import re

from ..model import User

from ..error import UserNotFound, InterfaceException, ValidateException

def rehash(hash):

    if not re.match(r'^[a-f0-9]{15,}$', hash.lower()):

        raise ValidateException()

    return True

def validate(**kargs):

    def v(f):

        def new_f(*a,**k):

            for i in kargs:

                kargs[i](k[i])

            return f(*a,**k)

        new_f.__name__ = f.__name__

        return new_f

    return v

@validate(userhash=rehash)

def getuser(userhash, session):

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

    if user is None:

        raise UserNotFound()

    else:

        return user

def with_user(f):

    def new_f(*args,**kargs):

        args=list(args)

        try:

            userhash = kargs["apikey"]

            del kargs["apikey"]

        except KeyError:

            try:

                userhash = args[1]

                del args[1]

            except IndexError:

                raise InterfaceException() 

        def _gotResult(_user):

            kargs["user"]=_user

            return f(*args,**kargs)

        return getuser(userhash=userhash).addCallback(_gotResult)

    new_f.__name__ = f.__name__

    return new_f