## $Id: course.py 7207 2011-11-26 08:54:59Z henrik $
##
## Copyright (C) 2011 Uli Fouquet & Henrik Bettermann
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##
"""Courses.
"""
import grok
from zope.catalog.interfaces import ICatalog
from zope.interface import implementedBy
from zope.component import getUtility
from zope.component.interfaces import IFactory, ComponentLookupError
from waeup.sirp.university.interfaces import ICourse, ICourseAdd

class Course(grok.Model):
    """A university course.
    """
    grok.implements(ICourse, ICourseAdd)

    def __init__(self,
                 title=u'Unnamed Course',
                 code=u'NA',
                 credits=0,
                 passmark=40,
                 semester=1, **kw):
        super(Course, self).__init__(**kw)
        self.title = title
        self.code = code
        self.credits = credits
        self.passmark = passmark
        self.semester = semester

    def longtitle(self):
        return "%s (%s)" % (self.title,self.code)

class CourseFactory(grok.GlobalUtility):
    """A factory for courses.
    """
    grok.implements(IFactory)
    grok.name(u'waeup.Course')
    title = u"Create a new course.",
    description = u"This factory instantiates new course instances."

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

    def getInterfaces(self):
        return implementedBy(Course)

@grok.subscribe(ICourse, grok.IObjectRemovedEvent)
def handle_course_removed(course, event):
    """If a course is deleted, we make sure that also referrers in a
       certificatecontainer are removed.
    """
    code = course.code

    # Find all certificatecourses that refer to given course...
    try:
        cat = getUtility(ICatalog, name='certcourses_catalog')
    except ComponentLookupError:
        # catalog not available. This might happen during tests.
        return

    results = cat.searchResults(course_code=(code, code))
    for certcourse in results:
        # Remove that referrer...
        cert = certcourse.__parent__
        cert.delCourseRef(code)
        cert._p_changed = True
    return