#!/usr/bin/python2 -O
# vim: fileencoding=utf-8

#
# The Qubes OS Project, https://www.qubes-os.org/
#
# Copyright (C) 2014-2015
#                   Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
# Copyright (C) 2015  Wojtek Porczyk <woju@invisiblethingslab.com>
#
# 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; either version 2 of the License, or
# (at your option) any later version.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

import multiprocessing
import logging
import os
import shutil
import subprocess
import unittest

import lxml.etree
import sys

import qubes.backup
import qubes.qubes

VMPREFIX = 'test-'


#: :py:obj:`True` if running in dom0, :py:obj:`False` otherwise
in_dom0 = False

#: :py:obj:`False` if outside of git repo,
#: path to root of the directory otherwise
in_git = False

try:
    import libvirt
    libvirt.openReadOnly(qubes.qubes.defaults['libvirt_uri']).close()
    in_dom0 = True
except libvirt.libvirtError:
    pass

try:
    in_git = subprocess.check_output(
        ['git', 'rev-parse', '--show-toplevel']).strip()
except subprocess.CalledProcessError:
    # git returned nonzero, we are outside git repo
    pass
except OSError:
    # command not found; let's assume we're outside
    pass


def skipUnlessDom0(test_item):
    '''Decorator that skips test outside dom0.

    Some tests (especially integration tests) have to be run in more or less
    working dom0. This is checked by connecting to libvirt.
    ''' # pylint: disable=invalid-name

    return unittest.skipUnless(in_dom0, 'outside dom0')(test_item)


def skipUnlessGit(test_item):
    '''Decorator that skips test outside git repo.

    There are very few tests that an be run only in git. One example is
    correctness of example code that won't get included in RPM.
    ''' # pylint: disable=invalid-name

    return unittest.skipUnless(in_git, 'outside git tree')(test_item)


class _AssertNotRaisesContext(object):
    """A context manager used to implement TestCase.assertNotRaises methods.

    Stolen from unittest and hacked. Regexp support stripped.
    """

    def __init__(self, expected, test_case, expected_regexp=None):
        self.expected = expected
        self.failureException = test_case.failureException

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, tb):
        if exc_type is None:
            return True

        try:
            exc_name = self.expected.__name__
        except AttributeError:
            exc_name = str(self.expected)

        if issubclass(exc_type, self.expected):
            raise self.failureException(
                "{0} raised".format(exc_name))
        else:
            # pass through
            return False

        self.exception = exc_value # store for later retrieval


class BeforeCleanExit(BaseException):
    pass

class QubesTestCase(unittest.TestCase):
    '''Base class for Qubes unit tests.
    '''

    def __init__(self, *args, **kwargs):
        super(QubesTestCase, self).__init__(*args, **kwargs)
        self.longMessage = True
        self.log = logging.getLogger('{}.{}.{}'.format(
            self.__class__.__module__,
            self.__class__.__name__,
            self._testMethodName))


    def __str__(self):
        return '{}/{}/{}'.format(
            '.'.join(self.__class__.__module__.split('.')[2:]),
            self.__class__.__name__,
            self._testMethodName)


    def tearDown(self):
        super(QubesTestCase, self).tearDown()

        result = self._resultForDoCleanups
        l = result.failures \
            + result.errors \
            + [(tc, None) for tc in result.unexpectedSuccesses]

        if getattr(result, 'do_not_clean', False) \
                and filter((lambda (tc, exc): tc is self), l):
            raise BeforeCleanExit()


    def assertNotRaises(self, excClass, callableObj=None, *args, **kwargs):
        """Fail if an exception of class excClass is raised
           by callableObj when invoked with arguments args and keyword
           arguments kwargs. If a different type of exception is
           raised, it will not be caught, and the test case will be
           deemed to have suffered an error, exactly as for an
           unexpected exception.

           If called with callableObj omitted or None, will return a
           context object used like this::

                with self.assertRaises(SomeException):
                    do_something()

           The context manager keeps a reference to the exception as
           the 'exception' attribute. This allows you to inspect the
           exception after the assertion::

               with self.assertRaises(SomeException) as cm:
                   do_something()
               the_exception = cm.exception
               self.assertEqual(the_exception.error_code, 3)
        """
        context = _AssertNotRaisesContext(excClass, self)
        if callableObj is None:
            return context
        with context:
            callableObj(*args, **kwargs)


    def assertXMLEqual(self, xml1, xml2):
        '''Check for equality of two XML objects.

        :param xml1: first element
        :param xml2: second element
        :type xml1: :py:class:`lxml.etree._Element`
        :type xml2: :py:class:`lxml.etree._Element`
        ''' # pylint: disable=invalid-name

        self.assertEqual(xml1.tag, xml2.tag)
        self.assertEqual(xml1.text, xml2.text)
        self.assertItemsEqual(xml1.keys(), xml2.keys())
        for key in xml1.keys():
            self.assertEqual(xml1.get(key), xml2.get(key))


class SystemTestsMixin(object):
    def setUp(self):
        '''Set up the test.

        .. warning::
            This method instantiates QubesVmCollection acquires write lock for
            it. You can use is as :py:attr:`qc`. You can (and probably
            should) release the lock at the end of setUp in subclass
        '''

        super(SystemTestsMixin, self).setUp()

        self.qc = qubes.qubes.QubesVmCollection()
        self.qc.lock_db_for_writing()
        self.qc.load()

        self.conn = libvirt.open(qubes.qubes.defaults['libvirt_uri'])

        self.remove_test_vms()


    def tearDown(self):
        super(SystemTestsMixin, self).tearDown()

        try: self.qc.lock_db_for_writing()
        except qubes.qubes.QubesException: pass
        self.qc.load()

        self.remove_test_vms()

        self.qc.save()
        self.qc.unlock_db()
        del self.qc

        self.conn.close()


    def make_vm_name(self, name):
        return VMPREFIX + name

    def save_and_reload_db(self):
        self.qc.save()
        self.qc.unlock_db()
        self.qc.lock_db_for_writing()
        self.qc.load()

    def _remove_vm_qubes(self, vm):
        vmname = vm.name

        try:
            # XXX .is_running() may throw libvirtError if undefined
            if vm.is_running():
                vm.force_shutdown()
        except: pass

        try: vm.remove_from_disk()
        except: pass

        try: vm.libvirt_domain.undefine()
        except libvirt.libvirtError: pass

        self.qc.pop(vm.qid)
        del vm

        # Now ensure it really went away. This may not have happened,
        # for example if vm.libvirtDomain malfunctioned.
        try:
            dom = self.conn.lookupByName(vmname)
        except: pass
        else:
            self._remove_vm_libvirt(dom)

        self._remove_vm_disk(vmname)


    def _remove_vm_libvirt(self, dom):
        try:
            dom.destroy()
        except libvirt.libvirtError: # not running
            pass
        dom.undefine()


    def _remove_vm_disk(self, vmname):
        for dirspec in (
                'qubes_appvms_dir',
                'qubes_servicevms_dir',
                'qubes_templates_dir'):
            dirpath = os.path.join(qubes.qubes.system_path['qubes_base_dir'],
                qubes.qubes.system_path[dirspec], vmname)
            if os.path.exists(dirpath):
                if os.path.isdir(dirpath):
                    shutil.rmtree(dirpath)
                else:
                    os.unlink(dirpath)


    def remove_vms(self, vms):
        for vm in vms: self._remove_vm_qubes(vm)
        self.save_and_reload_db()


    def remove_test_vms(self):
        '''Aggresively remove any domain that has name in testing namespace.

        .. warning::
            The test suite hereby claims any domain whose name starts with
            :py:data:`VMPREFIX` as fair game. This is needed to enforce sane
            test executing environment. If you have domains named ``test-*``,
            don't run the tests.
        '''

        # first, remove them Qubes-way
        something_removed = False
        for vm in self.qc.values():
            if vm.name.startswith(VMPREFIX):
                self._remove_vm_qubes(vm)
                something_removed = True
        if something_removed:
            self.save_and_reload_db()

        # now remove what was only in libvirt
        for dom in self.conn.listAllDomains():
            if dom.name().startswith(VMPREFIX):
                self._remove_vm_libvirt(dom)

        # finally remove anything that is left on disk
        vmnames = set()
        for dirspec in (
                'qubes_appvms_dir',
                'qubes_servicevms_dir',
                'qubes_templates_dir'):
            dirpath = os.path.join(qubes.qubes.system_path['qubes_base_dir'],
                qubes.qubes.system_path[dirspec])
            for name in os.listdir(dirpath):
                if name.startswith(VMPREFIX):
                    vmnames.add(name)
        for vmname in vmnames:
            self._remove_vm_disk(vmname)



class BackupTestsMixin(SystemTestsMixin):
    def setUp(self):
        super(BackupTestsMixin, self).setUp()
        self.error_detected = multiprocessing.Queue()
        self.verbose = False

        if self.verbose:
            print >>sys.stderr, "-> Creating backupvm"

        # TODO: allow non-default template
        self.backupvm = self.qc.add_new_vm("QubesAppVm",
            name=self.make_vm_name('backupvm'),
            template=self.qc.get_default_template())
        self.backupvm.create_on_disk(verbose=self.verbose)

        self.backupdir = os.path.join(os.environ["HOME"], "test-backup")
        if os.path.exists(self.backupdir):
            shutil.rmtree(self.backupdir)
        os.mkdir(self.backupdir)


    def tearDown(self):
        super(BackupTestsMixin, self).tearDown()
        shutil.rmtree(self.backupdir)


    def print_progress(self, progress):
        if self.verbose:
            print >> sys.stderr, "\r-> Backing up files: {0}%...".format(progress)


    def error_callback(self, message):
        self.error_detected.put(message)
        if self.verbose:
            print >> sys.stderr, "ERROR: {0}".format(message)


    def print_callback(self, msg):
        if self.verbose:
            print msg


    def fill_image(self, path, size=None, sparse=False):
        block_size = 4096

        if self.verbose:
            print >>sys.stderr, "-> Filling %s" % path
        f = open(path, 'w+')
        if size is None:
            f.seek(0, 2)
            size = f.tell()
        f.seek(0)

        for block_num in xrange(size/block_size):
            f.write('a' * block_size)
            if sparse:
                f.seek(block_size, 1)

        f.close()


    # NOTE: this was create_basic_vms
    def create_backup_vms(self):
        template=self.qc.get_default_template()

        vms = []
        vmname = self.make_vm_name('test1')
        if self.verbose:
            print >>sys.stderr, "-> Creating %s" % vmname
        testvm1 = self.qc.add_new_vm('QubesAppVm',
            name=vmname, template=template)
        testvm1.create_on_disk(verbose=self.verbose)
        vms.append(testvm1)
        self.fill_image(testvm1.private_img, 100*1024*1024)

        vmname = self.make_vm_name('testhvm1')
        if self.verbose:
            print >>sys.stderr, "-> Creating %s" % vmname
        testvm2 = self.qc.add_new_vm('QubesHVm', name=vmname)
        testvm2.create_on_disk(verbose=self.verbose)
        self.fill_image(testvm2.root_img, 1024*1024*1024, True)
        vms.append(testvm2)

        self.qc.save()

        return vms


    def make_backup(self, vms, prepare_kwargs=dict(), do_kwargs=dict(),
            target=None):
        # XXX: bakup_prepare and backup_do don't support host_collection
        self.qc.unlock_db()
        if target is None:
            target = self.backupdir
        try:
            files_to_backup = \
                qubes.backup.backup_prepare(vms,
                                      print_callback=self.print_callback,
                                      **prepare_kwargs)
        except qubes.qubes.QubesException as e:
            self.fail("QubesException during backup_prepare: %s" % str(e))

        try:
            qubes.backup.backup_do(target, files_to_backup, "qubes",
                             progress_callback=self.print_progress,
                             **do_kwargs)
        except qubes.qubes.QubesException as e:
            self.fail("QubesException during backup_do: %s" % str(e))

        self.qc.lock_db_for_writing()
        self.qc.load()


    def restore_backup(self, source=None, appvm=None, options=None):
        if source is None:
            backupfile = os.path.join(self.backupdir,
                                      sorted(os.listdir(self.backupdir))[-1])
        else:
            backupfile = source

        with self.assertNotRaises(qubes.qubes.QubesException):
            backup_info = qubes.backup.backup_restore_prepare(
                backupfile, "qubes",
                host_collection=self.qc,
                print_callback=self.print_callback,
                appvm=appvm,
                options=options or {})

        if self.verbose:
            qubes.backup.backup_restore_print_summary(backup_info)

        with self.assertNotRaises(qubes.qubes.QubesException):
            qubes.backup.backup_restore_do(
                backup_info,
                host_collection=self.qc,
                print_callback=self.print_callback if self.verbose else None,
                error_callback=self.error_callback)

        # maybe someone forgot to call .save()
        self.qc.load()

        errors = []
        while not self.error_detected.empty():
            errors.append(self.error_detected.get())
        self.assertTrue(len(errors) == 0,
                         "Error(s) detected during backup_restore_do: %s" %
                         '\n'.join(errors))
        if not appvm and not os.path.isdir(backupfile):
            os.unlink(backupfile)


    def create_sparse(self, path, size):
        f = open(path, "w")
        f.truncate(size)
        f.close()


def load_tests(loader, tests, pattern):
    # discard any tests from this module, because it hosts base classes
    tests = unittest.TestSuite()

    for modname in (
            'qubes.tests.basic',
            'qubes.tests.dom0_update',
            'qubes.tests.network',
            'qubes.tests.vm_qrexec_gui',
            'qubes.tests.backup',
            'qubes.tests.backupcompatibility',
            'qubes.tests.regressions',
            ):
        tests.addTests(loader.loadTestsFromName(modname))

    return tests


# vim: ts=4 sw=4 et