<?php
/**
 * Some color classes to help the widgets class
 *
 * @license GPL 2.0
 * @author Greg Priday
 */

/**
 * This is a very simple color conversion class. It just offers some static function for conversions.
 */
class SiteOrigin_Settings_Color {
	/**
	 * @param mixed $input A color representation.
	 *
	 * @return array An RGB array.
	 */
	public static function rgb( $input ) {
		if ( is_array( $input ) ) {
			return $input;
		} elseif ( is_float( $input ) ) {
			$input = 255 * $input;
		}

		return array( $input, $input, $input );
	}

	public static function hex2rgb( $hex ) {
		$hex = (string) $hex;

		if ( !is_string( $hex ) || $hex[0] != '#' ) {
			throw new Exception( 'Invalid hex color [' . $hex . ']' );
		}
		$hex = preg_replace( '/[^0-9A-Fa-f]/', '', $hex ); // Gets a proper hex string
		$rgb = array();

		if ( strlen( $hex ) == 6 ) { //If a proper hex code, convert using bitwise operation. No overhead... faster
			$color_val = hexdec( $hex );
			$rgb[0] = 0xFF & ( $color_val >> 0x10 );
			$rgb[1] = 0xFF & ( $color_val >> 0x8 );
			$rgb[2] = 0xFF & $color_val;
		} elseif ( strlen( $hex ) == 3 ) { //if shorthand notation, need some string manipulations
			$rgb[0] = hexdec( str_repeat( substr( $hex, 0, 1 ), 2 ) );
			$rgb[1] = hexdec( str_repeat( substr( $hex, 1, 1 ), 2 ) );
			$rgb[2] = hexdec( str_repeat( substr( $hex, 2, 1 ), 2 ) );
		} else {
			throw new Exception( 'Invalid hex color' );
		}

		foreach ( $rgb as $i => $p ) {
			$rgb[$i] = self::maxmin( round( $p ), 0, 255 );
		}

		return $rgb;
	}

	/**
	 * Convert RGB to HEX
	 */
	public static function rgb2hex( $rgb ) {
		$hex = '#';

		foreach ( $rgb as $p ) {
			$p = base_convert( $p, 10, 16 );
			$p = str_pad( $p, 2, '0', STR_PAD_LEFT );
			$hex .= $p;
		}

		return strtoupper( $hex );
	}

	/**
	 * Convert a HSV color to an RGB color.
	 *
	 * @param array $hsv HSV array with values 0-1
	 *
	 * @return array
	 */
	public static function hsv2rgb( $hsv ) {
		// The return RGB value
		$rgb = array();

		if ( $hsv[1] == 0 ) {
			$rgb = array_fill( 0, 3, $hsv[2] * 255 );
		} else {
			// Break hue into 6 possible segments
			$hue = $hsv[0] * 6;
			$hue_range = floor( $hue );

			$v = array(
				$hsv[2] * ( 1 - $hsv[1] ),
				$hsv[2] * ( 1 - $hsv[1] * ( $hue - $hue_range ) ),
				$hsv[2] * ( 1 - $hsv[1] * ( 1 - ( $hue - $hue_range ) ) ),
			);

			switch( $hue_range ) {
				case 0:
					$rgb[0] = $hsv[2];
					$rgb[1] = $v[2];
					$rgb[2] = $v[0];
					break;

				case 1:
					$rgb[0] = $v[1];
					$rgb[1] = $hsv[2];
					$rgb[2] = $v[0];
					break;

				case 2:
					$rgb[0] = $v[0];
					$rgb[1] = $hsv[2];
					$rgb[2] = $v[2];
					break;

				case 3:
					$rgb[0] = $v[0];
					$rgb[1] = $v[1];
					$rgb[2] = $hsv[2];
					break;

				case 4:
					$rgb[0] = $v[2];
					$rgb[1] = $v[0];
					$rgb[2] = $hsv[2];
					break;
				default:
					$rgb[0] = $hsv[2];
					$rgb[1] = $v[0];
					$rgb[2] = $v[1];
					break;
			}

			$rgb[0] = round( $rgb[0] * 255 );
			$rgb[1] = round( $rgb[1] * 255 );
			$rgb[2] = round( $rgb[2] * 255 );
		}

		// Make sure the parts are in the proper range
		foreach ( $rgb as $i => $p ) {
			$rgb[$i] = self::maxmin( round( $p ), 0, 255 );
		}

		return $rgb;
	}

	/**
	 * Converts an RGB color to an XYZ color.
	 *
	 * @param array $color The input color. Values from 0-255.
	 *
	 * @return array
	 */
	public static function rgb2xyz( array $rgb ) {
		foreach ( $rgb as $i => $c ) {
			$rgb[$i] /= 255;
		}

		foreach ( $rgb as $i => $c ) {
			if ( $c > 0.04045 ) {
				$rgb[$i] = pow( ( $c + 0.055 ) / 1.055, 2.4 );
			} else {
				$rgb[$i] = $c / 12.92;
			}

			$rgb[$i] = $rgb[$i] * 100;
		}

		//Observer. = 2¡, Illuminant = D65
		$xyz = array( 0, 0, 0 );
		$xyz[0] = $rgb[0] * 0.4124 + $rgb[1] * 0.3576 + $rgb[2] * 0.1805;
		$xyz[1] = $rgb[0] * 0.2126 + $rgb[1] * 0.7152 + $rgb[2] * 0.0722;
		$xyz[2] = $rgb[0] * 0.0193 + $rgb[1] * 0.1192 + $rgb[2] * 0.9505;

		return $xyz;
	}

	/**
	 * Convert a RGB color to a HSV color
	 *
	 * @param array $rgb RGB array with values 0-255
	 *
	 * @return array
	 */
	public static function rgb2hsv( $rgb ) {
		$rgb = self::rgb( $rgb );

		$rgb[0] = ( $rgb[0] / 255 );
		$rgb[1] = ( $rgb[1] / 255 );
		$rgb[2] = ( $rgb[2] / 255 );

		$min = min( $rgb[0], $rgb[1], $rgb[2] );
		$max = max( $rgb[0], $rgb[1], $rgb[2] );
		$del_max = $max - $min;

		$hsv = array( 0, 0, $max );

		if ( $del_max != 0 ) {
			$hsv[1] = $del_max / $max;

			$del_r = ( ( ( $del_max - $rgb[0] ) / 6 ) + ( $del_max / 2 ) ) / $del_max;
			$del_g = ( ( ( $del_max - $rgb[1] ) / 6 ) + ( $del_max / 2 ) ) / $del_max;
			$del_b = ( ( ( $del_max - $rgb[2] ) / 6 ) + ( $del_max / 2 ) ) / $del_max;

			if ( $rgb[0] == $max ) {
				$hsv[0] = $del_b - $del_g;
			} elseif ( $rgb[1] == $max ) {
				$hsv[0] = ( 1 / 3 ) + $del_r - $del_b;
			} elseif ( $rgb[2] == $max ) {
				$hsv[0] = ( 2 / 3 ) + $del_g - $del_r;
			}

			if ( $hsv[0] < 0 ) {
				$hsv[0]++;
			}

			if ( $hsv[0] > 1 ) {
				$hsv[0]--;
			}
		}

		return $hsv;
	}

	/**
	 * Converts a LAB color into RGB
	 */
	public static function lab2xyz( array $lab ) {
		foreach ( $lab as $i => $c ) {
			$lab[$i] *= 100;
		}

		// Observer= 2¡, Illuminant= D65
		$REF_X = 95.047;
		$REF_Y = 100.000;
		$REF_Z = 108.883;

		$xyz = array();

		$xyz[1] = ( $lab[0] + 16 ) / 116;
		$xyz[0] = $lab[1] / 500 + $xyz[1];
		$xyz[2] = $xyz[1] - $lab[2] / 200;

		foreach ( $xyz as $i => $c ) {
			if ( pow( $c, 3 ) > 0.008856 ) {
				$xyz[$i] = pow( $c, 3 );
			} else {
				$xyz[$i] = ( $c - 16 / 116 ) / 7.787;
			}
		}

		$xyz[0] *= $REF_X;
		$xyz[1] *= $REF_Y;
		$xyz[2] *= $REF_Z;

		return $xyz;
	}

	/**
	 * Convert XYZ color to a LAB color
	 */
	public static function xyz2lab( array $xyz ) {
		// Observer= 2¡, Illuminant= D65
		$REF_X = 95.047;
		$REF_Y = 100.000;
		$REF_Z = 108.883;

		$xyz[0] = $xyz[0] / $REF_X;
		$xyz[1] = $xyz[1] / $REF_Y;
		$xyz[2] = $xyz[2] / $REF_Z;

		foreach ( $xyz as $i => $c ) {
			if ( $c > 0.008856 ) {
				$xyz[$i] = pow( $c, 1 / 3 );
			} else {
				$xyz[$i] = ( 7.787 * $c ) + ( 16 / 116 );
			}
		}

		$lab = array();
		$lab[0] = ( 116 * $xyz[1] ) - 16;
		$lab[1] = 500 * ( $xyz[0] - $xyz[1] );
		$lab[2] = 200 * ( $xyz[1] - $xyz[2] );

		foreach ( $lab as $i => $c ) {
			$lab[$i] /= 100;
		}

		return $lab;
	}

	/**
	 * Convert an XYZ color to an RGB color
	 */
	public static function xyz2rgb( $xyz ) {
		// (Observer = 2¡, Illuminant = D65)
		$xyz[0] /= 100; //X from 0 to  95.047
		$xyz[1] /= 100; //Y from 0 to 100.000
		$xyz[2] /= 100; //Z from 0 to 108.883

		$rgb = array();

		$rgb[0] = $xyz[0] * 3.2406 + $xyz[1] * -1.5372 + $xyz[2] * -0.4986;
		$rgb[1] = $xyz[0] * -0.9689 + $xyz[1] * 1.8758 + $xyz[2] * 0.0415;
		$rgb[2] = $xyz[0] * 0.0557 + $xyz[1] * -0.2040 + $xyz[2] * 1.0570;

		foreach ( $rgb as $i => $c ) {
			if ( $c > 0.0031308 ) {
				$rgb[$i] = 1.055 * pow( $c, ( 1 / 2.4 ) ) - 0.055;
			} else {
				$rgb[$i] = 12.92 * $c;
			}
		}

		$rgb[0] = round( min( max( $rgb[0], 0 ), 1 ) * 255 );
		$rgb[1] = round( min( max( $rgb[1], 0 ), 1 ) * 255 );
		$rgb[2] = round( min( max( $rgb[2], 0 ), 1 ) * 255 );

		return $rgb;
	}

	// Combine the primary functions to create all 6 conversion functions

	/**
	 * Convert an RGB color to a LAB color.
	 */
	public static function rgb2lab( $rgb ) {
		$xyx = self::rgb2xyz( self::rgb( $rgb ) );

		return self::xyz2lab( $xyx );
	}

	/**
	 * Convert a LAB color to a
	 */
	public static function lab2rgb( $lab ) {
		$xyx = self::lab2xyz( $lab );

		return self::xyz2rgb( $xyx );
	}

	/**
	 * Convert a LAB color to HSV
	 */
	public static function lab2hsv( $lab ) {
		$rgb = self::lab2rgb( $lab );

		return self::rgb2hsv( $rgb );
	}

	/**
	 * Convert an HSV color to LAB
	 */
	public static function hsv2lab( $hsv ) {
		$rgb = self::hsv2rgb( $hsv );

		return self::rgb2lab( $rgb );
	}

	/**
	 * Makes sure that the given value falls inside a range.
	 */
	public static function maxmin( $i, $min, $max ) {
		return min( max( $i, $min ), $max );
	}

	public static function float2hex( $float ) {
		$hsv = array(
			0,
			0,
			$float,
		);

		return self::rgb2hex( self::hsv2rgb( $hsv ) );
	}
}
