<?php
namespace app\common\service\qrcode;

use think\facade\Request;
use Endroid\QrCode\QrCode;
use Endroid\QrCode\Writer\PngWriter;
use Endroid\QrCode\Color\Color;
use Endroid\QrCode\Encoding\Encoding;
use Endroid\QrCode\ErrorCorrectionLevel;
use Endroid\QrCode\RoundBlockSizeMode;
use Exception;

class QrcodeService
{
    /**
     * 生成二维码并保存到文件
     * @param string $content 二维码内容
     * @param string $filename 文件名（可选，不包含路径）
     * @param array $options 配置选项
     * @return array 返回结果信息
     */
    public function saveImage(string $content, string $filename = '', array $options = []): array
    {
        try {
            // 验证内容
            if (empty($content)) {
                throw new Exception('二维码内容不能为空');
            }

            // 默认配置
            $defaultOptions = [
                'size' => 200,                    // 图片尺寸
                'margin' => 10,                   // 边距
                'foreground_color' => '#000000',  // 前景色（黑色）
                'background_color' => '#FFFFFF',  // 背景色（白色）
                'error_correction' => 'high',     // 容错级别：low, medium, quartile, high
                'encoding' => 'UTF-8',            // 编码
                'round_block_size' => false,      // 圆角模块
                'validate_result' => false,       // 验证结果
            ];

            // 合并配置
            $config = array_merge($defaultOptions, $options);

            // 生成文件名
            if (empty($filename)) {
                $filename = $this->generateFilename($content);
            }

            // 确保是PNG格式
            $filename = $this->ensurePngExtension($filename);

            // 生成二维码
            $imageData = $this->generateQrCode($content, $config);

            // 保存文件
            $saveInfo = $this->saveToFile($imageData, $filename);

            return [
                'file_url' => $saveInfo['path']
            ];

        } catch (Exception $e) {
            return [
                'success' => false,
                'message' => '二维码生成失败',
                'error' => $e->getMessage(),
                'content' => $content
            ];
        }
    }

    /**
     * 生成二维码图片数据
     */
    private function generateQrCode(string $content, array $config): string
    {
        // 创建二维码对象
        $qrCode = QrCode::create($content)
            ->setEncoding(new Encoding($config['encoding']))
            ->setErrorCorrectionLevel($this->getErrorCorrectionLevel($config['error_correction']))
            ->setSize($config['size'])
            ->setMargin($config['margin'])
            ->setRoundBlockSizeMode($config['round_block_size'] ?
                RoundBlockSizeMode::Margin : RoundBlockSizeMode::None)
            ->setForegroundColor(new Color(
                $this->hexToR($config['foreground_color']),
                $this->hexToG($config['foreground_color']),
                $this->hexToB($config['foreground_color'])
            ))
            ->setBackgroundColor(new Color(
                $this->hexToR($config['background_color']),
                $this->hexToG($config['background_color']),
                $this->hexToB($config['background_color'])
            ));

        // 创建写入器
        $writer = new PngWriter();

        // 生成二维码
        $result = $writer->write($qrCode);

        // 如果需要验证
        if ($config['validate_result']) {
            $reader = new \Endroid\QrCode\Reader\Reader();
            try {
                $reader->read($result->getString());
            } catch (\Exception $e) {
                throw new Exception('二维码验证失败: ' . $e->getMessage());
            }
        }

        return $result->getString();
    }

    /**
     * 保存图片到文件
     */
    private function saveToFile(string $imageData, string $filename): array
    {
        // 创建存储目录（按日期分类）
        $dateDir = date('Ymd');
        $saveDir = 'uploads/qrcode/' . $dateDir . '/';
        $relativePath = $saveDir . $filename;

        // 获取完整路径
        $rootPath = app()->getRootPath();
        $fullPath = $rootPath . 'public/' . $relativePath;

        // 确保目录存在
        $dirPath = dirname($fullPath);
        if (!is_dir($dirPath)) {
            if (!mkdir($dirPath, 0755, true)) {
                throw new Exception('无法创建目录: ' . $dirPath);
            }
        }

        // 保存文件
        if (file_put_contents($fullPath, $imageData) === false) {
            throw new Exception('无法保存文件到: ' . $fullPath);
        }

        // 验证文件是否保存成功
        if (!file_exists($fullPath) || filesize($fullPath) === 0) {
            throw new Exception('文件保存失败或文件大小为0');
        }

        // 生成可访问的URL
        $domain = Request::domain();
        $fileUrl = $domain . '/' . $relativePath;

        return [
            'filename' => $filename,
            'path' => $relativePath,
            'full_path' => $fullPath,
            'url' => $fileUrl
        ];
    }

    /**
     * 生成唯一的文件名
     */
    private function generateFilename(string $content): string
    {
        $timestamp = time();
        $hash = substr(md5($content . $timestamp), 0, 8);
        return 'qrcode_' . date('YmdHis') . '_' . $hash . '.png';
    }

    /**
     * 确保文件扩展名为.png
     */
    private function ensurePngExtension(string $filename): string
    {
        $pathinfo = pathinfo($filename);

        // 如果没有扩展名或扩展名不是png，则添加.png
        if (!isset($pathinfo['extension']) || strtolower($pathinfo['extension']) !== 'png') {
            $filename = ($pathinfo['filename'] ?? 'qrcode') . '.png';
        }

        return $filename;
    }

    /**
     * 获取错误纠正级别
     */
    private function getErrorCorrectionLevel(string $level): ErrorCorrectionLevel
    {
        $levels = [
            'low' => ErrorCorrectionLevel::Low,
            'medium' => ErrorCorrectionLevel::Medium,
            'quartile' => ErrorCorrectionLevel::Quartile,
            'high' => ErrorCorrectionLevel::High,
        ];

        return $levels[$level] ?? ErrorCorrectionLevel::High;
    }

    /**
     * 从十六进制颜色获取R值
     */
    private function hexToR(string $hex): int
    {
        $hex = ltrim($hex, '#');
        if (strlen($hex) == 3) {
            $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
        }
        return hexdec(substr($hex, 0, 2));
    }

    /**
     * 从十六进制颜色获取G值
     */
    private function hexToG(string $hex): int
    {
        $hex = ltrim($hex, '#');
        if (strlen($hex) == 3) {
            $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
        }
        return hexdec(substr($hex, 2, 2));
    }

    /**
     * 从十六进制颜色获取B值
     */
    private function hexToB(string $hex): int
    {
        $hex = ltrim($hex, '#');
        if (strlen($hex) == 3) {
            $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
        }
        return hexdec(substr($hex, 4, 2));
    }

    /**
     * 生成二维码并返回Base64编码
     * @param string $content 二维码内容
     * @param array $options 配置选项
     * @return string Base64编码的图片
     */
    public function generateBase64(string $content, array $options = []): string
    {
        try {
            $defaultOptions = [
                'size' => 300,
                'margin' => 10,
                'foreground_color' => '#000000',
                'background_color' => '#FFFFFF',
                'error_correction' => 'high',
            ];

            $config = array_merge($defaultOptions, $options);
            $imageData = $this->generateQrCode($content, $config);

            return 'data:image/png;base64,' . base64_encode($imageData);

        } catch (Exception $e) {
            throw new Exception('生成Base64二维码失败: ' . $e->getMessage());
        }
    }

    /**
     * 直接生成并输出二维码图片
     * @param string $content 二维码内容
     * @param array $options 配置选项
     * @return \think\Response
     */
    public function generateResponse(string $content, array $options = [])
    {
        try {
            $defaultOptions = [
                'size' => 300,
                'margin' => 10,
                'foreground_color' => '#000000',
                'background_color' => '#FFFFFF',
                'error_correction' => 'high',
            ];

            $config = array_merge($defaultOptions, $options);
            $imageData = $this->generateQrCode($content, $config);

            return response($imageData)
                ->contentType('image/png')
                ->header('Cache-Control', 'public, max-age=3600');

        } catch (Exception $e) {
            return response('二维码生成失败: ' . $e->getMessage())
                ->contentType('text/plain')
                ->code(500);
        }
    }
}