from zope.component import queryUtility, getUtility
from zope.annotation.interfaces import IAnnotations

from Acquisition import aq_base

from plone.contentrules.engine.interfaces import IRuleStorage
from plone.contentrules.engine.interfaces import IRuleAssignmentManager

from plone.contentrules.rule.rule import Rule as BaseRule

from OFS.SimpleItem import SimpleItem
from BTrees.OOBTree import OOSet
from Products.CMFCore.interfaces import ISiteRoot

ANNOTATION_KEY = "plone.app.contentrules.ruleassignments"

class Rule(SimpleItem, BaseRule):
    """A Zope 2 version of a rule, subject to acqusition, but otherwise
    identical.
    """

def get_assignments(rule):
    annotations = IAnnotations(rule)
    return annotations.setdefault(ANNOTATION_KEY, OOSet())
    
# Events that keep track of rule-to-assignment mappings
    
def rule_removed(rule, event):
    
    storage = queryUtility(IRuleStorage)
    rule_name = rule.__name__
    
    if storage is None:
        return
    
    portal = getUtility(ISiteRoot)
    for path in get_assignments(rule):
        container = portal.unrestrictedTraverse(path)
        if container is not None:
            assignable = IRuleAssignmentManager(container, None)
            if assignable is not None and rule_name in assignable:
                del assignable[rule_name]
    
def container_moved(container, event):
    
    if event.oldParent is None or event.newParent is None or event.oldName is None:
        return
    
    assignable = IRuleAssignmentManager(container, None)
    storage = queryUtility(IRuleStorage)
    
    if assignable is None or storage is None:
        return
    
    old_path = "%s/%s" % ('/'.join(event.oldParent.getPhysicalPath()), event.oldName,)
    new_path = '/'.join(container.getPhysicalPath())
    
    if aq_base(event.object) is not aq_base(container):
        new_path_of_moved = '/'.join(event.object.getPhysicalPath())
        old_path = old_path + new_path[len(new_path_of_moved):]
    
    for rule_name in assignable.keys():
        rule = storage.get(rule_name, None)
        if rule is not None:
            assignments = get_assignments(rule)
            if old_path in assignments:
                assignments.remove(old_path)
                assignments.insert(new_path)
    
def container_removed(container, event):
    
    assignable = IRuleAssignmentManager(container, None)
    storage = queryUtility(IRuleStorage)
    
    if assignable is None or storage is None:
        return
    
    path = '/'.join(container.getPhysicalPath())
    for rule_name in assignable.keys():
        rule = storage.get(rule_name, None)
        if rule is not None:
            assignments = get_assignments(rule)
            if path in assignments:
                assignments.remove(path)