#include "modbus-tcp.h"

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

char tcp_buffer[1024];

#define MAX_REG 25

uint16_t registers[MAX_REG];

static err_t modbus_incomming_data(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err){
	u16_t len;

	if (p != NULL){
		printf("data not null\n");
		//here im going to procces the modbusdata
		len = p->tot_len;

		//putting the bufer in the register array
		for(int i=0; i<len; i++ ) {
			registers[i] = p->payload[i];//getting the error "void value not ignored as it ought to be" on this line
		}

		if(registers[7] == 0x10){// Check if it's a Modbus Write Multiple Registers request (0x10)
			printf("in writing multiple register mode\n");
		}
	} else if (err == ERR_OK){
		tcp_close(pcb);//when everithing was ok close the tcpconnection
	}
	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
}