from twisted.internet import defer

try:

    from inspect import getcallargs

except ImportError:

    from ..inspect_getcallargs import getcallargs

from decorator import decorator

from .schema import User

from .dbdefer import dbdefer

from ..validate import validate, vHash

from ..error import UserNotFound, InterfaceException

@validate(kwd="apikey", func=vHash, minlength=15, maxlength=15)

@dbdefer

def getuser(session, apikey):

    """Returns a valid user object.

    :param session: a valid session object (is created by decorator :func:`iro.model.dbdefer.dbdefer`)

    :param string apikey: a vaild apikey (only [0-9a-f] is allowed)

    :return: a :class:`iro.model.schema.User` object

    :raises: :exc:`iro.error.UserNotFound`

    """

    user = session.query(User).filter_by(apikey=apikey).first()

    if user is None:

        raise UserNotFound()

    else:

        return user

@decorator

def vUser(f,*args,**kargs):

    """A Decorator to verify the apikey and execute the function with a valid :class:`iro.model.schema.User` instead of the apikey.

    The decorator expect the apikey in the **user** parameter.

    :return: a defer

    """ 

    kp=getcallargs(f,*args,**kargs)

    try:

        apikey = kp["user"]

    except KeyError:

        raise InterfaceException() 

    def _gotResult(_user):

        kp["user"]=_user

        e =  defer.maybeDeferred(f,**kp)

        return e

    d = defer.maybeDeferred(getuser, apikey=apikey)

    return d.addCallback(_gotResult)