#!/usr/bin/env python
"""Mutation check for the reviewer-R2 fixes: each mutant reverts ONE fix in a private copy of the tree and
tests/test_p2_r2_review.py must go red.

    .venv/bin/python scripts/p2/mutation_check_r2.py

Same method as scripts/p2/mutation_check_integration.py (scratch tree under .tmp; the working tree is never
modified). Exit status 1 if any mutant survives or any mutation does not apply exactly once.
"""

from __future__ import annotations

import json
import os
import shutil
import subprocess
import sys
import tempfile
from pathlib import Path

REPO = Path(__file__).resolve().parents[2]

MUTANTS = [
    # (id, file, old, new, test selector)
    ("D1 guard: borrowed lock not tied to the holder", "align/utils/guard.py",
     "            _die_with_parent(int(parent_pid))\n", "", "borrowed"),
    ("D2 guard: pdeathsig failure ignored", "align/utils/guard.py",
     "    if rc != 0:\n        raise PreflightRefused(\n            f\"inherit_heavy_job_lock: prctl", "    if False:\n        raise PreflightRefused(\n            f\"inherit_heavy_job_lock: prctl", "pdeathsig_failure"),
    ("D3 guard: parent death before prctl ignored", "align/utils/guard.py",
     "    if os.getppid() != parent_pid:\n        raise PreflightRefused(f\"inherit_heavy_job_lock: parent", "    if False:\n        raise PreflightRefused(f\"inherit_heavy_job_lock: parent", "parent_that_died"),
    ("S1 supervisor: stop signal before child recorded ignored", "scripts/p2/launch_baseline.py",
     "            if self.stop:\n                # A stop signal that landed between", "            if False:\n                # A stop signal that landed between", "stop_signal"),
    ("S2 supervisor: zombie leader counted as alive", "scripts/p2/launch_baseline.py",
     "if int(rest[2]) == pgid and rest[0] != \"Z\":", "if int(rest[2]) == pgid:", "zombie"),
    ("S3 supervisor: group liveness ignores non-leader members", "scripts/p2/launch_baseline.py",
     "if int(rest[2]) == pgid and rest[0] != \"Z\":", "if int(entry) == pgid and rest[0] != \"Z\":", "live_member"),
    ("R1 lean_gen: model_rev not compared on resume", "extras/vllm_rollout/lean_gen.py",
     "if r.get(\"model_rev\") != model_rev:", "if False:", "another_models_output"),
    ("R2 lean_gen: seed not compared on resume", "extras/vllm_rollout/lean_gen.py",
     "elif r.get(\"sampling\", {}).get(\"seed\") != want:", "elif False:", "base_seed"),
    ("R3 lean_gen: sampling params not compared on resume", "extras/vllm_rollout/lean_gen.py",
     "elif r.get(\"sampling\", {}).get(\"temperature\") != temperature or r.get(\"sampling\", {}).get(\"top_p\") != top_p:", "elif False:", "sampling_parameters"),
    ("R4 lean_gen: conflict count truncated", "extras/vllm_rollout/lean_gen.py",
     "    if n_bad > len(bad):", "    if False:", "bounded"),
    ("R5 lean_gen: prompt module change ignored", "extras/vllm_rollout/lean_gen.py",
     "if s.get(\"lean_prompts_sha256\") != prompts_sha256})", "if False})", "prompt_module_edited"),
    ("R6 lean_gen: resume check not wired into main", "extras/vllm_rollout/lean_gen.py",
     "    conflicts = resume_conflicts(a.out, rev, a.seed)\n", "    conflicts = []\n", "main_refuses"),
    ("P1 sft.py: repo root not put on sys.path", "scripts/sft.py",
     "sys.path.insert(0, str(Path(__file__).resolve().parent.parent))\n", "", "sft_script"),
    ("H1 shm sweep: segments a live process holds are removed", "scripts/p2/launch_baseline.py",
     "or path in held:", "or False:", "sweep_removes"),
    ("H2 shm sweep: no time bound (other jobs' old segments removed)", "scripts/p2/launch_baseline.py",
     "or st.st_mtime < since", "or False", "sweep_removes"),
    ("H3 shm sweep: any file name removed", "scripts/p2/launch_baseline.py",
     "if not re.fullmatch(SHM_NAME_RE, name):", "if False:", "sweep_removes"),
    ("H4 shm sweep: not run after the child exits", "scripts/p2/launch_baseline.py",
     "        gone, nbytes = sweep_orphan_shm(started_at)\n", "        gone, nbytes = [], 0\n", "run_child_sweeps"),
    ("T1 conftest: a held heavy-job lock is not seen by gpu tests", "tests/conftest.py",
     "            return None if f\"pid={os.getpid()}\" in label.split() else (label or \"unknown holder\")", "            return None", "gpu_test_guard"),
    ("T2 conftest: own lock blocks own tests", "tests/conftest.py",
     "None if f\"pid={os.getpid()}\" in label.split() else (label or \"unknown holder\")", "(label or \"unknown holder\")", "gpu_test_guard"),
]


def main() -> int:
    (REPO / ".tmp").mkdir(exist_ok=True)
    work = Path(tempfile.mkdtemp(dir=REPO / ".tmp", prefix="mutr2_"))
    results = []
    try:
        for mid, rel, old, new, sel in MUTANTS:
            tree = work / mid.split()[0]
            shutil.copytree(REPO, tree, ignore=shutil.ignore_patterns(".tmp", ".venv", ".venv-rollout", ".cache", "__pycache__", ".git", "hf_cache"), dirs_exist_ok=True)
            src = (tree / rel).read_text()
            if src.count(old) != 1:
                results.append({"mutant": mid, "status": "BAD_MUTANT", "count": src.count(old)})
                print(results[-1], flush=True)
                continue
            (tree / rel).write_text(src.replace(old, new))
            env = dict(os.environ, PYTHONPATH=str(tree))
            r = subprocess.run([str(REPO / ".venv/bin/python"), "-m", "pytest", "tests/test_p2_r2_review.py", "-q", "-x", "-k", sel,
                                "-p", "no:cacheprovider"], cwd=tree, capture_output=True, text=True, env=env, timeout=600)
            results.append({"mutant": mid, "status": "killed" if r.returncode == 1 else ("SURVIVED" if r.returncode == 0 else f"BAD_SELECTOR_rc{r.returncode}"), "tail": r.stdout.strip().splitlines()[-1:]})
            print(results[-1], flush=True)
            shutil.rmtree(tree, ignore_errors=True)
    finally:
        shutil.rmtree(work, ignore_errors=True)
    bad = [r for r in results if r["status"] != "killed"]
    print(json.dumps({"mutants": len(results), "killed": len(results) - len(bad), "not_killed": bad}, indent=1))
    return 1 if bad else 0


if __name__ == "__main__":
    raise SystemExit(main())