"""Forced SSH command: accept only a fixed verb, UUID, revision and image digest."""

import fcntl
import json
import os
from pathlib import Path
import subprocess
import sys

from reconcile import attempt, validate_request


def parse_command(value):
    parts = value.split()
    if len(parts) != 4 or parts[0] != "run":
        raise ValueError("Only the fixed run command is allowed")
    return validate_request({"schema_version": 1, "request_id": parts[1],
                             "revision": parts[2], "image": parts[3]})


def run(root, request):
    state = root / "state/requests"
    state.mkdir(parents=True, mode=0o700, exist_ok=True)
    with (root / "state/agent.lock").open("a") as lock:
        try:
            fcntl.flock(lock, fcntl.LOCK_EX | fcntl.LOCK_NB)
        except BlockingIOError:
            raise ValueError("Another job is active")
        for path in state.glob("*.json"):
            if json.loads(path.read_text()).get("status") == "attempted":
                raise ValueError("Unknown previous outcome requires investigation")
        return attempt(request, state, root / "compose.runtime.yaml", root / "app.env", private_log=True)


def main():
    os.umask(0o077)
    try:
        # Fixed location: the SSH caller cannot override the stack or environment.
        root = Path.home() / "containers/car-tracker"
        request = parse_command(os.environ.get("SSH_ORIGINAL_COMMAND", ""))
        return run(root, request)
    except (OSError, ValueError, KeyError, TypeError, subprocess.SubprocessError):
        print("Run refused or failed before completion. Inspect private host state/logs; do not automatically retry.")
        return 70


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