"""Catalog index node adapters that only clear the index when
needed."""

from Products.GenericSetup.PluginIndexes.exportimport import PluggableIndexNodeAdapter as PluggableIndexBase
from Products.GenericSetup.PluginIndexes.exportimport import DateIndexNodeAdapter as DateIndexBase
from Products.GenericSetup.PluginIndexes.exportimport import DateRangeIndexNodeAdapter as DateRangeIndexBase
from Products.GenericSetup.PluginIndexes.exportimport import FilteredSetNodeAdapter as FilteredSetBase

class PluggableIndexNodeAdapter(PluggableIndexBase):
    """Only clear the index when needed."""

    def _importNode(self, node):
        """Import the object from the DOM node.
        """
        indexed_attrs = []
        for child in node.childNodes:
            if child.nodeName == 'indexed_attr':
                indexed_attrs.append(
                                  child.getAttribute('value').encode('utf-8'))
        if getattr(self.context, 'indexed_attrs', None) != indexed_attrs:
            self.context.indexed_attrs = indexed_attrs
            self.context.clear()

    node = property(PluggableIndexBase._exportNode, _importNode)

class DateIndexNodeAdapter(DateIndexBase):
    """Only clear the index when needed."""

    def _importNode(self, node):
        """Import the object from the DOM node.
        """
        if self.environ.shouldPurge():
            self._purgeProperties()

        if node != self._extractProperties():
            self._initProperties(node)
            self.context.clear()

    node = property(DateIndexBase._exportNode, _importNode)

class DateRangeIndexNodeAdapter(DateRangeIndexBase):
    """Only clear the index when needed."""

    def _importNode(self, node):
        """Import the object from the DOM node.
        """
        since_field = node.getAttribute('since_field').encode('utf-8')
        until_field = node.getAttribute('until_field').encode('utf-8')
        if (self.context.getSinceField() != since_field or
            self.context.getUntilField() != until_field):
            self.context._edit(since_field, until_field)
            self.context.clear()

    node = property(DateRangeIndexBase._exportNode, _importNode)

class FilteredSetNodeAdapter(FilteredSetBase):
    """Only clear the index when needed."""

    def _importNode(self, node):
        """Import the object from the DOM node.
        """
        expr = node.getAttribute('expression').encode('utf-8')
        if self.context.getExpression() != expr:
            self.context.setExpression(expr)
            self.context.clear()

    node = property(FilteredSetBase._exportNode, _importNode)