# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

# MA  02110-1301, USA.

"""

Created on 2010-04-28

@author: marcink

SimpleHG middleware for handling mercurial protocol request (push/clone etc.)

It's implemented with basic auth function

"""

from itertools import chain

from mercurial.error import RepoError

from mercurial.hgweb import hgweb

from mercurial.hgweb.request import wsgiapplication

from paste.auth.basic import AuthBasicAuthenticator

from paste.httpheaders import REMOTE_USER, AUTH_TYPE

from rhodecode.lib.auth import authfunc, HasPermissionAnyMiddleware, \

    get_user_cached

from rhodecode.lib.utils import is_mercurial, make_ui, invalidate_cache, \

    check_repo_fast, ui_sections

from webob.exc import HTTPNotFound, HTTPForbidden, HTTPInternalServerError

from rhodecode.lib.utils import action_logger

import logging

import os

import traceback

log = logging.getLogger(__name__)

class SimpleHg(object):

    def __init__(self, application, config):

        self.application = application

        self.config = config

        #authenticate this mercurial request using 

        self.authenticate = AuthBasicAuthenticator('', authfunc)

    def __call__(self, environ, start_response):

        if not is_mercurial(environ):

            return self.application(environ, start_response)

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

        # AUTHENTICATE THIS MERCURIAL REQUEST

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

        username = REMOTE_USER(environ)

        if not username:

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

            result = self.authenticate(environ)

            if isinstance(result, str):

                AUTH_TYPE.update(environ, 'basic')

                REMOTE_USER.update(environ, result)

            else:

                return result.wsgi_application(environ, start_response)

        try:

            repo_name = '/'.join(environ['PATH_INFO'].split('/')[1:])

            if repo_name.endswith('/'):

                repo_name = repo_name.rstrip('/')

        except:

            log.error(traceback.format_exc())

            return HTTPInternalServerError()(environ, start_response)

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

        # CHECK PERMISSIONS FOR THIS REQUEST

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

        action = self.__get_action(environ)

        if action:

            username = self.__get_environ_user(environ)

            try:

                user = self.__get_user(username)

            except:

                log.error(traceback.format_exc())

                return HTTPInternalServerError()(environ, start_response)

            #check permissions for this repository

                if not HasPermissionAnyMiddleware('repository.read',

                                                  'repository.write',

                                                  'repository.admin')\

                                                    (user, repo_name):

                    return HTTPForbidden()(environ, start_response)

            #log action    

            proxy_key = 'HTTP_X_REAL_IP'

            def_key = 'REMOTE_ADDR'

            ipaddr = environ.get(proxy_key, environ.get(def_key, '0.0.0.0'))

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

        # MERCURIAL REQUEST HANDLING

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

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

        self.baseui = make_ui('db')

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

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

        #quick check if that dir exists...

        if check_repo_fast(repo_name, self.basepath):

            return HTTPNotFound()(environ, start_response)

        try:

            app = wsgiapplication(self.__make_app)

        except RepoError, e:

            if str(e).find('not found') != -1:

                return HTTPNotFound()(environ, start_response)

        except Exception:

            log.error(traceback.format_exc())

            return HTTPInternalServerError()(environ, start_response)

        #invalidate cache on push

        if action == 'push':

            self.__invalidate_cache(repo_name)

            messages = []

            messages.append('thank you for using rhodecode')

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

        else:

    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

        """

        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(str(self.repo_path), baseui=self.baseui)

        return  self.__load_web_settings(hgserve)

    def __get_environ_user(self, environ):

        return environ.get('REMOTE_USER')

    def __get_user(self, username):

        return get_user_cached(username)

    def __get_action(self, environ):

        """

        Maps mercurial request commands into a pull or push command.

        """

        mapping = {'changegroup': 'pull',

                   'changegroupsubset': 'pull',

                   'stream_out': 'pull',

                   'listkeys': 'pull',

                   'unbundle': 'push',

                   'pushkey': 'push', }

        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, ipaddr):

        action_logger(user, action, repo, ipaddr)

    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):

        hgserve.repo.ui = self.baseui

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

        repoui = make_ui('file', hgrc, False)

        if repoui:

            #overwrite our ui instance with the section from hgrc file

            for section in ui_sections:

                for k, v in repoui.configitems(section):

                    hgserve.repo.ui.setconfig(section, k, v)

        return hgserve