"""
内置平台解析器 — 每个返回 (fetch_url, headers_override, extract_fn)

添加新平台: 在模块底部调用 _reg() 注册即可。
"""
import json
import re
import xml.etree.ElementTree as ET
import aiohttp

BUILTIN = {}

def _reg(name, url, parser_fn, headers=None):
    BUILTIN[name] = {'url': url, 'parser': parser_fn, 'headers': headers or {}}

# ---- 国内平台 ----

_reg('weibo_hot',
     'https://weibo.com/ajax/side/hotSearch',
     lambda data: [
         {'title': item.get('word', ''),
          'url': f'https://s.weibo.com/weibo?q={item.get("word","")}',
          'heat_score': item.get('raw_hot', item.get('num', 0))}
         for item in data.get('data', {}).get('realtime', [])[:50]
         if isinstance(item, dict) and item.get('word')
     ],
     {'User-Agent': 'Mozilla/5.0', 'X-Requested-With': 'XMLHttpRequest'})

_reg('zhihu_hot',
     'https://www.zhihu.com/api/v3/feed/topstory/hot-lists/total?limit=50',
     lambda data: [
         {'title': item.get('target', {}).get('title', ''),
          'url': f'https://www.zhihu.com/question/{item.get("target",{}).get("id","")}',
          'heat_score': int(str(item.get('detail_text', '0'))
                          .replace('万','0000').replace('亿','00000000')
                          .replace('热度','').strip() or 0),
          'summary': (item.get('target', {}).get('excerpt', '') or '')[:500]}
         for item in data.get('data', []) if isinstance(item, dict)
     ],
     {'User-Agent': 'Mozilla/5.0'})

_reg('baidu_hot',
     'https://top.baidu.com/board?tab=realtime',
     lambda data: [
         {'title': item.get('word', ''),
          'url': item.get('url', ''),
          'heat_score': int(item.get('hotScore', 0)),
          'summary': item.get('desc', '')}
         for item in (data.get('data', {}).get('cards', [{}])[0].get('content', []))
         if isinstance(item, dict)
     ],
     {'User-Agent': 'Mozilla/5.0'})

_reg('toutiao_hot',
     'https://www.toutiao.com/hot-event/hot-board/?origin=toutiao_pc',
     lambda data: [
         {'title': item.get('Title', ''),
          'url': item.get('Url', ''),
          'heat_score': int(float(item.get('HotValue', 0)))}
         for item in (data.get('data', []) if isinstance(data.get('data'), list) else [])[:50]
         if isinstance(item, dict) and item.get('Title')
     ],
     {'User-Agent': 'Mozilla/5.0', 'Referer': 'https://www.toutiao.com/'})

_reg('bilibili_hot',
     'https://api.bilibili.com/x/web-interface/popular?ps=50',
     lambda data: [
         {'title': item.get('title', ''),
          'url': f'https://www.bilibili.com/video/{item.get("bvid","")}',
          'heat_score': item.get('stat', {}).get('view', 0),
          'summary': item.get('desc', '')[:500],
          'engagement_count': item.get('stat', {}).get('like', 0),
          'comment_count': item.get('stat', {}).get('reply', 0),
          'share_count': item.get('stat', {}).get('share', 0),
          'category': item.get('tname', '')}
         for item in data.get('data', {}).get('list', [])
         if isinstance(item, dict) and item.get('title')
     ],
     {'User-Agent': 'Mozilla/5.0', 'Referer': 'https://www.bilibili.com/'})

_reg('douyin_hot',
     'https://dy.feigua.cn/api/hot/board',
     lambda data: [
         {'title': item.get('title', item.get('word', '')),
          'url': item.get('url', ''),
          'heat_score': int(item.get('hot_value', item.get('heat', 0)))}
         for item in (data.get('data', []) if isinstance(data.get('data'), list) else [])[:50]
         if isinstance(item, dict)
     ],
     {'User-Agent': 'Mozilla/5.0'})

_reg('36kr_hot',
     'https://www.36kr.com/api/search/list/info-flow/hot?pageSize=30',
     lambda data: [
         {'title': item.get('title', ''),
          'url': f'https://www.36kr.com/p/{item.get("id","")}',
          'heat_score': item.get('total_count', 0),
          'summary': (item.get('summary', '') or '')[:500]}
         for item in data.get('data', {}).get('items', [])
         if isinstance(item, dict) and item.get('title')
     ],
     {'User-Agent': 'Mozilla/5.0'})

# ---- 海外平台 ----

_reg('github_trending',
     'https://api.github.com/search/repositories?q=stars:>1&sort=stars&order=desc&per_page=20',
     lambda data: [
         {'title': item.get('full_name', ''),
          'url': item.get('html_url', ''),
          'heat_score': item.get('stargazers_count', 0),
          'summary': (item.get('description', '') or '')[:500],
          'category': item.get('language', '')}
         for item in data.get('items', []) if isinstance(item, dict)
     ],
     {'Accept': 'application/vnd.github.v3+json', 'User-Agent': 'HotspotRadar/1.0'})

_reg('hackernews',
     'https://hacker-news.firebaseio.com/v0/topstories.json',
     None,  # 特殊: 两步抓取, 见 engine.py
     {'User-Agent': 'Mozilla/5.0'})

_reg('v2ex_hot',
     'https://www.v2ex.com/api/topics/hot.json',
     lambda data: [
         {'title': item.get('title', ''),
          'url': item.get('url', ''),
          'heat_score': item.get('replies', 0) * 10,
          'summary': (item.get('content', '') or '')[:500],
          'comment_count': item.get('replies', 0),
          'category': item.get('node', {}).get('title', '')
                     if isinstance(item.get('node'), dict) else ''}
         for item in data if isinstance(item, dict) and item.get('title')
     ],
     {'User-Agent': 'Mozilla/5.0'})

_reg('rsshub', None, None, {})  # url 来自 source 配置

# ---- 通用提取器 ----

def extract_json_path(data, config):
    """简易 JSONPath: $.data.list[*] → {title, url, heat_score, ...}"""
    path = config.get('item_path', '$[*]')
    fm = config.get('field_map', {})

    if path.startswith('$.'):
        path = path[2:]
    elif path.startswith('$'):
        path = path[1:]

    parts = []
    for p in path.split('.'):
        p = p.strip()
        if not p: continue
        if p.endswith('[*]'):
            parts.append(p[:-3]); parts.append('*')
        else:
            parts.append(p)

    items = data
    for part in parts:
        if part == '*':
            continue
        if isinstance(items, dict):
            items = items.get(part)
        elif isinstance(items, list):
            items = [i.get(part) for i in items if isinstance(i, dict)]
            items = [x for sub in items for x in (sub if isinstance(sub, list) else [sub])]
        else:
            return []
    if not isinstance(items, list):
        items = [items] if items else []

    result = []
    for item in items:
        if not isinstance(item, dict):
            continue
        entry = {
            'title':        _field(item, fm.get('title', 'title')),
            'url':          _field(item, fm.get('url', 'url')),
            'heat_score':   float(_field(item, fm.get('heat_score', '0')) or 0),
            'summary':      str(_field(item, fm.get('summary', '')) or '')[:500],
            'category':     str(_field(item, fm.get('category', '')) or ''),
            'tags':         str(_field(item, fm.get('tags', '')) or ''),
            'engagement_count': int(_field(item, fm.get('engagement_count', '0')) or 0),
            'comment_count':    int(_field(item, fm.get('comment_count', '0')) or 0),
            'share_count':      int(_field(item, fm.get('share_count', '0')) or 0),
        }
        if entry['title']:
            result.append(entry)
    return result

def _field(obj, path):
    if not path or not isinstance(obj, dict):
        return obj if not isinstance(obj, dict) else ''
    val = obj
    for p in path.split('.'):
        if isinstance(val, dict):
            val = val.get(p, '')
        else:
            return ''
    return val

def extract_css(html, config):
    """CSS 选择器提取 (轻量正则版)"""
    results = []
    for m in re.finditer(
        r'<a[^>]+href=["\']([^"\']+)["\'][^>]*>([^<]*)</a>',
        html, re.IGNORECASE | re.DOTALL
    ):
        url, title = m.group(1), m.group(2).strip()
        if len(title) >= 3:
            results.append({
                'title': title[:200], 'url': url[:2000],
                'heat_score': 60, 'summary': '',
                'category': '', 'tags': '',
                'engagement_count': 0, 'comment_count': 0, 'share_count': 0,
            })
    return results[:100]

def extract_regex(text, config):
    pattern = config.get('item_regex', '')
    fm = config.get('field_map', {})
    if not pattern: return []
    results = []
    for m in re.finditer(pattern, text, re.DOTALL):
        gd = m.groupdict()
        entry = {
            'title': gd.get(fm.get('title', 'title'), '')[:200],
            'url': gd.get(fm.get('url', 'url'), ''),
            'heat_score': float(gd.get(fm.get('heat_score', '0'), 0) or 0),
            'summary': str(gd.get(fm.get('summary', ''), ''))[:500],
            'category': '', 'tags': '',
            'engagement_count': 0, 'comment_count': 0, 'share_count': 0,
        }
        if entry['title']:
            results.append(entry)
    return results

def extract_rss(xml_text):
    items = []
    try:
        root = ET.fromstring(xml_text)
        ns_a = 'http://www.w3.org/2005/Atom'
        for item in root.findall('.//item'):
            items.append({
                'title': item.findtext('title', '')[:200],
                'url': item.findtext('link', ''),
                'summary': (item.findtext('description', '') or '')[:500],
                'heat_score': 80, 'category': item.findtext('category', ''),
                'tags': '', 'engagement_count': 0, 'comment_count': 0, 'share_count': 0,
            })
        if not items:
            for e in root.findall(f'.//{{{ns_a}}}entry'):
                link = e.find(f'{{{ns_a}}}link')
                items.append({
                    'title': e.findtext(f'{{{ns_a}}}title', '')[:200],
                    'url': link.get('href', '') if link is not None else '',
                    'summary': (e.findtext(f'{{{ns_a}}}summary', '') or '')[:500],
                    'heat_score': 70, 'category': '',
                    'tags': '', 'engagement_count': 0, 'comment_count': 0, 'share_count': 0,
                })
    except ET.ParseError:
        pass
    return items

async def fetch_hn(session):
    """HackerNews 两步抓取"""
    items = []
    try:
        async with session.get(
            'https://hacker-news.firebaseio.com/v0/topstories.json',
            timeout=aiohttp.ClientTimeout(total=15)
        ) as resp:
            ids = await resp.json()
        for sid in ids[:30]:
            try:
                async with session.get(
                    f'https://hacker-news.firebaseio.com/v0/item/{sid}.json',
                    timeout=aiohttp.ClientTimeout(total=10)
                ) as r2:
                    s = await r2.json()
                if s and s.get('title'):
                    items.append({
                        'title': s.get('title', '')[:200],
                        'url': s.get('url', f'https://news.ycombinator.com/item?id={sid}'),
                        'heat_score': s.get('score', 0),
                        'engagement_count': s.get('score', 0),
                        'comment_count': s.get('descendants', 0),
                        'summary': '', 'category': s.get('type', ''),
                        'tags': '', 'share_count': 0,
                    })
            except Exception:
                continue
    except Exception:
        pass
    return items