"""
herd.py -- grok-based web application for managing mammoths
"""
import grok
from zope import schema, interface, component
from zope.app.intid import IntIds
from zope.app.intid.interfaces import IIntIds
from zope.app.catalog.catalog import Catalog
from zope.app.catalog.interfaces import ICatalog
from zope.app.catalog.field import FieldIndex

def setup_catalog(catalog):
    catalog['name'] = FieldIndex('name', IMammoth) # only index mammoths

class Herd(grok.Application, grok.Container):
    """Root application object and container for Mammoth objects.
    Also sets up a catalog with a field index for indexing mammoths."""

    grok.local_utility(IntIds, provides=IIntIds) # necessary for catalog
    grok.local_utility(Catalog, provides=ICatalog, setup=setup_catalog)


class HerdIndex(grok.View):
    """Default view for herd objects.  It lets you search for mammoths
    inside the herd and add new mammoths.

    Actual HTML rendering by herd_templates/herdindex.pt (which is
    automatically found according to the name of this Python module
    and the name of this view class)"""

    grok.context(Herd) # indicates which model the view is for
    grok.name('index') # URL name of the view

    def update(self):
        """This method is executed before the template is rendered.
        It allows us to perform operations such as processing request
        parameters or precomputing stuff that the template may need."""
        query = self.request.form.get('query')
        if not query:
            return
        catalog = component.getUtility(ICatalog)
        self.search_results = catalog.searchResults(name=(query, query))


class IMammoth(interface.Interface):
    """Data schema for mammoths"""

    name = schema.TextLine(
        title=u'Name',
        description=u'Name of the Mammoth',
        )

class Mammoth(grok.Model):
    grok.implements(IMammoth)

    def __init__(self, name):
        self.name = name # this attribute will be indexed by the FieldIndex


class AddMammoth(grok.AddForm):
    """Form that creates a new mammoth."""
    grok.context(Herd)

    form_fields = grok.Fields(id=schema.TextLine(title=u"URL name"))
    form_fields += grok.AutoFields(IMammoth) # deduce form fields from schema

    @grok.action('Add mammoth')
    def add(self, id, name):
        self.context[id] = Mammoth(name)
        self.redirect(self.url(self.context))