#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>

#include <unistd.h>
#include <argp.h>

#include <gtk/gtk.h>

#include <modbus/modbus.h>
#include <modbus/modbus-rtu.h>
//GLOBALS
extern const char *__progname;
int debug = 0;
char *ttyDevice = "/dev/ttyUSB2";
char *modbusSlaveAddress = "1";
modbus_t *modbusDeviceContext;

enum DPSRegisters {
    dpsUSET  = 0x0000,
    dpsISET  = 0x0001,
    dpsUOUT  = 0x0002,
    dpsIOUT  = 0x0003,
    dpsPOWER = 0x0004,
    dpsUIN   = 0x0005,
    dpsKLOCK = 0x0006,
    dpsPROT  = 0x0007,
    dpsCVCC  = 0x0008,
    dpsONOFF = 0x0009,
    dpsB_LED = 0x000A,
    dpsMODEL = 0x000B,
    dpsVERS  = 0x000C,
};

uint16_t modbusRead(uint16_t reg)
{
    uint16_t register_val[2];
    if (modbus_read_registers(modbusDeviceContext, reg, 1, register_val) != 1) { //(context, base, count, result)
        return 0;
    } else {
        return register_val[0];
    }
}
uint16_t modbusWrite(uint16_t reg, uint16_t val)
{
    return modbus_write_register(modbusDeviceContext, reg, val); //(context, base, count, result)
}

int main (int argc, char **argv)
{


    int c;
    opterr = 0;

    while ((c = getopt (argc, argv, "p:a:d")) != -1)
        switch (c) {
        case 'a':
            //slave address
            modbusSlaveAddress = optarg;
            break;
        case 'd':
            debug = 1;
            break;
        case 'p':
            ttyDevice = optarg;
            break;
        case '?':
            if (optopt == 'p' || optopt == 'a')
                fprintf (stderr, "Option -%c requires an argument.\n", optopt);
            else if (isprint (optopt))
                fprintf (stderr, "Unknown option `-%c'.\n", optopt);
            else
                fprintf (stderr,
                         "Unknown option character `\\x%x'.\n",
                         optopt);
            return 1;
        }
    // end while

    if (debug) {
        printf ("%s starting...\n"
                "----\n"
                " Port: %s\n"
                "SAddr: %s\n\n"
                , __progname, ttyDevice, modbusSlaveAddress);
    }

    gtk_init (&argc, &argv);

    modbusDeviceContext = modbus_new_rtu(ttyDevice, 9600, 'N', 8, 1);
    if (modbusDeviceContext == NULL) {
        fprintf(stderr, "Unable to create the libmodbus context\n");
        return -1;
    }

    if (debug) modbus_set_debug(modbusDeviceContext, TRUE);

    if (modbus_connect(modbusDeviceContext) == -1) {
        fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
        modbus_free(modbusDeviceContext);
        return -1;
    }

    modbus_set_slave(modbusDeviceContext, atoi(modbusSlaveAddress));

    int mod = modbusRead(dpsMODEL);
    int ver = modbusRead(dpsVERS);
    if (mod == 3005 && ver==13) {
        printf("DPS-%d v%d", mod,ver);
    } else {
        printf("DPS module not detected on %s",ttyDevice);
    }

    modbus_close(modbusDeviceContext);
    modbus_free(modbusDeviceContext);


//int index;
// for (index = optind; index < argc; index++)
//   printf ("Non-option argument %s\n", argv[index]);
    return 0;
}