/*********************************************************************************
 *      Copyright:  (C) 2018 LingYun I.o.T Studio  <www.iot-yun.com>
 *                  All rights reserved.
 *
 *       Filename:  socket_client.c
 *    Description:  This is a sample socket client demo program.
 *                  Usage: socket_client -i 192.168.2.18 -p 6666
 *                 
 *        Version:  1.0.0(06/08/2012~)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "06/08/2012 02:50:51 PM"
 *                 
 ********************************************************************************/

/* Some Unix Program Standard head file  */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <getopt.h> /* getopt_long */
#include <libgen.h> /* getopt_long */

/* Socket Program head file */
#include <sys/types.h>   
#include <sys/socket.h>
#include <netinet/in.h> /* sockaddr_in{} and other Internet define */

#include <errno.h>      /* strerror(), perror(), errno head file*/
#include <arpa/inet.h>  /* For inet_pton() */

#define MAX_BUF_SIZE                       1024

#define LOGON_INFO                         "lingyun:www.iot-yun.com"

#define MAJOR            1
#define MINOR            0
#define REVER            0

void print_version(char *progname)
{
    printf("%s Version 1.0.0\n", progname);
    printf("Copyright (C) 2012 Guo Wenxue<guowenxue@gmail.com>.\n");
    return;
}

void print_usage(char *progname)
{
    print_version(progname); 
    
    printf("Usage: %s [OPTION]...\n", progname);
    printf(" %s is a socket client test program, which used to logon server and send string to server\n", progname);

    printf("\nMandatory arguments to long options are mandatory for short options too:\n");

    printf(" -i[ipaddr  ]  Socket server IP address\n");
    printf(" -p[port    ]  Socket server port address\n");
    printf(" -h[help    ]  Display this help information\n");
    printf(" -v[version ]  Display the program version\n");

    printf("\nExample: %s -i 192.168.2.18 -p 8900\n", progname);
    return ;
}


/* Argc is the program linux running command arguments count, and argv is 
 * the arguments string value. All of the arguments take as string.
 */
int main(int argc, char **argv)
{
    int                       sockfd, len, rv;
    int                       opt;
    char                     *progname = NULL;
    char                     *server_ip = NULL;
    unsigned short            server_port = 0;
    char                      buf[MAX_BUF_SIZE];
    struct sockaddr_in        servaddr;

    struct option             long_options[] = 
    { 
        {"ipaddr", required_argument, NULL, 'i'},
        {"port", required_argument, NULL, 'p'},
        {"version", no_argument, NULL, 'v'},
        {"help", no_argument, NULL, 'h'},
        {NULL, 0, NULL, 0}
    };

    progname = basename(argv[0]);

    /*  Parser the command line parameters */
    while ((opt = getopt_long(argc, argv, "i:p:vh", long_options, NULL)) != -1)
    {
        switch (opt)
        {
            case 'p':
                server_port = atoi(optarg);
                break;

            case 'i':
                server_ip = optarg;
                break;

            case 'v':
                print_version(progname); /*  Defined in version.h */
                return EXIT_SUCCESS;

            case 'h':  /*  Get help information */
                print_usage(progname);
                return EXIT_SUCCESS;

            default:
                break;
        }
    }

    if(NULL==server_ip || 0==server_port) 
    {
        print_usage(progname);
        return -1;
    }

    /* Open an IPV4(AF_INET) TCP(SOCK_STREAM) Socket File Description, UDP socket should 
     * use SOCK_DGRAM,We can use linux command "man socket" to see this function manual
     */
    if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        /* strerror() is the 1st way to display the failure reason, argument 
         * errno is a globle variable defined in <errno.h>, we can use linux command 
         * "man strerror" to see this function manual*/
        printf("Use socket() to create a TCP socket failure: %s\n", strerror(errno));
        return -1;
    }

    /* Now we set the Server Information, include IPV4 or IPV6, Server Port, Server IP address  */
    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family = AF_INET;   /* Set it as IPV4 protocal */
    servaddr.sin_port = htons(server_port); /*Server port*/ 

    /* argv[1] we take as Server IP address, it's the second arguments in running command  */
    if (inet_pton(AF_INET, server_ip, &servaddr.sin_addr) <= 0) 
    {
        printf("Use inet_pton() to set the Server IP address failure.\n");
        rv = -2;
        goto CleanUp;
    }

    /* Now call connect() function to connect to the server, we can use linux command "man connect" 
     * to see this function manual */
    if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
    {
        printf("Connect to the server [%s:%d] failure: %s\n", server_ip, server_port, strerror(errno));
        rv = -3;
        goto CleanUp;
    }
    printf("Connect to Server [%s:%d] ok\n", server_ip, server_port);

#ifdef CONFIG_VERIFY_USER
    if( write(sockfd, LOGON_INFO, strlen(LOGON_INFO)) < 0)
    {
        printf("Write logon information to server failure: %s\n", strerror(errno));
        goto CleanUp;
    }

    /* Once we connect to the server successfully, we can receive the data from the socket socekt */
    memset(buf, 0, sizeof(buf));
    if( (len = read(sockfd, buf, MAX_BUF_SIZE)) < 0) 
    {
        printf("socket read data from server[%s] failure:%s\n", server_ip, strerror(errno));
        goto CleanUp;
    }
    else if( 0 == len ) 
    {
        printf("logon to server[%s] failure and socket disconnected\n", server_ip);
        goto CleanUp;
    }

    /* socket read data from server */
    if( strncasecmp(buf, "passed", 6) )
    {
        printf("Logon to server[%s] failure: %s\n", server_ip, buf);
        goto CleanUp;
    }
    printf("Logon to server successfully!\n");
#endif

    while(1)
    {
        printf("\nplease input string to send to server:\n==> ");

        memset(buf, 0, sizeof(buf));
        fgets(buf, sizeof(buf), stdin);
        write(sockfd, buf, strlen(buf));

        memset(buf, 0, sizeof(buf));
        rv=read(sockfd, buf, sizeof(buf));
        if(rv <= 0)
        {
            printf("ERROR:socket disconnected or get error\n");
            goto CleanUp;
        }

        printf("<== %s\n", buf);
    }


CleanUp:
    close(sockfd);  /* We must close socket File Description when program exit*/
    return 0;
}