# -*- coding: utf-8 -*-
from AccessControl import getSecurityManager
from Products.CMFCore.interfaces import IContentish
from Products.CMFCore.utils import getToolByName
from plone.app.folder.folder import IATUnifiedFolder
from plone.app.layout.nextprevious.interfaces import INextPreviousProvider
from zope.component import adapter
from zope.interface import implementer


@implementer(INextPreviousProvider)
@adapter(IATUnifiedFolder)
class NextPrevious(object):
    """ adapter for acting as a next/previous provider """

    def __init__(self, context):
        self.context = context
        props = getToolByName(context, 'portal_properties').site_properties
        self.vat = props.getProperty('typesUseViewActionInListings', ())
        self.security = getSecurityManager()
        order = context.getOrdering()
        if not isinstance(order, list):
            order = order.idsInOrder()
        if not isinstance(order, list):
            order = None
        self.order = order

    @property
    def enabled(self):
        return self.context.getNextPreviousEnabled()

    def getNextItem(self, obj):
        """ return info about the next item in the container """
        if not self.order:
            return None
        pos = self.context.getObjectPosition(obj.getId())
        for oid in self.order[pos+1:]:
            data = self.getData(self.context[oid])
            if data:
                return data

    def getPreviousItem(self, obj):
        """ return info about the previous item in the container """
        if not self.order:
            return None
        order_reversed = list(reversed(self.order))
        pos = order_reversed.index(obj.getId())
        for oid in order_reversed[pos+1:]:
            data = self.getData(self.context[oid])
            if data:
                return data

    def getData(self, obj):
        """ return the expected mapping, see `INextPreviousProvider` """
        if not self.security.checkPermission('View', obj):
            return None
        elif not IContentish.providedBy(obj):
            # do not return a not contentish object
            # such as a local workflow policy for example (#11234)
            return None

        ptype = obj.portal_type
        url = obj.absolute_url()
        if ptype in self.vat:       # "use view action in listings"
            url += '/view'
        return dict(
            id=obj.getId(),
            url=url,
            title=obj.Title(),
            description=obj.Description(),
            portal_type=ptype
        )