"""University departments.
"""
import grok
from zope.component import createObject
from zope.component.interfaces import IFactory
from zope.interface import implementedBy
from waeup.sirp.university.interfaces import IDepartment

class Department(grok.Container):
    """A university department.
    """
    grok.implements(IDepartment)

    # A simple counter for ids.
    next_id = 0L
    
    def __init__(self,
                 title=u'Unnamed Department',
                 title_prefix=u'department',
                 code=u"NA", **kw):
        super(Department, self).__init__(**kw)
        self.title = title
        self.title_prefix = title_prefix
        self.code = code
        self.courses = createObject(u'waeup.CourseContainer')
        self.courses.__parent__ = self
        self.courses.__name__ = 'courses'
        self.certificates = createObject(u'waeup.CertificateContainer')
        self.certificates.__parent__ = self
        self.certificates.__name__ = 'certificates'

    def traverse(self, name):
        """Deliver appropriate containers, if someone wants to go to courses
        or departments.
        """
        if name == 'courses':
            return self.courses
        elif name == 'certificates':
            return self.certificates
        return None
        

class DepartmentFactory(grok.GlobalUtility):
    """A factory for department containers.
    """
    grok.implements(IFactory)
    grok.name(u'waeup.Department')
    title = u"Create a new department.",
    description = u"This factory instantiates new department instances."

    def __call__(self, *args, **kw):
        return Department(*args, **kw)

    def getInterfaces(self):
        """Get interfaces of objects provided by this factory.
        """
        return implementedBy(Department)