"""User-authorized SSH polling until the complete handoff transfer succeeds."""
import fcntl
import json
import os
from pathlib import Path
import subprocess
import sys
import time
from datetime import datetime, timezone

ROOT = Path(__file__).resolve().parent
STATE = Path('/opt/neiro/.handoff-monitor')
STATE.mkdir(exist_ok=True)


def report(phase, **details):
    data = {'updated_utc': datetime.now(timezone.utc).isoformat(),
            'pid': os.getpid(), 'phase': phase, **details}
    temporary = STATE / 'status.tmp'
    temporary.write_text(json.dumps(data, ensure_ascii=False, indent=2) + '\n')
    temporary.replace(STATE / 'status.json')
    print(json.dumps(data, ensure_ascii=False), flush=True)


def main():
    with (STATE / 'lock').open('w') as lock:
        try:
            fcntl.flock(lock, fcntl.LOCK_EX | fcntl.LOCK_NB)
        except BlockingIOError:
            print('Monitor already running', flush=True)
            return
        (STATE / 'pid').write_text(str(os.getpid()) + '\n')
        ssh = ['ssh', '-i', str(Path.home() / '.ssh/id_ed25519_snw'),
               '-o', 'IdentitiesOnly=yes', '-o', 'BatchMode=yes',
               '-o', 'ConnectTimeout=8', 'int@10.9.8.230', 'true']
        attempt = 0
        while True:
            attempt += 1
            started = time.monotonic()
            report('checking', attempt=attempt)
            try:
                probe = subprocess.run(ssh, capture_output=True, text=True, timeout=15)
                if probe.returncode == 0:
                    report('transferring', attempt=attempt)
                    transfer = subprocess.run([sys.executable, str(ROOT / 'save_handoff.py')])
                    if transfer.returncode == 0:
                        report('succeeded', destination='int@10.9.8.230:/mnt/c/KNP/cats-dogs')
                        return
                    report('retrying_transfer', exit_code=transfer.returncode)
                else:
                    report('waiting_for_ssh', attempt=attempt, error=probe.stderr.strip())
            except Exception as error:
                report('waiting_for_ssh', attempt=attempt, error=str(error))
            time.sleep(max(1, 30 - (time.monotonic() - started)))


if __name__ == '__main__':
    main()