from __future__ import annotations

import importlib.util
import os
import sys
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import MagicMock, patch

from django.test import SimpleTestCase


CELERY_MODULE_PATH = (
    Path(__file__).resolve().parents[3] / "src" / "core" / "celery.py"
)


def _load_module(module_name: str):
    spec = importlib.util.spec_from_file_location(module_name, CELERY_MODULE_PATH)
    module = importlib.util.module_from_spec(spec)
    assert spec.loader is not None
    spec.loader.exec_module(module)
    return module


class CeleryModuleTest(SimpleTestCase):
    def test_import_requires_django_settings_module(self):
        with patch.dict(os.environ, {}, clear=True):
            with self.assertRaisesMessage(
                RuntimeError,
                "DJANGO_SETTINGS_MODULE is not set.",
            ):
                _load_module("isolated_core_celery_missing")

    def test_import_runs_startup_checks_for_worker_runtime(self):
        app_mock = MagicMock()
        app_mock.conf = SimpleNamespace()

        with patch.dict(os.environ, {"DJANGO_SETTINGS_MODULE": "settings.test"}, clear=True):
            with patch.object(sys, "argv", ["celery", "-A", "project", "worker"]):
                with patch("apps.core.startup_checks.run_startup_checks") as checks_mock:
                    with patch("celery.Celery", return_value=app_mock):
                        module = _load_module("isolated_core_celery_worker")

        checks_mock.assert_called_once_with(component="celery")
        app_mock.config_from_object.assert_called_once_with(
            "django.conf:settings",
            namespace="CELERY",
        )
        app_mock.autodiscover_tasks.assert_called_once_with()
        self.assertEqual(module.app, app_mock)

    def test_debug_task_prints_request(self):
        with patch.dict(os.environ, {"DJANGO_SETTINGS_MODULE": "settings.test"}, clear=True):
            with patch.object(sys, "argv", ["python", "manage.py", "shell"]):
                module = _load_module("isolated_core_celery_debug")

        with patch("builtins.print") as print_mock:
            module.debug_task.run()

        print_mock.assert_called_once()