#!/usr/bin/env python3
"""Minimal cross-platform pty driver for the admin-init CLI tests.

Forks a child on a real pseudo-terminal so the CLI sees a TTY and runs its
raw-mode password prompts. Forwards a prepared input file to the child's stdin
and copies child output to stdout. Writes the child's exit code to a file so
the Node test can read it deterministically.

Used instead of `expect` (not installed on CI) or BSD `script` (injects a stray
EOT byte when stdin is a regular file, corrupting the first prompt value).
"""
import os
import pty
import select
import sys

argv = sys.argv[1:]
exit_file = os.environ.get("PTY_EXIT_FILE", "")
stdin_file = os.environ.get("PTY_STDIN_FILE", "")

pid, master = pty.fork()
if pid == 0:
    # Child: replace with the target command. argv[0] is an absolute node path.
    os.execvp(argv[0], argv)
    os._exit(127)

in_fd = os.open(stdin_file, os.O_RDONLY) if stdin_file else -1
open_stdin = in_fd >= 0
try:
    while True:
        fds = [master]
        if open_stdin:
            fds.append(in_fd)
        try:
            readable, _, _ = select.select(fds, [], [], 30.0)
        except (OSError, ValueError):
            break
        if not readable:
            break
        if master in readable:
            try:
                data = os.read(master, 4096)
            except OSError:
                break
            if not data:
                break
            os.write(1, data)
        if open_stdin and in_fd in readable:
            data = os.read(in_fd, 4096)
            if data:
                os.write(master, data)
            else:
                open_stdin = False
                os.close(in_fd)
finally:
    try:
        _, status = os.waitpid(pid, 0)
    except ChildProcessError:
        status = 0
    code = os.waitstatus_to_exitcode(status) if hasattr(os, "waitstatus_to_exitcode") else (status >> 8)
    if exit_file:
        try:
            with open(exit_file, "w") as handle:
                handle.write(str(code))
        except OSError:
            pass