import contextlib
from datetime import datetime
from io import StringIO
from textwrap import dedent

from django.conf import settings
from django.core.management import CommandError
from django.core.management import call_command
from django.test import TransactionTestCase, override_settings
from django.utils import timezone
from django.utils.encoding import smart_str

from constance.models import Constance
from constance import config


class CliTestCase(TransactionTestCase):
    def setUp(self):
        self.out = StringIO()

    def test_help(self):
        with contextlib.suppress(SystemExit):
            call_command("constance", "--help")

    def test_list(self):
        call_command("constance", "list", stdout=self.out)

        self.assertEqual(
            set(self.out.getvalue().splitlines()),
            set(
                dedent(
                    smart_str(
                        """        BOOL_VALUE\tTrue
        EMAIL_VALUE\ttest@example.com
        INT_VALUE\t1
        LINEBREAK_VALUE\tSpam spam
        DATE_VALUE\t2010-12-24
        TIME_VALUE\t23:59:59
        TIMEDELTA_VALUE\t1 day, 2:03:00
        STRING_VALUE\tHello world
        CHOICE_VALUE\tyes
        DECIMAL_VALUE\t0.1
        DATETIME_VALUE\t2010-08-23 11:29:24
        FLOAT_VALUE\t3.1415926536
        JSON_VALUE\t{'key': 'value', 'key2': 2, 'key3': [1, 2, 3], 'key4': {'key': 'value'}, 'key5': datetime.date(2019, 1, 1), 'key6': None}
        LIST_VALUE\t[1, '1', datetime.date(2019, 1, 1)]
"""  # noqa: E501
                    )
                ).splitlines()
            ),
        )

    def test_get(self):
        call_command("constance", *("get EMAIL_VALUE".split()), stdout=self.out)

        self.assertEqual(self.out.getvalue().strip(), "test@example.com")

    def test_set(self):
        call_command("constance", *("set EMAIL_VALUE blah@example.com".split()), stdout=self.out)

        self.assertEqual(config.EMAIL_VALUE, "blah@example.com")

        call_command("constance", *("set", "DATETIME_VALUE", "2011-09-24", "12:30:25"), stdout=self.out)

        expected = datetime(2011, 9, 24, 12, 30, 25)
        if settings.USE_TZ:
            expected = timezone.make_aware(expected)
        self.assertEqual(config.DATETIME_VALUE, expected)

    def test_get_invalid_name(self):
        self.assertRaisesMessage(
            CommandError,
            "NOT_A_REAL_CONFIG is not defined in settings.CONSTANCE_CONFIG",
            call_command,
            "constance",
            "get",
            "NOT_A_REAL_CONFIG",
        )

    def test_set_invalid_name(self):
        self.assertRaisesMessage(
            CommandError,
            "NOT_A_REAL_CONFIG is not defined in settings.CONSTANCE_CONFIG",
            call_command,
            "constance",
            "set",
            "NOT_A_REAL_CONFIG",
            "foo",
        )

    def test_set_invalid_value(self):
        self.assertRaisesMessage(
            CommandError,
            "Enter a valid email address.",
            call_command,
            "constance",
            "set",
            "EMAIL_VALUE",
            "not a valid email",
        )

    def test_set_invalid_multi_value(self):
        self.assertRaisesMessage(
            CommandError,
            "Enter a list of values.",
            call_command,
            "constance",
            "set",
            "DATETIME_VALUE",
            "2011-09-24 12:30:25",
        )

    def test_delete_stale_records(self):
        self._populate_database_with_default_values()
        initial_count = Constance.objects.count()

        Constance.objects.create(key="STALE_KEY", value=None)
        call_command("constance", "remove_stale_keys", stdout=self.out)

        self.assertEqual(Constance.objects.count(), initial_count, msg=self.out)

    @override_settings(
        CONSTANCE_DATABASE_PREFIX='constance:',
    )
    def test_delete_stale_records_respects_prefix(self):
        self._populate_database_with_default_values()
        initial_count = Constance.objects.count()

        call_command('constance', 'remove_stale_keys', stdout=self.out)

        self.assertEqual(Constance.objects.count(), initial_count, msg=self.out)

    def _populate_database_with_default_values(self):
        """
        Helper function to populate the database with default values defined
        in settings since that's not done automatically at startup
        """
        for key, (value, *_) in settings.CONSTANCE_CONFIG.items():
            Constance.objects.create(key=f'{getattr(settings, "CONSTANCE_DATABASE_PREFIX", "")}{key}', value=value)