views.py

"""

Auth views
~~~~~~~~~~
"""
import functools

from pyramid.security import (
    remember,
    forget,
    authenticated_userid,
)

from colander import (
    Invalid,
)

from mylib.views import (
    InvalidDataError,
)

from .models import (
    AuthUser,
)

from .schemas import (
    Login,
)


def data_schema(schema, message=None, status=400):
    """Adds client data validation to a request

    The schema validates the client data, not route parameters.

    The validated data will be added to the request under 'validated_data'
    """

    def decorator(view):

        @functools.wraps(view)
        def wrapper(request):
            try:
                data = schema().deserialize(request.client_data())
            except Invalid as e:
                raise InvalidDataError(message=message,
                                       errors=e.asdict(),
                                       status=status)

            setattr(request, 'validated_data', data)

            return view(request)

        return wrapper

    return decorator


def validate(validator, message=None, status=400):
    """Run a validator before the view

    The validator method should raise an error if validation failed.

    The validator will be called like this: validator(request).
    """

    def decorator(view):

        @functools.wraps(view)
        def wrapper(request):
            validator(request)
            return view(request)

        return wrapper

    return decorator


def require_not_authenticated(request):

    if authenticated_userid(request):
        raise InvalidDataError(message='You are already logged in')


@data_schema(schema=Login)
@validate(require_not_authenticated)
def login(request):
    """Login user"""

    user_data = request.validated_data

    user = request.db_session.query(
        AuthUser).filter_by(
                username=user_data['username']).first()

    if not user or not user.validate_password(user_data['password']):
        raise InvalidDataError(message='Invalid login')

    headers = remember(request, user.id)
    request.response.headerlist.extend(headers)

    return request.response


def require_authenticated(request):

    if not authenticated_userid(request):
        raise InvalidDataError(message='You are not logged in')


@validate(require_authenticated)
def logout(request):
    """Logout user"""

    headers = forget(request)
    request.response.headerlist.extend(headers)

    return request.response


def includeme(config):

    config.add_view(view=login,
                    route_name='auth.login',
                    request_method='POST',
                    renderer='json',
                    content_type='application/json')

    config.add_route('auth.login',
                     request_method='POST',
                     pattern='/login')

    config.add_view(view=logout,
                    route_name='auth.logout',
                    request_method='POST',
                    renderer='json',
                    content_type='application/json')

    config.add_route('auth.logout',
                     request_method='POST',
                     pattern='/logout')