/*********************************************************************************
 *      Copyright:  (C) 2025 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  iotc.c
 *    Description:  This is temperature monitor client program runs on RPi
 *
 *        Version:  1.0.0(10/20/2025)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "10/20/2025 09:48:51 PM"
 *
 * Pin connection:
 *
 *          vcc   --- #Pin1 ( 3.3v )
 *          DQ    --- #Pin7 (BCM GPIO4)
 *          GND   --- #Pin9 ( GND  )
 *
 * /boot/config.txt:
 *
 *          dtoverlay=w1-gpio-pullup,gpiopin=4
 *
 ********************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <time.h>
#include <math.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <getopt.h>


void print_usage(char *progname)
{
    printf("%s usage: \n", progname);
    printf("  -i(--ipaddr): sepcify server IP address\n");
    printf("  -p(--port): sepcify server port.\n");
    printf("  -h(--Help): print this help information.\n");

    return ;
}

int ds18b20_get_temperature(float *temp);

int main(int argc, char **argv)
{
    int                     conn_fd = -1;
    int                     rv = -1;
    char                    buf[1024];
    char                   *servip = "127.0.0.1";
    int                     port = 0;
    struct sockaddr_in      serv_addr;
    float                   temp;
    int                     interval = 10;

    int                     ch;
    struct option           opts[] = {
        {"interval", required_argument, NULL, 'I'},
        {"ipaddr", required_argument, NULL, 'i'},
        {"port", required_argument, NULL, 'p'},
        {"help", no_argument, NULL, 'h'},
        {NULL, 0, NULL, 0}
    };

    /* parser command line input arguments */
    while( (ch=getopt_long(argc, argv, "I:i:p:h", opts, NULL)) != -1 )
    {
        switch(ch)
        {
            case 'I':
                interval=atoi(optarg);
                break;

            case 'i':
                servip=optarg;
                break;

            case 'p':
                port=atoi(optarg);
                break;

            case 'h':
                print_usage(argv[0]);
                return 0;
        }
    }

    /* socket client must specify server IP address and port */
    if( !servip || !port )
    {
        print_usage(argv[0]);
        return 1;
    }

    /* create TCP socket */
    conn_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(conn_fd < 0)
    {
        printf("create socket failure: %s\n", strerror(errno));
        return 2;
    }

    /* set server IP address and port into $server_addr */
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(port);
    inet_aton( servip, &serv_addr.sin_addr );

    /* connect to socket server */
    if( connect(conn_fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr))  < 0)
    {
        printf("connect to server [%s:%d] failure: %s\n", servip, port, strerror(errno));
        return 3;
    }

    while(1)
    {
        /* DS18B20 sample temperature */
        if( ds18b20_get_temperature(&temp) < 0 )
        {
            printf("ERROR: ds18b20 get temperature failure\n");
            return 1;
        }
        snprintf(buf, sizeof(buf), "Current temperature: %.3f ℃", temp);

        /* send message to socket server */
        if( write(conn_fd, buf, strlen(buf)) < 0 )
        {
            printf("Write data to server [%s:%d] failure: %s\n", servip, port, strerror(errno));
            goto cleanup;
        }
        printf("Send temperature: %.3f ℃ to socket server okay\n", temp);

        sleep(interval);
    }

cleanup:
    close(conn_fd);
    return 0;
}


/* File Content:
   pi@raspberrypi:~/guowenxue $ cat /sys/bus/w1/devices/28-041731f7c0ff/w1_slave
   3a 01 4b 46 7f ff 0c 10 a5 : crc=a5 YES
   3a 01 4b 46 7f ff 0c 10 a5 t=19625
   */

int ds18b20_get_temperature(float *temp)
{
    char            w1_path[50] = "/sys/bus/w1/devices/";
    char            chip[20];
    char            buf[128];
    DIR            *dirp;
    struct dirent  *direntp;
    int             fd =-1;
    char           *ptr;
    float           value;
    int             found = 0;
    int             rv = 0;

    if( !temp )
    {
        return -1;
    }

    /*+-------------------------------------------------------------------+
     *|  open dierectory /sys/bus/w1/devices to get chipset Serial Number |
     *+-------------------------------------------------------------------+*/

    if((dirp = opendir(w1_path)) == NULL)
    {
        printf("opendir error: %s\n", strerror(errno));
        return -2;
    }

    while((direntp = readdir(dirp)) != NULL)
    {
        if(strstr(direntp->d_name,"28-"))
        {
            /* find and get the chipset SN filename */
            strcpy(chip, direntp->d_name);
            found = 1;
            break;
        }
    }
    closedir(dirp);

    if( !found )
    {
        printf("Can not find ds18b20 in %s\n", w1_path);
        return -3;
    }

    /*+------------------------------------------------------------------+
     *|  Generate DS18B20 full path: /sys/bus/w1/devices/28-xx/w1_slave  |
     *+------------------------------------------------------------------+*/

    strncat(w1_path, chip, sizeof(w1_path)-strlen(w1_path));
    strncat(w1_path, "/w1_slave", sizeof(w1_path)-strlen(w1_path));


    /*+------------------------------------------------------------------+
     *|  Open and read temperature: /sys/bus/w1/devices/28-xx/w1_slave   |
     *+------------------------------------------------------------------+*/

    if( (fd=open(w1_path, O_RDONLY)) < 0 )
    {
        printf("open %s error: %s\n", w1_path, strerror(errno));
        return -4;
    }

    if(read(fd, buf, sizeof(buf)) < 0)
    {
        printf("read %s error: %s\n", w1_path, strerror(errno));
        rv = -5;
        goto cleanup;
    }

    ptr = strstr(buf, "t=");
    if( !ptr )
    {
        printf("ERROR: Can not get temperature\n");
        rv = -6;
        goto cleanup;
    }

    ptr+=2;

    /*+------------------------------------------------------------------+
     *|         Convert temperature string value to float value          |
     *+------------------------------------------------------------------+*/

    *temp = atof(ptr)/1000;

cleanup:
    close(fd);
    return 0;
}