#include "rfid_handler.h"
#include "users.h"
#include "main.h"

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
#include <string.h>

void *uartListener(void *arg)
{
    char *uart_address = (char *)arg;
    int uart = open(uart_address, O_RDWR | O_NOCTTY | O_NDELAY);
    if (uart == -1)
    {
        perror("Failed to open UART");
        return NULL;
    }

    struct termios options;
    tcgetattr(uart, &options);

    cfsetispeed(&options, B9600);
    cfsetospeed(&options, B9600);
    options.c_cflag &= ~PARENB;
    options.c_cflag &= ~CSTOPB;
    options.c_cflag &= ~CSIZE;
    options.c_cflag |= CS8;
    options.c_cflag |= CREAD | CLOCAL;

    options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
    options.c_iflag &= ~(IXON | IXOFF | IXANY);
    options.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL);
    options.c_oflag &= ~OPOST;

    options.c_cc[VMIN] = 1;
    options.c_cc[VTIME] = 0;

    if (tcsetattr(uart, TCSANOW, &options) != 0)
    {
        perror("tcsetattr");
        exit(EXIT_FAILURE);
    }


     enum
    {
        SYNC0,
        SYNC1,
        READING_PACKET
    } state = SYNC0;
    uint8_t packet[6];
    int packet_index = 0;

    while (1)
    {
        uint8_t byte;
        ssize_t n = read(uart, &byte, 1);
        if (n == -1)
        {
            perror("read");
            exit(EXIT_FAILURE);
        }

        switch (state)
        {
        case SYNC0:
            if (byte == 0x55)
            {
                packet[0] = byte;
                packet_index = 1;
                state = SYNC1;
            }
            break;

        case SYNC1:
            if (byte == 0xFF)
            {
                packet[1] = byte;
                packet_index = 2;
                state = READING_PACKET;
            }
            else
            {
                state = SYNC0;
            }
            break;

        case READING_PACKET:
            packet[packet_index++] = byte;
            if (packet_index == 6)
            {
                uint8_t crc = 0;
                for (int i = 0; i < 5; i++)
                {
                    crc ^= packet[i];
                }

                if (crc == packet[5])
                {
                    
                }
                else
                {
                    //fprintf(stderr, "Chyba CRC!\n");
                }
                state = SYNC0;
            }
            break;
        }
    }

    close(uart);
    return NULL;
}

void parseIncommingPacket(BYTE * _packet)
{
    
}