#include <pwd.h>
#ifdef __APPLE__
#include <util.h>
#include <sys/ioctl.h>
#else
#include <pty.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

// compile with gcc term.c -lutil
int main(int argc, char **argv) {
    if (argc < 2) {
        printf("usage: %s ROM [LOGIN]\n", argv[0]);
        return 1;
    }
    char *rom = argv[1]; // find term.rom
    int login = argc > 2; // any extra arg signals login shell

    // detect the user's shell
    char *shell = getenv("SHELL");
    if (shell == NULL) {
        struct passwd *passwd = getpwuid(getuid());
        if (passwd != NULL) {
            shell = passwd->pw_shell;
        }
    }
    if (shell == NULL) {
        shell = "/bin/sh";
    }

    // allocate a pty, fork, inititialize file descriptor
    int fdm = -1; // allocate file descriptor
    pid_t pid = forkpty(&fdm, NULL, NULL, NULL);

    if (pid < 0) { // failure
        perror("fork failed");
        return 1;
    } else if (pid == 0) { // child
        setenv("TERM", "ansi", 1);
        // execute shell
        if (login) {
            execlp(shell, shell, "-l", "-i", NULL);
        } else {
            execlp(shell, shell, NULL);
        }
        perror("exec bash failed");
    } else { // parent
        struct winsize ws = {23, 80, 8, 12}; // rows, cols, xps, ypx
        ioctl(fdm, TIOCSWINSZ, &ws); // set term window size
        dup2(fdm, 0); // use fdm for stdin
        dup2(fdm, 1); // use fdm for stdout
        execlp("uxnemu", "uxnemu", rom, NULL); // exec uxnemu
        perror("exec uxnemu failed");
    }
}