import re
from decorator import decorator

from twisted.internet import defer

from inspect import getcallargs
from .error import ValidateException

def vBool(value, field):
    '''Validator for boolean values'''
    t=[True, 1, "true", "True", "TRUE"]
    f=[False, 0, "false", "False", "FALSE"]
    if value in t:
        return True
    elif value in f:
        return False
    else:
        raise ValidateException(field=field, msg='%s is not boolean' % field)


def vHash(value,field,minlength=None,maxlength=None):
    '''Validator for hash values'''
    if not re.match(r'^[a-f0-9]*$', value.lower()):
        raise ValidateException(field=field)
    if minlength and len(value)<minlength:
        raise ValidateException(field=field)
    if maxlength and len(value)>maxlength:
        raise ValidateException(field=field)
    return value

def vTel(value,field):
    return value

def vEmail(value, field):
    return value

def validate(kwd,func, need=True,*args,**kargs):
    '''validate decorator
    use it like this:
        @validate(kwd=userhash, func=vuserhash)
        f(userhash)
    that will validate usrhash with the function vuserhash.
    Every validate function should raise an Exception, if the the value is not valid'''
    @decorator
    def v(f,*a,**k):
        kp=getcallargs(f,*a,**k)
        def dfunc(*x,**y):
            return None
        try:
            if need or kp[kwd] is not None:
                dfunc=func
        except KeyError:
            if need:
                raise ValidateException(field=kwd,msg="%s is nessasary"%kwd)

        def _gotResult(value):
            kp[kwd] = value
            e = defer.maybeDeferred(f,**kp)
            return e
        d = defer.maybeDeferred(dfunc, kp[kwd],kwd,*args,**kargs)
        return d.addCallback(_gotResult)
    return v