from unittest import TestCase

from inspect import Signature, Parameter, signature

from ...traitlets import HasTraits, Int, Unicode

from ..decorators import signature_has_traits


class TestExpandSignature(TestCase):

    def test_no_init(self):
        @signature_has_traits
        class Foo(HasTraits):
            number1 = Int()
            number2 = Int()
            value = Unicode('Hello')

        parameters = signature(Foo).parameters
        parameter_names = list(parameters)

        self.assertIs(parameters['args'].kind, Parameter.VAR_POSITIONAL)
        self.assertEqual('args', parameter_names[0])

        self.assertIs(parameters['number1'].kind, Parameter.KEYWORD_ONLY)
        self.assertIs(parameters['number2'].kind, Parameter.KEYWORD_ONLY)
        self.assertIs(parameters['value'].kind, Parameter.KEYWORD_ONLY)

        self.assertIs(parameters['kwargs'].kind, Parameter.VAR_KEYWORD)
        self.assertEqual('kwargs', parameter_names[-1])

        f = Foo(number1=32, value='World')
        self.assertEqual(f.number1, 32)
        self.assertEqual(f.number2, 0)
        self.assertEqual(f.value, 'World')

    def test_partial_init(self):
        @signature_has_traits
        class Foo(HasTraits):
            number1 = Int()
            number2 = Int()
            value = Unicode('Hello')

            def __init__(self, arg1, **kwargs):
                self.arg1 = arg1

                super(Foo, self).__init__(**kwargs)

        parameters = signature(Foo).parameters
        parameter_names = list(parameters)

        self.assertIs(parameters['arg1'].kind, Parameter.POSITIONAL_OR_KEYWORD)
        self.assertEqual('arg1', parameter_names[0])

        self.assertIs(parameters['number1'].kind, Parameter.KEYWORD_ONLY)
        self.assertIs(parameters['number2'].kind, Parameter.KEYWORD_ONLY)
        self.assertIs(parameters['value'].kind, Parameter.KEYWORD_ONLY)

        self.assertIs(parameters['kwargs'].kind, Parameter.VAR_KEYWORD)
        self.assertEqual('kwargs', parameter_names[-1])

        f = Foo(1, number1=32, value='World')
        self.assertEqual(f.arg1, 1)
        self.assertEqual(f.number1, 32)
        self.assertEqual(f.number2, 0)
        self.assertEqual(f.value, 'World')

    def test_duplicate_init(self):
        @signature_has_traits
        class Foo(HasTraits):
            number1 = Int()
            number2 = Int()

            def __init__(self, number1, **kwargs):
                self.test = number1

                super(Foo, self).__init__(number1=number1, **kwargs)

        parameters = signature(Foo).parameters
        parameter_names = list(parameters)

        self.assertListEqual(parameter_names, ['number1', 'number2', 'kwargs'])

        f = Foo(number1=32, number2=36)
        self.assertEqual(f.test, 32)
        self.assertEqual(f.number1, 32)
        self.assertEqual(f.number2, 36)

    def test_full_init(self):
        @signature_has_traits
        class Foo(HasTraits):
            number1 = Int()
            number2 = Int()
            value = Unicode('Hello')

            def __init__(self, arg1, arg2=None, *pos_args, **kw_args):
                self.arg1 = arg1
                self.arg2 = arg2
                self.pos_args = pos_args
                self.kw_args = kw_args

                super(Foo, self).__init__(*pos_args, **kw_args)

        parameters = signature(Foo).parameters
        parameter_names = list(parameters)

        self.assertIs(parameters['arg1'].kind, Parameter.POSITIONAL_OR_KEYWORD)
        self.assertEqual('arg1', parameter_names[0])

        self.assertIs(parameters['arg2'].kind, Parameter.POSITIONAL_OR_KEYWORD)
        self.assertEqual('arg2', parameter_names[1])

        self.assertIs(parameters['pos_args'].kind, Parameter.VAR_POSITIONAL)
        self.assertEqual('pos_args', parameter_names[2])

        self.assertIs(parameters['number1'].kind, Parameter.KEYWORD_ONLY)
        self.assertIs(parameters['number2'].kind, Parameter.KEYWORD_ONLY)
        self.assertIs(parameters['value'].kind, Parameter.KEYWORD_ONLY)

        self.assertIs(parameters['kw_args'].kind, Parameter.VAR_KEYWORD)
        self.assertEqual('kw_args', parameter_names[-1])

        f = Foo(1, 3, 45, 'hey', number1=32, value='World')
        self.assertEqual(f.arg1, 1)
        self.assertEqual(f.arg2, 3)
        self.assertTupleEqual(f.pos_args, (45, 'hey'))
        self.assertEqual(f.number1, 32)
        self.assertEqual(f.number2, 0)
        self.assertEqual(f.value, 'World')

    def test_no_kwargs(self):
        with self.assertRaises(RuntimeError):
            @signature_has_traits
            class Foo(HasTraits):
                number1 = Int()
                number2 = Int()

                def __init__(self, arg1, arg2=None):
                    pass