import os
from pathlib import Path
import sys
import tempfile
from datetime import datetime, timedelta, timezone
import unittest


ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT / 'app'))

import worker_assignment_runner as runner
from runtime_security import ensure_private_directory


@unittest.skipUnless(sys.platform.startswith('linux'), 'requires Linux renameat2')
class LinuxWorkerRunnerHandoffTests(unittest.TestCase):
    def create_root(self, temporary, generation):
        work = ensure_private_directory(os.path.join(temporary, 'work'), reject_reparse=True)
        started = datetime.now(timezone.utc)
        assignment = {
            'reservation': {'reservation_id': 17},
            'deadlines': {}, 'compatibility': {}, 'scan_kwargs': {},
            'event_scan_options': {}, 'queue_policy': {}, 'limits': {},
            'scan_policy': {}, 'execution_snapshot': {},
            'execution_snapshot_sha256': 'a' * 64, 'execution_plan': {},
        }
        value = runner.build_runner_input(
            assignment, generation=generation, slot_id=0,
            scan_started_at=started.isoformat(timespec='milliseconds').replace('+00:00', 'Z'),
            scan_deadline_at=(started + timedelta(seconds=60)).isoformat(
                timespec='milliseconds',
            ).replace('+00:00', 'Z'),
        )
        name = runner.runner_root_name(0, 17, generation)
        paths, _digest = runner.create_runner_root(work, name, value)
        return work, name, paths

    def test_timeout_generation_moves_atomically_to_janitor_namespace(self):
        with tempfile.TemporaryDirectory() as temporary:
            work, name, paths = self.create_root(temporary, 'a' * 32)
            reference = runner.transfer_runner_to_janitor(work, name, 'a' * 32)
            self.assertEqual(reference, f'abandoned/{name}')
            self.assertFalse(os.path.exists(paths['root']))
            self.assertTrue(os.path.isdir(os.path.join(work, *reference.split('/'))))

    def test_retry_handoff_is_idempotent_after_durable_move(self):
        with tempfile.TemporaryDirectory() as temporary:
            work, name, _paths = self.create_root(temporary, 'b' * 32)
            first = runner.transfer_runner_to_janitor(work, name, 'b' * 32)
            second = runner.transfer_runner_to_janitor(work, name, 'b' * 32)
            self.assertEqual(first, second)

    def test_existing_destination_never_replaces_another_generation_tree(self):
        with tempfile.TemporaryDirectory() as temporary:
            work, name, paths = self.create_root(temporary, 'c' * 32)
            abandoned = ensure_private_directory(
                os.path.join(work, 'abandoned'), reject_reparse=True,
            )
            os.makedirs(os.path.join(abandoned, name))
            with self.assertRaises(runner.RunnerProtocolError):
                runner.transfer_runner_to_janitor(work, name, 'c' * 32)
            self.assertTrue(os.path.isdir(paths['root']))


if __name__ == '__main__':
    unittest.main()