from django import template
from django.utils.safestring import mark_safe

register = template.Library()


@register.filter
def highlight(text, word):
    """
    Retorna texto com highlight.
    """

    begin_mark = 0
    end_mark = 0

    if word.lower() in text.lower():
        for i in word.lower():
            for j in text.lower()[end_mark:]:
                if i == j:
                    end_mark += 1
                    break
                else:
                    begin_mark += 1
                    end_mark += 1
                    continue

    text_to_replace = text[begin_mark:end_mark]
    
    text = text.replace(text_to_replace, "<b>%s</b>" % text_to_replace)

    return mark_safe(text)