<?php

namespace common\helpers;

/**
 * Class ImageUrl
 * @package app\wx\helpers
 */
class ColorUtils
{
    /**
     * RGB转 十六进制
     * @param $rgb RGB颜色的字符串 如：rgb(255,255,255);
     * @return string 十六进制颜色值 如：#FFFFFF
     */
    public static function RGBToHex($rgb)
    {
        $regexp = "/^rgb\(([0-9]{0,3})\,\s*([0-9]{0,3})\,\s*([0-9]{0,3})\)/";
        $re = preg_match($regexp, $rgb, $match);
        $re = array_shift($match);
        $hexColor = "#";
        $hex = array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F');
        for ($i = 0; $i < 3; $i++) {
            $r = null;
            $c = $match[$i];
            $hexAr = array();
            while ($c > 16) {
                $r = $c % 16;
                $c = ($c / 16) >> 0;
                array_push($hexAr, $hex[$r]);
            }
            array_push($hexAr, $hex[$c]);
            $ret = array_reverse($hexAr);
            $item = implode('', $ret);
            $item = str_pad($item, 2, '0', STR_PAD_LEFT);
            $hexColor .= $item;
        }
        return $hexColor;
    }

    /**
     * 十六进制 转 RGB数组
     */
    public static function hex2rgb($hexColor)
    {
        $color = str_replace('#', '', $hexColor);
        if (strlen($color) > 3) {
            $rgb = array(
                'r' => hexdec(substr($color, 0, 2)),
                'g' => hexdec(substr($color, 2, 2)),
                'b' => hexdec(substr($color, 4, 2))
            );
        } else {
            $color = $hexColor;
            $r = substr($color, 0, 1) . substr($color, 0, 1);
            $g = substr($color, 1, 1) . substr($color, 1, 1);
            $b = substr($color, 2, 1) . substr($color, 2, 1);
            $rgb = array(
                'r' => hexdec($r),
                'g' => hexdec($g),
                'b' => hexdec($b)
            );
        }
        return $rgb;
    }
}