"""HTML helpers for ESPD rich-text content."""

from __future__ import annotations

import re
from html import unescape


def html_to_plain(html: str) -> str:
    if not html:
        return ""
    text = html
    text = re.sub(r"(?i)<br\s*/?>", "\n", text)
    text = re.sub(r"(?i)</p\s*>", "\n\n", text)
    text = re.sub(r"(?i)</h[1-6]\s*>", "\n\n", text)
    text = re.sub(r"(?i)</li\s*>", "\n", text)
    text = re.sub(r"(?i)<li[^>]*>", "• ", text)
    text = re.sub(r"(?i)</tr\s*>", "\n", text)
    text = re.sub(r"(?i)</td\s*>", "\t", text)
    text = re.sub(r"<[^>]+>", "", text)
    text = unescape(text)
    text = re.sub(r"\n{3,}", "\n\n", text)
    return text.strip()


def plain_to_html(text: str) -> str:
    if not text:
        return ""
    parts = [p.strip() for p in text.replace("\r\n", "\n").split("\n\n") if p.strip()]
    if not parts:
        parts = [text.strip()] if text.strip() else []
    return "".join(f"<p>{p.replace(chr(10), '<br/>')}</p>" for p in parts)