import pytest

from pandas.util._validators import validate_args_and_kwargs

_fname = "func"


def test_invalid_total_length_max_length_one():
    compat_args = ("foo",)
    kwargs = {"foo": "FOO"}
    args = ("FoO", "BaZ")

    min_fname_arg_count = 0
    max_length = len(compat_args) + min_fname_arg_count
    actual_length = len(kwargs) + len(args) + min_fname_arg_count

    msg = (
        fr"{_fname}\(\) takes at most {max_length} "
        fr"argument \({actual_length} given\)"
    )

    with pytest.raises(TypeError, match=msg):
        validate_args_and_kwargs(_fname, args, kwargs, min_fname_arg_count, compat_args)


def test_invalid_total_length_max_length_multiple():
    compat_args = ("foo", "bar", "baz")
    kwargs = {"foo": "FOO", "bar": "BAR"}
    args = ("FoO", "BaZ")

    min_fname_arg_count = 2
    max_length = len(compat_args) + min_fname_arg_count
    actual_length = len(kwargs) + len(args) + min_fname_arg_count

    msg = (
        fr"{_fname}\(\) takes at most {max_length} "
        fr"arguments \({actual_length} given\)"
    )

    with pytest.raises(TypeError, match=msg):
        validate_args_and_kwargs(_fname, args, kwargs, min_fname_arg_count, compat_args)


@pytest.mark.parametrize("args,kwargs", [((), {"foo": -5, "bar": 2}), ((-5, 2), {})])
def test_missing_args_or_kwargs(args, kwargs):
    bad_arg = "bar"
    min_fname_arg_count = 2

    compat_args = {"foo": -5, bad_arg: 1}

    msg = (
        fr"the '{bad_arg}' parameter is not supported "
        fr"in the pandas implementation of {_fname}\(\)"
    )

    with pytest.raises(ValueError, match=msg):
        validate_args_and_kwargs(_fname, args, kwargs, min_fname_arg_count, compat_args)


def test_duplicate_argument():
    min_fname_arg_count = 2

    compat_args = {"foo": None, "bar": None, "baz": None}
    kwargs = {"foo": None, "bar": None}
    args = (None,)  # duplicate value for "foo"

    msg = fr"{_fname}\(\) got multiple values for keyword argument 'foo'"

    with pytest.raises(TypeError, match=msg):
        validate_args_and_kwargs(_fname, args, kwargs, min_fname_arg_count, compat_args)


def test_validation():
    # No exceptions should be raised.
    compat_args = {"foo": 1, "bar": None, "baz": -2}
    kwargs = {"baz": -2}

    args = (1, None)
    min_fname_arg_count = 2

    validate_args_and_kwargs(_fname, args, kwargs, min_fname_arg_count, compat_args)