#define _XOPEN_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <utmp.h>
#include <string.h>
#include <pty.h>
#include <stdlib.h>
#include "vt100_headless.h"
#include "vt100.h"

struct vt100_headless *vt100_headless_init(void)
{
    return malloc(sizeof(struct vt100_headless));
}

static void set_non_canonical(struct vt100_headless *this, int fd)
{
    struct termios termios;

    ioctl(fd, TCGETS, &this->backup);
    ioctl(fd, TCGETS, &termios);
    termios.c_iflag |= ICANON;
    termios.c_cc[VMIN] = 1;
    termios.c_cc[VTIME] = 0;
    ioctl(fd, TCSETS, &termios);
}

static void restore_termios(struct vt100_headless *this, int fd)
{
    ioctl(fd, TCSETS, &this->backup);
}

/* static void debug(struct vt100_headless *this, char *title) */
/* { */
/*     unsigned int argc; */

/*     fprintf(stderr, "%s ", title); */
/*     for (argc = 0; argc < this->term->argc; ++argc) */
/*     { */
/*         fprintf(stderr, "%d", this->term->argv[argc]); */
/*         if (argc != this->term->argc - 1) */
/*             fprintf(stderr, ", "); */
/*     } */
/*     fprintf(stderr, "\n"); */
/* } */

#ifndef NDEBUG
static void strdump(char *str)
{
    while (*str != '\0')
    {
        if (*str >= ' ' && *str <= '~')
            fprintf(stderr, "%c", *str);
        else
            fprintf(stderr, "\\0%o", *str);
        str += 1;
    }
    fprintf(stderr, "\n");
}
#endif

static int main_loop(struct vt100_headless *this)
{
    char buffer[4096];
    fd_set rfds;
    int retval;
    ssize_t read_size;

    while (42)
    {
        FD_ZERO(&rfds);
        FD_SET(this->master, &rfds);
        FD_SET(0, &rfds);
        retval = select(this->master + 1, &rfds, NULL, NULL, NULL);
        if (retval == -1)
        {
            perror("select()");
        }
        if (FD_ISSET(0, &rfds))
        {
            read_size = read(0, &buffer, 4096);
            if (read_size == -1)
            {
                perror("read");
                return EXIT_FAILURE;
            }
            buffer[read_size] = '\0';
            write(this->master, buffer, read_size);
        }
        if (FD_ISSET(this->master, &rfds))
        {
            read_size = read(this->master, &buffer, 4096);
            if (read_size == -1)
            {
                perror("read");
                return EXIT_FAILURE;
            }
            buffer[read_size] = '\0';
#ifndef NDEBUG
            strdump(buffer);
#endif
            terminal_read_str(this->term->terminal, buffer);
            this->changed(this);
        }
    }
}

void vt100_headless_fork(struct vt100_headless *this,
                         const char *progname,
                         char *const argv[])
{
    int child;
    struct winsize winsize;

    set_non_canonical(this, 0);
    winsize.ws_row = 24;
    winsize.ws_col = 24;
    child = forkpty(&this->master, NULL, NULL, NULL);
    if (child == CHILD)
    {
        setsid();
        putenv("TERM=vt100");
        execvp(progname, argv);
        return ;
    }
    else
    {
        this->term = vt100_init(terminal_default_unimplemented);
        ioctl(this->master, TIOCSWINSZ, &winsize);
        this->term->terminal->fd = this->master;
        main_loop(this);
    }
    restore_termios(this, 0);
}