"""
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 nose
import tempfile
import functools

from ..func_inspect import filter_args, get_func_name, get_func_code, \
        _clean_win_chars
from ..memory import Memory


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


def f2(x):
    pass


# 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.
mem = Memory(cachedir=tempfile.gettempdir())


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


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


def i(x=1):
    pass


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


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


class Klass(object):

    def f(self, x):
        return x


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

def test_filter_args():
    yield nose.tools.assert_equal, filter_args(f, [], (1, )),\
                                              {'x': 1, 'y': 0}
    yield nose.tools.assert_equal, filter_args(f, ['x'], (1, )),\
                                              {'y': 0}
    yield nose.tools.assert_equal, filter_args(f, ['y'], (0, )),\
                                               {'x': 0}
    yield nose.tools.assert_equal, filter_args(f, ['y'], (0, ),
                                               dict(y=1)), {'x': 0}
    yield nose.tools.assert_equal, filter_args(f, ['x', 'y'],
                                               (0, )), {}
    yield nose.tools.assert_equal, filter_args(f, [], (0,),
                                               dict(y=1)), {'x': 0, 'y': 1}
    yield nose.tools.assert_equal, filter_args(f, ['y'], (),
                                               dict(x=2, y=1)), {'x': 2}

    yield nose.tools.assert_equal, filter_args(i, [], (2, )), {'x': 2}
    yield nose.tools.assert_equal, filter_args(f2, [], (),
                                               dict(x=1)), {'x': 1}


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


def test_filter_varargs():
    yield nose.tools.assert_equal, filter_args(h, [], (1, )), \
                            {'x': 1, 'y': 0, '*': [], '**': {}}
    yield nose.tools.assert_equal, filter_args(h, [], (1, 2, 3, 4)), \
                            {'x': 1, 'y': 2, '*': [3, 4], '**': {}}
    yield nose.tools.assert_equal, filter_args(h, [], (1, 25),
                                               dict(ee=2)), \
                            {'x': 1, 'y': 25, '*': [], '**': {'ee': 2}}
    yield nose.tools.assert_equal, filter_args(h, ['*'], (1, 2, 25),
                                               dict(ee=2)), \
                            {'x': 1, 'y': 2, '**': {'ee': 2}}


def test_filter_kwargs():
    nose.tools.assert_equal(filter_args(k, [], (1, 2), dict(ee=2)),
                            {'*': [1, 2], '**': {'ee': 2}})
    nose.tools.assert_equal(filter_args(k, [], (3, 4)),
                            {'*': [3, 4], '**': {}})


def test_filter_args_2():
    nose.tools.assert_equal(filter_args(j, [], (1, 2), dict(ee=2)),
                            {'x': 1, 'y': 2, '**': {'ee': 2}})

    nose.tools.assert_raises(ValueError, filter_args, f, 'a', (None, ))
    # Check that we capture an undefined argument
    nose.tools.assert_raises(ValueError, filter_args, f, ['a'], (None, ))
    ff = functools.partial(f, 1)
    # filter_args has to special-case partial
    nose.tools.assert_equal(filter_args(ff, [], (1, )),
                            {'*': [1], '**': {}})
    nose.tools.assert_equal(filter_args(ff, ['y'], (1, )),
                            {'*': [1], '**': {}})


def test_func_name():
    yield nose.tools.assert_equal, 'f', get_func_name(f)[1]
    # Check that we are not confused by the decoration
    yield nose.tools.assert_equal, 'g', get_func_name(g)[1]


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


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()
    nose.tools.assert_not_equal(filter_args(a.f, [], (1, )),
                                filter_args(b.f, [], (1, )))


def test_filter_args_error_msg():
    """ Make sure that filter_args returns decent error messages, for the
        sake of the user.
    """
    nose.tools.assert_raises(ValueError, filter_args, f, [])


def test_clean_win_chars():
    string = r'C:\foo\bar\main.py'
    mangled_string = _clean_win_chars(string)
    for char in ('\\', ':', '<', '>', '!'):
        nose.tools.assert_false(char in mangled_string)
