from zope.component import getUtilitiesFor
from zope.schema.interfaces import IVocabularyFactory
from zope.schema.vocabulary import SimpleTerm, SimpleVocabulary


class VocabulariesVocabulary(object):

    """Vocabulary for a list of available vocabulary factories
    """

    def __call__(self, context):
        terms = []
        for name, vocabulary in getUtilitiesFor(IVocabularyFactory):
            doc = (vocabulary.__doc__ or '').strip().split('\n')
            doc = [l.strip() for l in doc if l.strip()]
            if len(doc) > 0:
                terms.append(
                    SimpleTerm(name, name, "%s - %s" % (name, doc[0])))
            else:
                terms.append(SimpleTerm(name, name, name))

        terms = sorted(terms, key=lambda term: term.token)
        return SimpleVocabulary(terms)