"""Exclusive ownership with real competing processes (T11)."""

from __future__ import annotations

import subprocess
import sys
import time
from pathlib import Path

import pytest

from wf_scheduling.ownership import (
    SchedulerOwnership,
    SecondOwnerError,
)


def test_second_owner_rejected_while_held(tmp_path: Path) -> None:
    first = SchedulerOwnership(tmp_path, owner="proc-A").acquire()
    try:
        with pytest.raises(SecondOwnerError):
            SchedulerOwnership(tmp_path, owner="proc-B").acquire()
    finally:
        first.release()
    # After release, a new owner acquires.
    second = SchedulerOwnership(tmp_path, owner="proc-B").acquire()
    second.release()


def test_competing_process_cannot_acquire_while_held(tmp_path: Path) -> None:
    holder = SchedulerOwnership(tmp_path, owner="parent").acquire()
    try:
        script_path = tmp_path / "compete.py"
        script_path.write_text(
            "import sys\n"
            "sys.path.insert(0, '.')\n"
            "from pathlib import Path\n"
            "from wf_scheduling.ownership import SchedulerOwnership, SecondOwnerError\n"
            f"root = Path({str(tmp_path)!r})\n"
            "try:\n"
            "    SchedulerOwnership(root, owner='child').acquire()\n"
            "except SecondOwnerError:\n"
            "    print('second-owner-rejected')\n"
            "    raise SystemExit(0)\n"
            "print('unexpectedly-acquired')\n"
            "raise SystemExit(1)\n",
            encoding="utf-8",
        )
        proc = subprocess.run(
            [sys.executable, str(script_path)],
            capture_output=True,
            text=True,
            timeout=30,
            cwd=Path(__file__).resolve().parents[2],
        )
        assert proc.returncode == 0, proc.stderr
        assert "second-owner-rejected" in proc.stdout
    finally:
        holder.release()


def test_lock_released_on_process_death(tmp_path: Path) -> None:
    script_path = tmp_path / "hold.py"
    script_path.write_text(
        "import sys, time\n"
        "sys.path.insert(0, '.')\n"
        "from pathlib import Path\n"
        "from wf_scheduling.ownership import SchedulerOwnership\n"
        f"root = Path({str(tmp_path)!r})\n"
        "own = SchedulerOwnership(root, owner='dying').acquire()\n"
        "print('acquired', flush=True)\n"
        "time.sleep(30)\n",
        encoding="utf-8",
    )
    proc = subprocess.Popen(
        [sys.executable, str(script_path)],
        cwd=Path(__file__).resolve().parents[2],
        stdout=subprocess.PIPE,
        text=True,
    )
    try:
        assert proc.stdout is not None
        line = proc.stdout.readline()
        assert "acquired" in line
        # Competing acquisition fails while the child lives.
        with pytest.raises(SecondOwnerError):
            SchedulerOwnership(tmp_path, owner="parent").acquire()
    finally:
        proc.kill()
        proc.wait(timeout=30)
    # After process death the OS releases the held lock; allow a beat.
    acquired = None
    for _ in range(50):
        try:
            acquired = SchedulerOwnership(tmp_path, owner="parent").acquire()
            break
        except SecondOwnerError:
            time.sleep(0.1)
    assert acquired is not None
    acquired.release()