# Authors:
#   Jason Gerard DeRose <jderose@redhat.com>
#
# Copyright (C) 2008  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; version 2 only
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

"""
Common utility functions and classes for unit tests.
"""

import inspect
import os
from os import path
import tempfile
import shutil
import ipalib
from ipalib.plugable import Plugin



class TempDir(object):
    def __init__(self):
        self.__path = tempfile.mkdtemp(prefix='ipa.tests.')
        assert self.path == self.__path

    def __get_path(self):
        assert path.abspath(self.__path) == self.__path
        assert self.__path.startswith('/tmp/ipa.tests.')
        assert path.isdir(self.__path) and not path.islink(self.__path)
        return self.__path
    path = property(__get_path)

    def rmtree(self):
        if self.__path is not None:
            shutil.rmtree(self.path)
            self.__path = None

    def makedirs(self, *parts):
        d = self.join(*parts)
        if not path.exists(d):
            os.makedirs(d)
        assert path.isdir(d) and not path.islink(d)
        return d

    def touch(self, *parts):
        d = self.makedirs(*parts[:-1])
        f = path.join(d, parts[-1])
        assert not path.exists(f)
        open(f, 'w').close()
        assert path.isfile(f) and not path.islink(f)
        return f

    def write(self, content, *parts):
        d = self.makedirs(*parts[:-1])
        f = path.join(d, parts[-1])
        assert not path.exists(f)
        open(f, 'w').write(content)
        assert path.isfile(f) and not path.islink(f)
        return f

    def join(self, *parts):
        return path.join(self.path, *parts)

    def __del__(self):
        self.rmtree()


class TempHome(TempDir):
    def __init__(self):
        super(TempHome, self).__init__()
        self.__home = os.environ['HOME']
        os.environ['HOME'] = self.path


class ExceptionNotRaised(Exception):
    """
    Exception raised when an *expected* exception is *not* raised during a
    unit test.
    """
    msg = 'expected %s'

    def __init__(self, expected):
        self.expected = expected

    def __str__(self):
        return self.msg % self.expected.__name__


def assert_equal(val1, val2):
    """
    Assert ``val1`` and ``val2`` are the same type and of equal value.
    """
    assert type(val1) is type(val2), '%r != %r' % (val1, val2)
    assert val1 == val2, '%r != %r' % (val1, val2)


def raises(exception, callback, *args, **kw):
    """
    Tests that the expected exception is raised; raises ExceptionNotRaised
    if test fails.
    """
    raised = False
    try:
        callback(*args, **kw)
    except exception, e:
        raised = True
    if not raised:
        raise ExceptionNotRaised(exception)
    return e


def getitem(obj, key):
    """
    Works like getattr but for dictionary interface. Use this in combination
    with raises() to test that, for example, KeyError is raised.
    """
    return obj[key]


def setitem(obj, key, value):
    """
    Works like setattr but for dictionary interface. Use this in combination
    with raises() to test that, for example, TypeError is raised.
    """
    obj[key] = value


def delitem(obj, key):
    """
    Works like delattr but for dictionary interface. Use this in combination
    with raises() to test that, for example, TypeError is raised.
    """
    del obj[key]


def no_set(obj, name, value='some_new_obj'):
    """
    Tests that attribute cannot be set.
    """
    raises(AttributeError, setattr, obj, name, value)


def no_del(obj, name):
    """
    Tests that attribute cannot be deleted.
    """
    raises(AttributeError, delattr, obj, name)


def read_only(obj, name, value='some_new_obj'):
    """
    Tests that attribute is read-only. Returns attribute.
    """
    # Test that it cannot be set:
    no_set(obj, name, value)

    # Test that it cannot be deleted:
    no_del(obj, name)

    # Return the attribute
    return getattr(obj, name)


def is_prop(prop):
    return type(prop) is property


class ClassChecker(object):
    __cls = None
    __subcls = None

    def __get_cls(self):
        if self.__cls is None:
            self.__cls = self._cls
        assert inspect.isclass(self.__cls)
        return self.__cls
    cls = property(__get_cls)

    def __get_subcls(self):
        if self.__subcls is None:
            self.__subcls = self.get_subcls()
        assert inspect.isclass(self.__subcls)
        return self.__subcls
    subcls = property(__get_subcls)

    def get_subcls(self):
        raise NotImplementedError(
            self.__class__.__name__,
            'get_subcls()'
        )







def check_TypeError(value, type_, name, callback, *args, **kw):
    """
    Tests a standard TypeError raised with `errors.raise_TypeError`.
    """
    e = raises(TypeError, callback, *args, **kw)
    assert e.value is value
    assert e.type is type_
    assert e.name == name
    assert type(e.name) is str
    assert str(e) == ipalib.errors.TYPE_FORMAT % (name, type_, value)
    return e


def get_api(**kw):
    """
    Returns (api, home) tuple.

    This function returns a tuple containing an `ipalib.plugable.API`
    instance and a `TempHome` instance.
    """
    home = TempHome()
    api = ipalib.create_api(mode='unit_test')
    api.env.in_tree = True
    for (key, value) in kw.iteritems():
        api.env[key] = value
    return (api, home)


def create_test_api(**kw):
    """
    Returns (api, home) tuple.

    This function returns a tuple containing an `ipalib.plugable.API`
    instance and a `TempHome` instance.
    """
    home = TempHome()
    api = ipalib.create_api(mode='unit_test')
    api.env.in_tree = True
    for (key, value) in kw.iteritems():
        api.env[key] = value
    return (api, home)


class PluginTester(object):
    __plugin = None

    def __get_plugin(self):
        if self.__plugin is None:
            self.__plugin = self._plugin
        assert issubclass(self.__plugin, Plugin)
        return self.__plugin
    plugin = property(__get_plugin)

    def register(self, *plugins, **kw):
        """
        Create a testing api and register ``self.plugin``.

        This method returns an (api, home) tuple.

        :param plugins: Additional \*plugins to register.
        :param kw: Additional \**kw args to pass to `create_test_api`.
        """
        (api, home) = create_test_api(**kw)
        api.register(self.plugin)
        for p in plugins:
            api.register(p)
        return (api, home)

    def finalize(self, *plugins, **kw):
        (api, home) = self.register(*plugins, **kw)
        api.finalize()
        return (api, home)

    def instance(self, namespace, *plugins, **kw):
        (api, home) = self.finalize(*plugins, **kw)
        o = api[namespace][self.plugin.__name__]
        return (o, api, home)


class DummyUGettext(object):
    __called = False

    def __init__(self):
        self.translation = u'The translation'

    def __call__(self, message):
        assert type(message) is str
        assert self.__called is False
        self.__called = True
        self.message = message
        return self.translation


class DummyUNGettext(object):
    __called = False

    def __init__(self):
        self.translation_singular = u'The singular translation'
        self.translation_plural = u'The plural translation'

    def __call__(self, singular, plural, n):
        assert type(singular) is str
        assert type(plural) is str
        assert type(n) is int
        assert self.__called is False
        self.__called = True
        self.singular = singular
        self.plural = plural
        self.n = n
        if n == 1:
            return self.translation_singular
        return self.translation_plural