"""
Test the func_inspect module.
"""

# Author: Gael Varoquaux <gael dot varoquaux at normalesup dot org>
# Copyright (c) 2009 Gael Varoquaux
# License: BSD Style, 3 clauses.

import functools

from joblib.func_inspect import filter_args, get_func_name, get_func_code
from joblib.func_inspect import _clean_win_chars, format_signature
from joblib.memory import Memory
from joblib.test.common import with_numpy
from joblib.testing import fixture, parametrize, raises
from joblib._compat import PY3_OR_LATER


###############################################################################
# Module-level functions and fixture, for tests
def f(x, y=0):
    pass


def g(x):
    pass


def h(x, y=0, *args, **kwargs):
    pass


def i(x=1):
    pass


def j(x, y, **kwargs):
    pass


def k(*args, **kwargs):
    pass


@fixture(scope='module')
def cached_func(tmpdir_factory):
    # Create a Memory object to test decorated functions.
    # We should be careful not to call the decorated functions, so that
    # cache directories are not created in the temp dir.
    cachedir = tmpdir_factory.mktemp("joblib_test_func_inspect")
    mem = Memory(cachedir.strpath)

    @mem.cache
    def cached_func_inner(x):
        return x

    return cached_func_inner


class Klass(object):

    def f(self, x):
        return x


###############################################################################
# Tests


@parametrize('func,args,filtered_args',
             [(f, [[], (1, )], {'x': 1, 'y': 0}),
              (f, [['x'], (1, )], {'y': 0}),
              (f, [['y'], (0, )], {'x': 0}),
              (f, [['y'], (0, ), {'y': 1}], {'x': 0}),
              (f, [['x', 'y'], (0, )], {}),
              (f, [[], (0,), {'y': 1}], {'x': 0, 'y': 1}),
              (f, [['y'], (), {'x': 2, 'y': 1}], {'x': 2}),
              (g, [[], (), {'x': 1}], {'x': 1}),
              (i, [[], (2, )], {'x': 2})])
def test_filter_args(func, args, filtered_args):
    assert filter_args(func, *args) == filtered_args


def test_filter_args_method():
    obj = Klass()
    assert filter_args(obj.f, [], (1, )) == {'x': 1, 'self': obj}


@parametrize('func,args,filtered_args',
             [(h, [[], (1, )],
               {'x': 1, 'y': 0, '*': [], '**': {}}),
              (h, [[], (1, 2, 3, 4)],
               {'x': 1, 'y': 2, '*': [3, 4], '**': {}}),
              (h, [[], (1, 25), {'ee': 2}],
               {'x': 1, 'y': 25, '*': [], '**': {'ee': 2}}),
              (h, [['*'], (1, 2, 25), {'ee': 2}],
               {'x': 1, 'y': 2, '**': {'ee': 2}})])
def test_filter_varargs(func, args, filtered_args):
    assert filter_args(func, *args) == filtered_args


test_filter_kwargs_extra_params = []
if PY3_OR_LATER:
    m1 = m2 = None
    # The following statements raise SyntaxError in python 2
    # because kwargonly is not supported
    exec("def m1(x, *, y): pass")
    exec("def m2(x, *, y, z=3): pass")
    test_filter_kwargs_extra_params.extend([
        (m1, [[], (1,), {'y': 2}], {'x': 1, 'y': 2}),
        (m2, [[], (1,), {'y': 2}], {'x': 1, 'y': 2, 'z': 3})
    ])


@parametrize('func,args,filtered_args',
             [(k, [[], (1, 2), {'ee': 2}],
               {'*': [1, 2], '**': {'ee': 2}}),
              (k, [[], (3, 4)],
               {'*': [3, 4], '**': {}})] +
             test_filter_kwargs_extra_params)
def test_filter_kwargs(func, args, filtered_args):
    assert filter_args(func, *args) == filtered_args


def test_filter_args_2():
    assert (filter_args(j, [], (1, 2), {'ee': 2}) ==
            {'x': 1, 'y': 2, '**': {'ee': 2}})

    ff = functools.partial(f, 1)
    # filter_args has to special-case partial
    assert filter_args(ff, [], (1, )) == {'*': [1], '**': {}}
    assert filter_args(ff, ['y'], (1, )) == {'*': [1], '**': {}}


@parametrize('func,funcname', [(f, 'f'), (g, 'g'),
                               (cached_func, 'cached_func')])
def test_func_name(func, funcname):
    # Check that we are not confused by decoration
    # here testcase 'cached_func' is the function itself
    assert get_func_name(func)[1] == funcname


def test_func_name_on_inner_func(cached_func):
    # Check that we are not confused by decoration
    # here testcase 'cached_func' is the 'cached_func_inner' function
    # returned by 'cached_func' fixture
    assert get_func_name(cached_func)[1] == 'cached_func_inner'


def test_func_inspect_errors():
    # Check that func_inspect is robust and will work on weird objects
    assert get_func_name('a'.lower)[-1] == 'lower'
    assert get_func_code('a'.lower)[1:] == (None, -1)
    ff = lambda x: x
    assert get_func_name(ff, win_characters=False)[-1] == '<lambda>'
    assert get_func_code(ff)[1] == __file__.replace('.pyc', '.py')
    # Simulate a function defined in __main__
    ff.__module__ = '__main__'
    assert get_func_name(ff, win_characters=False)[-1] == '<lambda>'
    assert get_func_code(ff)[1] == __file__.replace('.pyc', '.py')


if PY3_OR_LATER:
    # Avoid flake8 F821 "undefined name" warning. func_with_kwonly_args and
    # func_with_signature are redefined in the exec statement a few lines below
    def func_with_kwonly_args():
        pass

    def func_with_signature():
        pass

    # exec is needed to define a function with a keyword-only argument and a
    # function with signature while avoiding a SyntaxError on Python 2
    exec("""
def func_with_kwonly_args(a, b, *, kw1='kw1', kw2='kw2'): pass

def func_with_signature(a: int, b: int) -> None: pass
""")

    def test_filter_args_python_3():
        assert (
            filter_args(func_with_kwonly_args, [], (1, 2),
                        {'kw1': 3, 'kw2': 4}) ==
            {'a': 1, 'b': 2, 'kw1': 3, 'kw2': 4})

        # filter_args doesn't care about keyword-only arguments so you
        # can pass 'kw1' into *args without any problem
        with raises(ValueError) as excinfo:
            filter_args(func_with_kwonly_args, [], (1, 2, 3), {'kw2': 2})
        excinfo.match("Keyword-only parameter 'kw1' was passed as positional "
                      "parameter")

        assert (
            filter_args(func_with_kwonly_args, ['b', 'kw2'], (1, 2),
                        {'kw1': 3, 'kw2': 4}) ==
            {'a': 1, 'kw1': 3})

        assert (filter_args(func_with_signature, ['b'], (1, 2)) == {'a': 1})


def test_bound_methods():
    """ Make sure that calling the same method on two different instances
        of the same class does resolv to different signatures.
    """
    a = Klass()
    b = Klass()
    assert filter_args(a.f, [], (1, )) != filter_args(b.f, [], (1, ))


@parametrize('exception,regex,func,args',
             [(ValueError, 'ignore_lst must be a list of parameters to ignore',
               f, ['bar', (None, )]),
              (ValueError, r'Ignore list: argument \'(.*)\' is not defined',
               g, [['bar'], (None, )]),
              (ValueError, 'Wrong number of arguments',
               h, [[]])])
def test_filter_args_error_msg(exception, regex, func, args):
    """ Make sure that filter_args returns decent error messages, for the
        sake of the user.
    """
    with raises(exception) as excinfo:
        filter_args(func, *args)
    excinfo.match(regex)


def test_filter_args_no_kwargs_mutation():
    """None-regression test against 0.12.0 changes.

    https://github.com/joblib/joblib/pull/75

    Make sure filter args doesn't mutate the kwargs dict that gets passed in.
    """
    kwargs = {'x': 0}
    filter_args(g, [], [], kwargs)
    assert kwargs == {'x': 0}


def test_clean_win_chars():
    string = r'C:\foo\bar\main.py'
    mangled_string = _clean_win_chars(string)
    for char in ('\\', ':', '<', '>', '!'):
        assert char not in mangled_string


@parametrize('func,args,kwargs,sgn_expected',
             [(g, [list(range(5))], {}, 'g([0, 1, 2, 3, 4])'),
              (k, [1, 2, (3, 4)], {'y': True}, 'k(1, 2, (3, 4), y=True)')])
def test_format_signature(func, args, kwargs, sgn_expected):
    # Test signature formatting.
    path, sgn_result = format_signature(func, *args, **kwargs)
    assert sgn_result == sgn_expected


def test_format_signature_long_arguments():
    shortening_threshold = 1500
    # shortening gets it down to 700 characters but there is the name
    # of the function in the signature and a few additional things
    # like dots for the ellipsis
    shortening_target = 700 + 10

    arg = 'a' * shortening_threshold
    _, signature = format_signature(h, arg)
    assert len(signature) < shortening_target

    nb_args = 5
    args = [arg for _ in range(nb_args)]
    _, signature = format_signature(h, *args)
    assert len(signature) < shortening_target * nb_args

    kwargs = {str(i): arg for i, arg in enumerate(args)}
    _, signature = format_signature(h, **kwargs)
    assert len(signature) < shortening_target * nb_args

    _, signature = format_signature(h, *args, **kwargs)
    assert len(signature) < shortening_target * 2 * nb_args


@with_numpy
def test_format_signature_numpy():
    """ Test the format signature formatting with numpy.
    """


def test_special_source_encoding():
    from joblib.test.test_func_inspect_special_encoding import big5_f
    func_code, source_file, first_line = get_func_code(big5_f)
    assert first_line == 5
    assert "def big5_f():" in func_code
    assert "test_func_inspect_special_encoding" in source_file


def _get_code():
    from joblib.test.test_func_inspect_special_encoding import big5_f
    return get_func_code(big5_f)[0]


def test_func_code_consistency():
    from joblib.parallel import Parallel, delayed
    codes = Parallel(n_jobs=2)(delayed(_get_code)() for _ in range(5))
    assert len(set(codes)) == 1
