from metasqlobject.classinst import classinstancemethod
from metasqlobject.declarative import counter

__all__ = ['BoundAttribute']

class BoundAttribute(object):

    name = None
    bound_class = None

    def __init__(self, bound_class=None, name=None,
                 _copyfrom=None, **kw):
        self.declarative_count = counter.next()
        if _copyfrom is not None:
            for k, v in _copyfrom.__dict__.items():
                if (not k.startswith('__')
                    and k != 'declarative_count'):
                    setattr(self, k, v)
        if name is not None:
            self.name = name
        for k, v in kw.items():
            setattr(self, k, v)
        if bound_class is not None:
            self.bound_class = bound_class

    def __repr__(self):
        s = '<%s object %s' % (
            self.__class__.__name__, self.declarative_count)
        if self.bound_class:
            s += ' for %s.%s' % (
                self.bound_class.__module__,
                self.bound_class.__name__)
        if self.name:
            s += ' name=%r' % self.name
        else:
            s += ' unnamed'
        s += self.extra_repr()
        s += '>'
        return s

    def extra_repr(self):
        return ''
    
    def __addtoclass__(self, cls, bound_class, name):
        if self is None:
            me = cls(bound_class=bound_class, name=name)
        else:
            me = self.__class__(
                bound_class=bound_class, name=name,
                _copyfrom=self)
        setattr(bound_class, name, me)
        me.bind_to_class(bound_class, name)
        bound_class.__addtosubclass__.append(name)

    __addtoclass__ = classinstancemethod(__addtoclass__)

    def bind_to_class(self, bound_class, name):
        pass