# -*- 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/>.

"""

    Pylons middleware initialization

"""

from routes.middleware import RoutesMiddleware

from paste.cascade import Cascade

from paste.registry import RegistryManager

from paste.urlparser import StaticURLParser

from paste.deploy.converters import asbool

from paste.gzipper import make_gzip_middleware

from pylons.middleware import ErrorHandler, StatusCodeRedirect

from pylons.wsgiapp import PylonsApp

from kallithea.lib.middleware.simplehg import SimpleHg

from kallithea.lib.middleware.simplegit import SimpleGit

from kallithea.lib.middleware.https_fixup import HttpsFixup

from kallithea.lib.middleware.sessionmiddleware import SecureSessionMiddleware

from kallithea.config.environment import load_environment

from kallithea.lib.middleware.wrapper import RequestWrapper

def make_app(global_conf, full_stack=True, static_files=True, **app_conf):

    """Create a Pylons WSGI application and return it

    ``global_conf``

        The inherited configuration for this application. Normally from

        the [DEFAULT] section of the Paste ini file.

    ``full_stack``

        Whether or not this application provides a full WSGI stack (by

        default, meaning it handles its own exceptions and errors).

        Disable full_stack when this application is "managed" by

        another WSGI middleware.

    ``app_conf``

        The application's local configuration. Normally specified in

        the [app:<name>] section of the Paste ini file (where <name>

        defaults to main).

    """

    # Configure the Pylons environment

    config = load_environment(global_conf, app_conf)

    # The Pylons WSGI app

    app = PylonsApp(config=config)

    # Routing/Session/Cache Middleware

    app = SecureSessionMiddleware(app, config)

    # CUSTOM MIDDLEWARE HERE (filtered by error handling middlewares)

    if asbool(config['pdebug']):

        from kallithea.lib.profiler import ProfilingMiddleware

        app = ProfilingMiddleware(app)

    if asbool(full_stack):

        from kallithea.lib.middleware.sentry import Sentry

        from kallithea.lib.middleware.errormator import Errormator

        if Errormator and asbool(config['app_conf'].get('errormator')):

            app = Errormator(app, config)

        elif Sentry:

            app = Sentry(app, config)

        # Handle Python exceptions

        app = ErrorHandler(app, global_conf, **config['pylons.errorware'])

        # Display error documents for 401, 403, 404 status codes (and

        # 500 when debug is disabled)

        # Note: will buffer the output in memory!

        if asbool(config['debug']):

            app = StatusCodeRedirect(app)

        else:

            app = StatusCodeRedirect(app, [400, 401, 403, 404, 500])

        # we want our low level middleware to get to the request ASAP. We don't

        # need any pylons stack middleware in them - especially no StatusCodeRedirect buffering

        app = SimpleHg(app, config)

        app = SimpleGit(app, config)

        # Enable https redirects based on HTTP_X_URL_SCHEME set by proxy

        if any(asbool(config.get(x)) for x in ['https_fixup', 'force_https', 'use_htsts']):

            app = HttpsFixup(app, config)

        app = RequestWrapper(app, config) # logging

    # Establish the Registry for this application

    app = RegistryManager(app) # thread / request-local module globals / variables

    if asbool(static_files):

        # Serve static files

        static_app = StaticURLParser(config['pylons.paths']['static_files'])

        app = Cascade([static_app, app])

        app = make_gzip_middleware(app, global_conf, compress_level=1)

    app.config = config

    return app

                except ObjectDeletedError:

                    # since we use heavy caching sometimes it happens that we get

                    # deleted objects here, we just skip them

                    pass

        user_ips = UserIpMap.query().filter(UserIpMap.user_id == user_id)

        if cache:

            user_ips = user_ips.options(FromCache("sql_cache_short",

                                                  "get_user_ips_%s" % user_id))

        for ip in user_ips:

            try:

                _set.add(ip.ip_addr)

            except ObjectDeletedError:

                # since we use heavy caching sometimes it happens that we get

                # deleted objects here, we just skip them

                pass

        return _set or set(['0.0.0.0/0', '::/0'])

def set_available_permissions(config):

    """

    This function will propagate pylons globals with all available defined

    permission given in db. We don't want to check each time from db for new

    permissions since adding a new permission also requires application restart

    ie. to decorate new views with the newly created permission

    :param config: current pylons config instance

    """

    log.info('getting information about all available permissions')

    try:

        sa = meta.Session

        all_perms = sa.query(Permission).all()

        config['available_permissions'] = [x.permission_name for x in all_perms]

    finally:

        meta.Session.remove()

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

# CHECK DECORATORS

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

def _redirect_to_login(message=None):

    """Return an exception that must be raised. It will redirect to the login

    page which will redirect back to the current URL after authentication.

    The optional message will be shown in a flash message."""

    from kallithea.lib import helpers as h

    if message:

        h.flash(h.literal(message), category='warning')

    p = request.path_qs

    log.debug('Redirecting to login page, origin: %s', p)

    return HTTPFound(location=url('login_home', came_from=p))

class LoginRequired(object):

    """

    Must be logged in to execute this function else

    redirect to login page

    :param api_access: if enabled this checks only for valid auth token

        and grants access based on valid token

    """

    def __init__(self, api_access=False):

        self.api_access = api_access

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        controller = fargs[0]

        user = controller.authuser

        loc = "%s:%s" % (controller.__class__.__name__, func.__name__)

        log.debug('Checking access for user %s @ %s', user, loc)

        if not AuthUser.check_ip_allowed(user, controller.ip_addr):

            raise _redirect_to_login(_('IP %s not allowed') % controller.ip_addr)

        # check if we used an API key and it's a valid one

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

        if api_key is not None:

            # explicit controller is enabled or API is in our whitelist

            if self.api_access or allowed_api_access(loc, api_key=api_key):

                if api_key in user.api_keys:

                    log.info('user %s authenticated with API key ****%s @ %s',

                             user, api_key[-4:], loc)

                    return func(*fargs, **fkwargs)

                else:

                    log.warning('API key ****%s is NOT valid', api_key[-4:])

                    raise _redirect_to_login(_('Invalid API key'))

            else:

                # controller does not allow API access

                log.warning('API access to %s is not allowed', loc)

                raise HTTPForbidden()

            raise HTTPMethodNotAllowed()

        _method = request.params.get('_method')

        if _method is None:

            pass # no override, no problem

        else:

            raise HTTPMethodNotAllowed()

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

        if secure_form.token_key in request.GET:

            log.error('CSRF key leak detected')

            session.pop(secure_form.token_key, None)

            session.save()

            from kallithea.lib import helpers as h

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

                    category='error')

        # 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.

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

            token = request.POST.get(secure_form.token_key)

            if not token or token != secure_form.authentication_token():

                log.error('CSRF check failed')

                raise HTTPForbidden()

        # 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 HTTPBadRequest()

        # regular user authentication

        if user.is_authenticated or user.is_default_user:

            log.info('user %s authenticated with regular auth @ %s', user, loc)

            return func(*fargs, **fkwargs)

        else:

            log.warning('user %s NOT authenticated with regular auth @ %s', user, loc)

            raise _redirect_to_login()

class NotAnonymous(object):

    """

    Must be logged in to execute this function else

    redirect to login page"""

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        cls = fargs[0]

        self.user = cls.authuser

        log.debug('Checking if user is not anonymous @%s', cls)

        if self.user.is_default_user:

            raise _redirect_to_login(_('You need to be a registered user to '

                                       'perform this action'))

        else:

            return func(*fargs, **fkwargs)

class PermsDecorator(object):

    """Base class for controller decorators"""

    def __init__(self, *required_perms):

        self.required_perms = set(required_perms)

        self.user_perms = None

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        cls = fargs[0]

        self.user = cls.authuser

        self.user_perms = self.user.permissions

        log.debug('checking %s permissions %s for %s %s',

          self.__class__.__name__, self.required_perms, cls, self.user)

        if self.check_permissions():

            log.debug('Permission granted for %s %s', cls, self.user)

            return func(*fargs, **fkwargs)

        else:

            log.debug('Permission denied for %s %s', cls, self.user)

            if self.user.is_default_user:

                raise _redirect_to_login(_('You need to be signed in to view this page'))

            else:

                raise HTTPForbidden()

    def check_permissions(self):

        """Dummy function for overriding"""

        raise Exception('You have to write this function in child class')

class HasPermissionAnyDecorator(PermsDecorator):

    """

    Checks for access permission for any of given predicates. In order to