#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <syslog.h>
#include <pthread.h>
#include "serial.h"
#include "log.h"
#include "config.h"
#include "gpio.h"
#include "runtime.h"
#include "mf700.h"
#include "reader.h"

int serial_interfaceattribs(int *fd, int speed){
    struct termios tty;

    if (tcgetattr(*fd, &tty) < 0) {
        char *log;
        if(asprintf(&log, "Error from tcgetattr: %s", strerror(errno)) > 0 ){
          writesyslog(LOG_ERR, log);
        }
        free(log);
        return -1;
    }

    cfsetospeed(&tty, (speed_t)speed);
    cfsetispeed(&tty, (speed_t)speed);

    tty.c_cflag |= (CLOCAL | CREAD);    	/* ignore modem controls */
    tty.c_cflag &= ~(unsigned)CSIZE;
    tty.c_cflag |= CS8;         		/* 8-bit characters */
    tty.c_cflag &= ~(unsigned)PARENB;     	/* no parity bit */
    tty.c_cflag &= ~(unsigned)CSTOPB;     	/* only need 1 stop bit */
    tty.c_cflag &= ~CRTSCTS;    		/* no hardware flowcontrol */
    tty.c_iflag &= ~((unsigned)IXON | (unsigned)IXOFF | (unsigned)IXANY);	// Turn off flow control

    /* setup for non-canonical raw  mode */
    cfmakeraw(&tty);

    /* fetch bytes as they become available */
    tty.c_cc[VMIN] = 73;
    tty.c_cc[VTIME] = 1; //block time out 0.1 sec

    if (tcsetattr(*fd, TCSANOW, &tty) != 0) {
        char *log;
        if(asprintf(&log, "Error from tcsetter: %s", strerror(errno)) > 0 ){
          writesyslog(LOG_ERR, log);
        }
        free(log);
        return -1;
    }
    return 0;
}

int openserialport(struct serialport_t *serial, char *serialpath){
  serial->fd = open(serialpath, O_RDWR | O_NOCTTY | O_SYNC);
  if (serial->fd < 0) {
    char *log;
    if(asprintf(&log, "Error opening %s: %s", serialpath, strerror(errno)) > 0 ){
      writesyslog(LOG_ERR, log);
    }
    free(log);
    printf("Serial port error %s\n", serialpath);
    return -1;
  }
  serial_interfaceattribs(&serial->fd, BAUDRATE);
  return 0;
}

struct serialport_t sharedbuffer;

//read serial port thread
void *readserialport(void *ptr){
  unsigned char chr;
  struct serialport_t *serial;
  serial = (struct serialport_t *) ptr;

  unsigned int idx = 0;
  while(1){
    ssize_t len1 = read(serial->fd, &chr, sizeof(chr));
    if (len1 > 0){
      if ((chr == '\r' || chr == '\n') && idx == 72){
        serial->buff[idx] = '\0';

        pthread_mutex_lock(&sharedbuffermutex);
        memcpy(&sharedbuffer, serial, sizeof(struct serialport_t));
        pthread_cond_signal(&sharedbuffersignal);
        pthread_mutex_unlock(&sharedbuffermutex);

        idx = 0;
      }else if (idx > 72){
        idx = 0;
      }else if (chr == ACK || chr == NACK ){
        idx = 0;
      }else {
        serial->buff[idx] = chr;
        idx++;
      }
    }
  }
}

void *serialdatawatch(void *ptr){
  struct config_t *config;
  config = (struct config_t *) ptr;

  while(1) {
    pthread_mutex_lock(&sharedbuffermutex);
    //wait for signal from serial read
    pthread_cond_wait(&sharedbuffersignal, &sharedbuffermutex);

    struct reader_t reader;
    reader.fd = sharedbuffer.fd;
    reader.reader = sharedbuffer.reader;
    reader.config = config;
    memcpy(reader.buff, sharedbuffer.buff, sizeof(reader.buff));

    readerrequest(&reader, config);

    //remove all credential data from buffer
    memset(&sharedbuffer, 0, sizeof(struct serialport_t));

    pthread_mutex_unlock(&sharedbuffermutex);
  }
}