src/WeChatOcrCpp/main.cpp


// 在所有包含之前定义这个宏
#define WIN32_LEAN_AND_MEAN  // for httplib.h

#include <iostream>
#include <thread>
#include <chrono>
#include <atomic>
#include <windows.h>

#include "ImageOcr.h"
#include "Wchtcr.h"
#include "Utilities.h"

#include "nlohmann/json.hpp"

#include "httplib.h"

#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/videoio.hpp>
#include <opencv2/imgproc.hpp>

#include <format>



using json = nlohmann::json;

// DLL 入口点
BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) {
    switch (ul_reason_for_call) {
    case DLL_PROCESS_ATTACH:
        // 初始化代码
        break;
    case DLL_THREAD_ATTACH:
        break;
    case DLL_THREAD_DETACH:
        break;
    case DLL_PROCESS_DETACH:
        // 清理代码
        break;
    }
    return TRUE;
}

extern "C" {
    __declspec(dllexport) const char* rec(const char* pth_img) {
        thread_local static std::string result;
		Wchtcr wchtcr;
        result = wchtcr.rec(pth_img);
        return result.c_str();
    }
}

// 启动HTTP服务器的函数
void StartHttpServer(int port) {
    httplib::Server svr;

    std::atomic<int> totalTasks(0);  // 使用原子类型确保线程安全

    // 添加POST接口，接收base64编码的图片
    svr.Post("/wechatocr", [&totalTasks, &port](const httplib::Request& req, httplib::Response& res) {

		std::string msg_Warning_waiting = std::vformat("{{\"msg\":\"warning: waiting previous task done. port {}\" }}", std::make_format_args(port));
		std::string msg_Err_noParam = std::vformat("{{\"msg\":\"error: not have img param. port {}\" }}", std::make_format_args(port));
		std::string msg_Err_genFilename = std::vformat("{{\"msg\":\"error: gen tmp filename fail. port {}\" }}", std::make_format_args(port));
		std::string msg_Err_rec_fail = std::vformat("{{\"msg\":\"error: rec fail port {}\" }}", std::make_format_args(port));

         try {

    //        while (totalTasks + 1 > 1) {
    //            std::cout << "########## Warning: Max tasks overflow, Total tasks " << totalTasks << " waitting now... "  << std::endl;
				//std::this_thread::sleep_for(std::chrono::milliseconds(1000)); // 等待 1 秒
    //        }

           

            if (totalTasks > 0) {
                res.status = 201;
                res.set_content(msg_Warning_waiting, "application/json");
                return;
            }

			std::cout << "********* Received a new task. Total tasks: " << ++totalTasks << std::endl;

            // 检查Content-Type
            const auto& content_type = req.get_header_value("Content-Type");
            std::string body_content = req.body;

            // 如果是URL编码的JSON，先解码
            if (content_type.find("application/json") != std::string::npos &&
                req.body.find("%") != std::string::npos) {
                // 使用httplib内置的decode_path函数解码URL编码的内容
                body_content = httplib::detail::decode_path(req.body, true);
            }

            // 解析请求体中的JSON数据
            json request_data = json::parse(body_content);

            // 获取base64编码的图片数据
            std::string base64_image;
            if (request_data.contains("img")) {
                base64_image = request_data["img"].get<std::string>();
            }
            else {
                --totalTasks;
                res.status = 500;
                res.set_content(msg_Err_noParam, "application/json");
                return;
            }

            std::vector<unsigned char> b64_buf = Utilities::Base64Decode_Raw(base64_image);

            cv::Mat img_orgin = cv::imdecode(b64_buf, -1);

            char tempPath[MAX_PATH], tempFile[MAX_PATH];
            GetTempPathA(MAX_PATH, tempPath);              // 获取系统临时目录
            if (GetTempFileNameA(tempPath, "TMP", 0, tempFile) == 0) { // "TMP"为前缀，0表示自动生成唯一编号
                --totalTasks;
                res.status = 201;
                res.set_content(msg_Err_genFilename, "application/json");
                return;
            }
            strcat_s(tempFile, ".jpg");

            cv::imwrite(tempFile, img_orgin);

            //cv::imshow("原图", img_orgin);

            //cv::waitKey(0);

            // 调用rec函数进行OCR识别
            std::string result = rec(tempFile);
			if (result.empty()) {
				--totalTasks;
				res.status = 201;
				res.set_content(msg_Err_rec_fail, "application/json");
				return;
			}

            json jsn = json::parse(result);
			jsn["port"] = port; // 添加端口号到结果中
            result = jsn.dump(4);

            --totalTasks;
            
            std::cout << "one task done. Total tasks:" << totalTasks << std::endl;

            // 返回识别结果
            res.status = 200;
            res.set_content(result, "application/json");

            // 删除临时文件
            std::remove(tempFile);

            return;
        }
        catch (const std::exception& e) {
            --totalTasks;
            res.status = 201;
            std::string error_msg = e.what();
			std::string msg_exception = std::vformat("{\"msg\":\"error: server error. {} port {}\" }", std::make_format_args(error_msg, port) );
            res.set_content(msg_exception, "application/json");
            return;
        }

        
    });

    // 添加一个简单的GET接口，用于测试服务器是否正常运行
    svr.Get("/", [](const httplib::Request&, httplib::Response& res) {
        res.set_content("OCR Sever running ....", "text/plain");
        });

    std::cout << "OCR Sever running ... : " << port << std::endl;
    svr.listen("0.0.0.0", port);
}

int main(int argc, char* argv[])
{
	//Wchtcr wchtcr;
    //   
    //std::string result = wchtcr.rec("data/0025.jpg");
	//json jsn;
	//std::string jsn_str;

    // 默认端口号
    int port = 7788;
    
    // 如果提供了命令行参数，使用第一个参数作为端口号
    if (argc > 1) {
        try {
            port = std::stoi(argv[1]);
            if (port <= 0 || port > 65535) {
                std::cout << "Invalid port number. Using default port 7788." << std::endl;
                port = 7788;
            }
        } catch (const std::exception& e) {
            std::cout << "Invalid port number format. Using default port 7788." << std::endl;
            port = 7788;
        }
    }

    // 启动HTTP服务器，使用指定的端口
    std::thread server_thread(StartHttpServer, port);

    // 分离线程，让它在后台运行
    server_thread.detach();

    do {
        // 主线程可以做其他事情，或者等待用户输入退出
        //std::cout << "ok." << std::endl;
        std::cin.get();
    } while (true);

    std::string result = rec("t2.jpg");
    json jsn;
    std::string jsn_str;
    
    try {
		 jsn = json::parse(result);
		 jsn_str = jsn.dump(4);
    }
	catch (const std::exception& e) {
		std::cerr << "OCR识别异常: " << e.what() << std::endl;
		return 1;
	}

    return 0;
}