// TODO: set this for entire crate when possible
#![deny(unsafe_op_in_unsafe_fn)]

use crate::{
    header::{fcntl, sys_ioctl, unistd},
    io::{Cursor, Write},
    platform::types::{c_char, c_int, c_void},
};

pub(super) unsafe fn openpty(name: &mut [u8]) -> Result<(c_int, c_int), ()> {
    //TODO: wrap in auto-close struct
    let master = unsafe { fcntl::open(c"/dev/ptmx".as_ptr(), fcntl::O_RDWR | fcntl::O_NOCTTY, 0) };
    if master < 0 {
        return Err(());
    }

    let mut lock: c_int = 0;
    if unsafe {
        sys_ioctl::ioctl(
            master,
            sys_ioctl::TIOCSPTLCK,
            &mut lock as *mut c_int as *mut c_void,
        )
    } != 0
    {
        unistd::close(master);
        return Err(());
    }

    let mut ptn: c_int = 0;
    if unsafe {
        sys_ioctl::ioctl(
            master,
            sys_ioctl::TIOCGPTN,
            &mut ptn as *mut c_int as *mut c_void,
        )
    } != 0
    {
        unistd::close(master);
        return Err(());
    }

    let mut cursor = Cursor::new(name);
    write!(cursor, "/dev/pts/{}\0", ptn);

    let slave = unsafe {
        fcntl::open(
            cursor.get_ref().as_ptr() as *const c_char,
            fcntl::O_RDWR | fcntl::O_NOCTTY,
            0,
        )
    };
    if slave < 0 {
        unistd::close(master);
        return Err(());
    }

    Ok((master, slave))
}