#include <rtthread.h>

//#include <lwip/sockets.h> /* 使用BSD Socket接口必须包含sockets.h这个头文件 */
#include <sys/socket.h> /* 使用BSD socket,需要包含sockets.h头文件 */
#include "netdb.h"

static const char send_data[] = "This is TCP Server from RT-Thread."; /* 发送用到的数据 */
void tcpserv(void* parameter)
{
   char *recv_data; /* 用于接收的指针,后面会做一次动态分配以请求可用内存 */
   rt_uint32_t sin_size;
   int sock, connected, bytes_received;
   struct sockaddr_in server_addr, client_addr;
   rt_bool_t stop = RT_FALSE; /* 停止标志 */
   int ret;

   recv_data = rt_malloc(1024); /* 分配接收用的数据缓冲 */
   if (recv_data == RT_NULL)
   {
       rt_kprintf("No memory\n");
       return;
   }

   /* 一个socket在使用前,需要预先创建出来,指定SOCK_STREAM为TCP的socket */
   if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
   {
       /* 创建失败的错误处理 */
       rt_kprintf("Socket error\n");

       /* 释放已分配的接收缓冲 */
       rt_free(recv_data);
       return;
   }

   /* 初始化服务端地址 */
   server_addr.sin_family = AF_INET;
   server_addr.sin_port = htons(5000); /* 服务端工作的端口 */
   server_addr.sin_addr.s_addr = INADDR_ANY;
   rt_memset(&(server_addr.sin_zero),8, sizeof(server_addr.sin_zero));

   /* 绑定socket到服务端地址 */
   if (bind(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1)
   {
       /* 绑定失败 */
       rt_kprintf("Unable to bind\n");

       /* 释放已分配的接收缓冲 */
       rt_free(recv_data);
       return;
   }

   /* 在socket上进行监听 */
   if (listen(sock, 5) == -1)
   {
       rt_kprintf("Listen error\n");

       /* release recv buffer */
       rt_free(recv_data);
       return;
   }

   rt_kprintf("\nTCPServer Waiting for client on port 5000...\n");
   while(stop != RT_TRUE)
   {
       sin_size = sizeof(struct sockaddr_in);

       /* 接受一个客户端连接socket的请求,这个函数调用是阻塞式的 */
       connected = accept(sock, (struct sockaddr *)&client_addr, &sin_size);
       /* 返回的是连接成功的socket */

       /* 接受返回的client_addr指向了客户端的地址信息 */
       rt_kprintf("I got a connection from (%s , %d)\n",
                  inet_ntoa(client_addr.sin_addr),ntohs(client_addr.sin_port));

       /* 客户端连接的处理 */
       while (1)
       {
           /* 发送数据到connected socket */
           ret = send(connected, send_data, strlen(send_data), 0);
           if (ret < 0)
           {
                /* 发送失败,关闭这个连接 */
                closesocket(connected);
                rt_kprintf("\nsend error,close the socket.\r\n");
                break;
           }
           else if (ret == 0)
           {
                /* 打印send函数返回值为0的警告信息 */
                rt_kprintf("\n Send warning,send function return 0.\r\n");
           }

           /* 从connected socket中接收数据,接收buffer是1024大小,但并不一定能够收到1024大小的数据 */
           bytes_received = recv(connected,recv_data, 1024, 0);
           if (bytes_received < 0)
           {
               /* 接收失败,关闭这个connected socket */
               closesocket(connected);
               break;
           }
           else if (bytes_received == 0)
           {
               /* 打印recv函数返回值为0的警告信息 */
               rt_kprintf("\nReceived warning,recv function return 0.\r\n");
               continue;
           }

           /* 有接收到数据,把末端清零 */
           recv_data[bytes_received] = '\0';
           if (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
           {
               /* 如果是首字母是q或Q,关闭这个连接 */
               closesocket(connected);
               break;
           }
           else if (strcmp(recv_data, "exit") == 0)
           {
               /* 如果接收的是exit,则关闭整个服务端 */
               closesocket(connected);
               stop = RT_TRUE;
               break;
           }
           else
           {
               /* 在控制终端显示收到的数据 */
               rt_kprintf("RECEIVED DATA = %s \n" , recv_data);
           }
       }
   }

   /* 退出服务 */
   closesocket(sock);

   /* 释放接收缓冲 */
   rt_free(recv_data);

   return ;
}

#ifdef RT_USING_FINSH
#include <finsh.h>
/* 输出tcpserv函数到finsh shell中 */
FINSH_FUNCTION_EXPORT(tcpserv, startup tcp server);
#endif