# MERCURIAL REQUEST HANDLING

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

            environ['PATH_INFO'] = '/'#since we wrap into hgweb, reset the path

            self.baseui = make_ui(self.config['hg_app_repo_conf'])

            self.basepath = self.config['base_path']

            self.repo_path = os.path.join(self.basepath, repo_name)

            try:

                app = wsgiapplication(self.__make_app)

            except Exception:

                log.error(traceback.format_exc())

                return HTTPNotFound()(environ, start_response)

            #invalidate cache on push

            if action == 'push':

                self.__invalidate_cache(repo_name)

            messages = ['thanks for using hg app !']

            return self.msg_wrapper(app, environ, start_response, messages)            

    def msg_wrapper(self, app, environ, start_response, messages):

        """

        Wrapper for custom messages that come out of mercurial respond messages

        is a list of messages that the user will see at the end of response 

        from merurial protocol actions that involves remote answers

        @param app:

        @param environ:

        @param start_response:

        """

        def custom_messages(msg_list):

            for msg in msg_list:

                yield msg + '\n'

        org_response = app(environ, start_response)

        return chain(org_response, custom_messages(messages))

    def __make_app(self):

        hgserve = hgweb(self.repo_path)

        return  self.__load_web_settings(hgserve)

    def __get_environ_user(self, environ):

        return environ.get('REMOTE_USER')

    def __get_action(self, environ):

        """

        Maps mercurial request commands into a pull or push command.

        @param environ:

        """

        for qry in environ['QUERY_STRING'].split('&'):

            if qry.startswith('cmd'):

                cmd = qry.split('=')[-1]

                if mapping.has_key(cmd):

                    return mapping[cmd]

    def __log_user_action(self, user, action, repo):

        sa = meta.Session

        try:

            user_log = UserLog()

            user_log.user_id = user.user_id

            user_log.action = action

            user_log.repository = repo.replace('/', '')

            user_log.action_date = datetime.now()

            sa.add(user_log)

            sa.commit()

            log.info('Adding user %s, action %s on %s',

                                            user.username, action, repo)

        except Exception as e:

            sa.rollback()

            log.error('could not log user action:%s', str(e))

    def __invalidate_cache(self, repo_name):

        """we know that some change was made to repositories and we should

        invalidate the cache to see the changes right away but only for

        push requests"""

        invalidate_cache('cached_repo_list')

        invalidate_cache('full_changelog', repo_name)

    def __load_web_settings(self, hgserve):

        repoui = make_ui(os.path.join(self.repo_path, '.hg', 'hgrc'), False)

        #set the global ui for hgserve

        hgserve.repo.ui = self.baseui

        if repoui:

            #set the repository based config

            hgserve.repo.ui = repoui

        return hgserve