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#include <pthread.h>
#include <signal.h>
#include "hl.h"
void cli_data_handle (void *arg);
void sig_child_handle(int signo)
{
    if(SIGCHLD == signo) {
        waitpid(-1, NULL,  WNOHANG);
    }
}
int main (void)
{
    int fd = -1;
    struct sockaddr_in sin;
    signal(SIGCHLD, sig_child_handle);    
    /* 1. 创建socket fd */
    if ((fd = socket (AF_INET, SOCK_STREAM, 0)) < 0) {
        perror ("socket");
        exit (1);
    }
    /*优化4： 允许绑定地址快速重用 */
    int b_reuse = 1;
    setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &b_reuse, sizeof (int));
    /*2. 绑定 */
    /*2.1 填充struct sockaddr_in结构体变量 */
    bzero (&sin, sizeof (sin));
    sin.sin_family = AF_INET;
    sin.sin_port = htons (SERV_PORT);    //网络字节序的端口号
    /*优化1: 让服务器程序能绑定在任意的IP上 */
#if 1
    sin.sin_addr.s_addr = htonl (INADDR_ANY);
#else
    if (inet_pton (AF_INET, SERV_IP_ADDR, (void *) &sin.sin_addr) != 1) {
        perror ("inet_pton");
        exit (1);
    }
#endif
    //set time over
    struct timeval tv;
    tv.tv_sec = 10;
    tv.tv_usec = 0;
    setsockopt(fd,SOL_SOCKET,SO_RCVTIMEO,&tv,sizeof(tv));
    /*2.2 绑定 */
    if (bind (fd, (struct sockaddr *) &sin, sizeof (sin)) < 0) {
        perror ("bind");
        exit (1);
    }
    /*3. 调用listen()把主动套接字变成被动套接字 */
    if (listen (fd, BACKLOG) < 0) {
        perror ("listen");
        exit (1);
    }
    printf ("Server starting....OK!\n");
    int newfd = -1;
    /*4. 阻塞等待客户端连接请求 */
        struct sockaddr_in cin;
        socklen_t addrlen = sizeof (cin);
        while(1) {
                pid_t pid = -1;
                if ((newfd = accept (fd, (struct sockaddr *) &cin, &addrlen)) < 0) {
                    perror ("accept");
                    break;
                }
        /*创建一个子进程用于处理已建立连接的客户的交互数据*/
        if((pid = fork()) < 0) {
            perror("fork");
            break;
        }
        if(0 == pid) {  //子进程中
            close(fd);
            char ipv4_addr[16];
            if (!inet_ntop (AF_INET, (void *) &cin.sin_addr, ipv4_addr, sizeof (cin))) {
                            perror ("inet_ntop");
                            exit (1);
                        }
                        printf ("Clinet(%s:%d) is connected!\n", ipv4_addr, ntohs(cin.sin_port));    
            cli_data_handle(&newfd);        
            return 0;    
        } else { //实际上此处 pid >0, 父进程中 
            close(newfd);
        }
    }        
    close (fd);
    return 0;
}
void cli_data_handle (void *arg)
{
    int newfd = *(int *) arg;
    printf ("Child handling process: newfd =%d\n", newfd);
    //..和newfd进行数据读写
    int ret = -1;
    char buf[BUFSIZ];
    char resp_buf[BUFSIZ+10];
    while (1) {
        bzero (buf, BUFSIZ);
        do {
            ret = read (newfd, buf, BUFSIZ - 1);
        } while (ret < 0 && EINTR == errno);
        if (ret < 0) {
            perror ("read");
            exit (1);
        }
        if (!ret) {                //对方已经关闭
            break;
        }
        printf ("Receive data: %s\n", buf);
        bzero(resp_buf,BUFSIZ+10);
        strncpy(resp_buf,SERV_RESP_STR,strlen(SERV_RESP_STR));
        strcat(resp_buf,buf);
        do{
            write(newfd,resp_buf,strlen(resp_buf));    
        }while(ret<0 && EINTR ==errno);
        if (!strncasecmp (buf, QUIT_STR, strlen (QUIT_STR))) {    //用户输入了quit字符
            printf ("Client(fd=%d) is exiting!\n", newfd);
            break;
        }
        bzero(resp_buf, BUFSIZ+10);
        strncpy(resp_buf, SERV_RESP_STR, strlen(SERV_RESP_STR));
        strcat(resp_buf, buf);     
        do {
            ret = write(newfd, resp_buf, strlen(resp_buf));    
        }while(ret < 0 && EINTR == errno);
    }
    close (newfd);
}