from datetime import timedelta

from tests import RQTestCase
from tests.fixtures import div_by_zero, erroneous_callback, save_exception, save_result, say_hello

from rq import Queue, Worker
from rq.job import Job, JobStatus, UNEVALUATED
from rq.worker import SimpleWorker


class QueueCallbackTestCase(RQTestCase):

    def test_enqueue_with_success_callback(self):
        """Test enqueue* methods with on_success"""
        queue = Queue(connection=self.testconn)

        # Only functions and builtins are supported as callback
        with self.assertRaises(ValueError):
            queue.enqueue(say_hello, on_success=Job.fetch)

        job = queue.enqueue(say_hello, on_success=print)

        job = Job.fetch(id=job.id, connection=self.testconn)
        self.assertEqual(job.success_callback, print)

        job = queue.enqueue_in(timedelta(seconds=10), say_hello, on_success=print)

        job = Job.fetch(id=job.id, connection=self.testconn)
        self.assertEqual(job.success_callback, print)

    def test_enqueue_with_failure_callback(self):
        """queue.enqueue* methods with on_failure is persisted correctly"""
        queue = Queue(connection=self.testconn)

        # Only functions and builtins are supported as callback
        with self.assertRaises(ValueError):
            queue.enqueue(say_hello, on_failure=Job.fetch)

        job = queue.enqueue(say_hello, on_failure=print)

        job = Job.fetch(id=job.id, connection=self.testconn)
        self.assertEqual(job.failure_callback, print)

        job = queue.enqueue_in(timedelta(seconds=10), say_hello, on_failure=print)

        job = Job.fetch(id=job.id, connection=self.testconn)
        self.assertEqual(job.failure_callback, print)


class WorkerCallbackTestCase(RQTestCase):
    def test_success_callback(self):
        """Test success callback is executed only when job is successful"""
        queue = Queue(connection=self.testconn)
        worker = SimpleWorker([queue])

        job = queue.enqueue(say_hello, on_success=save_result)

        # Callback is executed when job is successfully executed
        worker.work(burst=True)
        self.assertEqual(job.get_status(), JobStatus.FINISHED)
        self.assertEqual(
            self.testconn.get('success_callback:%s' % job.id).decode(),
            job.result
        )

        job = queue.enqueue(div_by_zero, on_success=save_result)
        worker.work(burst=True)
        self.assertEqual(job.get_status(), JobStatus.FAILED)
        self.assertFalse(self.testconn.exists('success_callback:%s' % job.id))

    def test_erroneous_success_callback(self):
        """Test exception handling when executing success callback"""
        queue = Queue(connection=self.testconn)
        worker = Worker([queue])

        # If success_callback raises an error, job will is considered as failed
        job = queue.enqueue(say_hello, on_success=erroneous_callback)
        worker.work(burst=True)
        self.assertEqual(job.get_status(), JobStatus.FAILED)

    def test_failure_callback(self):
        """Test failure callback is executed only when job a fails"""
        queue = Queue(connection=self.testconn)
        worker = SimpleWorker([queue])

        job = queue.enqueue(div_by_zero, on_failure=save_exception)

        # Callback is executed when job is successfully executed
        worker.work(burst=True)
        self.assertEqual(job.get_status(), JobStatus.FAILED)
        job.refresh()
        print(job.exc_info)
        self.assertIn('div_by_zero',
                      self.testconn.get('failure_callback:%s' % job.id).decode())

        job = queue.enqueue(div_by_zero, on_success=save_result)
        worker.work(burst=True)
        self.assertEqual(job.get_status(), JobStatus.FAILED)
        self.assertFalse(self.testconn.exists('failure_callback:%s' % job.id))

        # TODO: add test case for error while executing failure callback


class JobCallbackTestCase(RQTestCase):

    def test_job_creation_with_success_callback(self):
        """Ensure callbacks are created and persisted properly"""
        job = Job.create(say_hello)
        self.assertIsNone(job._success_callback_name)
        # _success_callback starts with UNEVALUATED
        self.assertEqual(job._success_callback, UNEVALUATED)
        self.assertEqual(job.success_callback, None)
        # _success_callback becomes `None` after `job.success_callback` is called if there's no success callback
        self.assertEqual(job._success_callback, None)

        # job.success_callback is assigned properly
        job = Job.create(say_hello, on_success=print)
        self.assertIsNotNone(job._success_callback_name)
        self.assertEqual(job.success_callback, print)
        job.save()

        job = Job.fetch(id=job.id, connection=self.testconn)
        self.assertEqual(job.success_callback, print)

    def test_job_creation_with_failure_callback(self):
        """Ensure failure callbacks are persisted properly"""
        job = Job.create(say_hello)
        self.assertIsNone(job._failure_callback_name)
        # _failure_callback starts with UNEVALUATED
        self.assertEqual(job._failure_callback, UNEVALUATED)
        self.assertEqual(job.failure_callback, None)
        # _failure_callback becomes `None` after `job.failure_callback` is called if there's no failure callback
        self.assertEqual(job._failure_callback, None)

        # job.failure_callback is assigned properly
        job = Job.create(say_hello, on_failure=print)
        self.assertIsNotNone(job._failure_callback_name)
        self.assertEqual(job.failure_callback, print)
        job.save()

        job = Job.fetch(id=job.id, connection=self.testconn)
        self.assertEqual(job.failure_callback, print)