# -*- coding: utf-8 -*-
from aldryn_search.base import AldrynIndexBase
from haystack import indexes
from haystack.utils.highlighting import Highlighter as _Highlighter


class SearchIndex(AldrynIndexBase):
    text = indexes.NgramField(document=True, use_template=False)


class Highlighter(_Highlighter):
    def render_html(self, highlight_locations=None, start_offset=None, end_offset=None):
        return super(Highlighter, self).render_html(
            highlight_locations=highlight_locations,
            start_offset=max(0, start_offset - 20),
            end_offset=end_offset + 20
        )