import logging

import re

from .database import WithSession

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):

    with WithSession() as 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)

        logging.debug("Entering %s"%f.__name__)

        try:

            kargs["user"]=getuser(userhash = kargs["apikey"])

            del kargs["apikey"]

        except KeyError:

            try:

                kargs["user"]=getuser(userhash = args[1])

            except IndexError:

                raise InterfaceException() 

            del args[1]

        ret=f(*args,**kargs)

        logging.debug("Exited %s"%f.__name__)

        return ret

    new_f.__name__ = f.__name__

    return new_f