from __future__ import annotations

from typing import List, Dict, Optional

import requests
from bs4 import BeautifulSoup
from datetime import datetime
import hashlib

from app.crawlers.base import BaseCrawler


class TemplateCrawler(BaseCrawler):
    """範本：建立新站點時複製本檔並改名。

    必要實作：fetch_page 與 parse_items
    - parse_items 請回傳包含 title、可選 link、scraped_at、hash 的清單
    """

    def __init__(self, config, logger):
        super().__init__(name="Template Site", config=config, logger=logger, data_filename='template_site.json')
        self.url = "https://example.com"
        self.headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
        }

    def fetch_page(self) -> Optional[str]:
        try:
            resp = requests.get(self.url, headers=self.headers, timeout=30)
            resp.raise_for_status()
            return resp.text
        except requests.RequestException as e:
            self.logger.error(f"獲取網頁失敗: {e}")
            self.stats['errors'] += 1
            return None

    def parse_items(self, html_content: str) -> List[Dict]:
        soup = BeautifulSoup(html_content, 'html.parser')
        items: List[Dict] = []

        # TODO: 依站點結構實作解析邏輯，以下為示意
        for a in soup.select('a')[:5]:
            title = a.get_text(strip=True)
            link = a.get('href')
            if title and len(title) > 5:
                items.append({
                    'title': title,
                    'link': link,
                    'scraped_at': datetime.now().isoformat(),
                    'hash': hashlib.md5(title.encode()).hexdigest()[:8],
                })
        return items