# -*- 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.base

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

The base Controller API

Provides the BaseController class for subclassing. And usage in different

controllers

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: Oct 06, 2010

:author: marcink

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

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

"""

import datetime

import logging

import traceback

import warnings

import decorator

import paste.auth.basic

import paste.httpexceptions

import paste.httpheaders

import webob.exc

from tg import TGController, config, render_template, request, response, session

from tg import tmpl_context as c

from tg.i18n import ugettext as _

from kallithea import BACKENDS, __version__

from kallithea.config.routing import url

from kallithea.lib import auth_modules

from kallithea.lib.auth import AuthUser, HasPermissionAnyMiddleware

from kallithea.lib.compat import json

from kallithea.lib.exceptions import UserCreationError

from kallithea.lib.utils import get_repo_slug, is_valid_repo

from kallithea.lib.utils2 import AttributeDict, safe_int, safe_str, safe_unicode, set_hook_environment, str2bool

from kallithea.lib.vcs.exceptions import ChangesetDoesNotExistError, EmptyRepositoryError, RepositoryError

from kallithea.model import meta

from kallithea.model.db import PullRequest, Repository, Setting, User

from kallithea.model.scm import ScmModel

log = logging.getLogger(__name__)

def render(template_path):

    return render_template({'url': url}, 'mako', template_path)

def _filter_proxy(ip):

    """

    HEADERS can have multiple ips inside the left-most being the original

    client, and each successive proxy that passed the request adding the IP

    address where it received the request from.

    :param ip:

    """

    if ',' in ip:

        _ips = ip.split(',')

        _first_ip = _ips[0].strip()

        log.debug('Got multiple IPs %s, using %s', ','.join(_ips), _first_ip)

        return _first_ip

    return ip

def _get_ip_addr(environ):

    proxy_key = 'HTTP_X_REAL_IP'

    proxy_key2 = 'HTTP_X_FORWARDED_FOR'

    def_key = 'REMOTE_ADDR'

    ip = environ.get(proxy_key)

    if ip:

        return _filter_proxy(ip)

    ip = environ.get(proxy_key2)

    if ip:

        return _filter_proxy(ip)

    ip = environ.get(def_key, '0.0.0.0')

    return _filter_proxy(ip)

def _get_access_path(environ):

    """Return PATH_INFO from environ ... using tg.original_request if available."""

    org_req = environ.get('tg.original_request')

    if org_req is not None:

        environ = org_req.environ

    return environ.get('PATH_INFO')

def log_in_user(user, remember, is_external_auth, ip_addr):

    """

    Log a `User` in and update session and cookies. If `remember` is True,

    the session cookie is set to expire in a year; otherwise, it expires at

    the end of the browser session.

    Returns populated `AuthUser` object.

    """

    # It should not be possible to explicitly log in as the default user.

    assert not user.is_default_user, user

    auth_user = AuthUser.make(dbuser=user, is_external_auth=is_external_auth, ip_addr=ip_addr)

    if auth_user is None:

        return None

    user.update_lastlogin()

    meta.Session().commit()

    # Start new session to prevent session fixation attacks.

    session.invalidate()

    session['authuser'] = cookie = auth_user.to_cookie()

    # If they want to be remembered, update the cookie.

    # NOTE: Assumes that beaker defaults to browser session cookie.

    if remember:

        t = datetime.datetime.now() + datetime.timedelta(days=365)

        session._set_cookie_expires(t)

    session.save()

    log.info('user %s is now authenticated and stored in '

             'session, session attrs %s', user.username, cookie)

    # dumps session attrs back to cookie

    session._update_cookie_out()

    return auth_user

class BasicAuth(paste.auth.basic.AuthBasicAuthenticator):

    def __init__(self, realm, authfunc, auth_http_code=None):

        self.realm = realm

        self.authfunc = authfunc

        self._rc_auth_http_code = auth_http_code

    def build_authentication(self, environ):

        head = paste.httpheaders.WWW_AUTHENTICATE.tuples('Basic realm="%s"' % self.realm)

        # Consume the whole body before sending a response

        try:

            request_body_size = int(environ.get('CONTENT_LENGTH', 0))

        except (ValueError):

            request_body_size = 0

        environ['wsgi.input'].read(request_body_size)

        if self._rc_auth_http_code and self._rc_auth_http_code == '403':

            # return 403 if alternative http return code is specified in

            # Kallithea config

            return paste.httpexceptions.HTTPForbidden(headers=head)

        return paste.httpexceptions.HTTPUnauthorized(headers=head)

    def authenticate(self, environ):

        authorization = paste.httpheaders.AUTHORIZATION(environ)

        if not authorization:

            return self.build_authentication(environ)

        (authmeth, auth) = authorization.split(' ', 1)

        if 'basic' != authmeth.lower():

            return self.build_authentication(environ)

        auth = auth.strip().decode('base64')

        _parts = auth.split(':', 1)

        if len(_parts) == 2:

            username, password = _parts

            if self.authfunc(username, password, environ) is not None:

                return username

        return self.build_authentication(environ)

    __call__ = authenticate

class BaseVCSController(object):

    """Base controller for handling Mercurial/Git protocol requests

    (coming from a VCS client, and not a browser).

    """

    scm_alias = None # 'hg' / 'git'

    def __init__(self, application, config):

        self.application = application

        self.config = config

        # base path of repo locations

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

        # authenticate this VCS request using the authentication modules

        self.authenticate = BasicAuth('', auth_modules.authenticate,

                                      config.get('auth_ret_code'))

    @classmethod

    def parse_request(cls, environ):

        """If request is parsed as a request for this VCS, return a namespace with the parsed request.

        If the request is unknown, return None.

        """

        raise NotImplementedError()

    def _authorize(self, environ, action, repo_name, ip_addr):

        """Authenticate and authorize user.

        Since we're dealing with a VCS client and not a browser, we only

        support HTTP basic authentication, either directly via raw header

        inspection, or by using container authentication to delegate the

        authentication to the web server.

        Returns (user, None) on successful authentication and authorization.

        Returns (None, wsgi_app) to send the wsgi_app response to the client.

        """

        # Use anonymous access if allowed for action on repo.

        default_user = User.get_default_user(cache=True)

        default_authuser = AuthUser.make(dbuser=default_user, ip_addr=ip_addr)

        if default_authuser is None:

            log.debug('No anonymous access at all') # move on to proper user auth

        else:

            if self._check_permission(action, default_authuser, repo_name):

                return default_authuser, None

            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 = safe_str(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):

        """

        Checks permissions using action (push/pull) user and repository

        name

        :param action: 'push' or 'pull' action

        :param user: `User` instance

        :param repo_name: repository name

        """

        if action == 'push':

            if not HasPermissionAnyMiddleware('repository.write',

                                              'repository.admin')(authuser,

                                                                  repo_name):

                return False

        else:

            #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, safe_str(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)

class BaseController(TGController):

    def _before(self, *args, **kwargs):

        """

        _before is called before controller methods and after __call__

        """

        if request.needs_csrf_check:

            # CSRF protection: Whenever a request has ambient authority (whether

            # through a session cookie or its origin IP address), it must include

            # the correct token, unless the HTTP method is GET or HEAD (and thus

            # guaranteed to be side effect free. In practice, the only situation

            # where we allow side effects without ambient authority is when the

            # authority comes from an API key; and that is handled above.

            from kallithea.lib import helpers as h

            token = request.POST.get(h.session_csrf_secret_name)

            if not token or token != h.session_csrf_secret_token():

                log.error('CSRF check failed')

                raise webob.exc.HTTPForbidden()

        c.kallithea_version = __version__

        rc_config = Setting.get_app_settings()

        # Visual options

        c.visual = AttributeDict({})

        ## DB stored

        c.visual.show_public_icon = str2bool(rc_config.get('show_public_icon'))

        c.visual.show_private_icon = str2bool(rc_config.get('show_private_icon'))

        c.visual.stylify_metalabels = str2bool(rc_config.get('stylify_metalabels'))

        c.visual.page_size = safe_int(rc_config.get('dashboard_items', 100))

        c.visual.admin_grid_items = safe_int(rc_config.get('admin_grid_items', 100))

        c.visual.repository_fields = str2bool(rc_config.get('repository_fields'))

        c.visual.show_version = str2bool(rc_config.get('show_version'))

        c.visual.use_gravatar = str2bool(rc_config.get('use_gravatar'))

        c.visual.gravatar_url = rc_config.get('gravatar_url')

        c.ga_code = rc_config.get('ga_code')

        # TODO: replace undocumented backwards compatibility hack with db upgrade and rename ga_code

        if c.ga_code and '<' not in c.ga_code:

            c.ga_code = '''<script type="text/javascript">

                var _gaq = _gaq || [];

                _gaq.push(['_setAccount', '%s']);

                _gaq.push(['_trackPageview']);

                (function() {

                    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;

                    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';

                    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);

                    })();

            </script>''' % c.ga_code

        c.site_name = rc_config.get('title')

        c.clone_uri_tmpl = rc_config.get('clone_uri_tmpl') or Repository.DEFAULT_CLONE_URI

        c.clone_ssh_tmpl = rc_config.get('clone_ssh_tmpl') or Repository.DEFAULT_CLONE_SSH

        ## INI stored

        c.visual.allow_repo_location_change = str2bool(config.get('allow_repo_location_change', True))

        c.visual.allow_custom_hooks_settings = str2bool(config.get('allow_custom_hooks_settings', True))

        c.ssh_enabled = str2bool(config.get('ssh_enabled', False))

        c.instance_id = config.get('instance_id')

        c.issues_url = config.get('bugtracker', url('issues_url'))

        # END CONFIG VARS

        c.repo_name = get_repo_slug(request)  # can be empty

        c.backends = BACKENDS.keys()

        self.cut_off_limit = safe_int(config.get('cut_off_limit'))

        c.my_pr_count = PullRequest.query(reviewer_id=request.authuser.user_id, include_closed=False).count()

        self.scm_model = ScmModel()

    @staticmethod

    def _determine_auth_user(session_authuser, ip_addr):

        """

        Create an `AuthUser` object given the API key/bearer token

        (if any) and the value of the authuser session cookie.

        Returns None if no valid user is found (like not active or no access for IP).

        """

        # Authenticate by session cookie

        # In ancient login sessions, 'authuser' may not be a dict.

        # In that case, the user will have to log in again.

        # v0.3 and earlier included an 'is_authenticated' key; if present,

        # this must be True.

        if isinstance(session_authuser, dict) and session_authuser.get('is_authenticated', True):

            return AuthUser.from_cookie(session_authuser, ip_addr=ip_addr)

        # Authenticate by auth_container plugin (if enabled)

        if any(

            plugin.is_container_auth

            for plugin in auth_modules.get_auth_plugins()

        ):

            try:

                user_info = auth_modules.authenticate('', '', request.environ)

            except UserCreationError as e:

                from kallithea.lib import helpers as h

                h.flash(e, 'error', logf=log.error)

            else:

                if user_info is not None:

                    username = user_info['username']

                    user = User.get_by_username(username, case_insensitive=True)

                    return log_in_user(user, remember=False, is_external_auth=True, ip_addr=ip_addr)

        # User is default user (if active) or anonymous

        default_user = User.get_default_user(cache=True)

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

        if authuser is None: # fall back to anonymous

            authuser = AuthUser(dbuser=default_user) # TODO: somehow use .make?

        return authuser

    @staticmethod

    def _basic_security_checks():

        """Perform basic security/sanity checks before processing the request."""

        # Only allow the following HTTP request methods.

        if request.method not in ['GET', 'HEAD', 'POST']:

            raise webob.exc.HTTPMethodNotAllowed()

        # Also verify the _method override - no longer allowed.

        if request.params.get('_method') is None:

            pass # no override, no problem

        else:

            raise webob.exc.HTTPMethodNotAllowed()

        # Make sure CSRF token never appears in the URL. If so, invalidate it.

        from kallithea.lib import helpers as h

        if h.session_csrf_secret_name in request.GET:

            log.error('CSRF key leak detected')

            session.pop(h.session_csrf_secret_name, None)

            session.save()

            h.flash(_('CSRF token leak has been detected - all form tokens have been expired'),

                    category='error')

        # WebOb already ignores request payload parameters for anything other

        # than POST/PUT, but double-check since other Kallithea code relies on

        # this assumption.

        if request.method not in ['POST', 'PUT'] and request.POST:

            log.error('%r request with payload parameters; WebOb should have stopped this', request.method)

            raise webob.exc.HTTPBadRequest()

    def __call__(self, environ, context):

        try:

            ip_addr = _get_ip_addr(environ)

            self._basic_security_checks()

            api_key = request.GET.get('api_key')

            try:

                # Request.authorization may raise ValueError on invalid input

                type, params = request.authorization

            except (ValueError, TypeError):

                pass

            else:

                if type.lower() == 'bearer':

                    api_key = params # bearer token is an api key too

            if api_key is None:

                authuser = self._determine_auth_user(

                    session.get('authuser'),

                    ip_addr=ip_addr,

                )

                needs_csrf_check = request.method not in ['GET', 'HEAD']

            else:

                dbuser = User.get_by_api_key(api_key)

                if dbuser is None:

                    log.info('No db user found for authentication with API key ****%s from %s',

                             api_key[-4:], ip_addr)

                authuser = AuthUser.make(dbuser=dbuser, is_external_auth=True, ip_addr=ip_addr)

                needs_csrf_check = False # API key provides CSRF protection

            if authuser is None:

                log.info('No valid user found')

                raise webob.exc.HTTPForbidden()

            # set globals for auth user

            request.authuser = authuser

            request.ip_addr = ip_addr

            request.needs_csrf_check = needs_csrf_check

            log.info('IP: %s User: %s accessed %s',

                request.ip_addr, request.authuser,

                safe_unicode(_get_access_path(environ)),

            )

            return super(BaseController, self).__call__(environ, context)

        except webob.exc.HTTPException as e:

            return e

class BaseRepoController(BaseController):