#include "modbus-tcp.h"

#include <tcp.h>
#include <string.h>

char tcp_buffer[1024];

struct Data_Modbus {//registers to hold the data of the modbus
	uint16_t reg_00;//
	uint16_t reg_01;//
	uint16_t reg_03;//
};

struct Data_Modbus datamodbus;

/*
static err_t echo_recv( void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err )
{
    int i;
    int len;
    char *pc;

    if ( err == ERR_OK && p != NULL )
    {
        tcp_recved( pcb, p->tot_len );
        pc = (char *)p->payload;
        len =p->tot_len;

        for( i=0; i<len; i++ )
        {
            tcp_buffer[i] = pc[i];
        }

        if( tcp_buffer[0] == 'X' )
            echo_close( pcb );

        pbuf_free( p );

        if( len > tcp_sndbuf( pcb ) )
            len= tcp_sndbuf( pcb );

        tcp_write( pcb, tcp_buffer, len, 0 );
        tcp_sent( pcb, NULL );
    }
    else
    {
        pbuf_free( p );
    }

    if( err == ERR_OK && p == NULL )
    {
        echo_close( pcb );
    }

    return ERR_OK;
}
*/

static err_t modbus_incomming_data(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err){
	int i;
	int len;
	char *pc;
	printf("data incomming\n");


	return ERR_OK;
}

static err_t modbus_accept(void *arg, struct tcp_pcb *pcb, err_t err )
{
    LWIP_UNUSED_ARG( arg );//Eliminates compiler warning about unused arguments
    LWIP_UNUSED_ARG( err );//Eliminates compiler warning about unused arguments
    tcp_setprio( pcb, TCP_PRIO_MIN );//Sets the priority of a connection.
    tcp_recv( pcb, modbus_incomming_data);//sets which function is being called when new data arives
    tcp_err( pcb, NULL );//sets the function thats called when an error ocours
    tcp_poll( pcb, NULL, 4 );//the aplication is being polled every 4 seconds
    tcp_write( pcb, "TEST\r\n", 8, 0 );//pcb , data , lenght in bytes , apiflags
    printf("connected\n");
    tcp_sent( pcb, NULL );//Specifies the callback function that should be called when data has successfully been received

    return ERR_OK;
}

void modbus_init( void )
{
    struct tcp_pcb *modbus_pcb;
    modbus_pcb = tcp_new();//creating a new tcp pcb
    tcp_bind(modbus_pcb, IP_ADDR_ANY, MODBUSPOORT);//bind the modbus_pcb to port 502

    modbus_pcb = tcp_listen( modbus_pcb );//listen
    tcp_accept(modbus_pcb, modbus_accept);//set callback function
}