**@#+
   * Regexes for matching and extracting colours
   */
  const MATCH = '/^((#([\da-f]{6}|[\da-f]{3}))|transparent|{CSS_COLOURS})/';
  const EXTRACT_3 = '/#([\da-f])([\da-f])([\da-f])$/';
  const EXTRACT_6 = '/#([\da-f]{2})([\da-f]{2})([\da-f]{2})/';
  const TRANSPARENT = 'transparent';
  /**@#-*/

  /**@#-*/
  public static $svgColours = array(
    'aliceblue'              => '#f0f8ff',
    'antiquewhite'          => '#faebd7',
    'aqua'                  => '#00ffff',
    'aquamarine'            => '#7fffd4',
    'azure'                  => '#f0ffff',
    'beige'                  => '#f5f5dc',
    'bisque'                => '#ffe4c4',
    'black'                  => '#000000',
    'blanchedalmond'        => '#ffebcd',
    'blue'                  => '#0000ff',
    'blueviolet'            => '#8a2be2',
    'brown'                  => '#a52a2a',
    'burlywood'              => '#deb887',
    'cadetblue'              => '#5f9ea0',
    'chartreuse'            => '#7fff00',
    'chocolate'              => '#d2691e',
    'coral'                  => '#ff7f50',
    'cornflowerblue'        => '#6495ed',
    'cornsilk'              => '#fff8dc',
    'crimson'                => '#dc143c',
    'cyan'                  => '#00ffff',
    'darkblue'              => '#00008b',
    'darkcyan'              => '#008b8b',
    'darkgoldenrod'          => '#b8860b',
    'darkgreen'              => '#006400',
    'darkkhaki'              => '#bdb76b',
    'darkmagenta'            => '#8b008b',
    'darkolivegreen'        => '#556b2f',
    'darkorange'            => '#ff8c00',
    'darkorchid'            => '#9932cc',
    'darkred'                => '#8b0000',
    'darksalmon'            => '#e9967a',
    'darkseagreen'          => '#8fbc8f',
    'darkslateblue'          => '#483d8b',
    'darkslategray'          => '#2f4f4f',
    'darkslategrey'          => '#2f4f4f',
    'darkturquoise'          => '#00ced1',
    'darkviolet'            => '#9400d3',
    'deeppink'              => '#ff1493',
    'deepskyblue'            => '#00bfff',
    'dimgray'                => '#696969',
    'dimgrey'                => '#696969',
    'dodgerblue'            => '#1e90ff',
    'firebrick'              => '#b22222',
    'floralwhite'            => '#fffaf0',
    'forestgreen'            => '#228b22',
    'fuchsia'                => '#ff00ff',
    'gainsboro'              => '#dcdcdc',
    'ghostwhite'            => '#f8f8ff',
    'gold'                  => '#ffd700',
    'goldenrod'              => '#daa520',
    'gray'                  => '#808080',
    'green'                  => '#008000',
    'greenyellow'            => '#adff2f',
    'grey'                  => '#808080',
    'honeydew'              => '#f0fff0',
    'hotpink'                => '#ff69b4',
    'indianred'              => '#cd5c5c',
    'indigo'                => '#4b0082',
    'ivory'                  => '#fffff0',
    'khaki'                  => '#f0e68c',
    'lavender'              => '#e6e6fa',
    'lavenderblush'          => '#fff0f5',
    'lawngreen'              => '#7cfc00',
    'lemonchiffon'          => '#fffacd',
    'lightblue'              => '#add8e6',
    'lightcoral'            => '#f08080',
    'lightcyan'              => '#e0ffff',
    'lightgoldenrodyellow'  => '#fafad2',
    'lightgray'              => '#d3d3d3',
    'lightgreen'            => '#90ee90',
    'lightgrey'              => '#d3d3d3',
    'lightpink'              => '#ffb6c1',
    'lightsalmon'            => '#ffa07a',
    'lightseagreen'          => '#20b2aa',
    'lightskyblue'          => '#87cefa',
    'lightslategray'        => '#778899',
    'lightslategrey'        => '#778899',
    'lightsteelblue'        => '#b0c4de',
    'lightyellow'            => '#ffffe0',
    'lime'                  => '#00ff00',
    'limegreen'              => '#32cd32',
    'linen'                  => '#faf0e6',
    'magenta'                => '#ff00ff',
    'maroon'                => '#800000',
    'mediumaquamarine'      => '#66cdaa',
    'mediumblue'            => '#0000cd',
    'mediumorchid'          => '#ba55d3',
    'mediumpurple'          => '#9370db',
    'mediumseagreen'        => '#3cb371',
    'mediumslateblue'        => '#7b68ee',
    'mediumspringgreen'      => '#00fa9a',
    'mediumturquoise'        => '#48d1cc',
    'mediumvioletred'        => '#c71585',
    'midnightblue'          => '#191970',
    'mintcream'              => '#f5fffa',
    'mistyrose'              => '#ffe4e1',
    'moccasin'              => '#ffe4b5',
    'navajowhite'            => '#ffdead',
    'navy'                  => '#000080',
    'oldlace'                => '#fdf5e6',
    'olive'                  => '#808000',
    'olivedrab'              => '#6b8e23',
    'orange'                => '#ffa500',
    'orangered'              => '#ff4500',
    'orchid'                => '#da70d6',
    'palegoldenrod'          => '#eee8aa',
    'palegreen'              => '#98fb98',
    'paleturquoise'          => '#afeeee',
    'palevioletred'          => '#db7093',
    'papayawhip'            => '#ffefd5',
    'peachpuff'              => '#ffdab9',
    'peru'                  => '#cd853f',
    'pink'                  => '#ffc0cb',
    'plum'                  => '#dda0dd',
    'powderblue'            => '#b0e0e6',
    'purple'                => '#800080',
    'red'                    => '#ff0000',
    'rosybrown'              => '#bc8f8f',
    'royalblue'              => '#4169e1',
    'saddlebrown'            => '#8b4513',
    'salmon'                => '#fa8072',
    'sandybrown'            => '#f4a460',
    'seagreen'              => '#2e8b57',
    'seashell'              => '#fff5ee',
    'sienna'                => '#a0522d',
    'silver'                => '#c0c0c0',
    'skyblue'                => '#87ceeb',
    'slateblue'              => '#6a5acd',
    'slategray'              => '#708090',
    'slategrey'              => '#708090',
    'snow'                  => '#fffafa',
    'springgreen'            => '#00ff7f',
    'steelblue'              => '#4682b4',
    'tan'                    => '#d2b48c',
    'teal'                  => '#008080',
    'thistle'                => '#d8bfd8',
    'tomato'                => '#ff6347',
    'turquoise'              => '#40e0d0',
    'violet'                => '#ee82ee',
    'wheat'                  => '#f5deb3',
    'white'                  => '#ffffff',
    'whitesmoke'            => '#f5f5f5',
    'yellow'                => '#ffff00',
    'yellowgreen'            => '#9acd32'
  );

  /**
   * @var array reverse array (value => name) of named SVG1.0 colours
   */
  public static $_svgColours;

  /**
  * @var array reverse array (value => name) of named HTML4 colours
  */
  public static $_html4Colours = array(
    '#000000' => 'black',
    '#000080' => 'navy',
    '#0000ff' => 'blue',
    '#008000' => 'green',
    '#008080' => 'teal',
    '#00ff00' => 'lime',
    '#00ffff' => 'aqua',
    '#800000' => 'maroon',
    '#800080' => 'purple',
    '#808000' => 'olive',
    '#808080' => 'gray',
    '#c0c0c0' => 'silver',
    '#ff0000' => 'red',
    '#ff00ff' => 'fuchsia',
    '#ffff00' => 'yellow',
    '#ffffff' => 'white',
  );

  public static $regex;

  /**@#+
   * RGB colour components
   */
  /**
   * @var array RGB colour components. Used to check for RGB attributes.
   */
  public static $rgb = array('red', 'green', 'blue');
  /**
   * @var integer red component. 0 - 255
   */
  public $red;
  /**
   * @var integer green component. 0 - 255
   */
  public $green;
  /**
   * @var integer blue component. 0 - 255
   */
  public $blue;
  /**@#-*/
  /**@#+
   * HSL colour components
   */
  /**
   * @var array HSL colour components. Used to check for HSL attributes.
   */
  public static $hsl = array('hue', 'saturation', 'lightness');
  /**
   * @var float hue component. 0 - 360
   */
  public $hue;
  /**
   * @var float saturation component. 0 - 100
   */
  public $saturation;
  /**
   * @var float lightness component. 0 - 100
   */
  public $lightness;
  /**@#-*/
  /**
   * @var float alpha component. 0 - 1
   */
  public $alpha = 1;

  /**
   * Constructs an RGB or HSL color object, optionally with an alpha channel.
   * RGB values must be between 0 and 255. Saturation and lightness values must
   * be between 0 and 100. The alpha value must be between 0 and 1.
   * The colour can be specified as:
   *  + a string that is an SVG colour or of the form #rgb or #rrggbb
   *  + an array with either 'red', 'green', and 'blue' keys, and optionally
   * an alpha key.
   *  + an array with 'hue', 'saturation', and 'lightness' keys, and optionally
   * an alpha key.
   * + an array of red, green, and blue values, and optionally an alpha value.
   * @param mixed the colour
   * @return SassColour
   */
  public function __construct($colour)
  {
    if (is_string($colour)) {
      $colour = strtolower($colour);
      if ($colour === self::TRANSPARENT) {
        $this->red = 0;
        $this->green = 0;
        $this->blue = 0;
        $this->alpha = 0;
      } else {
        if (array_key_exists($colour, self::$svgColours)) {
          $colour = self::$svgColours[$colour];
        }
        if (preg_match(self::EXTRACT_3, $colour, $matches)) {
          for ($i = 1; $i < 4; $i++) {
            $matches[$i] = str_repeat($matches[$i], 2);
          }
        } else {
          preg_match(self::EXTRACT_6, $colour, $matches);
        }

        if (empty($matches)) {
        }
        $this->red   = intval($matches[1], 16);
        $this->green = intval($matches[2], 16);
        $this->blue  = intval($matches[3], 16);
        $this->alpha = 1;
      }
    } elseif (is_array($colour)) {
      $scheme = $this->assertValid($colour);
      if ($scheme == 'rgb') {
        $this->red   = $colour['red'];
        $this->green = $colour['green'];
        $this->blue  = $colour['blue'];
        $this->alpha = (isset($colour['alpha']) ? $colour['alpha'] : 1);
      } elseif ($scheme == 'hsl') {
        $this->hue        = $colour['hue'];
        $this->saturation = $colour['saturation'];
        $this->lightness  = $colour['lightness'];
        $this->alpha      = (isset($colour['alpha']) ? $colour['alpha'] : 1);
      } else {
        $this->red   = $colour[0];
        $this->green = $colour[1];
        $this->blue  = $colour[2];
        $this->alpha = (isset($colour[3]) ? $colour[3] : 1);
      }
    } else {

    }
  }

  /**
   * Colour addition
   * @param mixed SassColour|SassNumber value to add
   * @return sassColour the colour result
   */
  public function op_plus($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {
        return new SassString($this->toString() . $other->value);

      }
      $this->red   = $this->getRed()   + $other->value;
      $this->green = $this->getGreen() + $other->value;
      $this->blue  = $this->getBlue()  + $other->value;
    } elseif (!$other instanceof SassColour) {
      return new SassString($this->toString() . $other->value);

    } else {
      $this->red   = $this->getRed()   + $other->getRed();
      $this->green = $this->getGreen() + $other->getGreen();
      $this->blue  = $this->getBlue()  + $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour subraction
   * @param mixed value (SassColour or SassNumber) to subtract
   * @return sassColour the colour result
   */
  public function op_minus($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = $this->getRed()   - $other->value;
      $this->green = $this->getGreen() - $other->value;
      $this->blue  = $this->getBlue()  - $other->value;
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = $this->getRed()   - $other->getRed();
      $this->green = $this->getGreen() - $other->getGreen();
      $this->blue  = $this->getBlue()  - $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour multiplication
   * @param mixed SassColour|SassNumber value to multiply by
   * @return sassColour the colour result
   */
  public function op_times($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = $this->getRed()   * $other->value;
      $this->green = $this->getGreen() * $other->value;
      $this->blue  = $this->getBlue()  * $other->value;
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = $this->getRed()   * $other->getRed();
      $this->green = $this->getGreen() * $other->getGreen();
      $this->blue  = $this->getBlue()  * $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour division
   * @param mixed value (SassColour or SassNumber) to divide by
   * @return sassColour the colour result
   */
  public function op_div($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = $this->getRed()   / $other->value;
      $this->green = $this->getGreen() / $other->value;
      $this->blue  = $this->getBlue()  / $other->value;
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = $this->getRed()   / $other->getRed();
      $this->green = $this->getGreen() / $other->getGreen();
      $this->blue  = $this->getBlue()  / $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour modulus
   * @param mixed value (SassColour or SassNumber) to divide by
   * @return sassColour the colour result
   */
  public function op_modulo($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = fmod($this->getRed(), $other->value);
      $this->green = fmod($this->getGreen(), $other->value);
      $this->blue  = fmod($this->getBlue(), $other->value);
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = fmod($this->getRed(), $other->getRed());
      $this->green = fmod($this->getGreen(), $other->getGreen());
      $this->blue  = fmod($this->getBlue(), $other->getBlue());
    }

    return $this;
  }

  /**
   * Colour bitwise AND
   * @param mixed value (SassColour or SassNumber) to bitwise AND with
   * @return sassColour the colour result
   */
  public function op_bw_and($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = $this->getRed()   & $other->value;
      $this->green = $this->getGreen() & $other->value;
      $this->blue  = $this->getBlue()  & $other->value;
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = $this->getRed()   & $other->getRed();
      $this->green = $this->getGreen() & $other->getGreen();
      $this->blue  = $this->getBlue()  & $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour bitwise OR
   * @param mixed value (SassColour or SassNumber) to bitwise OR with
   * @return sassColour the colour result
   */
  public function op_bw_or($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = $this->getRed()   | $other->value;
      $this->green = $this->getGreen() | $other->value;
      $this->blue  = $this->getBlue()  | $other->value;
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = $this->getRed()   | $other->getRed();
      $this->green = $this->getGreen() | $other->getGreen();
      $this->blue  = $this->getBlue()  | $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour bitwise XOR
   * @param mixed value (SassColour or SassNumber) to bitwise XOR with
   * @return sassColour the colour result
   */
  public function op_bw_xor($other)
  {
    if ($other instanceof SassNumber) {
      if (!$other->isUnitless()) {

      }
      $this->red   = $this->getRed()   ^ $other->value;
      $this->green = $this->getGreen() ^ $other->value;
      $this->blue  = $this->getBlue()  ^ $other->value;
    } elseif (!$other instanceof SassColour) {

    } else {
      $this->red   = $this->getRed()   ^ $other->getRed();
      $this->green = $this->getGreen() ^ $other->getGreen();
      $this->blue  = $this->getBlue()  ^ $other->getBlue();
    }

    return $this;
  }

  /**
   * Colour bitwise NOT
   * @return sassColour the colour result
   */
  public function op_not()
  {
      $this->red   = ~$this->getRed();
      $this->green = ~$this->getGreen();
      $this->blue  = ~$this->getBlue();

    return $this;
  }

  /**
   * Colour bitwise Shift Left
   * @param sassNumber amount to shift left by
   * @return sassColour the colour result
   */
  public function op_shiftl($other)
  {
    if (!$other instanceof SassNumber ||!$other->isUnitless()) {

    }
    $this->red   = $this->getRed()   << $other->value;
    $this->green = $this->getGreen() << $other->value;
    $this->blue  = $this->getBlue()  << $other->value;

    return $this;
  }

  /**
   * Colour bitwise Shift Right
   * @param sassNumber amount to shift right by
   * @return sassColour the colour result
   */
  public function op_shiftr($other)
  {
    if (!$other instanceof SassNumber || !$other->isUnitless()) {

    }
    $this->red   = $this->getRed()   >> $other->value;
    $this->green = $this->getGreen() >> $other->value;
    $this->blue  = $this->getBlue()  >> $other->value;

    return $this;
  }

  /**
  * Returns a copy of this colour with one or more channels changed.
  * RGB or HSL attributes may be changed, but not both at once.
  * @param array attributes to change
  */
  public function with($attributes)
  {
    if ($this->assertValid($attributes, false) === 'hsl') {
      $colour = array_merge(array(
        'hue'        => $this->getHue(),
        'saturation' => $this->getSaturation(),
        'lightness'  => $this->getLightness(),
        'alpha'      => $this->alpha
      ), $attributes);
    } else {
      $colour = array_merge(array(
        'red'   => $this->getRed(),
        'green' => $this->getGreen(),
        'blue'  => $this->getBlue(),
        'alpha' => $this->alpha
        ), $attributes);
    }

    $colour = new SassColour($colour);
    $colour->getRed(); # will get RGB and HSL

    return $colour;
  }

  /**
   * Returns the alpha component (opacity) of this colour.
   * @return float the alpha component (opacity) of this colour.
   */
  public function getAlpha($value = false)
  {
    if ($value && isset($this->alpha->$value)) {
      return $this->alpha->value;
    }

    return $this->alpha;
  }

  /**
   * Returns the hue of this colour.
   * @return float the hue of this colour.
   */
  public function getHue($value = false)
  {
    if (is_null($this->hue)) {
      $this->rgb2hsl();
    }
    if ($value && isset($this->hue->value)) {
      return $this->hue->value;
    }

    return $this->hue;
  }

  /**
   * Returns the saturation of this colour.
   * @return float the saturation of this colour.
   */
  public function getSaturation($value = false)
  {
    if (is_null($this->saturation)) {
      $this->rgb2hsl();
    }
    if ($value && isset($this->saturation->value)) {
      return $this->saturation->value;
    }

    return $this->saturation;
  }

  /**
   * Returns the lightness of this colour.
   * @return float the lightness of this colour.
   */
  public function getLightness($value = false)
  {
    if (is_null($this->lightness)) {
      $this->rgb2hsl();
    }
    if ($value && isset($this->lightness->value)) {
      return $this->lightness->value;
    }

    return $this->lightness;
  }

  /**
   * Returns the blue component of this colour.
   * @return integer the blue component of this colour.
   */
  public function getBlue($value = false)
  {
    if (is_null($this->blue)) {
      $this->hsl2rgb();
    }
    if ($value && isset($this->blue->value)) {
      return $this->blue->value;
    }

    return max(0, min(255, str_replace(',','.',round($this->blue))));
  }

  /**
   * Returns the green component of this colour.
   * @return integer the green component of this colour.
   */
  public function getGreen($value = false)
  {
    if (is_null($this->green)) {
      $this->hsl2rgb();
    }
    if ($value && isset($this->green->value)) {
      return $this->green->value;
    }

    return max(0, min(255, str_replace(',','.',round($this->green))));
  }

  /**
   * Returns the red component of this colour.
   * @return integer the red component of this colour.
   */
  public function getRed($value = false)
  {
    if (is_null($this->red)) {
      $this->hsl2rgb();
    }
    if ($value && isset($this->red->value)) {
      return $this->red->value;
    }

    return max(0, min(255, str_replace(',','.',round($this->red))));
  }

  /**
   * Returns an array with the RGB components of this colour.
   * @return array the RGB components of this colour
   */
  public function getRgb()
  {
    return array($this->red, $this->green, $this->blue);
  }

  /**
   * Returns an array with the RGB and alpha components of this colour.
   * @return array the RGB and alpha components of this colour
   */
  public function getRgba()
  {
    return array($this->getRed(), $this->getGreen(), $this->getBlue(), $this->alpha);
  }

  /**
   * Returns an array with the HSL components of this colour.
   * @return array the HSL components of this colour
   */
  public function getHsl()
  {
    return array($this->getHue(), $this->getSaturation(), $this->getLightness());
  }

  /**
   * Returns an array with the HSL and alpha components of this colour.
   * @return array the HSL and alpha components of this colour
   */
  public function getHsla()
  {
    return array($this->getHue(), $this->getSaturation(), $this->getLightness(), $this->alpha);
  }

  /**
   * Returns the value of this colour.
   * @return array the colour
   * @deprecated
   */
  public function getValue()
  {
    return $this->rgb;
  }

  /**
   * Returns whether this colour object is translucent; that is, whether the alpha channel is non-1.
   * @return boolean true if this colour is translucent, false if not
   */
  public function isTranslucent()
  {
    return $this->alpha < 1;
  }

  /**
   * Converts the colour to a string.
   * @param boolean whether to use CSS3 SVG1.0 colour names
    * @return string the colour as a named colour, rgba(r,g,g,a) or #rrggbb
   */
  public function toString($css3 = true)
  {
    $rgba = $this->getRgba();

    foreach ($rgba as $k => $v) {
      if (is_object($v)) {
        $rgba[$k] = $v->value;
      }
    }

    if ($rgba[3] == 0) {
      return 'transparent';
    } elseif ($rgba[3] < 1) {
      $rgba[3] = str_replace(',','.',round($rgba[3], 2));

      return sprintf('rgba(%d, %d, %d, %s)', $rgba[0], $rgba[1], $rgba[2], $rgba[3]);
    } else {
      $colour = sprintf('#%02x%02x%02x', str_replace(',','.',round($rgba[0])), str_replace(',','.',round($rgba[1])), str_replace(',','.',round($rgba[2])));
    }

    if ($css3) {
      if (empty(self::$_svgColours)) {
        self::$_svgColours = array_flip(self::$svgColours);
      }

      return (array_key_exists($colour, self::$_svgColours) ? self::$_svgColours[$colour] : $colour);
    } else {
      return (array_key_exists($colour, self::$_html4Colours) ? self::$_html4Colours[$colour] : $colour);
    }
  }

  public function asHex($inc_hash = TRUE)
  {
    return sprintf(($inc_hash ? '#' : '') . '%02x%02x%02x', str_replace(',','.',round($this->red)), str_replace(',','.',round($this->green)), str_replace(',','.',round($this->blue)));
  }

  /**
   * Converts from HSL to RGB colourspace
   * Algorithm from the CSS3 spec: {@link http://www.w3.org/TR/css3-color/#hsl-color}
   * @uses hue2rgb()
   */
  public function hsl2rgb()
  {
    $h = $this->getHue(true) / 360;
    $s = $this->getSaturation(true) / 100;
    $l = $this->getLightness(true) / 100;

    $q = $l < 0.5 ? $l * (1 + $s)
                  : $l + $s - $l * $s;
    $p = 2 * $l - $q;

    $this->red   = $this->hue2rgb($p, $q, $h + 1/3);
    $this->green = $this->hue2rgb($p, $q, $h);
    $this->blue  = $this->hue2rgb($p, $q, $h - 1/3);
  }

  /**
   * Converts from hue to RGB colourspace
   */
  public function hue2rgb($p, $q, $t)
  {
    if ($t < 0)
      $t += 1;
    if ($t > 1)
      $t -= 1;

    if ($t < 1/6)
      $p = $p + ($q - $p) * 6 * $t;
    else if ($t < 1/2)
      $p = $q;
    else if ($t < 2/3)
      $p = $p + ($q - $p) * (2/3 - $t) * 6;

    return str_replace(',','.',round($p * 255));
  }

  /**
   * Converts from RGB to HSL colourspace
   * Algorithm adapted from {@link http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript}
   */
  public function rgb2hsl()
  {
    list($r, $g, $b) = array($this->red / 255, $this->green / 255, $this->blue / 255);

    $max = max($r, $g, $b);
    $min = min($r, $g, $b);
    $d = $max - $min;

    if ($max == $min) {
      $h = 0;
      $s = 0;
    } elseif ($max == $r)
      $h = 60 * ($g - $b) / $d;
    else if ($max == $g)
      $h = 60 * ($b - $r) / $d + 120;
    else if ($max == $b)
      $h = 60 * ($r - $g) / $d + 240;

    $l = ($max + $min) / 2;

   if ($l > 0.5)
      $s = (2 - $max - $min) != 0 ? $d / (2 - $max - $min) : 0;
    else
      $s = ($max + $min) != 0 ? $d / ($max + $min) : 0;

    while ($h > 360) $h -= 360;
    while ($h < 0) $h += 360;

    $this->hue = $h;
    $this->saturation = $s * 100;
    $this->lightness = $l * 100;
  }

  /**
  * Asserts that the colour space is valid.
  * Returns the name of the colour space: 'rgb' if red, green, or blue keys given;
  * 'hsl' if hue, saturation or lightness keys given; null if a non-associative array
  * @param array the colour to test
  * @param boolean whether all colour space keys must be given
  * @return string name of the colour space
  * @throws SassColourException if mixed colour space keys given or not all
  * keys for a colour space are required but not given (contructor)
  */
  public function assertValid($colour, $all = true)
  {
    if (array_key_exists('red', $colour) || array_key_exists('green', $colour) || array_key_exists('blue', $colour)) {
      if (array_key_exists('hue', $colour) || array_key_exists('saturation', $colour) || array_key_exists('lightness', $colour)) {

      }
      if ($all && (!array_key_exists('red', $colour) || !array_key_exists('green', $colour) || !array_key_exists('blue', $colour))) {

      }

      return 'rgb';
    } elseif (array_key_exists('hue', $colour) || array_key_exists('saturation', $colour) || array_key_exists('lightness', $colour)) {
      if ($all && (!array_key_exists('hue', $colour) || !array_key_exists('saturation', $colour) || !array_key_exists('lightness', $colour))) {

      }

      return 'hsl';
    } elseif ($all && sizeof($colour) < 3) {

    }
  }

  /**
   * Returns a value indicating if a token of this type can be matched at
   * the start of the subject string.
   * @param string the subject string
   * @return mixed match at the start of the string or false if no match
   */
  public static function isa($subject)
  {
    if (empty(self::$regex)) {
      self::$regex = str_replace('{CSS_COLOURS}', join('|', array_reverse(array_keys(self::$svgColours))), self::MATCH);
    }

    return (preg_match(self::$regex, strtolower($subject), $matches) ?
      $matches[0] : false);
  }

  public function nth($i)
  {
    if ($i == 1) return clone $this;
    return new SassBoolean(false);
  }

  public function length()
  {
    return 1;
  }
}
