import re
import logging

logger = logging.getLogger(__name__)


def _strip_strikethrough(text: str) -> str:
    return re.sub(r"~~(.+?)~~", r"\1", text)


def _convert_links(text: str) -> str:
    def replacer(m):
        link_text = m.group(1)
        url = m.group(2)
        return f"{link_text} ( {url} )"

    return re.sub(r"\[([^\]]+)\]\(([^)]+)\)", replacer, text)


def _strip_headings(text: str) -> str:
    def replacer(m):
        level = len(m.group(1))
        heading_text = m.group(2).strip()
        if level <= 1:
            return f"*{heading_text}*"
        return heading_text

    return re.sub(r"^(#{1,6})\s+(.+)$", replacer, text, flags=re.MULTILINE)


def _strip_table_syntax(text: str) -> str:
    lines = text.split("\n")
    result = []

    for line in lines:
        stripped = line.strip()
        if stripped.startswith("|") and stripped.endswith("|"):
            if "---" in stripped and "|" in stripped:
                continue
            cells = [c.strip() for c in stripped.split("|")[1:-1]]
            result.append("  ".join(cells))
        else:
            result.append(line)

    return "\n".join(result)


def clean_for_zoom(text: str) -> str:
    if not text:
        return ""

    text = _strip_strikethrough(text)
    text = _convert_links(text)
    text = _strip_headings(text)
    text = _strip_table_syntax(text)

    return text.strip()


def markdown_to_zoom(md_text: str) -> str:
    return clean_for_zoom(md_text)


def sanitize_text(text: str) -> str:
    """
    清理文本以适配 Zoom Chat 的 Markdown 限制。

    去除 Zoom 不支持的 Markdown 语法：
    - 删除线 (~~text~~) → text
    - 链接 ([text](url)) → text ( url )
    - 标题 (# title) → *title* (一级) 或 title (其余)
    - 表格 → 空格分隔的纯文本

    Args:
        text: 原始 Markdown 文本

    Returns:
        清理后的纯文本
    """
    return clean_for_zoom(text)


def native_to_markdown(native_content: dict | str) -> str:
    if isinstance(native_content, dict):
        return native_content.get("content", native_content.get("text", ""))
    return str(native_content)