#!/usr/bin/env python3
"""Recover interrupted Python profile mutation safely after process/reboot restart."""

from __future__ import annotations

import argparse
import importlib.util
import json
from pathlib import Path


HERE = Path(__file__).resolve().parent


def load_module(name: str, filename: str):
    spec = importlib.util.spec_from_file_location(name, HERE / filename)
    module = importlib.util.module_from_spec(spec)
    assert spec.loader
    spec.loader.exec_module(module)
    return module


installer = load_module("boot_profile_installer", "install-python-profile.py")
journal_api = load_module("boot_profile_journal", "atomic-profile-journal.py")


def recover(journal: Path, checkpoint: Path, target: Path) -> dict:
    current = journal_api.read_verified(journal)
    if current is None:
        return {"action": "none", "reason": "journal_absent"}
    state = current["state"]
    if state in {"installing", "rollback_required"}:
        result = installer.recover(journal, checkpoint, target)
        return {"action": "rollback_recovered", **result}
    if state in {"installed", "rolled_back"}:
        return {"action": "none", "reason": f"terminal_{state}"}
    if state in {"profile_selected", "checkpoint_ready"}:
        return {"action": "none", "reason": f"non_mutating_{state}"}
    raise ValueError(f"UNKNOWN_JOURNAL_STATE:{state}")


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument("--journal", type=Path, required=True)
    parser.add_argument("--checkpoint", type=Path, required=True)
    parser.add_argument("--target", type=Path, required=True)
    args = parser.parse_args()
    try:
        result = recover(args.journal, args.checkpoint, args.target)
    except Exception as error:
        print(json.dumps({"recovered": False, "code": str(error)}, sort_keys=True))
        return 1
    print(json.dumps(result, sort_keys=True))
    return 0


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