"""DuckDuckGo 搜索源 — 免费，无需 API key"""

import time
import requests
from providers.base import BaseProvider, SearchResult


class DuckDuckGoProvider(BaseProvider):
    name = 'duckduckgo'
    display_name = 'DuckDuckGo'
    needs_api_key = False
    enabled = False  # 国内网络不可用，默认关闭
    priority = 30

    def __init__(self, config: dict):
        super().__init__(config)

    def search(self, query: str, max_results: int = 10) -> list:
        results = []

        # 1. 先尝试 Instant Answer API（获取摘要和主题）
        try:
            url = 'https://api.duckduckgo.com/'
            params = {
                'q': query,
                'format': 'json',
                'no_html': 1,
                'skip_disambig': 1,
            }
            resp = requests.get(url, params=params, timeout=8)
            if resp.status_code == 200:
                data = resp.json()
                # Abstract
                abstract = data.get('AbstractText', '')
                if abstract and data.get('AbstractURL'):
                    results.append(SearchResult(
                        title=data.get('Heading', 'DuckDuckGo 摘要'),
                        url=data['AbstractURL'],
                        content=abstract,
                        score=0.9,
                        source=self.name,
                    ))
                # Related topics
                for topic in data.get('RelatedTopics', []):
                    if 'Topics' in topic:
                        for sub in topic['Topics'][:3]:
                            if sub.get('Text'):
                                results.append(SearchResult(
                                    title=sub.get('Text', '')[:80],
                                    url=sub.get('FirstURL', ''),
                                    content=sub.get('Text', ''),
                                    score=0.7,
                                    source=self.name,
                                ))
                    elif topic.get('Text'):
                        results.append(SearchResult(
                            title=topic.get('Text', '')[:80],
                            url=topic.get('FirstURL', ''),
                            content=topic.get('Text', ''),
                            score=0.7,
                            source=self.name,
                        ))
        except requests.exceptions.RequestException:
            pass

        # 2. 如果结果不够，再抓取 HTML 版本获取更多结果
        if len(results) < max_results:
            try:
                url = 'https://html.duckduckgo.com/html/'
                resp = requests.post(url, data={'q': query}, timeout=15,
                                     headers={'User-Agent': 'Mozilla/5.0'})
                if resp.status_code == 200:
                    html = resp.text
                    more = self._parse_html_results(html, max_results - len(results))
                    results.extend(more)
            except requests.exceptions.RequestException:
                pass

        # 去重
        seen_urls = set()
        unique = []
        for r in results:
            if r.url and r.url not in seen_urls:
                seen_urls.add(r.url)
                unique.append(r)

        return unique[:max_results]

    def _parse_html_results(self, html: str, limit: int) -> list:
        """简单解析 DuckDuckGo HTML 搜索结果"""
        results = []
        # 按 <a rel="nofollow" 分割找链接
        for block in html.split('<a rel="nofollow"')[1:]:
            if len(results) >= limit:
                break
            try:
                # 提取 URL
                href_start = block.find('href="')
                if href_start == -1:
                    continue
                href_start += 6
                href_end = block.find('"', href_start)
                url = block[href_start:href_end]

                # 提取标题 (在 <a 标签后找 >xxx</a>)
                title_start = block.find('>', href_end)
                if title_start == -1:
                    continue
                title_start += 1
                title_end = block.find('</a>', title_start)
                title = self._clean_text(block[title_start:title_end])

                # 提取摘要（在 <a> 后的某个 <td> 或 <div> 中）
                snippet = ''
                for kw in ['class="result-snippet"', 'class="snippet"']:
                    idx = block.find(kw)
                    if idx != -1:
                        tag_close = block.find('>', idx) + 1
                        next_tag = block.find('<', tag_close)
                        if next_tag != -1:
                            snippet = self._clean_text(block[tag_close:next_tag])
                        break

                if url and title:
                    results.append(SearchResult(
                        title=title,
                        url=url,
                        content=snippet or title,
                        score=0.6,
                        source=self.name,
                    ))
            except Exception:
                continue
        return results

    @staticmethod
    def _clean_text(text: str) -> str:
        """清理 HTML 标签和多余空白"""
        import re
        text = re.sub(r'<[^>]+>', '', text)
        text = re.sub(r'\s+', ' ', text).strip()
        return text