cad-agent/src/AutoAgent/mcp.cpp

#include "StdAfx.h"
#include "cadsdk.h"
#include <winsock2.h>
#include <ws2tcpip.h>
#include <thread>
#include <atomic>
#include <nlohmann/json.hpp>

#pragma comment(lib, "ws2_32.lib")

static std::thread g_serverThread;
static std::atomic<bool> g_bRunning(false);
static SOCKET g_listenSocket = INVALID_SOCKET;

// 用于跨线程传递数据的结构体
struct TaskData
{
	std::string rawJson;
};

// 真正执行绘图的回调函数 (此函数由 AutoCAD 主线程调度运行)
static void MainThreadCallback(void *pData)
{
	TaskData *pTask = static_cast<TaskData *>(pData);
	if (pTask == nullptr)
	{
		return;
	}

	try
	{
		// 1. 解析 JSON 指令
		auto j = nlohmann::json::parse(pTask->rawJson);
		if (j.contains("cmd") && j["cmd"] == "draw_circle")
		{
			double x = j.value("x", 0.0);
			double y = j.value("y", 0.0);
			double r = j.value("r", 100.0);

			// 2. 锁定当前活动文档 (跨线程操作后的绝对必要步骤)
			AcApDocument *pDoc = acDocManager->curDocument();
			if (pDoc)
			{
				acDocManager->lockDocument(pDoc, AcAp::kWrite, nullptr, nullptr, false);

				// 3. 常规 ObjectARX 绘图逻辑
				AcDbDatabase *pDb = pDoc->database();
				AcDbBlockTable *pBlockTable = nullptr;
				pDb->getBlockTable(pBlockTable, AcDb::kForRead);

				AcDbBlockTableRecord *pBTR = nullptr;
				pBlockTable->getAt(ACDB_MODEL_SPACE, pBTR, AcDb::kForWrite);
				pBlockTable->close();

				AcGePoint3d center(x, y, 0.0);
				AcGeVector3d normal(0.0, 0.0, 1.0);
				AcDbCircle *pCircle = new AcDbCircle(center, normal, r);

				AcDbObjectId circleId;
				pBTR->appendAcDbEntity(circleId, pCircle);

				pBTR->close();
				pCircle->close();

				acDocManager->unlockDocument(pDoc);
				acutPrintf(_T("\n[MCP Server] 成功在坐标(%.2f, %.2f)绘制了半径为%.2f的圆\n"), x, y, r);
			}
		}
	}
	catch (...)
	{
		acutPrintf(_T("\n[MCP Server] JSON 解析或执行异常!\n"));
	}

	// 4. 清理由 Socket 线程在堆上分配的内存
	delete pTask;
}

// TCP 监听后台线程
static void TcpServerLoop()
{
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2, 2), &wsaData);

	g_listenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	sockaddr_in serverAddr = { 0 };
	serverAddr.sin_family = AF_INET;
	inet_pton(AF_INET, "127.0.0.1", &serverAddr.sin_addr);
	serverAddr.sin_port = htons(8080);

	bind(g_listenSocket, (sockaddr *)&serverAddr, sizeof(serverAddr));
	listen(g_listenSocket, SOMAXCONN);

	while (g_bRunning)
	{
		// 使用 select 模型实现带超时的轮询，确保插件卸载时线程能正常退出
		fd_set readSet;
		FD_ZERO(&readSet);
		FD_SET(g_listenSocket, &readSet);

		timeval timeout = { 1, 0 }; // 1秒超时机制
		int ret = select(0, &readSet, nullptr, nullptr, &timeout);

		if (ret > 0 && FD_ISSET(g_listenSocket, &readSet))
		{
			SOCKET clientSocket = accept(g_listenSocket, nullptr, nullptr);
			if (clientSocket != INVALID_SOCKET)
			{
				char recvBuf[2048] = { 0 };
				int bytesReceived = recv(clientSocket, recvBuf, sizeof(recvBuf) - 1, 0);
				if (bytesReceived > 0)
				{
					// 将数据拷贝到堆内存，准备派发给主线程
					TaskData *pTask = new TaskData;
					pTask->rawJson = recvBuf;

					// 核心：委托 AutoCAD 主线程在下一个消息循环中执行回调
					acDocManager->executeInApplicationContext(MainThreadCallback, pTask);
				}
				closesocket(clientSocket);
			}
		}
	}

	closesocket(g_listenSocket);
	WSACleanup();
}

namespace mcp
{
	bool init_mcp()
	{
		g_bRunning = true;
		g_serverThread = std::thread(TcpServerLoop);
		acutPrintf(_T("\n[MCP Server] 后台 TCP 监听线程已启动 (端口: 8080)...\n"));
	}
	
	bool close_mcp()
	{
		g_bRunning = false;
		if (g_serverThread.joinable())
		{
			g_serverThread.join();
		}
		acutPrintf(_T("\n[MCP Server] 插件已卸载，线程已关闭。\n"));
	}
}