from __future__ import annotations

import re

_LINK_PATTERN = re.compile(r"\[([^\]]*)\]\([^)]*\)")
_IMG_PATTERN = re.compile(r"!\[([^\]]*)\]\([^)]*\)")
_BOLD_PATTERN = re.compile(r"\*\*(.+?)\*\*")
_BOLD_ALT_PATTERN = re.compile(r"__(.+?)__")
_ITALIC_PATTERN = re.compile(r"\*(.+?)\*")
_ITALIC_ALT_PATTERN = re.compile(r"_(.+?)_")
_STRIKETHROUGH_PATTERN = re.compile(r"~~(.+?)~~")
_FENCED_CODE_PATTERN = re.compile(r"```[^\n]*\n(.*?)```", re.DOTALL)
_INLINE_CODE_PATTERN = re.compile(r"`([^`]+)`")
_HEADING_PATTERN = re.compile(r"^#{1,6}\s+", re.MULTILINE)
_UNORDERED_LIST_PATTERN = re.compile(r"^[\-\*]\s+", re.MULTILINE)
_ORDERED_LIST_PATTERN = re.compile(r"^\d+\.\s+", re.MULTILINE)
_BLOCKQUOTE_PATTERN = re.compile(r"^>\s?", re.MULTILINE)
_HR_PATTERN = re.compile(r"^[\-\*_]{3,}\s*$", re.MULTILINE)
_MULTISPACE_PATTERN = re.compile(r"[ \t]+")
_MULTINEWLINE_PATTERN = re.compile(r"\n{3,}")


def strip_twitch_markdown(text: str) -> str:
    if not text:
        return text

    text = _IMG_PATTERN.sub("", text)

    text = _LINK_PATTERN.sub(r"\1", text)

    text = _FENCED_CODE_PATTERN.sub(r"\1", text)

    text = _HR_PATTERN.sub("", text)

    text = _BOLD_PATTERN.sub(r"\1", text)
    text = _BOLD_ALT_PATTERN.sub(r"\1", text)

    text = _ITALIC_PATTERN.sub(r"\1", text)
    text = _ITALIC_ALT_PATTERN.sub(r"\1", text)

    text = _STRIKETHROUGH_PATTERN.sub(r"\1", text)

    text = _INLINE_CODE_PATTERN.sub(r"\1", text)

    text = _HEADING_PATTERN.sub("", text)

    text = _ORDERED_LIST_PATTERN.sub("", text)
    text = _UNORDERED_LIST_PATTERN.sub("", text)

    text = _BLOCKQUOTE_PATTERN.sub("", text)

    text = _MULTISPACE_PATTERN.sub(" ", text)
    text = _MULTINEWLINE_PATTERN.sub("\n\n", text)

    return text.strip()