<?php

/**
 * Helper class for working with color values.
 *
 * @since 1.0
 */
final class FLBuilderColor {

	/**
	 * Converts a hex string into an array of RGB values.
	 *
	 * @since 1.0
	 * @param string $hex A hex color value without the # sign.
	 * @return array An array of RGB values.
	 */
	static public function hex_to_rgb( $hex ) {
		return array(
			'r' => hexdec( substr( $hex,0,2 ) ),
			'g' => hexdec( substr( $hex,2,2 ) ),
			'b' => hexdec( substr( $hex,4,2 ) ),
		);
	}

	/**
	 * Adjusts the brightness of a hex color value based on
	 * the number of steps provided.
	 *
	 * @since 1.0
	 * @param string $hex A hex color value without the # sign.
	 * @param int $steps The number of steps to adjust the color.
	 * @param string $type The type of adjustment to make. Either lighten, darken or reverse.
	 * @return string The adjusted hex string.
	 */
	static public function adjust_brightness( $hex, $steps, $type ) {
		// Get rgb vars.
		$rgb = self::hex_to_rgb( $hex );
		$r = $rgb['r'];
		$g = $rgb['g'];
		$b = $rgb['b'];

		// Should we darken the color?
		if ( 'reverse' == $type && $r + $g + $b > 382 ) {
			$steps = -$steps;
		} elseif ( 'darken' == $type ) {
			$steps = -$steps;
		}

		// Build the new color.
		$steps = max( -255, min( 255, $steps ) );

		$r = max( 0,min( 255,$r + $steps ) );
		$g = max( 0,min( 255,$g + $steps ) );
		$b = max( 0,min( 255,$b + $steps ) );

		$r_hex = str_pad( dechex( $r ), 2, '0', STR_PAD_LEFT );
		$g_hex = str_pad( dechex( $g ), 2, '0', STR_PAD_LEFT );
		$b_hex = str_pad( dechex( $b ), 2, '0', STR_PAD_LEFT );

		return $r_hex . $g_hex . $b_hex;
	}
}
