from __future__ import annotations

import importlib.util
import os
import sys
from pathlib import Path
from types import ModuleType, 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), 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
        ), patch.object(sys, "argv", ["celery", "-A", "project", "worker"]), patch(
            "apps.core.startup_checks.run_startup_checks"
        ) as checks_mock, 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)
        self.assertIn("parse-industrial-production-daily", module.app.conf.beat_schedule)
        self.assertIn("parse-manufactures-daily", module.app.conf.beat_schedule)
        self.assertIn("parse-industrial-products-daily", module.app.conf.beat_schedule)
        self.assertIn("parse-inspections-weekly", module.app.conf.beat_schedule)

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

        fake_tasks_module = ModuleType("apps.parsers.tasks")
        apply_async_mock = MagicMock(return_value=SimpleNamespace(id="task-123"))
        fake_tasks_module.parse_all_sources = SimpleNamespace(
            apply_async=apply_async_mock
        )

        with patch.object(module, "settings", SimpleNamespace(
            CELERY_STARTUP_REFRESH_ENABLED=True,
            CELERY_STARTUP_REFRESH_LOCK_KEY="startup-lock",
            CELERY_STARTUP_REFRESH_LOCK_TTL_SECONDS=120,
            CELERY_STARTUP_REFRESH_DELAY_SECONDS=45,
        )), patch.object(module.cache, "add", return_value=True) as add_mock, patch.dict(
            sys.modules, {"apps.parsers.tasks": fake_tasks_module}
        ):
            module._queue_startup_sources_refresh()

        add_mock.assert_called_once_with("startup-lock", "1", timeout=120)
        apply_async_mock.assert_called_once_with(countdown=45)

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

        fake_tasks_module = ModuleType("apps.parsers.tasks")
        apply_async_mock = MagicMock()
        fake_tasks_module.parse_all_sources = SimpleNamespace(
            apply_async=apply_async_mock
        )

        with patch.object(module, "settings", SimpleNamespace(
            CELERY_STARTUP_REFRESH_ENABLED=True,
            CELERY_STARTUP_REFRESH_LOCK_KEY="startup-lock",
            CELERY_STARTUP_REFRESH_LOCK_TTL_SECONDS=120,
            CELERY_STARTUP_REFRESH_DELAY_SECONDS=45,
        )), patch.object(module.cache, "add", return_value=False), patch.dict(
            sys.modules, {"apps.parsers.tasks": fake_tasks_module}
        ):
            module._queue_startup_sources_refresh()

        apply_async_mock.assert_not_called()

    def test_debug_task_prints_request(self):
        with patch.dict(
            os.environ, {"DJANGO_SETTINGS_MODULE": "settings.test"}, clear=True
        ), 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()