"""
Prefixes headers with the specified string.

Usage:
MyExtension = get_heading_injector(prefix)
"""
import marko.block
from marko.helpers import MarkoExtension


def __create_heading_renderer(prefix: str):
    class HeadingRenderer:
        PREFIX = prefix

        def render_heading(self, element: marko.block.Heading):
            return f"<h{element.level}>{HeadingRenderer.PREFIX}{self.render_children(element)}</h{element.level}>\n"

    return HeadingRenderer


def get_heading_injector(prefix: str):
    return MarkoExtension(
        renderer_mixins=[__create_heading_renderer(prefix)]
    )