log.debug('Not authorized to access this repository as anonymous user')

        username = None

        #==============================================================

        # DEFAULT PERM FAILED OR ANONYMOUS ACCESS IS DISABLED SO WE

        # NEED TO AUTHENTICATE AND ASK FOR AUTH USER PERMISSIONS

        #==============================================================

        # try to auth based on environ, container auth methods

        log.debug('Running PRE-AUTH for container based authentication')

        pre_auth = auth_modules.authenticate('', '', environ)

        if pre_auth is not None and pre_auth.get('username'):

            username = pre_auth['username']

        log.debug('PRE-AUTH got %s as username', username)

        # If not authenticated by the container, running basic auth

        if not username:

            self.authenticate.realm = self.config['realm']

            result = self.authenticate(environ)

            if isinstance(result, str):

                paste.httpheaders.AUTH_TYPE.update(environ, 'basic')

                paste.httpheaders.REMOTE_USER.update(environ, result)

                username = result

            else:

                return None, result.wsgi_application

        #==============================================================

        # CHECK PERMISSIONS FOR THIS REQUEST USING GIVEN USERNAME

        #==============================================================

        try:

            user = User.get_by_username_or_email(username)

        except Exception:

            log.error(traceback.format_exc())

            return None, webob.exc.HTTPInternalServerError()

        authuser = AuthUser.make(dbuser=user, ip_addr=ip_addr)

        if authuser is None:

            return None, webob.exc.HTTPForbidden()

        if not self._check_permission(action, authuser, repo_name):

            return None, webob.exc.HTTPForbidden()

        return user, None

    def _handle_request(self, environ, start_response):

        raise NotImplementedError()

    def _check_permission(self, action, authuser, repo_name):

        """

        :param repo_name: repository name

        """

        if action == 'push':

            if not HasPermissionAnyMiddleware('repository.write',

                                              'repository.admin')(authuser,

                                                                  repo_name):

                return False

            #any other action need at least read permission

            if not HasPermissionAnyMiddleware('repository.read',

                                              'repository.write',

                                              'repository.admin')(authuser,

                                                                  repo_name):

                return False

        return True

    def _get_ip_addr(self, environ):

        return _get_ip_addr(environ)

    def __call__(self, environ, start_response):

        try:

            # try parsing a request for this VCS - if it fails, call the wrapped app

            parsed_request = self.parse_request(environ)

            if parsed_request is None:

                return self.application(environ, start_response)

            # skip passing error to error controller

            environ['pylons.status_code_redirect'] = True

            # quick check if repo exists...

            if not is_valid_repo(parsed_request.repo_name, self.basepath, self.scm_alias):

                raise webob.exc.HTTPNotFound()

            if parsed_request.action is None:

                # Note: the client doesn't get the helpful error message

                raise webob.exc.HTTPBadRequest('Unable to detect pull/push action for %r! Are you using a nonstandard command or client?' % parsed_request.repo_name)

            #======================================================================

            # CHECK PERMISSIONS

            #======================================================================

            ip_addr = self._get_ip_addr(environ)

            user, response_app = self._authorize(environ, parsed_request.action, parsed_request.repo_name, ip_addr)

            if response_app is not None:

                return response_app(environ, start_response)

            #======================================================================

            # REQUEST HANDLING

            #======================================================================

            set_hook_environment(user.username, ip_addr,

                parsed_request.repo_name, self.scm_alias, parsed_request.action)

            try:

                log.info('%s action on %s repo "%s" by "%s" from %s',

                         parsed_request.action, self.scm_alias, parsed_request.repo_name, user.username, ip_addr)

                app = self._make_app(parsed_request)

                return app(environ, start_response)

            except Exception:

                log.error(traceback.format_exc())

                raise webob.exc.HTTPInternalServerError()

        except webob.exc.HTTPException as e:

            return e(environ, start_response)