# Copyright 2010-2011 OpenStack Foundation
# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
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"""Common utilities used in testing"""

import os
import shutil
import subprocess
import sys

import fixtures
import testresources
import testtools
from testtools import content

from pbr import options


class DiveDir(fixtures.Fixture):
    """Dive into given directory and return back on cleanup.

    :ivar path: The target directory.
    """

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

    def setUp(self):
        super(DiveDir, self).setUp()
        self.addCleanup(os.chdir, os.getcwd())
        os.chdir(self.path)


class BaseTestCase(testtools.TestCase, testresources.ResourcedTestCase):

    def setUp(self):
        super(BaseTestCase, self).setUp()
        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 30)
        try:
            test_timeout = int(test_timeout)
        except ValueError:
            # If timeout value is invalid, fail hard.
            print("OS_TEST_TIMEOUT set to invalid value"
                  " defaulting to no timeout")
            test_timeout = 0
        if test_timeout > 0:
            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))

        if os.environ.get('OS_STDOUT_CAPTURE') in options.TRUE_VALUES:
            stdout = self.useFixture(fixtures.StringStream('stdout')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stdout', stdout))
        if os.environ.get('OS_STDERR_CAPTURE') in options.TRUE_VALUES:
            stderr = self.useFixture(fixtures.StringStream('stderr')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))
        self.log_fixture = self.useFixture(
            fixtures.FakeLogger('pbr'))

        # Older git does not have config --local, so create a temporary home
        # directory to permit using git config --global without stepping on
        # developer configuration.
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.FakeLogger())
        # TODO(lifeless) we should remove PBR_VERSION from the environment.
        # rather than setting it, because thats not representative - we need to
        # test non-preversioned codepaths too!
        self.useFixture(fixtures.EnvironmentVariable('PBR_VERSION', '0.0'))

        self.temp_dir = self.useFixture(fixtures.TempDir()).path
        self.package_dir = os.path.join(self.temp_dir, 'testpackage')
        shutil.copytree(os.path.join(os.path.dirname(__file__), 'testpackage'),
                        self.package_dir)
        self.addCleanup(os.chdir, os.getcwd())
        os.chdir(self.package_dir)
        self.addCleanup(self._discard_testpackage)
        # Tests can opt into non-PBR_VERSION by setting preversioned=False as
        # an attribute.
        if not getattr(self, 'preversioned', True):
            self.useFixture(fixtures.EnvironmentVariable('PBR_VERSION'))
            setup_cfg_path = os.path.join(self.package_dir, 'setup.cfg')
            with open(setup_cfg_path, 'rt') as cfg:
                content = cfg.read()
            content = content.replace(u'version = 0.1.dev', u'')
            with open(setup_cfg_path, 'wt') as cfg:
                cfg.write(content)

    def _discard_testpackage(self):
        # Remove pbr.testpackage from sys.modules so that it can be freshly
        # re-imported by the next test
        for k in list(sys.modules):
            if (k == 'pbr_testpackage' or
                    k.startswith('pbr_testpackage.')):
                del sys.modules[k]

    def run_pbr(self, *args, **kwargs):
        return self._run_cmd('pbr', args, **kwargs)

    def run_setup(self, *args, **kwargs):
        return self._run_cmd(sys.executable, ('setup.py',) + args, **kwargs)

    def _run_cmd(self, cmd, args=[], allow_fail=True, cwd=None):
        """Run a command in the root of the test working copy.

        Runs a command, with the given argument list, in the root of the test
        working copy--returns the stdout and stderr streams and the exit code
        from the subprocess.

        :param cwd: If falsy run within the test package dir, otherwise run
            within the named path.
        """
        cwd = cwd or self.package_dir
        result = _run_cmd([cmd] + list(args), cwd=cwd)
        if result[2] and not allow_fail:
            raise Exception("Command failed retcode=%s" % result[2])
        return result


class CapturedSubprocess(fixtures.Fixture):
    """Run a process and capture its output.

    :attr stdout: The output (a string).
    :attr stderr: The standard error (a string).
    :attr returncode: The return code of the process.

    Note that stdout and stderr are decoded from the bytestrings subprocess
    returns using error=replace.
    """

    def __init__(self, label, *args, **kwargs):
        """Create a CapturedSubprocess.

        :param label: A label for the subprocess in the test log. E.g. 'foo'.
        :param *args: The *args to pass to Popen.
        :param **kwargs: The **kwargs to pass to Popen.
        """
        super(CapturedSubprocess, self).__init__()
        self.label = label
        self.args = args
        self.kwargs = kwargs
        self.kwargs['stderr'] = subprocess.PIPE
        self.kwargs['stdin'] = subprocess.PIPE
        self.kwargs['stdout'] = subprocess.PIPE

    def setUp(self):
        super(CapturedSubprocess, self).setUp()
        proc = subprocess.Popen(*self.args, **self.kwargs)
        out, err = proc.communicate()
        self.out = out.decode('utf-8', 'replace')
        self.err = err.decode('utf-8', 'replace')
        self.addDetail(self.label + '-stdout', content.text_content(self.out))
        self.addDetail(self.label + '-stderr', content.text_content(self.err))
        self.returncode = proc.returncode
        if proc.returncode:
            raise AssertionError(
                'Failed process args=%r, kwargs=%r, returncode=%s' % (
                    self.args, self.kwargs, proc.returncode))
        self.addCleanup(delattr, self, 'out')
        self.addCleanup(delattr, self, 'err')
        self.addCleanup(delattr, self, 'returncode')


def _run_cmd(args, cwd):
    """Run the command args in cwd.

    :param args: The command to run e.g. ['git', 'status']
    :param cwd: The directory to run the comamnd in.
    :return: ((stdout, stderr), returncode)
    """
    print('Running %s' % ' '.join(args))
    p = subprocess.Popen(
        args, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
        stderr=subprocess.PIPE, cwd=cwd)
    streams = tuple(s.decode('latin1').strip() for s in p.communicate())
    print('STDOUT:')
    print(streams[0])
    print('STDERR:')
    print(streams[1])
    return (streams) + (p.returncode,)


def _config_git():
    _run_cmd(
        ['git', 'config', '--global', 'user.email', 'example@example.com'],
        None)
    _run_cmd(
        ['git', 'config', '--global', 'user.name', 'OpenStack Developer'],
        None)
    _run_cmd(
        ['git', 'config', '--global', 'user.signingkey',
         'example@example.com'], None)
