:param sep:

    :param strip:

    """

    if isinstance(obj, (basestring)):

        lst = obj.split(sep)

        if strip:

            lst = [v.strip() for v in lst]

        return lst

    elif isinstance(obj, (list, tuple)):

        return obj

    elif obj is None:

        return []

    else:

        return [obj]

def convert_line_endings(line, mode):

    """

    Converts a given line  "line end" according to given mode

    Available modes are::

        0 - Unix

        1 - Mac

        2 - DOS

    :param line: given line to convert

    :param mode: mode to convert to

    :rtype: str

    :return: converted line according to mode

    """

    from string import replace

    if mode == 0:

        line = replace(line, '\r\n', '\n')

        line = replace(line, '\r', '\n')

    elif mode == 1:

        line = replace(line, '\r\n', '\r')

        line = replace(line, '\n', '\r')

    elif mode == 2:

        line = re.sub("\r(?!\n)|(?<!\r)\n", "\r\n", line)

    return line

def detect_mode(line, default):

    """

    Detects line break for given line, if line break couldn't be found

    given default value is returned

    :param line: str line

    :param default: default

    :rtype: int

    :return: value of line end on of 0 - Unix, 1 - Mac, 2 - DOS

    """

    if line.endswith('\r\n'):

        return 2

    elif line.endswith('\n'):

        return 0

    elif line.endswith('\r'):

        return 1

    else:

        return default

def generate_api_key():

    """

    Generates a random (presumably unique) API key.

    This value is used in URLs and "Bearer" HTTP Authorization headers,

    which in practice means it should only contain URL-safe characters

    (RFC 3986):

        unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"

    """

    # Hexadecimal certainly qualifies as URL-safe.

    return binascii.hexlify(os.urandom(20))

def safe_int(val, default=None):

    """

    Returns int() of val if val is not convertable to int use default

    instead

    :param val:

    :param default:

    """

    try:

        val = int(val)

    except (ValueError, TypeError):

        val = default

    return val

def safe_unicode(str_, from_encoding=None):

    """

    safe unicode function. Does few trick to turn str_ into unicode

    In case of UnicodeDecode error we try to return it with encoding detected

    by chardet library if it fails fallback to unicode with errors replaced

    :param str_: string to decode

    :rtype: unicode

    :returns: unicode object

    """

    if isinstance(str_, unicode):

        return str_

    if not from_encoding:

        import kallithea

        DEFAULT_ENCODINGS = aslist(kallithea.CONFIG.get('default_encoding',

                                                        'utf-8'), sep=',')

        from_encoding = DEFAULT_ENCODINGS

    if not isinstance(from_encoding, (list, tuple)):

        from_encoding = [from_encoding]

    try:

        return unicode(str_)

    except UnicodeDecodeError:

        pass

    for enc in from_encoding:

        try:

            return unicode(str_, enc)

        except UnicodeDecodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(str_)['encoding']

        if encoding is None:

            raise Exception()

        return str_.decode(encoding)

    except (ImportError, UnicodeDecodeError, Exception):

        return unicode(str_, from_encoding[0], 'replace')

def safe_str(unicode_, to_encoding=None):

    """

    safe str function. Does few trick to turn unicode_ into string

    In case of UnicodeEncodeError we try to return it with encoding detected

    by chardet library if it fails fallback to string with errors replaced

    :param unicode_: unicode to encode

    :rtype: str

    :returns: str object

    """

    # if it's not basestr cast to str

    if not isinstance(unicode_, basestring):

        return str(unicode_)

    if isinstance(unicode_, str):

        return unicode_

    if not to_encoding:

        import kallithea

        DEFAULT_ENCODINGS = aslist(kallithea.CONFIG.get('default_encoding',

                                                        'utf-8'), sep=',')

        to_encoding = DEFAULT_ENCODINGS

    if not isinstance(to_encoding, (list, tuple)):

        to_encoding = [to_encoding]

    for enc in to_encoding:

        try:

            return unicode_.encode(enc)

        except UnicodeEncodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(unicode_)['encoding']

        if encoding is None:

            raise UnicodeEncodeError()

        return unicode_.encode(encoding)

    except (ImportError, UnicodeEncodeError):

        return unicode_.encode(to_encoding[0], 'replace')

def remove_suffix(s, suffix):

    if s.endswith(suffix):

        s = s[:-1 * len(suffix)]

    return s

def remove_prefix(s, prefix):

    if s.startswith(prefix):

        s = s[len(prefix):]

    return s

def age(prevdate, show_short_version=False, now=None):

    """

    turns a datetime into an age string.

    If show_short_version is True, then it will generate a not so accurate but shorter string,

    example: 2days ago, instead of 2 days and 23 hours ago.

    :param prevdate: datetime object

    :param show_short_version: if it should approximate the date and return a shorter string

    :rtype: unicode

    :returns: unicode words describing age

    """

    now = now or datetime.datetime.now()

    order = ['year', 'month', 'day', 'hour', 'minute', 'second']

    deltas = {}

    future = False

    if prevdate > now:

        now, prevdate = prevdate, now

        future = True

    if future:

        prevdate = prevdate.replace(microsecond=0)

    # Get date parts deltas

    from dateutil import relativedelta

    for part in order:

        d = relativedelta.relativedelta(now, prevdate)

        deltas[part] = getattr(d, part + 's')

    # Fix negative offsets (there is 1 second between 10:59:59 and 11:00:00,

    # not 1 hour, -59 minutes and -59 seconds)

    for num, length in [(5, 60), (4, 60), (3, 24)]:  # seconds, minutes, hours

        part = order[num]

        carry_part = order[num - 1]

        if deltas[part] < 0:

            deltas[part] += length

            deltas[carry_part] -= 1

    # Same thing for days except that the increment depends on the (variable)

    # number of days in the month

    month_lengths = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    if deltas['day'] < 0:

        if prevdate.month == 2 and (prevdate.year % 4 == 0 and

            (prevdate.year % 100 != 0 or prevdate.year % 400 == 0)

        ):

            deltas['day'] += 29

        else:

            deltas['day'] += month_lengths[prevdate.month - 1]

        deltas['month'] -= 1

    if deltas['month'] < 0:

        deltas['month'] += 12

        deltas['year'] -= 1

    # In short version, we want nicer handling of ages of more than a year

    if show_short_version:

        if deltas['year'] == 1:

            # ages between 1 and 2 years: show as months

            deltas['month'] += 12

            deltas['year'] = 0

        if deltas['year'] >= 2:

            # ages 2+ years: round

            if deltas['month'] > 6:

                deltas['year'] += 1

                deltas['month'] = 0

    # Format the result

    fmt_funcs = {

        'year': lambda d: ungettext(u'%d year', '%d years', d) % d,

        'month': lambda d: ungettext(u'%d month', '%d months', d) % d,

        'day': lambda d: ungettext(u'%d day', '%d days', d) % d,

        'hour': lambda d: ungettext(u'%d hour', '%d hours', d) % d,

        'minute': lambda d: ungettext(u'%d minute', '%d minutes', d) % d,

        'second': lambda d: ungettext(u'%d second', '%d seconds', d) % d,

    }

    for i, part in enumerate(order):

        value = deltas[part]

        if value == 0:

            continue

        if i < 5:

            sub_part = order[i + 1]

            sub_value = deltas[sub_part]

        else:

            sub_value = 0

        if sub_value == 0 or show_short_version:

            if future:

                return _('in %s') % fmt_funcs[part](value)

            else:

                return _('%s ago') % fmt_funcs[part](value)

        if future:

            return _('in %s and %s') % (fmt_funcs[part](value),

                fmt_funcs[sub_part](sub_value))

        else:

            return _('%s and %s ago') % (fmt_funcs[part](value),

                fmt_funcs[sub_part](sub_value))

    return _('just now')

def uri_filter(uri):

    """

    Removes user:password from given url string

    :param uri:

    :rtype: unicode

    :returns: filtered list of strings

    """

    if not uri:

        return ''

    proto = ''

    for pat in ('https://', 'http://', 'git://'):

        if uri.startswith(pat):

            uri = uri[len(pat):]

            proto = pat

            break

    # remove passwords and username

    uri = uri[uri.find('@') + 1:]

    # get the port

    cred_pos = uri.find(':')

    if cred_pos == -1:

        host, port = uri, None

    else:

        host, port = uri[:cred_pos], uri[cred_pos + 1:]

    return filter(None, [proto, host, port])

def credentials_filter(uri):

    """

    Returns a url with removed credentials

    :param uri:

    """

    uri = uri_filter(uri)

    # check if we have port

    if len(uri) > 2 and uri[2]:

        uri[2] = ':' + uri[2]

    return ''.join(uri)

def get_clone_url(clone_uri_tmpl, prefix_url, repo_name, repo_id, username=None):

    parsed_url = urlobject.URLObject(prefix_url)

    prefix = safe_unicode(urllib.unquote(parsed_url.path.rstrip('/')))

    try:

        system_user = pwd.getpwuid(os.getuid()).pw_name

    except Exception: # TODO: support all systems - especially Windows

        system_user = 'kallithea' # hardcoded default value ...

    args = {

        'scheme': parsed_url.scheme,

        'user': safe_unicode(urllib.quote(safe_str(username or ''))),

        'netloc': parsed_url.netloc + prefix,  # like "hostname:port/prefix" (with optional ":port" and "/prefix")

        'prefix': prefix, # undocumented, empty or starting with /

        'repo': repo_name,

        'repoid': str(repo_id),

        'system_user': safe_unicode(system_user),

        'hostname': parsed_url.hostname,

    }

    url = re.sub('{([^{}]+)}', lambda m: args.get(m.group(1), m.group(0)), clone_uri_tmpl)

    # remove leading @ sign if it's present. Case of empty user

    url_obj = urlobject.URLObject(url)

    if not url_obj.username:

        url_obj = url_obj.with_username(None)

    return safe_unicode(url_obj)

def get_changeset_safe(repo, rev):

    """

    Safe version of get_changeset if this changeset doesn't exists for a

    repo it returns a Dummy one instead

    :param repo:

    :param rev:

    """

    from kallithea.lib.vcs.backends.base import BaseRepository

    from kallithea.lib.vcs.exceptions import RepositoryError

    from kallithea.lib.vcs.backends.base import EmptyChangeset

    if not isinstance(repo, BaseRepository):

        raise Exception('You must pass an Repository '

    try:

        cs = repo.get_changeset(rev)

    except (RepositoryError, LookupError):

        cs = EmptyChangeset(requested_revision=rev)

    return cs

def datetime_to_time(dt):

    if dt:

        return time.mktime(dt.timetuple())

def time_to_datetime(tm):

    if tm:

        if isinstance(tm, basestring):

            try:

                tm = float(tm)

            except ValueError:

                return

        return datetime.datetime.fromtimestamp(tm)

# Must match regexp in kallithea/public/js/base.js MentionsAutoComplete()

# Check char before @ - it must not look like we are in an email addresses.

# Matching is greedy so we don't have to look beyond the end.

MENTIONS_REGEX = re.compile(r'(?:^|(?<=[^a-zA-Z0-9]))@([a-zA-Z0-9][-_.a-zA-Z0-9]*[a-zA-Z0-9])')

def extract_mentioned_usernames(text):

    r"""

    Returns list of (possible) usernames @mentioned in given text.

    >>> extract_mentioned_usernames('@1-2.a_X,@1234 not@not @ddd@not @n @ee @ff @gg, @gg;@hh @n\n@zz,')

    ['1-2.a_X', '1234', 'ddd', 'ee', 'ff', 'gg', 'gg', 'hh', 'zz']

    """

    return MENTIONS_REGEX.findall(text)

def extract_mentioned_users(text):

    """ Returns set of actual database Users @mentioned in given text. """

    from kallithea.model.db import User

    result = set()

    for name in extract_mentioned_usernames(text):

        user = User.get_by_username(name, case_insensitive=True)

        if user is not None and not user.is_default_user:

            result.add(user)

    return result

class AttributeDict(dict):

    def __getattr__(self, attr):

        return self.get(attr, None)

    __setattr__ = dict.__setitem__

    __delattr__ = dict.__delitem__

def obfuscate_url_pw(engine):

    from sqlalchemy.engine import url as sa_url

    from sqlalchemy.exc import ArgumentError

    try:

        _url = sa_url.make_url(engine or '')

    except ArgumentError:

        return engine

    if _url.password:

        _url.password = 'XXXXX'

    return str(_url)

def get_hook_environment():

    """

    Get hook context by deserializing the global KALLITHEA_EXTRAS environment

    variable.

    Called early in Git out-of-process hooks to get .ini config path so the

    basic environment can be configured properly. Also used in all hooks to get

    information about the action that triggered it.

    """

    try:

        extras = json.loads(os.environ['KALLITHEA_EXTRAS'])

    except KeyError:

        raise Exception("Environment variable KALLITHEA_EXTRAS not found")

    try:

        for k in ['username', 'repository', 'scm', 'action', 'ip']:

            extras[k]

    except KeyError:

        raise Exception('Missing key %s in KALLITHEA_EXTRAS %s' % (k, extras))

    return AttributeDict(extras)

def set_hook_environment(username, ip_addr, repo_name, repo_alias, action=None):

    """Prepare global context for running hooks by serializing data in the

    global KALLITHEA_EXTRAS environment variable.

    Most importantly, this allow Git hooks to do proper logging and updating of

    caches after pushes.

    Must always be called before anything with hooks are invoked.

    """

    from kallithea import CONFIG

    extras = {

        'ip': ip_addr, # used in log_push/pull_action action_logger

        'username': username,

        'action': action or 'push_local', # used in log_push_action_raw_ids action_logger

        'repository': repo_name,

        'scm': repo_alias, # used to pick hack in log_push_action_raw_ids

        'config': CONFIG['__file__'], # used by git hook to read config

    }

    os.environ['KALLITHEA_EXTRAS'] = json.dumps(extras)

def get_current_authuser():

    """

    Gets kallithea user from threadlocal tmpl_context variable if it's

    defined, else returns None.

    """

    from tg import tmpl_context

    if hasattr(tmpl_context, 'authuser'):

        return tmpl_context.authuser

    return None

class OptionalAttr(object):

    """

    Special Optional Option that defines other attribute. Example::

        def test(apiuser, userid=Optional(OAttr('apiuser')):

            user = Optional.extract(userid)

            # calls

    """

    def __init__(self, attr_name):

        self.attr_name = attr_name

    def __repr__(self):

        return '<OptionalAttr:%s>' % self.attr_name

    def __call__(self):

        return self

# alias

OAttr = OptionalAttr

class Optional(object):

    """

    Defines an optional parameter::

        param = param.getval() if isinstance(param, Optional) else param

        param = param() if isinstance(param, Optional) else param

    is equivalent of::

        param = Optional.extract(param)

    """

    def __init__(self, type_):

        self.type_ = type_

    def __repr__(self):

        return '<Optional:%s>' % self.type_.__repr__()

    def __call__(self):

        return self.getval()

    def getval(self):

        """

        returns value from this Optional instance

        """

        if isinstance(self.type_, OAttr):

            # use params name

            return self.type_.attr_name

        return self.type_

    @classmethod

    def extract(cls, val):

        """

        Extracts value from Optional() instance

        :param val:

        :return: original value if it's not Optional instance else

            value of instance

        """

        if isinstance(val, cls):

            return val.getval()

        return val

def urlreadable(s, _cleanstringsub=re.compile('[^-a-zA-Z0-9./]+').sub):

    return _cleanstringsub('_', safe_str(s)).rstrip('_')

def recursive_replace(str_, replace=' '):

    """

    Recursive replace of given sign to just one instance

    :param str_: given string

    :param replace: char to find and replace multiple instances

    Examples::

    >>> recursive_replace("Mighty---Mighty-Bo--sstones",'-')

    'Mighty-Mighty-Bo-sstones'

    """

    if str_.find(replace * 2) == -1:

        return str_

    else:

        str_ = str_.replace(replace * 2, replace)

        return recursive_replace(str_, replace)

def repo_name_slug(value):

    """

    Return slug of name of repository

    This function is called on each creation/modification

    of repository to prevent bad names in repo

    """

    slug = remove_formatting(value)

    slug = strip_tags(slug)

    for c in r"""`?=[]\;'"<>,/~!@#$%^&*()+{}|: """:

        slug = slug.replace(c, '-')

    slug = recursive_replace(slug, '-')

    slug = collapse(slug, '-')

    return slug

def ask_ok(prompt, retries=4, complaint='Yes or no please!'):

    while True:

        ok = raw_input(prompt)

        if ok in ('y', 'ye', 'yes'):

            return True

        if ok in ('n', 'no', 'nop', 'nope'):

            return False

        retries = retries - 1

        if retries < 0:

            raise IOError

        print complaint

import re

from io import BytesIO

from itertools import chain

from subprocess import PIPE, Popen

from dulwich import objects

from dulwich.config import ConfigFile

from kallithea.lib.vcs.backends.base import BaseChangeset, EmptyChangeset

from kallithea.lib.vcs.conf import settings

from kallithea.lib.vcs.exceptions import ChangesetDoesNotExistError, ChangesetError, ImproperArchiveTypeError, NodeDoesNotExistError, RepositoryError, VCSError

from kallithea.lib.vcs.nodes import (

    AddedFileNodesGenerator, ChangedFileNodesGenerator, DirNode, FileNode, NodeKind, RemovedFileNodesGenerator, RootNode, SubModuleNode)

from kallithea.lib.vcs.utils import date_fromtimestamp, safe_int, safe_str, safe_unicode

from kallithea.lib.vcs.utils.lazy import LazyProperty

class GitChangeset(BaseChangeset):

    """

    Represents state of the repository at single revision.

    """

    def __init__(self, repository, revision):

        self._stat_modes = {}

        self.repository = repository

        revision = safe_str(revision)

        try:

            commit = self.repository._repo[revision]

            if isinstance(commit, objects.Tag):

                revision = safe_str(commit.object[1])

                commit = self.repository._repo.get_object(commit.object[1])

        except KeyError:

            raise RepositoryError("Cannot get object with id %s" % revision)

        self.raw_id = revision

        self.id = self.raw_id

        self.short_id = self.raw_id[:12]

        self._commit = commit

        self._tree_id = commit.tree

        self._committer_property = 'committer'

        self._author_property = 'author'

        self._date_property = 'commit_time'

        self._date_tz_property = 'commit_timezone'

        self.revision = repository.revisions.index(revision)

        self.nodes = {}

        self._paths = {}

    @LazyProperty

    def bookmarks(self):

        return ()

    @LazyProperty

    def message(self):

        return safe_unicode(self._commit.message)

    @LazyProperty

    def committer(self):

        return safe_unicode(getattr(self._commit, self._committer_property))

    @LazyProperty

    def author(self):

        return safe_unicode(getattr(self._commit, self._author_property))

    @LazyProperty

    def date(self):

        return date_fromtimestamp(getattr(self._commit, self._date_property),

                                  getattr(self._commit, self._date_tz_property))

    @LazyProperty

    def _timestamp(self):

        return getattr(self._commit, self._date_property)

    @LazyProperty

    def status(self):

        """

        Returns modified, added, removed, deleted files for current changeset

        """

        return self.changed, self.added, self.removed

    @LazyProperty

    def tags(self):

        _tags = []

        for tname, tsha in self.repository.tags.iteritems():

            if tsha == self.raw_id:

                _tags.append(tname)

        return _tags

    @LazyProperty

    def branch(self):

        # Note: This function will return one branch name for the changeset -

        # that might not make sense in Git where branches() is a better match

        # for the basic model

        heads = self.repository._heads(reverse=False)

        ref = heads.get(self.raw_id)

        if ref:

            return safe_unicode(ref)

    @LazyProperty

    def branches(self):

        heads = self.repository._heads(reverse=True)

        return [b for b in heads if heads[b] == self.raw_id] # FIXME: Inefficient ... and returning None!

    def _fix_path(self, path):

        """

        Paths are stored without trailing slash so we need to get rid off it if

        needed.

        """

        if path.endswith('/'):

            path = path.rstrip('/')

        return path

    def _get_id_for_path(self, path):

        path = safe_str(path)

        # FIXME: Please, spare a couple of minutes and make those codes cleaner;

        if path not in self._paths:

            path = path.strip('/')

            # set root tree

            tree = self.repository._repo[self._tree_id]

            if path == '':

                self._paths[''] = tree.id

                return tree.id

            splitted = path.split('/')

            dirs, name = splitted[:-1], splitted[-1]

            curdir = ''

            # initially extract things from root dir

            for item, stat, id in tree.iteritems():

                if curdir:

                    name = '/'.join((curdir, item))

                else:

                    name = item

                self._paths[name] = id

                self._stat_modes[name] = stat

            for dir in dirs:

                if curdir:

                    curdir = '/'.join((curdir, dir))

                else:

                    curdir = dir

                dir_id = None

                for item, stat, id in tree.iteritems():

                    if dir == item:

                        dir_id = id

                if dir_id:

                    # Update tree

                    tree = self.repository._repo[dir_id]

                    if not isinstance(tree, objects.Tree):

                        raise ChangesetError('%s is not a directory' % curdir)

                else:

                    raise ChangesetError('%s have not been found' % curdir)

                # cache all items from the given traversed tree

                for item, stat, id in tree.iteritems():

                    if curdir:

                        name = '/'.join((curdir, item))

                    else:

                        name = item

                    self._paths[name] = id

                    self._stat_modes[name] = stat

            if path not in self._paths:

                raise NodeDoesNotExistError("There is no file nor directory "

                    "at the given path '%s' at revision %s"

                    % (path, safe_str(self.short_id)))

        return self._paths[path]

    def _get_kind(self, path):

        obj = self.repository._repo[self._get_id_for_path(path)]

        if isinstance(obj, objects.Blob):

            return NodeKind.FILE

        elif isinstance(obj, objects.Tree):

            return NodeKind.DIR

    def _get_filectx(self, path):

        path = self._fix_path(path)

        if self._get_kind(path) != NodeKind.FILE:

            raise ChangesetError("File does not exist for revision %s at "

                " '%s'" % (self.raw_id, path))

        return path

    def _get_file_nodes(self):

        return chain(*(t[2] for t in self.walk()))

    @LazyProperty

    def parents(self):

        """

        Returns list of parents changesets.

        """

        return [self.repository.get_changeset(parent)

                for parent in self._commit.parents]

    @LazyProperty

    def children(self):

        """

        Returns list of children changesets.

        """

        rev_filter = settings.GIT_REV_FILTER

        so, se = self.repository.run_git_command(

            ['rev-list', rev_filter, '--children']

        )

        children = []

        pat = re.compile(r'^%s' % self.raw_id)

        for l in so.splitlines():

            if pat.match(l):

                childs = l.split(' ')[1:]

                children.extend(childs)

        return [self.repository.get_changeset(cs) for cs in children]

    def next(self, branch=None):

        if branch and self.branch != branch:

            raise VCSError('Branch option used on changeset not belonging '

                           'to that branch')

        cs = self

        while True:

            try:

                next_ = cs.revision + 1

                next_rev = cs.repository.revisions[next_]

            except IndexError:

                raise ChangesetDoesNotExistError

            cs = cs.repository.get_changeset(next_rev)

            if not branch or branch == cs.branch:

                return cs

    def prev(self, branch=None):

        if branch and self.branch != branch:

            raise VCSError('Branch option used on changeset not belonging '

                           'to that branch')

        cs = self

        while True:

            try:

                prev_ = cs.revision - 1

                if prev_ < 0:

                    raise IndexError

                prev_rev = cs.repository.revisions[prev_]

            except IndexError:

                raise ChangesetDoesNotExistError

            cs = cs.repository.get_changeset(prev_rev)