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

# 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, either version 3 of the License, or

# (at your option) any later version.

#

# 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, see <http://www.gnu.org/licenses/>.

"""

kallithea.lib.middleware.simplehg

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

SimpleHg middleware for handling mercurial protocol request

(push/clone etc.). It's implemented with basic auth function

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Apr 28, 2010

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import os

import logging

import traceback

from paste.httpheaders import REMOTE_USER, AUTH_TYPE

from webob.exc import HTTPNotFound, HTTPForbidden, HTTPInternalServerError, \

    HTTPNotAcceptable

from kallithea.model.db import User

from kallithea.lib.utils2 import safe_str, safe_unicode, fix_PATH, get_server_url, \

    _set_extras

from kallithea.lib.base import BaseVCSController, WSGIResultCloseCallback

from kallithea.lib.utils import make_ui, is_valid_repo, ui_sections

from kallithea.lib.vcs.utils.hgcompat import RepoError, hgweb_mod

from kallithea.lib.exceptions import HTTPLockedRC

from kallithea.lib import auth_modules

log = logging.getLogger(__name__)

def is_mercurial(environ):

    """

    Returns True if request's target is mercurial server - header

    ``HTTP_ACCEPT`` of such request would start with ``application/mercurial``.

    """

    http_accept = environ.get('HTTP_ACCEPT')

    path_info = environ['PATH_INFO']

    if http_accept and http_accept.startswith('application/mercurial'):

        ishg_path = True

    else:

        ishg_path = False

    log.debug('pathinfo: %s detected as Mercurial %s',

        path_info, ishg_path

    )

    return ishg_path

class SimpleHg(BaseVCSController):

    def _handle_request(self, environ, start_response):

        if not is_mercurial(environ):

            return self.application(environ, start_response)

        if not self._check_ssl(environ):

            return HTTPNotAcceptable('SSL REQUIRED !')(environ, start_response)

        ip_addr = self._get_ip_addr(environ)

        username = None

        # skip passing error to error controller

        environ['pylons.status_code_redirect'] = True

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

        # EXTRACT REPOSITORY NAME FROM ENV

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

        try:

            str_repo_name = environ['REPO_NAME'] = self.__get_repository(environ)

            assert isinstance(str_repo_name, str)

            repo_name = safe_unicode(str_repo_name)

            assert safe_str(repo_name) == str_repo_name, (str_repo_name, repo_name)

            log.debug('Extracted repo name is %s', repo_name)

        except Exception as e:

            log.error('error extracting repo_name: %r', e)

            return HTTPInternalServerError()(environ, start_response)

        # quick check if that dir exists...

        if not is_valid_repo(repo_name, self.basepath, 'hg'):

            return HTTPNotFound()(environ, start_response)

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

        # GET ACTION PULL or PUSH

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

        action = self.__get_action(environ)

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

        # CHECK ANONYMOUS PERMISSION

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

        if action in ['pull', 'push']:

            anonymous_user = User.get_default_user(cache=True)

            username = anonymous_user.username

            if anonymous_user.active:

                # ONLY check permissions if the user is activated

                anonymous_perm = self._check_permission(action, anonymous_user,

                                                        repo_name, ip_addr)

            else:

                anonymous_perm = False

            if not anonymous_user.active or not anonymous_perm:

                if not anonymous_user.active:

                    log.debug('Anonymous access is disabled, running '

                              'authentication')

                if not anonymous_perm:

                    log.debug('Not enough credentials 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 = \

                        safe_str(self.config['realm'])

                    result = self.authenticate(environ)

                    if isinstance(result, str):

                        AUTH_TYPE.update(environ, 'basic')

                        REMOTE_USER.update(environ, result)

                        username = result

                    else:

                        return result.wsgi_application(environ, start_response)

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

                # CHECK PERMISSIONS FOR THIS REQUEST USING GIVEN USERNAME

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

                try:

                    user = User.get_by_username_or_email(username)

                    if user is None or not user.active:

                        return HTTPForbidden()(environ, start_response)

                    username = user.username

                except Exception:

                    log.error(traceback.format_exc())

                    return HTTPInternalServerError()(environ, start_response)

                #check permissions for this repository

                perm = self._check_permission(action, user, repo_name, ip_addr)

                if not perm:

                    return HTTPForbidden()(environ, start_response)

        # extras are injected into mercurial UI object and later available

        # in hg hooks executed by kallithea

        from kallithea import CONFIG

        server_url = get_server_url(environ)

        extras = {

            'ip': ip_addr,

            'username': username,

            'action': action,

            'repository': repo_name,

            'scm': 'hg',

            'config': CONFIG['__file__'],

            'server_url': server_url,

            'make_lock': None,

            'locked_by': [None, None]

        }

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

        # MERCURIAL REQUEST HANDLING

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

        repo_path = os.path.join(safe_str(self.basepath), str_repo_name)

        log.debug('Repository path is %s', repo_path)

        # CHECK LOCKING only if it's not ANONYMOUS USER

        if username != User.DEFAULT_USER:

            log.debug('Checking locking on repository')

            (make_lock,

             locked,

             locked_by) = self._check_locking_state(

                            environ=environ, action=action,

                            repo=repo_name, user_id=user.user_id

                       )

            # store the make_lock for later evaluation in hooks

            extras.update({'make_lock': make_lock,

                           'locked_by': locked_by})

        fix_PATH()

        log.debug('HOOKS extras is %s', extras)

        baseui = make_ui('db')

        self.__inject_extras(repo_path, baseui, extras)

        try:

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

                     action, str_repo_name, safe_str(username), ip_addr)

            app = self.__make_app(repo_path, baseui, extras)

            result = app(environ, start_response)

            if action == 'push':

                result = WSGIResultCloseCallback(result,

                    lambda: self._invalidate_cache(repo_name))

            return result

        except RepoError as e:

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

                return HTTPNotFound()(environ, start_response)

        except HTTPLockedRC as e:

            log.debug('Locked, response %s: %s', e.code, e.title)

            return e(environ, start_response)

        except Exception:

            log.error(traceback.format_exc())

            return HTTPInternalServerError()(environ, start_response)

    def __make_app(self, repo_name, baseui, extras):

        """

        Make an wsgi application using hgweb, and inject generated baseui

        instance, additionally inject some extras into ui object

        """

    def __get_repository(self, environ):

        """

        Gets repository name out of PATH_INFO header

        :param environ: environ where PATH_INFO is stored

        """

        try:

            environ['PATH_INFO'] = self._get_by_id(environ['PATH_INFO'])

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

            if repo_name.endswith('/'):

                repo_name = repo_name.rstrip('/')

        except Exception:

            log.error(traceback.format_exc())

            raise

        return repo_name

    def __get_action(self, environ):

        """

        Maps mercurial request commands into a clone,pull or push command.

        This should always return a valid command string

        :param environ:

        """

        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 cmd in mapping:

                    return mapping[cmd]

                return 'pull'

        raise Exception('Unable to detect pull/push action !!'

                        'Are you using non standard command or client ?')

    def __inject_extras(self, repo_path, baseui, extras=None):

        """

        Injects some extra params into baseui instance

        also overwrites global settings with those takes from local hgrc file

        :param baseui: baseui instance

        :param extras: dict with extra params to put into baseui

        """

        hgrc = os.path.join(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):

                    baseui.setconfig(section, k, v)

        _set_extras(extras or {})