#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <signal.h>

#include "serial.h"
#include "pthread.h"
#include "download.h"

int tty_fd;
int stopped = 0;
char* port_name = "/dev/ttyUSB1";
pthread_t serial_reader;

void* serial_reader_func(void* arg) {
    unsigned char buf[255];
    while(1) {
        int n = read_serial_port(buf, sizeof(buf));
        if (n > 0) {
            write(tty_fd, buf, n);
        }
    }
}

int init() {
    int result = open_serial_port(port_name);
    pthread_create(&serial_reader, NULL, serial_reader_func, NULL);
    hard_reset_to_user_code();
    return result;
}

struct termios old_term_setting;

void close_tty() {
	tcsetattr(tty_fd, TCSANOW, &old_term_setting);
}

void sig_handler(int signal) {
    if (signal == SIGUSR1) {
        if (stopped) {
            stopped = 0;
            printf("\nSignal received, opening port.\r\n");
            if (init() < 0) {
                printf("Cannot open port.\r\n");
                close_tty();
                exit(1);
            }
        }
    } else if (signal == SIGUSR2) {
        if (!stopped) {
            stopped = 1;
            printf("\nSignal received, closing port. \r\n");
            pthread_cancel(serial_reader);
            close_serial_port();
        }
    } else if (signal == SIGINT) {
        printf("SIGINT received, exiting...\n");
        pthread_cancel(serial_reader);
        close_serial_port();
        close_tty();
        exit(0);
    }
}

int open_tty(void)
{
	int r, fd;
    struct termios term_setting;

	fd = open("/dev/tty", O_RDWR);
	if (fd < 0) return -1;
	r = tcgetattr(fd, &term_setting);
	if (r != 0) return -2;

    old_term_setting = term_setting;

	term_setting.c_oflag |= ( ONLRET );
	term_setting.c_iflag |= (/*IGNBRK |*/ BRKINT | IGNPAR);
	term_setting.c_iflag &= ~(ISTRIP);
	term_setting.c_lflag &= ~(ICANON |/* ISIG |*/ ECHO);
	term_setting.c_lflag |= ( ISIG );
	term_setting.c_cflag |= CREAD;
	term_setting.c_cc[VMIN] = 1;
	term_setting.c_cc[VTIME] = 1;
	r = tcsetattr(fd, TCSANOW, &term_setting);
	if (r != 0) return -3;
	return fd;
}

void install_sighandler() {
    struct sigaction action;
    sigemptyset (&action.sa_mask);
    sigaddset( &action.sa_mask, SIGINT );
    sigaddset( &action.sa_mask, SIGUSR1 );
    sigaddset( &action.sa_mask, SIGUSR2 );
    action.sa_flags = 0;
    action.sa_handler = sig_handler;
    sigaction(SIGINT, &action, NULL);
    sigaction(SIGUSR1, &action, NULL);
    sigaction(SIGUSR2, &action, NULL);
}

int main(int argc, char** argv) {
    if (argc == 2) {
        port_name = argv[1];
    }

    printf("Using %s as serial device.\n", port_name);

    char ttybuf[255];
    tty_fd = open_tty();
    if (tty_fd < 0) {
        printf("Error opening terminal.\n");
        return(1);
    }

    install_sighandler();

    if (init() < 0) {
        printf("Cannot open port.\r\n");
        exit(1);
    }

    while (1) {
        int n = read(tty_fd, ttybuf, sizeof(ttybuf));
        int i;

        /* check for 0x3 (ctrl-c), clean exit */
        for (i = 0; i < n; i++) {
            if (ttybuf[i] == 0x3) {
                if (i > 0) {
                    write_serial_port(ttybuf, i);
                }
                close_serial_port();
                close_tty();
                system("tset -c");
                return 0;
            }

        }
        write_serial_port(ttybuf,n);
    }

    close_tty();
    close_serial_port();
    return 0;
}