"""Decode and inspect public KHL HTML without executing scripts or retrying restrictions."""
from __future__ import annotations

import json
import re
from urllib.parse import urljoin, urlparse

from bs4 import BeautifulSoup, UnicodeDammit

BASE = 'https://www.khl.ru'
KINDS = ('players', 'coaches', 'officials')


def decode_response(response):
    # requests defaults text/html without a charset to ISO-8859-1. KHL's UTF-8
    # meta declaration must be decoded from bytes before parsing Russian names.
    content = getattr(response, 'content', None)
    if isinstance(content, bytes) and content:
        decoded = UnicodeDammit(content, is_html=True)
        if decoded.unicode_markup is not None:
            return decoded.unicode_markup, decoded.original_encoding or ''
    return str(getattr(response, 'text', '') or ''), str(getattr(response, 'encoding', '') or '')


def inspect_html(html):
    soup = BeautifulSoup(html, 'html.parser')
    compact = lambda value: re.sub(r'\s+', ' ', value).strip()
    title = compact(soup.title.get_text(' ', strip=True)) if soup.title else ''
    h1 = soup.find('h1')
    heading = compact(h1.get_text(' ', strip=True)) if h1 else ''
    for tag in soup(['script', 'style', 'noscript']):
        tag.decompose()
    body = compact(soup.get_text(' ', strip=True)).casefold().replace('ё', 'е')
    head = f'{title} {heading}'.casefold().replace('ё', 'е')
    status = next((int(m.group(1)) for text in (title, heading)
                   if (m := re.match(r'^\s*(?:(?:error|ошибка|http)\s*[:\-]?\s*)?([45]\d{2})(?:\b|$)', text, re.I))), None)
    restricted = status in (401, 403, 429) or any(term in head for term in (
        'access denied', 'forbidden', 'captcha', 'just a moment', 'проверка браузера', 'проверка безопасности', 'доступ ограничен', 'доступ запрещен'))
    restricted = restricted or (len(body) < 4000 and any(term in body for term in (
        'access_deny@khl.ru', 'вредоносная активность', 'доступ временно ограничен',
        'ваш доступ временно ограничили', 'verify you are human', 'подтвердите, что вы не робот',
        'access denied', 'forbidden', 'captcha', 'проверка браузера', 'доступ запрещен')))
    if restricted:
        reason = f'КХЛ ограничил доступ (HTML {status})' if status else 'КХЛ вернул страницу проверки или ограничения доступа'
    elif status:
        reason = f'КХЛ вернул страницу ошибки {status}'
    elif len(html) < 600 or '<html' not in html[:12000].casefold():
        reason = 'КХЛ вернул неполную HTML-страницу'
    else:
        reason = ''
    return {'title': title[:200], 'heading': heading[:200], 'html_characters': len(html),
            'text_characters': len(body), 'html_status': status, 'restricted': bool(restricted), 'reason': reason}


def person_url(kind, value):
    if kind not in KINDS or not isinstance(value, str):
        return None
    try:
        # Relative numeric links resolve against the directory, not site root.
        url = urlparse(urljoin(f'{BASE}/{kind}/', value.strip()))
        if url.scheme not in ('http', 'https') or url.hostname not in ('khl.ru', 'www.khl.ru') or url.username or url.password or url.port not in (None, 80, 443):
            return None
        match = re.fullmatch(rf'/{kind}/([1-9]\d{{0,14}})/?', url.path)
    except ValueError:
        return None
    return (int(match[1]), f'{BASE}/{kind}/{int(match[1])}/') if match else None


def person_link_nodes(soup, kind):
    for node in soup.select('[href], [data-href], [data-url]'):
        for attribute in ('href', 'data-href', 'data-url'):
            found = person_url(kind, node.get(attribute))
            if found:
                yield node, found
                break


def detail_urls(kind, html):
    soup = BeautifulSoup(html, 'html.parser')
    found = dict(item for _, item in person_link_nodes(soup, kind))
    # Hydrated/JSON-LD directories may embed canonical profile URLs in JSON.
    # Only actual URLs are accepted; arbitrary numeric ids are never enumerated.
    for script in soup.find_all('script', type=re.compile(r'^(?:application/(?:ld\+)?json)$', re.I)):
        raw = script.string or script.get_text()
        if len(raw) > 4_000_000:
            continue
        try:
            document = json.loads(raw)
        except (ValueError, RecursionError):
            continue
        pending = [document]
        visited = 0
        while pending and visited < 100000:
            item = pending.pop(); visited += 1
            if isinstance(item, dict):
                pending.extend(item.values())
            elif isinstance(item, list):
                pending.extend(item)
            elif isinstance(item, str):
                link = person_url(kind, item)
                if link:
                    found[link[0]] = link[1]
    return found