#!/usr/bin/env python3
"""
Run fish-tty-repro.js under a pseudo-TTY and drain output so Node never blocks on write.

Usage (from anywhere):
  python3 packages/bare-os-booter/scripts/run-fish-repro-pty.py

  BARE_OS_REPRO_SKIP_STDERR=1 python3 packages/bare-os-booter/scripts/run-fish-repro-pty.py

  BARE_OS_REPRO_PTY_ASSERT=1 ...  # exit 2 if green prompt not detected (CI guard)

Requires: Unix (pty). Not for Windows CI.
"""
from __future__ import annotations

import os
import pty
import select
import sys
import threading
import time

HERE = os.path.dirname(os.path.abspath(__file__))
BOOTER = os.path.dirname(HERE)


def main() -> int:
    chunks: list[bytes] = []

    def reader(master_fd: int, done: threading.Event) -> None:
        while not done.is_set():
            try:
                r, _, _ = select.select([master_fd], [], [], 0.2)
            except (OSError, ValueError):
                break
            if done.is_set():
                break
            if not r:
                continue
            try:
                data = os.read(master_fd, 65536)
            except OSError:
                break
            if not data:
                break
            chunks.append(data)

    pid, master_fd = pty.fork()
    if pid == 0:
        os.chdir(BOOTER)
        os.execlp("node", "node", os.path.join(HERE, "fish-tty-repro.js"))
        return 0  # unreachable

    done = threading.Event()
    t = threading.Thread(target=reader, args=(master_fd, done))
    t.start()
    time.sleep(0.6)
    os.write(master_fd, b"hello\n")
    time.sleep(0.35)
    os.write(master_fd, b"exit\n")
    # Wait for Node to exit before closing the PTY master (avoids exit code 1 / hang).
    _, status = os.waitpid(pid, 0)

    done.set()
    t.join(timeout=5.0)
    try:
        os.close(master_fd)
    except OSError:
        pass
    raw = b"".join(chunks)
    try:
        sys.stdout.buffer.write(raw)
    except BrokenPipeError:
        pass

    text = raw.decode("utf-8", errors="replace")
    ok_green = "\x1b[32m[user@bare-os" in text or "[user@bare-os" in text

    sys.stderr.write(
        f"\n--- pty harness: exit status {status}, bytes {len(raw)}, "
        f"saw_full_prompt_hint={ok_green} ---\n"
    )
    if os.environ.get("BARE_OS_REPRO_PTY_ASSERT") == "1" and not ok_green:
        sys.stderr.write("BARE_OS_REPRO_PTY_ASSERT: expected green [user@bare-os] prompt\n")
        return 2
    if os.WIFEXITED(status):
        return os.WEXITSTATUS(status)
    return 1


if __name__ == "__main__":
    sys.exit(main())