if url.startswith('git://'):

            return True

        if '+' in url[:url.find('://')]:

            url = url[url.find('+') + 1:]

        handlers = []

        url_obj = hg_url(url)

        test_uri, authinfo = url_obj.authinfo()

        url_obj.passwd = '*****'

        cleaned_uri = str(url_obj)

        if not test_uri.endswith('info/refs'):

            test_uri = test_uri.rstrip('/') + '/info/refs'

        if authinfo:

            # create a password manager

            passmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()

            passmgr.add_password(*authinfo)

            handlers.extend((httpbasicauthhandler(passmgr),

                             httpdigestauthhandler(passmgr)))

        o = urllib2.build_opener(*handlers)

        o.addheaders = [('User-Agent', 'git/1.7.8.0')]  # fake some git

        q = {"service": 'git-upload-pack'}

        qs = '?%s' % urllib.urlencode(q)

        cu = "%s%s" % (test_uri, qs)

        req = urllib2.Request(cu, None, {})

        try:

            resp = o.open(req)

            if resp.code != 200:

                raise Exception('Return Code is not 200')

        except Exception as e:

            # means it cannot be cloned

            raise urllib2.URLError("[%s] org_exc: %s" % (cleaned_uri, e))

        # now detect if it's proper git repo

        gitdata = resp.read()

        if 'service=git-upload-pack' not in gitdata:

            raise urllib2.URLError(

                "url [%s] does not look like an git" % cleaned_uri)

        return True

    def _get_repo(self, create, src_url=None, update_after_clone=False,

                  bare=False):

        if create and os.path.exists(self.path):

            raise RepositoryError("Location already exist")

        if src_url and not create:

            raise RepositoryError("Create should be set to True if src_url is "

                                  "given (clone operation creates repository)")

        try:

            if create and src_url:

                GitRepository._check_url(src_url)

                self.clone(src_url, update_after_clone, bare)

                return Repo(self.path)

            elif create:

                os.makedirs(self.path)

                if bare:

                    return Repo.init_bare(self.path)

                else:

                    return Repo.init(self.path)

            else:

                return Repo(self.path)

        except (NotGitRepository, OSError) as err:

            raise RepositoryError(err)

    def _get_all_revisions(self):

        # we must check if this repo is not empty, since later command

        # fails if it is. And it's cheaper to ask than throw the subprocess

        # errors

        try:

            self._repo.head()

        except KeyError:

            return []

        rev_filter = settings.GIT_REV_FILTER

        cmd = ['rev-list', rev_filter, '--reverse', '--date-order']

        try:

            so = self.run_git_command(cmd)

        except RepositoryError:

            # Can be raised for empty repositories

            return []

        return so.splitlines()

    def _get_all_revisions2(self):

        # alternate implementation using dulwich

        includes = [x[1][0] for x in self._parsed_refs.iteritems()

                    if x[1][1] != 'T']

        return [c.commit.id for c in self._repo.get_walker(include=includes)]

    def _get_revision(self, revision):

        """

        """

        if self._empty:

            raise EmptyRepositoryError("There are no changesets yet")

        if revision in (None, '', 'tip', 'HEAD', 'head', -1):

            try:

            except IndexError:

                msg = ("Revision %s does not exist for %s" % (revision, self))

                raise ChangesetDoesNotExistError(msg)

            # get by branch/tag name

            _ref_revision = self._parsed_refs.get(revision)

            if _ref_revision:  # and _ref_revision[1] in ['H', 'RH', 'T']:

                return _ref_revision[0]

            # maybe it's a tag ? we don't have them in self.revisions

                msg = ("Revision %s does not exist for %s" % (revision, self))

                raise ChangesetDoesNotExistError(msg)

    def get_ref_revision(self, ref_type, ref_name):

        """

        changeset at the given ``revision``.

        """

        return self._get_revision(ref_name)

    def _get_archives(self, archive_name='tip'):

        for i in [('zip', '.zip'), ('gz', '.tar.gz'), ('bz2', '.tar.bz2')]:

            yield {"type": i[0], "extension": i[1], "node": archive_name}

    def _get_url(self, url):

        """

        Returns normalized url. If schema is not given, would fall to

        filesystem (``file:///``) schema.

        """

        url = safe_str(url)

        if url != 'default' and '://' not in url:

            url = ':///'.join(('file', url))

        return url

    def get_hook_location(self):

        """

        returns absolute path to location where hooks are stored

        """

        loc = os.path.join(self.path, 'hooks')

        if not self.bare:

            loc = os.path.join(self.path, '.git', 'hooks')

        return loc

    @LazyProperty

    def name(self):

        return os.path.basename(self.path)

    @LazyProperty

    def last_change(self):

        """

        Returns last change made on this repository as datetime object

        """

        return date_fromtimestamp(self._get_mtime(), makedate()[1])

    def _get_mtime(self):

        try:

            return time.mktime(self.get_changeset().date.timetuple())

        except RepositoryError:

            idx_loc = '' if self.bare else '.git'

            # fallback to filesystem

            in_path = os.path.join(self.path, idx_loc, "index")

            he_path = os.path.join(self.path, idx_loc, "HEAD")

            if os.path.exists(in_path):

                return os.stat(in_path).st_mtime

            else:

                return os.stat(he_path).st_mtime

    @LazyProperty

    def description(self):

        undefined_description = u'unknown'

        _desc = self._repo.get_description()

        return safe_unicode(_desc or undefined_description)

    @LazyProperty

    def contact(self):

        undefined_contact = u'Unknown'

        return undefined_contact

    @property

    def branches(self):

        if not self.revisions:

            return {}

        sortkey = lambda ctx: ctx[0]

        _branches = [(x[0], x[1][0])

                     for x in self._parsed_refs.iteritems() if x[1][1] == 'H']

        return OrderedDict(sorted(_branches, key=sortkey, reverse=False))

    @LazyProperty

    def closed_branches(self):

        return {}

    @LazyProperty

    def tags(self):

        return self._get_tags()

    def _get_tags(self):

        if not self.revisions:

            return {}

        sortkey = lambda ctx: ctx[0]

        _tags = [(x[0], x[1][0])

                 for x in self._parsed_refs.iteritems() if x[1][1] == 'T']

        return OrderedDict(sorted(_tags, key=sortkey, reverse=True))

    def tag(self, name, user, revision=None, message=None, date=None,

            **kwargs):

        """

        Creates and returns a tag for the given ``revision``.

        :param name: name for new tag

        :param user: full username, i.e.: "Joe Doe <joe.doe@example.com>"

# -*- coding: utf-8 -*-

"""

    vcs.backends.hg.repository

    ~~~~~~~~~~~~~~~~~~~~~~~~~~

    Mercurial repository implementation.

    :created_on: Apr 8, 2010

    :copyright: (c) 2010-2011 by Marcin Kuzminski, Lukasz Balcerzak.

"""

import datetime

import logging

import os

import time

import urllib

import urllib2

from collections import OrderedDict

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

from kallithea.lib.vcs.exceptions import (

    BranchDoesNotExistError, ChangesetDoesNotExistError, EmptyRepositoryError, RepositoryError, TagAlreadyExistError, TagDoesNotExistError, VCSError)

from kallithea.lib.vcs.utils.hgcompat import (

    Abort, RepoError, RepoLookupError, clone, diffopts, get_contact, hex, hg_url, httpbasicauthhandler, httpdigestauthhandler, httppeer, localrepo, match_exact, nullid, patch, peer, scmutil, sshpeer, tag, ui)

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

from kallithea.lib.vcs.utils.paths import abspath

from .changeset import MercurialChangeset

from .inmemory import MercurialInMemoryChangeset

from .workdir import MercurialWorkdir

log = logging.getLogger(__name__)

class MercurialRepository(BaseRepository):

    """

    Mercurial repository backend

    """

    DEFAULT_BRANCH_NAME = 'default'

    scm = 'hg'

    def __init__(self, repo_path, create=False, baseui=None, src_url=None,

                 update_after_clone=False):

        """

        Raises RepositoryError if repository could not be find at the given

        ``repo_path``.

        :param repo_path: local path of the repository

        :param create=False: if set to True, would try to create repository if

           it does not exist rather than raising exception

        :param baseui=None: user data

        :param src_url=None: would try to clone repository from given location

        :param update_after_clone=False: sets update of working copy after

          making a clone

        """

        if not isinstance(repo_path, str):

            raise VCSError('Mercurial backend requires repository path to '

                           'be instance of <str> got %s instead' %

                           type(repo_path))

        self.path = abspath(repo_path)

        self.baseui = baseui or ui.ui()

        # We've set path and ui, now we can set _repo itself

        self._repo = self._get_repo(create, src_url, update_after_clone)

    @property

    def _empty(self):

        """

        Checks if repository is empty ie. without any changesets

        """

        # TODO: Following raises errors when using InMemoryChangeset...

        # return len(self._repo.changelog) == 0

        return len(self.revisions) == 0

    @LazyProperty

    def revisions(self):

        """

        Returns list of revisions' ids, in ascending order.  Being lazy

        attribute allows external tools to inject shas from cache.

        """

        return self._get_all_revisions()

    @LazyProperty

    def name(self):

        return os.path.basename(self.path)

    @LazyProperty

    def branches(self):

        return self._get_branches()

    @LazyProperty

    def closed_branches(self):

        return self._get_branches(normal=False, closed=True)

    @LazyProperty

    def allbranches(self):

        """

        List all branches, including closed branches.

        """

        return self._get_branches(closed=True)

    def _get_branches(self, normal=True, closed=False):

        """

        Gets branches for this repository

        Returns only not closed branches by default

        :param closed: return also closed branches for mercurial

        :param normal: return also normal branches

        """

        if self._empty:

            return {}

        bt = OrderedDict()

        for bn, _heads, tip, isclosed in sorted(self._repo.branchmap().iterbranches()):

            if isclosed:

                        ('Accept', 'application/mercurial-0.1')]

        q = {"cmd": 'between'}

        q.update({'pairs': "%s-%s" % ('0' * 40, '0' * 40)})

        qs = '?%s' % urllib.urlencode(q)

        cu = "%s%s" % (test_uri, qs)

        req = urllib2.Request(cu, None, {})

        try:

            resp = o.open(req)

            if resp.code != 200:

                raise Exception('Return Code is not 200')

        except Exception as e:

            # means it cannot be cloned

            raise urllib2.URLError("[%s] org_exc: %s" % (cleaned_uri, e))

        if not url_prefix: # skip svn+http://... (and git+... too)

            # now check if it's a proper hg repo

            try:

                httppeer.instance(repoui or ui.ui(), url, False).lookup('tip')

            except Exception as e:

                raise urllib2.URLError(

                    "url [%s] does not look like an hg repo org_exc: %s"

                    % (cleaned_uri, e))

        return True

    def _get_repo(self, create, src_url=None, update_after_clone=False):

        """

        Function will check for mercurial repository in given path and return

        a localrepo object. If there is no repository in that path it will

        raise an exception unless ``create`` parameter is set to True - in

        that case repository would be created and returned.

        If ``src_url`` is given, would try to clone repository from the

        location at given clone_point. Additionally it'll make update to

        working copy accordingly to ``update_after_clone`` flag

        """

        try:

            if src_url:

                url = safe_str(self._get_url(src_url))

                opts = {}

                if not update_after_clone:

                    opts.update({'noupdate': True})

                MercurialRepository._check_url(url, self.baseui)

                clone(self.baseui, url, self.path, **opts)

                # Don't try to create if we've already cloned repo

                create = False

            return localrepo.instance(self.baseui, self.path, create=create)

        except (Abort, RepoError) as err:

            if create:

                msg = "Cannot create repository at %s. Original error was %s" \

                    % (self.path, err)

            else:

                msg = "Not valid repository at %s. Original error was %s" \

                    % (self.path, err)

            raise RepositoryError(msg)

    @LazyProperty

    def in_memory_changeset(self):

        return MercurialInMemoryChangeset(self)

    @LazyProperty

    def description(self):

        undefined_description = u'unknown'

        _desc = self._repo.ui.config('web', 'description', None, untrusted=True)

        return safe_unicode(_desc or undefined_description)

    @LazyProperty

    def contact(self):

        undefined_contact = u'Unknown'

        return safe_unicode(get_contact(self._repo.ui.config)

                            or undefined_contact)

    @LazyProperty

    def last_change(self):

        """

        Returns last change made on this repository as datetime object

        """

        return date_fromtimestamp(self._get_mtime(), makedate()[1])

    def _get_mtime(self):

        try:

            return time.mktime(self.get_changeset().date.timetuple())

        except RepositoryError:

            # fallback to filesystem

            cl_path = os.path.join(self.path, '.hg', "00changelog.i")

            st_path = os.path.join(self.path, '.hg', "store")

            if os.path.exists(cl_path):

                return os.stat(cl_path).st_mtime

            else:

                return os.stat(st_path).st_mtime

    def _get_revision(self, revision):

        """

        :param revision: str or int or None

        """

        if self._empty:

            raise EmptyRepositoryError("There are no changesets yet")

        if revision in [-1, None]:

            revision = 'tip'

        try:

            if isinstance(revision, int):

                return self._repo[revision].hex()

            return scmutil.revsymbol(self._repo, revision).hex()

        except (IndexError, ValueError, RepoLookupError, TypeError):

            msg = ("Revision %s does not exist for %s" % (revision, self))

            raise ChangesetDoesNotExistError(msg)

        except (LookupError, ):

            msg = ("Ambiguous identifier `%s` for %s" % (revision, self))

            raise ChangesetDoesNotExistError(msg)

    def get_ref_revision(self, ref_type, ref_name):

        """

        Returns revision number for the given reference.

        """

        ref_name = safe_str(ref_name)

        if ref_type == 'rev' and not ref_name.strip('0'):

            return self.EMPTY_CHANGESET

        # lookup up the exact node id

        _revset_predicates = {

                'branch': 'branch',

                'book': 'bookmark',

                'tag': 'tag',

                'rev': 'id',

            }

        # avoid expensive branch(x) iteration over whole repo

        rev_spec = "%%s & %s(%%s)" % _revset_predicates[ref_type]

        try:

            revs = self._repo.revs(rev_spec, ref_name, ref_name)

        except LookupError:

            msg = ("Ambiguous identifier %s:%s for %s" % (ref_type, ref_name, self.name))

            raise ChangesetDoesNotExistError(msg)

        except RepoLookupError:

            msg = ("Revision %s:%s does not exist for %s" % (ref_type, ref_name, self.name))

            raise ChangesetDoesNotExistError(msg)

        if revs:

            revision = revs.last()

        else:

            # TODO: just report 'not found'?

            revision = ref_name

        return self._get_revision(revision)

    def _get_archives(self, archive_name='tip'):

        allowed = self.baseui.configlist("web", "allow_archive",

                                         untrusted=True)

        for i in [('zip', '.zip'), ('gz', '.tar.gz'), ('bz2', '.tar.bz2')]:

            if i[0] in allowed or self._repo.ui.configbool("web",

                                                           "allow" + i[0],

                                                           untrusted=True):

                yield {"type": i[0], "extension": i[1], "node": archive_name}

    def _get_url(self, url):

        """

        Returns normalized url. If schema is not given, would fall

        to filesystem

        (``file:///``) schema.

        """

        url = safe_str(url)

        if url != 'default' and '://' not in url:

            url = "file:" + urllib.pathname2url(url)

        return url

    def get_hook_location(self):

        """

        returns absolute path to location where hooks are stored

        """

        return os.path.join(self.path, '.hg', '.hgrc')

    def get_changeset(self, revision=None):

        """

        Returns ``MercurialChangeset`` object representing repository's

        changeset at the given ``revision``.

        """

        revision = self._get_revision(revision)

        changeset = MercurialChangeset(repository=self, revision=revision)

        return changeset

    def get_changesets(self, start=None, end=None, start_date=None,

                       end_date=None, branch_name=None, reverse=False, max_revisions=None):

        """

        Returns iterator of ``MercurialChangeset`` objects from start to end

        (both are inclusive)

        :param start: None, str, int or mercurial lookup format

        :param end:  None, str, int or mercurial lookup format

        :param start_date:

        :param end_date:

        :param branch_name:

        :param reversed: return changesets in reversed order

        """

        start_raw_id = self._get_revision(start)

        start_pos = self.revisions.index(start_raw_id) if start else None

        end_raw_id = self._get_revision(end)

        end_pos = self.revisions.index(end_raw_id) if end else None