/*********************************************************************************
 *      Copyright:  (C) 2021 Guo Wenxue <guowenxue@gmail.com> 
 *                  All rights reserved.
 *
 *       Filename:  comport.c
 *    Description:  This file used to do ioctl() on common device or communicate 
 *                  with serial port/TTY device.
 *                 
 *        Version:  1.0.0(5/1/2021~)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "5/1/2021 10:08:05 AM"
 *                 
 ********************************************************************************/
#include <getopt.h>
#include <libgen.h>
#include <sys/ioctl.h>

#include "comport.h"

unsigned char g_stop = 0;
unsigned char g_CtrlZ;

void print_version(char *name);
void usage(char *name);
void signal_handler(int i_sig);
void stdin_nonblock(void);
int kbhit(void);


int main(int argc, char **argv)
{
    int                opt = 0;
    int                rv = 0;
    int                i;

    comport_t          comport;
    int                baudrate = 115200;
    char              *settings = "8N1N";
    char              *dev_name = NULL;

    char               buf[512];
    unsigned char      disp_mode = 0x00;

    struct sigaction   sigact;

    struct option long_options[] = {
        {"device", required_argument, NULL, 'd'},
        {"baudrate", required_argument, NULL, 'b'},
        {"settings", required_argument, NULL, 's'},
        {"hex", no_argument, NULL, 'x'},
        {"version", no_argument, NULL, 'v'},
        {"help", no_argument, NULL, 'h'},
        {NULL, 0, NULL, 0}
    };

    while ((opt = getopt_long(argc, argv, "d:b:s:vh", long_options, NULL)) != -1)
    {
        switch (opt)
        {
          case 'd':
              dev_name = optarg;
              break;
              
          case 'b':
              baudrate = atoi(optarg);
              break;

          case 's':            /* Default settings as 8N1N */
              settings = optarg;
              break;

          case 'x':            /* Display receive data as Hex mode */
              disp_mode = 0x01;
              break;

          case 'v':            /* version */
              print_version(argv[0]);
              return 0;

          case 'h':            /* help */
              usage(argv[0]);
              return 0;

          default:
              break;
        }                       /* end of "switch(opt)" */
    }

    if (argc < 2)
    {
        usage(argv[0]);
        return 0;
    }

    if ( (rv=comport_open(&comport, dev_name, baudrate, settings)) < 0)
    {
        printf("Failed to open %s wth baudrate %d, %s. rv=%d\n", dev_name, baudrate, settings, rv);
        return -1;
    }

    stdin_nonblock();

    /* Process level signal handler */
    sigemptyset(&sigact.sa_mask);
    sigact.sa_flags = 0;
    sigact.sa_handler = signal_handler;

    sigaction(SIGTERM, &sigact, NULL);  /* catch terminate signal */
    sigaction(SIGINT, &sigact, NULL);   /* catch interrupt signal */
    sigaction(SIGSEGV, &sigact, NULL);  /* catch segmentation faults */
    sigaction(SIGTSTP, &sigact, NULL);  /* catch ctrl+Z */
    sigaction(SIGSTOP, &sigact, NULL);  /* catch ctrl+Z */

    while ( !g_stop )
    {
        rv = comport_recv(&comport, buf, sizeof(buf) - 1, 10);
        if ( rv > 0)
        {
            for (i=0; i<rv ; i++)
            {
                if (0 == disp_mode)
                    printf("%c", buf[i]);
                else
                    printf("%02X ", buf[i]);
            }
            fflush(stdout);
        }
        if (0 != kbhit())
        {
            rv = fgetc(stdin);

            if (0x0A == rv)
            {
                buf[0] = 0x0D; /* 13 == 0x0D */
            }
            else
            {
                buf[0] = rv;
            }

            comport_send(&comport, buf, 1);
        }
        else if (0x00 != g_CtrlZ)
        {
            g_CtrlZ = 0x00;
            buf[0] = 0x1A;
            comport_send(&comport, buf, 1);
        }
    }

    comport_close(&comport);
    return 0;
}  /* ----- End of main() ----- */


void print_version(char *name)
{
    char *progname = NULL;
    char *ptr = NULL;

    ptr = strdup(name);
    progname = basename(ptr);

    printf("%s v1.0.0 Build on %s\n", progname, __DATE__);
    printf("Copyright (C) 2021 guowenxue <guowenxue@gmail.com>\n");

    free(ptr);
    return;
}

void usage(char *name)
{
    char *progname = NULL;
    char *ptr = NULL;

    ptr = strdup(name);
    progname = basename(ptr);
    printf("Usage1: comport -d <device> [-b <baudrate>][-s <settings>] [-x]\n");
    printf(" -d[device  ]  device name\n");
    printf(" -b[baudrate]  device baudrate (115200, 57600, 19200, 9600), default is 115200\n");
    printf(" -s[settings]  device settings as like 8N1N(default setting)\n");
    printf("                 - data bits: 8, 7\n");
    printf("                 - parity: N=None, O=Odd, E=Even, S=Space\n");
    printf("                 - stop bits: 1, 0\n");
    printf("                 - flow control: N=None, H=Hardware, S=Software, B=Both\n");
    printf(" -x[hex     ]  display received data in hex format\n");

    printf(" -v[version ]  Display the program version\n");
    printf(" -h[help    ]  Display this help information\n");
    print_version(progname);

    free(ptr);

    return;
}


void signal_handler(int signum)
{
    if (SIGTERM == signum || SIGINT == signum)
    {
        g_stop = 1;
    }
    else if (SIGTSTP == signum)
    {
        g_CtrlZ = 1;
    }
}


void stdin_nonblock(void)
{
    struct termios ttystate;
    
    //get the terminal state
    tcgetattr(STDIN_FILENO, &ttystate);

    //turn off canonical mode
    ttystate.c_lflag &= ~ICANON;
    //minimum of number input read.
    ttystate.c_cc[VMIN] = 1;
    
    //set the terminal attributes.
    tcsetattr(STDIN_FILENO, TCSANOW, &ttystate);
}   
        
int kbhit(void)
{       
    struct timeval tv;
    fd_set fds;
    tv.tv_sec = 0; 
    tv.tv_usec = 0; 
    FD_ZERO(&fds);
    FD_SET(STDIN_FILENO, &fds); //STDIN_FILENO is 0
    select(STDIN_FILENO + 1, &fds, NULL, NULL, &tv);
    return FD_ISSET(STDIN_FILENO, &fds);
}