"""Tests the course modules and their functions"""
import ddt
import unittest
from datetime import datetime, timedelta
from dateutil import parser

import itertools
from fs.memoryfs import MemoryFS
from mock import Mock, patch
from pytz import utc
from xblock.runtime import KvsFieldData, DictKeyValueStore

import xmodule.course_module
from xmodule.modulestore.xml import ImportSystem, XMLModuleStore
from opaque_keys.edx.keys import CourseKey


ORG = 'test_org'
COURSE = 'test_course'

NOW = datetime.strptime('2013-01-01T01:00:00', '%Y-%m-%dT%H:%M:00').replace(tzinfo=utc)

_TODAY = datetime.now(utc)
_LAST_WEEK = _TODAY - timedelta(days=7)
_NEXT_WEEK = _TODAY + timedelta(days=7)


class CourseFieldsTestCase(unittest.TestCase):
    shard = 1

    def test_default_start_date(self):
        self.assertEqual(
            xmodule.course_module.CourseFields.start.default,
            datetime(2030, 1, 1, tzinfo=utc)
        )


class DummySystem(ImportSystem):
    @patch('xmodule.modulestore.xml.OSFS', lambda dir: MemoryFS())
    def __init__(self, load_error_modules):

        xmlstore = XMLModuleStore("data_dir", source_dirs=[],
                                  load_error_modules=load_error_modules)
        course_id = CourseKey.from_string('/'.join([ORG, COURSE, 'test_run']))
        course_dir = "test_dir"
        error_tracker = Mock()

        super(DummySystem, self).__init__(
            xmlstore=xmlstore,
            course_id=course_id,
            course_dir=course_dir,
            error_tracker=error_tracker,
            load_error_modules=load_error_modules,
            field_data=KvsFieldData(DictKeyValueStore()),
        )


def get_dummy_course(start, announcement=None, is_new=None, advertised_start=None, end=None, certs='end'):
    """Get a dummy course"""

    system = DummySystem(load_error_modules=True)

    def to_attrb(n, v):
        return '' if v is None else '{0}="{1}"'.format(n, v).lower()

    is_new = to_attrb('is_new', is_new)
    announcement = to_attrb('announcement', announcement)
    advertised_start = to_attrb('advertised_start', advertised_start)
    end = to_attrb('end', end)

    start_xml = '''
         <course org="{org}" course="{course}" display_organization="{org}_display" display_coursenumber="{course}_display"
                graceperiod="1 day" url_name="test"
                start="{start}"
                {announcement}
                {is_new}
                {advertised_start}
                {end}
                certificates_display_behavior="{certs}">
            <chapter url="hi" url_name="ch" display_name="CH">
                <html url_name="h" display_name="H">Two houses, ...</html>
            </chapter>
         </course>
     '''.format(
        org=ORG,
        course=COURSE,
        start=start,
        is_new=is_new,
        announcement=announcement,
        advertised_start=advertised_start,
        end=end,
        certs=certs,
    )

    return system.process_xml(start_xml)


class HasEndedMayCertifyTestCase(unittest.TestCase):
    """Double check the semantics around when to finalize courses."""
    shard = 1

    def setUp(self):
        super(HasEndedMayCertifyTestCase, self).setUp()

        system = DummySystem(load_error_modules=True)
        #sample_xml = """
        # <course org="{org}" course="{course}" display_organization="{org}_display" display_coursenumber="{course}_display"
        #        graceperiod="1 day" url_name="test"
        #        start="2012-01-01T12:00"
        #        {end}
        #        certificates_show_before_end={cert}>
        #    <chapter url="hi" url_name="ch" display_name="CH">
        #        <html url_name="h" display_name="H">Two houses, ...</html>
        #    </chapter>
        # </course>
        #""".format(org=ORG, course=COURSE)
        past_end = (datetime.now() - timedelta(days=12)).strftime("%Y-%m-%dT%H:%M:00")
        future_end = (datetime.now() + timedelta(days=12)).strftime("%Y-%m-%dT%H:%M:00")
        self.past_show_certs = get_dummy_course("2012-01-01T12:00", end=past_end, certs='early_with_info')
        self.past_show_certs_no_info = get_dummy_course("2012-01-01T12:00", end=past_end, certs='early_no_info')
        self.past_noshow_certs = get_dummy_course("2012-01-01T12:00", end=past_end, certs='end')
        self.future_show_certs = get_dummy_course("2012-01-01T12:00", end=future_end, certs='early_with_info')
        self.future_show_certs_no_info = get_dummy_course("2012-01-01T12:00", end=future_end, certs='early_no_info')
        self.future_noshow_certs = get_dummy_course("2012-01-01T12:00", end=future_end, certs='end')
        #self.past_show_certs = system.process_xml(sample_xml.format(end=past_end, cert=True))
        #self.past_noshow_certs = system.process_xml(sample_xml.format(end=past_end, cert=False))
        #self.future_show_certs = system.process_xml(sample_xml.format(end=future_end, cert=True))
        #self.future_noshow_certs = system.process_xml(sample_xml.format(end=future_end, cert=False))

    def test_has_ended(self):
        """Check that has_ended correctly tells us when a course is over."""
        self.assertTrue(self.past_show_certs.has_ended())
        self.assertTrue(self.past_show_certs_no_info.has_ended())
        self.assertTrue(self.past_noshow_certs.has_ended())
        self.assertFalse(self.future_show_certs.has_ended())
        self.assertFalse(self.future_show_certs_no_info.has_ended())
        self.assertFalse(self.future_noshow_certs.has_ended())

    def test_may_certify(self):
        """Check that may_certify correctly tells us when a course may wrap."""
        self.assertTrue(self.past_show_certs.may_certify())
        self.assertTrue(self.past_noshow_certs.may_certify())
        self.assertTrue(self.past_show_certs_no_info.may_certify())
        self.assertTrue(self.future_show_certs.may_certify())
        self.assertTrue(self.future_show_certs_no_info.may_certify())
        self.assertFalse(self.future_noshow_certs.may_certify())


class CourseSummaryHasEnded(unittest.TestCase):
    """ Test for has_ended method when end date is missing timezone information. """
    shard = 1

    def test_course_end(self):
        test_course = get_dummy_course("2012-01-01T12:00")
        bad_end_date = parser.parse("2012-02-21 10:28:45")
        summary = xmodule.course_module.CourseSummary(test_course.id, end=bad_end_date)
        self.assertTrue(summary.has_ended())


@ddt.ddt
class IsNewCourseTestCase(unittest.TestCase):
    """Make sure the property is_new works on courses"""
    shard = 1

    def setUp(self):
        super(IsNewCourseTestCase, self).setUp()

        # Needed for test_is_newish
        datetime_patcher = patch.object(
            xmodule.course_metadata_utils, 'datetime',
            Mock(wraps=datetime)
        )
        mocked_datetime = datetime_patcher.start()
        mocked_datetime.now.return_value = NOW
        self.addCleanup(datetime_patcher.stop)

    @patch('xmodule.course_metadata_utils.datetime.now')
    def test_sorting_score(self, gmtime_mock):
        gmtime_mock.return_value = NOW

        day1 = '2012-01-01T12:00'
        day2 = '2012-01-02T12:00'

        dates = [
            # Announce date takes priority over actual start
            # and courses announced on a later date are newer
            # than courses announced for an earlier date
            ((day1, day2, None), (day1, day1, None), self.assertLess),
            ((day1, day1, None), (day2, day1, None), self.assertEqual),

            # Announce dates take priority over advertised starts
            ((day1, day2, day1), (day1, day1, day1), self.assertLess),
            ((day1, day1, day2), (day2, day1, day2), self.assertEqual),

            # Later start == newer course
            ((day2, None, None), (day1, None, None), self.assertLess),
            ((day1, None, None), (day1, None, None), self.assertEqual),

            # Non-parseable advertised starts are ignored in preference to actual starts
            ((day2, None, "Spring"), (day1, None, "Fall"), self.assertLess),
            ((day1, None, "Spring"), (day1, None, "Fall"), self.assertEqual),

            # Partially parsable advertised starts should take priority over start dates
            ((day2, None, "October 2013"), (day2, None, "October 2012"), self.assertLess),
            ((day2, None, "October 2013"), (day1, None, "October 2013"), self.assertEqual),

            # Parseable advertised starts take priority over start dates
            ((day1, None, day2), (day1, None, day1), self.assertLess),
            ((day2, None, day2), (day1, None, day2), self.assertEqual),
        ]

        for a, b, assertion in dates:
            a_score = get_dummy_course(start=a[0], announcement=a[1], advertised_start=a[2]).sorting_score
            b_score = get_dummy_course(start=b[0], announcement=b[1], advertised_start=b[2]).sorting_score
            print "Comparing %s to %s" % (a, b)
            assertion(a_score, b_score)

    start_advertised_settings = [
        # start, advertised, result, is_still_default, date_time_result
        ('2012-12-02T12:00', None, 'Dec 02, 2012', False, u'Dec 02, 2012 at 12:00 UTC'),
        ('2012-12-02T12:00', '2011-11-01T12:00', 'Nov 01, 2011', False, u'Nov 01, 2011 at 12:00 UTC'),
        ('2012-12-02T12:00', 'Spring 2012', 'Spring 2012', False, 'Spring 2012'),
        ('2012-12-02T12:00', 'November, 2011', 'November, 2011', False, 'November, 2011'),
        (xmodule.course_module.CourseFields.start.default, None, 'TBD', True, 'TBD'),
        (xmodule.course_module.CourseFields.start.default, 'January 2014', 'January 2014', False, 'January 2014'),
    ]

    def test_start_date_is_default(self):
        for s in self.start_advertised_settings:
            d = get_dummy_course(start=s[0], advertised_start=s[1])
            self.assertEqual(d.start_date_is_still_default, s[3])

    def test_display_organization(self):
        descriptor = get_dummy_course(start='2012-12-02T12:00', is_new=True)
        self.assertNotEqual(descriptor.location.org, descriptor.display_org_with_default)
        self.assertEqual(descriptor.display_org_with_default, "{0}_display".format(ORG))

    def test_display_coursenumber(self):
        descriptor = get_dummy_course(start='2012-12-02T12:00', is_new=True)
        self.assertNotEqual(descriptor.location.course, descriptor.display_number_with_default)
        self.assertEqual(descriptor.display_number_with_default, "{0}_display".format(COURSE))

    def test_is_newish(self):
        descriptor = get_dummy_course(start='2012-12-02T12:00', is_new=True)
        assert descriptor.is_newish is True

        descriptor = get_dummy_course(start='2013-02-02T12:00', is_new=False)
        assert descriptor.is_newish is False

        descriptor = get_dummy_course(start='2013-02-02T12:00', is_new=True)
        assert descriptor.is_newish is True

        descriptor = get_dummy_course(start='2013-01-15T12:00')
        assert descriptor.is_newish is True

        descriptor = get_dummy_course(start='2013-03-01T12:00')
        assert descriptor.is_newish is True

        descriptor = get_dummy_course(start='2012-10-15T12:00')
        assert descriptor.is_newish is False

        descriptor = get_dummy_course(start='2012-12-31T12:00')
        assert descriptor.is_newish is True


class DiscussionTopicsTestCase(unittest.TestCase):
    shard = 1

    def test_default_discussion_topics(self):
        d = get_dummy_course('2012-12-02T12:00')
        self.assertEqual({'General': {'id': 'i4x-test_org-test_course-course-test'}}, d.discussion_topics)


class TeamsConfigurationTestCase(unittest.TestCase):
    """
    Tests for the configuration of teams and the helper methods for accessing them.
    """
    shard = 1

    def setUp(self):
        super(TeamsConfigurationTestCase, self).setUp()
        self.course = get_dummy_course('2012-12-02T12:00')
        self.course.teams_configuration = dict()
        self.count = itertools.count()

    def add_team_configuration(self, max_team_size=3, topics=None):
        """ Add a team configuration to the course. """
        teams_configuration = {}
        teams_configuration["topics"] = [] if topics is None else topics
        if max_team_size is not None:
            teams_configuration["max_team_size"] = max_team_size
        self.course.teams_configuration = teams_configuration

    def make_topic(self):
        """ Make a sample topic dictionary. """
        next_num = self.count.next()
        topic_id = "topic_id_{}".format(next_num)
        name = "Name {}".format(next_num)
        description = "Description {}".format(next_num)
        return {"name": name, "description": description, "id": topic_id}

    def test_teams_enabled_new_course(self):
        # Make sure we can detect when no teams exist.
        self.assertFalse(self.course.teams_enabled)

        # add topics
        self.add_team_configuration(max_team_size=4, topics=[self.make_topic()])
        self.assertTrue(self.course.teams_enabled)

        # remove them again
        self.add_team_configuration(max_team_size=4, topics=[])
        self.assertFalse(self.course.teams_enabled)

    def test_teams_enabled_max_size_only(self):
        self.add_team_configuration(max_team_size=4)
        self.assertFalse(self.course.teams_enabled)

    def test_teams_enabled_no_max_size(self):
        self.add_team_configuration(max_team_size=None, topics=[self.make_topic()])
        self.assertTrue(self.course.teams_enabled)

    def test_teams_max_size_no_teams_configuration(self):
        self.assertIsNone(self.course.teams_max_size)

    def test_teams_max_size_with_teams_configured(self):
        size = 4
        self.add_team_configuration(max_team_size=size, topics=[self.make_topic(), self.make_topic()])
        self.assertTrue(self.course.teams_enabled)
        self.assertEqual(size, self.course.teams_max_size)

    def test_teams_topics_no_teams(self):
        self.assertIsNone(self.course.teams_topics)

    def test_teams_topics_no_topics(self):
        self.add_team_configuration(max_team_size=4)
        self.assertEqual(self.course.teams_topics, [])

    def test_teams_topics_with_topics(self):
        topics = [self.make_topic(), self.make_topic()]
        self.add_team_configuration(max_team_size=4, topics=topics)
        self.assertTrue(self.course.teams_enabled)
        self.assertEqual(self.course.teams_topics, topics)


class SelfPacedTestCase(unittest.TestCase):
    """Tests for self-paced courses."""
    shard = 1

    def setUp(self):
        super(SelfPacedTestCase, self).setUp()
        self.course = get_dummy_course('2012-12-02T12:00')

    def test_default(self):
        self.assertFalse(self.course.self_paced)


class BypassHomeTestCase(unittest.TestCase):
    """Tests for setting which allows course home to be bypassed."""
    shard = 1

    def setUp(self):
        super(BypassHomeTestCase, self).setUp()
        self.course = get_dummy_course('2012-12-02T12:00')

    def test_default(self):
        self.assertFalse(self.course.bypass_home)


class CourseDescriptorTestCase(unittest.TestCase):
    """
    Tests for a select few functions from CourseDescriptor.

    I wrote these test functions in order to satisfy the coverage checker for
    PR #8484, which modified some code within CourseDescriptor. However, this
    class definitely isn't a comprehensive test case for CourseDescriptor, as
    writing a such a test case was out of the scope of the PR.
    """
    shard = 1

    def setUp(self):
        """
        Initialize dummy testing course.
        """
        super(CourseDescriptorTestCase, self).setUp()
        self.course = get_dummy_course(start=_TODAY, end=_NEXT_WEEK)

    def test_clean_id(self):
        """
        Test CourseDescriptor.clean_id.
        """
        self.assertEqual(
            self.course.clean_id(),
            "course_ORSXG5C7N5ZGOL3UMVZXIX3DN52XE43FF52GK43UL5ZHK3Q="
        )
        self.assertEqual(
            self.course.clean_id(padding_char='$'),
            "course_ORSXG5C7N5ZGOL3UMVZXIX3DN52XE43FF52GK43UL5ZHK3Q$"
        )

    def test_has_started(self):
        """
        Test CourseDescriptor.has_started.
        """
        self.course.start = _LAST_WEEK
        self.assertTrue(self.course.has_started())
        self.course.start = _NEXT_WEEK
        self.assertFalse(self.course.has_started())

    def test_number(self):
        """
        Test CourseDescriptor.number.
        """
        self.assertEqual(self.course.number, COURSE)

    def test_set_default_certificate_available_date(self):
        """
        The certificate_available_date field should default to two days
        after the course end date.
        """
        expected_certificate_available_date = self.course.end + timedelta(days=2)
        self.assertEqual(expected_certificate_available_date, self.course.certificate_available_date)
