#!/usr/bin/env python

# encoding: utf-8

# middleware to handle mercurial api calls

# Copyright (C) 2009-2010 Marcin Kuzminski <marcin@python-works.com>

# This program is free software; you can redistribute it and/or

# modify it under the terms of the GNU General Public License

# as published by the Free Software Foundation; version 2

# of the License or (at your opinion) any later version of the license.

# 

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

# 

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# 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 datetime import datetime

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 pylons_app.lib.auth import authfunc

from pylons_app.lib.utils import is_mercurial, make_ui, invalidate_cache

from pylons_app.model import meta

from pylons_app.model.db import UserLog, User

from webob.exc import HTTPNotFound

import logging

import os

log = logging.getLogger(__name__)

class SimpleHg(object):

    def __init__(self, application, config):

        self.application = application

        self.config = config

        #authenticate this mercurial request using 

        realm = '%s %s' % (config['hg_app_name'], 'mercurial repository')

        self.authenticate = AuthBasicAuthenticator(realm, authfunc)

    def __call__(self, environ, start_response):

        if not is_mercurial(environ):

            return self.application(environ, start_response)

        else:

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

            # AUTHENTICATE THIS MERCURIAL REQUEST

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

            username = REMOTE_USER(environ)

            if not username:

                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:])

            except Exception as e:

                log.error(e)

                return HTTPNotFound()(environ, start_response)

            #since we wrap into hgweb, just reset the path

            environ['PATH_INFO'] = '/'

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

            self.basepath = self.baseui.configitems('paths')[0][1]\

                                                            .replace('*', '')

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

            try:

                app = wsgiapplication(self.__make_app)

            except Exception as e:

                log.error(e)

                return HTTPNotFound()(environ, start_response)

            action = self.__get_action(environ)            

            #invalidate cache on push

            if action == 'push':

                self.__invalidate_cache(repo_name)

            if action:

                username = self.__get_environ_user(environ)

                self.__log_user_action(username, action, repo_name)

    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:

        """

        mapping = {

            'changegroup': 'pull',

            'changegroupsubset': 'pull',

            'unbundle': 'push',

            'stream_out': 'pull',

        }                    

        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, username, action, repo):

        sa = meta.Session

        try:

            user = sa.query(User).filter(User.username == username).one()

            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',

                                            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)