"""
tl;dr: all code code is licensed under simplified BSD, unless stated otherwise.

Unless stated otherwise in the source files, all code is copyright 2010 David
Wolever <david@wolever.net>. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

   1. Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of David Wolever.

"""
import re
import sys
import inspect
import warnings
from functools import wraps
from types import MethodType as MethodType
from collections import namedtuple

try:
    from collections import OrderedDict as MaybeOrderedDict
except ImportError:
    MaybeOrderedDict = dict

from unittest import TestCase

PY3 = sys.version_info[0] == 3
PY2 = sys.version_info[0] == 2


if PY3:
    # Python 3 doesn't have an InstanceType, so just use a dummy type.
    class InstanceType():
        pass
    lzip = lambda *a: list(zip(*a))
    text_type = str
    string_types = str,
    bytes_type = bytes
    def make_method(func, instance, type):
        if instance is None:
            return func
        return MethodType(func, instance)
else:
    from types import InstanceType
    lzip = zip
    text_type = unicode
    bytes_type = str
    string_types = basestring,
    def make_method(func, instance, type):
        return MethodType(func, instance, type)

_param = namedtuple("param", "args kwargs")

class param(_param):
    """ Represents a single parameter to a test case.

        For example::

            >>> p = param("foo", bar=16)
            >>> p
            param("foo", bar=16)
            >>> p.args
            ('foo', )
            >>> p.kwargs
            {'bar': 16}

        Intended to be used as an argument to ``@parameterized``::

            @parameterized([
                param("foo", bar=16),
            ])
            def test_stuff(foo, bar=16):
                pass
        """

    def __new__(cls, *args , **kwargs):
        return _param.__new__(cls, args, kwargs)

    @classmethod
    def explicit(cls, args=None, kwargs=None):
        """ Creates a ``param`` by explicitly specifying ``args`` and
            ``kwargs``::

                >>> param.explicit([1,2,3])
                param(*(1, 2, 3))
                >>> param.explicit(kwargs={"foo": 42})
                param(*(), **{"foo": "42"})
            """
        args = args or ()
        kwargs = kwargs or {}
        return cls(*args, **kwargs)

    @classmethod
    def from_decorator(cls, args):
        """ Returns an instance of ``param()`` for ``@parameterized`` argument
            ``args``::

                >>> param.from_decorator((42, ))
                param(args=(42, ), kwargs={})
                >>> param.from_decorator("foo")
                param(args=("foo", ), kwargs={})
            """
        if isinstance(args, param):
            return args
        elif isinstance(args, string_types):
            args = (args, )
        try:
            return cls(*args)
        except TypeError as e:
            if "after * must be" not in str(e):
                raise
            raise TypeError(
                "Parameters must be tuples, but %r is not (hint: use '(%r, )')"
                %(args, args),
            )

    def __repr__(self):
        return "param(*%r, **%r)" %self


class QuietOrderedDict(MaybeOrderedDict):
    """ When OrderedDict is available, use it to make sure that the kwargs in
        doc strings are consistently ordered. """
    __str__ = dict.__str__
    __repr__ = dict.__repr__


def parameterized_argument_value_pairs(func, p):
    """Return tuples of parameterized arguments and their values.

        This is useful if you are writing your own doc_func
        function and need to know the values for each parameter name::

            >>> def func(a, foo=None, bar=42, **kwargs): pass
            >>> p = param(1, foo=7, extra=99)
            >>> parameterized_argument_value_pairs(func, p)
            [("a", 1), ("foo", 7), ("bar", 42), ("**kwargs", {"extra": 99})]

        If the function's first argument is named ``self`` then it will be
        ignored::

            >>> def func(self, a): pass
            >>> p = param(1)
            >>> parameterized_argument_value_pairs(func, p)
            [("a", 1)]

        Additionally, empty ``*args`` or ``**kwargs`` will be ignored::

            >>> def func(foo, *args): pass
            >>> p = param(1)
            >>> parameterized_argument_value_pairs(func, p)
            [("foo", 1)]
            >>> p = param(1, 16)
            >>> parameterized_argument_value_pairs(func, p)
            [("foo", 1), ("*args", (16, ))]
    """
    argspec = inspect.getargspec(func)
    arg_offset = 1 if argspec.args[:1] == ["self"] else 0

    named_args = argspec.args[arg_offset:]

    result = lzip(named_args, p.args)
    named_args = argspec.args[len(result) + arg_offset:]
    varargs = p.args[len(result):]

    result.extend([
        (name, p.kwargs.get(name, default))
        for (name, default)
        in zip(named_args, argspec.defaults or [])
    ])

    seen_arg_names = {n for (n, _) in result}
    keywords = QuietOrderedDict(sorted([
        (name, p.kwargs[name])
        for name in p.kwargs
        if name not in seen_arg_names
    ]))

    if varargs:
        result.append(("*%s" %(argspec.varargs, ), tuple(varargs)))

    if keywords:
        result.append(("**%s" %(argspec.keywords, ), keywords))

    return result

def short_repr(x, n=64):
    """ A shortened repr of ``x`` which is guaranteed to be ``unicode``::

            >>> short_repr("foo")
            u"foo"
            >>> short_repr("123456789", n=4)
            u"12...89"
    """

    x_repr = repr(x)
    if isinstance(x_repr, bytes_type):
        try:
            x_repr = text_type(x_repr, "utf-8")
        except UnicodeDecodeError:
            x_repr = text_type(x_repr, "latin1")
    if len(x_repr) > n:
        x_repr = x_repr[:n//2] + "..." + x_repr[len(x_repr) - n//2:]
    return x_repr

def default_doc_func(func, num, p):
    if func.__doc__ is None:
        return None

    all_args_with_values = parameterized_argument_value_pairs(func, p)

    # Assumes that the function passed is a bound method.
    descs = ["%s=%s" %(n, short_repr(v)) for n, v in all_args_with_values]

    # The documentation might be a multiline string, so split it
    # and just work with the first string, ignoring the period
    # at the end if there is one.
    first, nl, rest = func.__doc__.lstrip().partition("\n")
    suffix = ""
    if first.endswith("."):
        suffix = "."
        first = first[:-1]
    args = "%s[with %s]" %(len(first) and " " or "", ", ".join(descs))
    return "".join([first.rstrip(), args, suffix, nl, rest])

def default_name_func(func, num, p):
    base_name = func.__name__
    name_suffix = "_%s" %(num, )
    if len(p.args) > 0 and isinstance(p.args[0], string_types):
        name_suffix += "_" + parameterized.to_safe_name(p.args[0])
    return base_name + name_suffix


# force nose for numpy purposes.
_test_runner_override = 'nose'
_test_runner_guess = False
_test_runners = set(["unittest", "unittest2", "nose", "nose2", "pytest"])
_test_runner_aliases = {
    "_pytest": "pytest",
}

def set_test_runner(name):
    global _test_runner_override
    if name not in _test_runners:
        raise TypeError(
            "Invalid test runner: %r (must be one of: %s)"
            %(name, ", ".join(_test_runners)),
        )
    _test_runner_override = name

def detect_runner():
    """ Guess which test runner we're using by traversing the stack and looking
        for the first matching module. This *should* be reasonably safe, as
        it's done during test disocvery where the test runner should be the
        stack frame immediately outside. """
    if _test_runner_override is not None:
        return _test_runner_override
    global _test_runner_guess
    if _test_runner_guess is False:
        stack = inspect.stack()
        for record in reversed(stack):
            frame = record[0]
            module = frame.f_globals.get("__name__").partition(".")[0]
            if module in _test_runner_aliases:
                module = _test_runner_aliases[module]
            if module in _test_runners:
                _test_runner_guess = module
                break
            if record[1].endswith("python2.6/unittest.py"):
                _test_runner_guess = "unittest"
                break
        else:
            _test_runner_guess = None
    return _test_runner_guess

class parameterized(object):
    """ Parameterize a test case::

            class TestInt(object):
                @parameterized([
                    ("A", 10),
                    ("F", 15),
                    param("10", 42, base=42)
                ])
                def test_int(self, input, expected, base=16):
                    actual = int(input, base=base)
                    assert_equal(actual, expected)

            @parameterized([
                (2, 3, 5)
                (3, 5, 8),
            ])
            def test_add(a, b, expected):
                assert_equal(a + b, expected)
        """

    def __init__(self, input, doc_func=None):
        self.get_input = self.input_as_callable(input)
        self.doc_func = doc_func or default_doc_func

    def __call__(self, test_func):
        self.assert_not_in_testcase_subclass()

        @wraps(test_func)
        def wrapper(test_self=None):
            test_cls = test_self and type(test_self)
            if test_self is not None:
                if issubclass(test_cls, InstanceType):
                    raise TypeError((
                        "@parameterized can't be used with old-style classes, but "
                        "%r has an old-style class. Consider using a new-style "
                        "class, or '@parameterized.expand' "
                        "(see http://stackoverflow.com/q/54867/71522 for more "
                        "information on old-style classes)."
                    ) %(test_self, ))

            original_doc = wrapper.__doc__
            for num, args in enumerate(wrapper.parameterized_input):
                p = param.from_decorator(args)
                unbound_func, nose_tuple = self.param_as_nose_tuple(test_self, test_func, num, p)
                try:
                    wrapper.__doc__ = nose_tuple[0].__doc__
                    # Nose uses `getattr(instance, test_func.__name__)` to get
                    # a method bound to the test instance (as opposed to a