"""
前台公开"关于本站"页面。

不需要登录，匿名可访问。Markdown 在模板里渲染。
"""
import re

import markdown as _markdown
from flask import Blueprint, render_template

from applications.models import About

bp = Blueprint('public_about', __name__, url_prefix='/site')


def _get_about() -> About:
    """复用 model 的种子逻辑，避免空表时炸"""
    a = About.query.get(1)
    if a is None:
        from applications.extensions import db
        a = About(id=1, site_name='旺珂 · 导航')
        db.session.add(a)
        db.session.commit()
    return a


@bp.get('/about')
def about():
    a = _get_about()
    html = _render_md(a.content_md)
    return render_template('public/about.html', about=a, content_html=html)


_URL_RE = re.compile(r'(https?://[^\s)<>"\\]+|[\w.+-]+@[\w-]+\.[\w.-]+)')


def _render_md(text: str) -> str:
    """Markdown → HTML；自动把裸链接/邮箱变可点；同时禁掉 script/iframe。"""
    if not text or not text.strip():
        return ''
    html = _markdown.markdown(
        text,
        extensions=['fenced_code', 'tables', 'nl2br', 'sane_lists'],
        output_format='html5',
    )
    # 防御：清掉 <script>/<iframe>
    html = re.sub(r'<\s*script[^>]*>.*?<\s*/\s*script\s*>', '', html, flags=re.I | re.S)
    html = re.sub(r'<\s*iframe[^>]*>.*?<\s*/\s*iframe\s*>', '', html, flags=re.I | re.S)
    return html