<?php

namespace app\common\library\share;

/**
 * 分享海报
 */
class Poster
{

    //海报元素最小变局
    protected static $minPadding = 0.9;
    //海报基准宽度
    protected static $basicWidth = 1024;


    /**
     * 创建海报
     * @param $nickName 昵称
     * @param $avatar 头像
     * @param $qrCode 二维码
     * @param $themes 风格 blue balck steel
     * @return false|string
     */
    public static function mkPoster($nickName,$avatar,$qrCode,$themes='blue') {
        $bgPath = MODULE_ROOT.'/public/assets/poster/'.$themes.'.jpg';

        $fontPath = MODULE_ROOT."/public/assets/poster/font/ding/DingTalk_JinBuTi_Regular.ttf";
        

        $posterItems = self::getPosterItems($themes,$nickName,$avatar,$qrCode);

        //用户信息
        //这是要插入到图片的文字
        if ($bgPath) {
            if (is_file($bgPath)) {
                //创建画布
                $bgCanvas = imagecreatefromstring(file_get_contents($bgPath));

                $bgW = imagesx($bgCanvas);
                $contrastSize =$bgW /self::$basicWidth ;
                
                foreach ($posterItems as $item){
                    if($item['attr']['x'] < (1-self::$minPadding) * $bgW){
                        $item['attr']['x'] = (1-self::$minPadding) * $bgW;
                    }

                    $sizeFields = ['x','y','w','h','size'];

                    foreach ($item['attr'] as $key => $option){
                        if(in_array($key,$sizeFields)){
                            $item['attr'][$key] = $option * $contrastSize;
                        }
                    }


                    switch ($item['type']){
                        case 'text':
                            $fontBox = imagettfbbox($item['attr']['size'], 0, $fontPath, $item['attr']['text']);
                            $newText = self::handleTextAlign($bgW,$fontBox[2],$item['attr']['text']);
                            if($newText != $item['attr']['text']){
                                $item['attr']['text'] = $newText;
                                $fontBox = imagettfbbox($item['attr']['size'], 0, $fontPath, $item['attr']['text']);
                            }
                            if(isset($item['align']) && $item['align']=='center'){
                                $item['attr']['x'] = ceil(($bgW - $fontBox[2])/2);
                            }
                            $color = ImageColorAllocate($bgCanvas, $item['attr']['color'][0],$item['attr']['color'][1],$item['attr']['color'][2]);

                            imagettftext($bgCanvas, $item['attr']['size'], $item['attr']['angle'], $item['attr']['x'], $item['attr']['y'], $color,$fontPath, $item['attr']['text']);
                            break;
                        case 'image':

                            if(isset($item['align']) && $item['align']=='center'){
                                $item['attr']['x'] = ceil(($bgW - $item['attr']['w'])/2);
                            }

                            imagecopyresampled($bgCanvas, $item['attr']['src_image'], $item['attr']['x'], $item['attr']['y'], 0, 0, $item['attr']['w'], $item['attr']['h'], imagesx($item['attr']['src_image']), imagesy($item['attr']['src_image']));
                            break;
                    }
                }

                ob_start();
                imagepng($bgCanvas);
                $imgSrc = base64_encode(ob_get_contents());
                ob_end_clean();
                //生成图片
                return $imgSrc;
            }
        }
        return false;
    }

    /**
     * 处理规定宽度内自动换行（imagettftext）
     * @return void
     */
    private static function handleTextAlign($bgW,$txtW,$text)
    {

        $minBgWidth = $bgW * self::$minPadding;

        if($txtW <= $minBgWidth){
            return $text;
        }

        $maxLineWordsLength = ceil(mb_strlen($text) * ($minBgWidth/ $txtW));

        $string = '';
        foreach (mb_str_split($text) as $index => $t){
            $string .= $t;
            if($index > 0 && ($index % $maxLineWordsLength) == 0){
                $string .= "\n";
            }
        }

        return $string;
    }

    /**
     * 获取海报元素
     * @param $bgType 海报背景类型
     * @param $nickName 昵称
     * @param $avatar 头像
     * @param $qrCode 二维码
     * @return array|array[]
     */
    public static function getPosterItems($bgType,$nickName,$avatar,$qrCode){
        $items = [
            'nickname'=>[
                'type'=>'text',
                'align'=>'center',
                'attr'=>[
                    'size'=>36,//字体大小
                    'x'=>480,//x轴
                    'y'=>380,//y轴
                    'text'=>$nickName,//内容
                    'angle'=>0,//角度,
                    'color'=>[255,255,255]//字体颜色rgb
                ]
            ],
            'recommend'=>[
                'type'=>'text',
                'align'=>'center',
                'attr'=>[
                    'size'=>26,//字体大小
                    'x'=>360,//x轴
                    'y'=>430,//y轴
                    'text'=>'向你推荐优质知识店铺',//内容
                    'angle'=>0,//角度,
                    'color'=>[255,255,255]//字体颜色rgb
                ]
            ],
            'tip'=>[
                'type'=>'text',
                'align'=>'center',
                'attr'=>[
                    'size'=>20,//字体大小
                    'x'=>400,//x轴
                    'y'=>1010,//y轴
                    'text'=>'长按识别，查看好课',//内容
                    'angle'=>0,//角度,
                    'color'=>[0,0,0]//字体颜色rgb
                ]
            ],

            'other'=>[
                'type'=>'text',
                'align'=>'center',
                'attr'=>[
                    'size'=>30,//字体大小
                    'x'=>400,//x轴
                    'y'=>1210,//y轴
                    'text'=>'不可错过的精品课程',//内容
                    'angle'=>0,//角度,
                    'color'=>[255,255,255]//字体颜色rgb
                ]
            ],
            'other1'=>[
                'type'=>'text',
                'align'=>'center',
                'attr'=>[
                    'size'=>35,//字体大小
                    'x'=>400,//x轴
                    'y'=>1280,//y轴
                    'text'=>'邀请你和我一起成长',//内容
                    'angle'=>0,//角度,
                    'color'=>[255,255,255]//字体颜色rgb
                ]
            ],
            'avatar'=>[
                'type'=>'image',
                'align'=>'center',
                'attr'=>[
                    'x'=>440,//x轴
                    'y'=>140,//y轴
                    'w'=>160,//宽度
                    'h'=>160,//高度
                    'src_image'=>'',//图像资源
                ]
            ],
            'qrcode'=>[
                'type'=>'image',
                'align'=>'center',
                'attr'=>[
                    'x'=>400,//x轴
                    'y'=>730,//y轴
                    'w'=>240,//宽度
                    'h'=>240,//高度
                    'src_image'=>'',//图像资源
                ]
            ]
        ];


        if($bgType=='steel'){
            $items['other1']['attr']['color'] = [209,141,56];
            $items['other']['attr']['color'] = [209,141,56];
            $items['tip']['attr']['color'] = [255,255,255];


            $items['qrcode']['attr']['y'] -= 160;
            $items['tip']['attr']['y'] -= 160;

            $items['other']['attr']['y'] -= 240;
            $items['other1']['attr']['y'] -= 240;
        }

        if($bgType=='black'){

            $items['qrcode']['attr']['y'] -= 100;
            $items['tip']['attr']['y'] -= 100;
            $items['tip']['attr']['color'] = [255,255,255];
            $items['other']['attr']['y'] -= 100;
            $items['other1']['attr']['y'] -= 100;
        }


        $items['qrcode']['attr']['src_image'] = imagecreatefromstring($qrCode);
        $items['avatar']['attr']['src_image'] = imagecreatefromstring(self::convertToCircleFromData($avatar));

        return $items;
    }


    /**
     * 图片转圆形
     * @param $imageData 二进制图片数据
     * @return false|string
     */
    public static function convertToCircleFromData($imageData) {
            // 创建内存中的图像资源
            $image = imagecreatefromstring($imageData);
            if (!$image) {
                return $imageData;
            }

            // 获取图像的宽度和高度
            $width = imagesx($image);
            $height = imagesy($image);

            // 创建一个新的透明图像
            $mask = imagecreatetruecolor($width, $height);
            imagesavealpha($mask, true);
            $transparent = imagecolorallocatealpha($mask, 0, 0, 0, 127);
            imagefill($mask, 0, 0, $transparent);

            // 绘制圆形
            $centerX = $width / 2;
            $centerY = $height / 2;
            $radius = min($width, $height) / 2;
            imagefilledellipse($mask, $centerX, $centerY, $radius * 2, $radius * 2, imagecolorallocate($mask, 255, 255, 255));

            // 创建一个新的透明图像来存储最终结果
            $output = imagecreatetruecolor($width, $height);
            imagesavealpha($output, true);
            imagefill($output, 0, 0, $transparent);

            // 应用遮罩到原始图像
            for ($x = 0; $x < $width; $x++) {
                for ($y = 0; $y < $height; $y++) {
                    $maskColor = imagecolorat($mask, $x, $y);
                    $alpha = 127 - ($maskColor >> 24);
                    if ($alpha > 0) {
                        $imageColor = imagecolorat($image, $x, $y);
                        $r = ($imageColor >> 16) & 0xFF;
                        $g = ($imageColor >> 8) & 0xFF;
                        $b = $imageColor & 0xFF;
                        $newColor = imagecolorallocatealpha($output, $r, $g, $b, 127 - $alpha);
                        imagesetpixel($output, $x, $y, $newColor);
                    }
                }
            }

            // 保存处理后的图像到内存
            ob_start();
            imagepng($output);
            $result = ob_get_clean();

            // 释放图像资源
            imagedestroy($image);
            imagedestroy($mask);
            imagedestroy($output);

            return $result;
        }

    }