import decimal

from django.core.exceptions import ValidationError
from django.forms import TypedChoiceField
from django.test import SimpleTestCase


class TypedChoiceFieldTest(SimpleTestCase):
    def test_typedchoicefield_1(self):
        f = TypedChoiceField(choices=[(1, "+1"), (-1, "-1")], coerce=int)
        self.assertEqual(1, f.clean("1"))
        msg = "'Select a valid choice. 2 is not one of the available choices.'"
        with self.assertRaisesMessage(ValidationError, msg):
            f.clean("2")

    def test_typedchoicefield_2(self):
        # Different coercion, same validation.
        f = TypedChoiceField(choices=[(1, "+1"), (-1, "-1")], coerce=float)
        self.assertEqual(1.0, f.clean("1"))

    def test_typedchoicefield_3(self):
        # This can also cause weirdness: be careful (bool(-1) == True,
        # remember)
        f = TypedChoiceField(choices=[(1, "+1"), (-1, "-1")], coerce=bool)
        self.assertTrue(f.clean("-1"))

    def test_typedchoicefield_4(self):
        # Even more weirdness: if you have a valid choice but your coercion
        # function can't coerce, you'll still get a validation error. Don't do
        # this!
        f = TypedChoiceField(choices=[("A", "A"), ("B", "B")], coerce=int)
        msg = "'Select a valid choice. B is not one of the available choices.'"
        with self.assertRaisesMessage(ValidationError, msg):
            f.clean("B")
        # Required fields require values
        with self.assertRaisesMessage(ValidationError, "'This field is required.'"):
            f.clean("")

    def test_typedchoicefield_5(self):
        # Non-required fields aren't required
        f = TypedChoiceField(
            choices=[(1, "+1"), (-1, "-1")], coerce=int, required=False
        )
        self.assertEqual("", f.clean(""))
        # If you want cleaning an empty value to return a different type, tell
        # the field

    def test_typedchoicefield_6(self):
        f = TypedChoiceField(
            choices=[(1, "+1"), (-1, "-1")],
            coerce=int,
            required=False,
            empty_value=None,
        )
        self.assertIsNone(f.clean(""))

    def test_typedchoicefield_has_changed(self):
        # has_changed should not trigger required validation
        f = TypedChoiceField(choices=[(1, "+1"), (-1, "-1")], coerce=int, required=True)
        self.assertFalse(f.has_changed(None, ""))
        self.assertFalse(f.has_changed(1, "1"))
        self.assertFalse(f.has_changed("1", "1"))

        f = TypedChoiceField(
            choices=[("", "---------"), ("a", "a"), ("b", "b")],
            coerce=str,
            required=False,
            initial=None,
            empty_value=None,
        )
        self.assertFalse(f.has_changed(None, ""))
        self.assertTrue(f.has_changed("", "a"))
        self.assertFalse(f.has_changed("a", "a"))

    def test_typedchoicefield_special_coerce(self):
        """
        A coerce function which results in a value not present in choices
        should raise an appropriate error (#21397).
        """

        def coerce_func(val):
            return decimal.Decimal("1.%s" % val)

        f = TypedChoiceField(
            choices=[(1, "1"), (2, "2")], coerce=coerce_func, required=True
        )
        self.assertEqual(decimal.Decimal("1.2"), f.clean("2"))
        with self.assertRaisesMessage(ValidationError, "'This field is required.'"):
            f.clean("")
        msg = "'Select a valid choice. 3 is not one of the available choices.'"
        with self.assertRaisesMessage(ValidationError, msg):
            f.clean("3")
