<?php
namespace app\service;
use think\Exception;

class UploadService
{
    /**
     * 处理表单文件上传并转发到目标服务器
     *
     * @param string $fileField 表单文件字段名
     * @param string $targetUrl 目标服务器URL
     * @param array $extraFields 额外传递的字段
     * @param array $headers 额外的请求头
     * @return array 包含上传结果的数组
     */
    public function uploadAndForward(string $fileField, string $targetUrl, array $extraFields = [], array $headers = []): array
    {
        // 获取上传的文件
        $file = request()->file($fileField);

        if (!$file) {
            return $this->createErrorResult('未上传文件或上传失败');
        }
        try {
            $config = config('app.upload_conf');
            $configs=[];
            foreach ($config as $key=>$con){
                $configs[] = $key.':'.$con;
            }

           // 验证文件
            $validate = validate([
                $fileField =>implode('|',$configs),
            ]);

            if (!$validate->check([$fileField => $file])) {
                return $this->createErrorResult($validate->getError());
            }

            // 使用cURL转发到目标服务器
            $result = $this->forwardToTargetServer($file, $targetUrl, $extraFields, $headers);

            return $result;
        } catch (\Exception $e) {
            return $this->createErrorResult('上传过程中发生异常: ' . $e->getMessage());
        }
    }

    /**
     * 使用cURL将文件转发到目标服务器
     *
     * @param \think\File $file 文件对象
     * @param string $targetUrl 目标URL
     * @param array $extraFields 额外字段
     * @param array $headers 请求头
     * @return array 包含响应信息的数组
     */
    private function forwardToTargetServer(\think\File $file, string $targetUrl, array $extraFields = [], array $headers = []): array
    {
        $ch = curl_init();

        try {
            // 设置基本选项
            curl_setopt($ch, CURLOPT_URL, $targetUrl);
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_HEADER, false);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, 300); // 5分钟超时

            // 构建上传数据
            $postData = [
                'file' => new \CURLFile(
                    $file->getPathname(),
                    $file->getOriginalMime(),
                    $file->getOriginalName()
                )
            ];

            // 添加额外字段
            $postData = array_merge($postData, $extraFields);

            curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);

            // 设置请求头
            $httpHeaders = [];
            foreach ($headers as $headerName => $headerValue) {
                $httpHeaders[] = "$headerName: $headerValue";
            }

            if (!empty($httpHeaders)) {
                curl_setopt($ch, CURLOPT_HTTPHEADER, $httpHeaders);
            }

            // 执行请求
            $response = curl_exec($ch);
            $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
            $curlInfo = curl_getinfo($ch);

            // 检查错误
            if ($response === false) {
                throw new Exception('cURL错误: ' . curl_error($ch));
            }

            return [
                'code' => 1,
                'http_code' => $httpCode,
                'response' => $response,
            ];
        } catch (\Exception $e) {
            return [
                'code' => 0,
                'error' => $e->getMessage()
            ];
        } finally {
            curl_close($ch);
        }
    }

    /**
     * 创建错误结果数组
     *
     * @param string $message 错误信息
     * @return array 错误结果
     */
    private function createErrorResult(string $message): array
    {
        return [
            'code' => 0,
            'error' => $message
        ];
    }
}