import httpx
import json
import redis
from typing import List, Dict, Optional
from datetime import datetime
import hashlib
from bs4 import BeautifulSoup
from .config import settings

class GoogleSearchService:
    def __init__(self):
        # Redis 연결
        self.redis_client = redis.Redis(
            host=settings.redis_host,
            port=settings.redis_port,
            db=settings.redis_db,
            decode_responses=True
        )
        
    def _get_cache_key(self, query: str, **kwargs) -> str:
        """캐시 키 생성"""
        cache_data = f"{query}_{kwargs}"
        return f"google_search:{hashlib.md5(cache_data.encode()).hexdigest()}"
    
    async def search_with_custom_api(
        self, 
        query: str, 
        num_results: int = 10,
        language: str = None,
        country: str = None,
        date_restrict: str = None,
        sort_by_date: bool = False
    ) -> Dict:
        """Google Custom Search API 사용"""
        if not settings.google_api_key or not settings.google_search_engine_id:
            return {
                "error": "Google API credentials not configured",
                "results": []
            }
        
        # 캐시 확인
        cache_key = self._get_cache_key(query, num=num_results, lang=language, country=country)
        cached = self.redis_client.get(cache_key)
        if cached:
            return json.loads(cached)
        
        url = "https://www.googleapis.com/customsearch/v1"
        
        all_results = []
        total_results_info = None
        
        # Google API는 한 번에 최대 10개만 반환, 20개를 원하면 2번 요청
        num_requests = min((num_results + 9) // 10, 2)  # 최대 2번 요청 (20개까지)
        
        async with httpx.AsyncClient() as client:
            for page in range(num_requests):
                start_index = page * 10 + 1
                current_num = min(10, num_results - page * 10)
                
                params = {
                    "key": settings.google_api_key,
                    "cx": settings.google_search_engine_id,
                    "q": query,
                    "num": current_num,
                    "start": start_index,  # 시작 인덱스
                    "hl": language or settings.default_language,
                    "gl": country or settings.default_country
                }
                
                # 날짜 제한 추가 (d7 = 일주일, m1 = 한달, y1 = 1년)
                if date_restrict:
                    params["dateRestrict"] = date_restrict
                
                # 날짜순 정렬 (Google Custom Search API에서는 sort=date 옵션)
                if sort_by_date:
                    params["sort"] = "date"
                
                try:
                    response = await client.get(url, params=params)
                    response.raise_for_status()
                    
                    data = response.json()
                    
                    # 첫 번째 요청에서만 전체 정보 저장
                    if page == 0:
                        total_results_info = {
                            "total_results": data.get("searchInformation", {}).get("totalResults"),
                            "search_time": data.get("searchInformation", {}).get("searchTime"),
                            "query": data.get("queries", {}).get("request", [{}])[0].get("searchTerms")
                        }
                    
                    # 결과 추가
                    for item in data.get("items", []):
                        all_results.append({
                            "title": item.get("title"),
                            "link": item.get("link"),
                            "snippet": item.get("snippet"),
                            "display_link": item.get("displayLink"),
                            "thumbnail": item.get("pagemap", {}).get("cse_thumbnail", [{}])[0].get("src") if "pagemap" in item else None
                        })
                    
                except Exception as e:
                    # 첫 번째 요청이 실패하면 에러 반환
                    if page == 0:
                        return {
                            "error": str(e),
                            "results": []
                        }
                    # 두 번째 요청이 실패하면 첫 번째 결과만 반환
                    break
        
        results = {
            "query": total_results_info.get("query") if total_results_info else query,
            "total_results": total_results_info.get("total_results") if total_results_info else "0",
            "search_time": total_results_info.get("search_time") if total_results_info else 0,
            "results": all_results[:num_results],  # 요청한 개수만큼만 반환
            "timestamp": datetime.utcnow().isoformat()
        }
        
        # 캐시 저장
        self.redis_client.setex(
            cache_key,
            settings.cache_ttl,
            json.dumps(results)
        )
        
        return results
    
    async def search_with_serpapi(
        self, 
        query: str,
        num_results: int = 10,
        language: str = None,
        country: str = None
    ) -> Dict:
        """SerpAPI 사용 (유료 서비스)"""
        if not settings.serpapi_key:
            return {
                "error": "SerpAPI key not configured",
                "results": []
            }
        
        # 캐시 확인
        cache_key = self._get_cache_key(query, num=num_results, lang=language, country=country)
        cached = self.redis_client.get(cache_key)
        if cached:
            return json.loads(cached)
        
        from serpapi import GoogleSearch
        
        params = {
            "q": query,
            "api_key": settings.serpapi_key,
            "num": num_results,
            "hl": language or settings.default_language,
            "gl": country or settings.default_country
        }
        
        try:
            search = GoogleSearch(params)
            results = search.get_dict()
            
            formatted_results = self._format_serpapi_results(results)
            
            # 캐시 저장
            self.redis_client.setex(
                cache_key,
                settings.cache_ttl,
                json.dumps(formatted_results)
            )
            
            return formatted_results
            
        except Exception as e:
            return {
                "error": str(e),
                "results": []
            }
    
    async def search_with_scraping(
        self,
        query: str,
        num_results: int = 10,
        language: str = None
    ) -> Dict:
        """웹 스크래핑으로 검색 (비추천, 제한적)"""
        # 캐시 확인
        cache_key = self._get_cache_key(query, num=num_results, lang=language)
        cached = self.redis_client.get(cache_key)
        if cached:
            return json.loads(cached)
        
        headers = {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
        }
        
        params = {
            "q": query,
            "num": num_results,
            "hl": language or settings.default_language
        }
        
        async with httpx.AsyncClient() as client:
            try:
                response = await client.get(
                    "https://www.google.com/search",
                    params=params,
                    headers=headers,
                    follow_redirects=True
                )
                
                soup = BeautifulSoup(response.text, 'html.parser')
                results = self._parse_google_html(soup)
                
                formatted_results = {
                    "query": query,
                    "total_results": len(results),
                    "results": results,
                    "timestamp": datetime.utcnow().isoformat()
                }
                
                # 캐시 저장
                self.redis_client.setex(
                    cache_key,
                    settings.cache_ttl,
                    json.dumps(formatted_results)
                )
                
                return formatted_results
                
            except Exception as e:
                return {
                    "error": str(e),
                    "results": []
                }
    
    def _format_google_results(self, data: Dict) -> Dict:
        """Google API 결과 포맷팅"""
        results = []
        
        for item in data.get("items", []):
            results.append({
                "title": item.get("title"),
                "link": item.get("link"),
                "snippet": item.get("snippet"),
                "display_link": item.get("displayLink"),
                "thumbnail": item.get("pagemap", {}).get("cse_thumbnail", [{}])[0].get("src") if "pagemap" in item else None
            })
        
        return {
            "query": data.get("queries", {}).get("request", [{}])[0].get("searchTerms"),
            "total_results": data.get("searchInformation", {}).get("totalResults"),
            "search_time": data.get("searchInformation", {}).get("searchTime"),
            "results": results,
            "timestamp": datetime.utcnow().isoformat()
        }
    
    def _format_serpapi_results(self, data: Dict) -> Dict:
        """SerpAPI 결과 포맷팅"""
        results = []
        
        for item in data.get("organic_results", []):
            results.append({
                "title": item.get("title"),
                "link": item.get("link"),
                "snippet": item.get("snippet"),
                "position": item.get("position"),
                "thumbnail": item.get("thumbnail"),
                "date": item.get("date")
            })
        
        # 관련 검색어
        related_searches = [
            item.get("query") for item in data.get("related_searches", [])
        ]
        
        return {
            "query": data.get("search_parameters", {}).get("q"),
            "total_results": data.get("search_information", {}).get("total_results"),
            "search_time": data.get("search_information", {}).get("time_taken_displayed"),
            "results": results,
            "related_searches": related_searches,
            "timestamp": datetime.utcnow().isoformat()
        }
    
    def _parse_google_html(self, soup: BeautifulSoup) -> List[Dict]:
        """HTML 파싱으로 검색 결과 추출"""
        results = []
        
        # 검색 결과 컨테이너 찾기
        for g in soup.find_all('div', class_='g'):
            anchors = g.find_all('a')
            if anchors:
                link = anchors[0].get('href', '')
                title_elem = g.find('h3')
                snippet_elem = g.find('span', class_='st') or g.find('div', class_='s')
                
                if title_elem and link:
                    results.append({
                        "title": title_elem.get_text(),
                        "link": link,
                        "snippet": snippet_elem.get_text() if snippet_elem else ""
                    })
        
        return results
    
    async def fetch_page_content(self, url: str) -> Dict:
        """웹 페이지의 전체 내용을 가져오기"""
        try:
            headers = {
                "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
            }
            
            async with httpx.AsyncClient(timeout=10.0) as client:
                response = await client.get(url, headers=headers, follow_redirects=True)
                response.raise_for_status()
                
                soup = BeautifulSoup(response.text, 'html.parser')
                
                # 불필요한 태그 제거
                for script in soup(["script", "style", "nav", "header", "footer"]):
                    script.decompose()
                
                # 본문 내용 추출 시도
                main_content = None
                
                # 1. article 태그 찾기
                article = soup.find('article')
                if article:
                    main_content = article.get_text()
                
                # 2. main 태그 찾기
                if not main_content:
                    main = soup.find('main')
                    if main:
                        main_content = main.get_text()
                
                # 3. 일반적인 콘텐츠 div 찾기
                if not main_content:
                    content_divs = soup.find_all('div', class_=lambda x: x and ('content' in x.lower() or 'article' in x.lower() or 'post' in x.lower()))
                    if content_divs:
                        main_content = ' '.join([div.get_text() for div in content_divs[:3]])
                
                # 4. 전체 body에서 텍스트 추출
                if not main_content:
                    body = soup.find('body')
                    if body:
                        main_content = body.get_text()
                    else:
                        main_content = soup.get_text()
                
                # 텍스트 정리
                main_content = ' '.join(main_content.split())
                
                # 제목 추출
                title = soup.find('title')
                title_text = title.get_text() if title else ""
                
                # 메타 설명 추출
                meta_desc = soup.find('meta', attrs={'name': 'description'})
                description = meta_desc.get('content', '') if meta_desc else ""
                
                return {
                    "url": url,
                    "title": title_text,
                    "description": description,
                    "content": main_content[:5000],  # 최대 5000자
                    "content_length": len(main_content),
                    "success": True
                }
                
        except Exception as e:
            return {
                "url": url,
                "error": str(e),
                "success": False
            }
    
    async def search_with_extended_snippet(
        self,
        query: str,
        num_results: int = 10,
        language: str = None,
        country: str = None
    ) -> Dict:
        """검색 후 확장된 snippet 가져오기 (메타 설명 + 첫 500자)"""
        # 먼저 일반 검색 수행
        search_results = await self.search_with_custom_api(
            query, num_results, language, country
        )
        
        if "error" in search_results:
            return search_results
        
        # 각 결과의 확장된 snippet 가져오기
        import asyncio
        
        async def fetch_extended_snippet(result):
            """개별 페이지의 확장된 snippet 가져오기"""
            enhanced_result = result.copy()
            
            if result.get("link"):
                try:
                    headers = {
                        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
                    }
                    
                    async with httpx.AsyncClient(timeout=5.0) as client:
                        response = await client.get(result["link"], headers=headers, follow_redirects=True)
                        response.raise_for_status()
                        
                        soup = BeautifulSoup(response.text, 'html.parser')
                        
                        # 메타 설명 추출
                        meta_desc = soup.find('meta', attrs={'name': 'description'})
                        if not meta_desc:
                            meta_desc = soup.find('meta', attrs={'property': 'og:description'})
                        
                        description = meta_desc.get('content', '') if meta_desc else ""
                        
                        # 본문 첫 부분 추출
                        for script in soup(["script", "style"]):
                            script.decompose()
                        
                        # 본문 텍스트 찾기
                        text_content = ""
                        for tag in ['article', 'main', 'div']:
                            elements = soup.find_all(tag)
                            for elem in elements:
                                text = elem.get_text().strip()
                                if len(text) > 200:  # 의미있는 텍스트만
                                    text_content = ' '.join(text.split())[:1000]
                                    break
                            if text_content:
                                break
                        
                        # 기존 snippet과 병합
                        extended_snippet = result.get("snippet", "")
                        if description and description not in extended_snippet:
                            extended_snippet = description + " ... " + extended_snippet
                        if text_content and len(extended_snippet) < 500:
                            extended_snippet = extended_snippet + " ... " + text_content[:500-len(extended_snippet)]
                        
                        enhanced_result["snippet"] = extended_snippet[:1000]  # 최대 1000자
                        enhanced_result["extended"] = True
                        
                except Exception as e:
                    # 실패 시 원본 snippet 유지
                    enhanced_result["extended"] = False
                    enhanced_result["fetch_error"] = str(e)
            
            return enhanced_result
        
        # 병렬로 모든 페이지 처리
        tasks = [fetch_extended_snippet(result) for result in search_results.get("results", [])]
        enhanced_results = await asyncio.gather(*tasks)
        
        return {
            **search_results,
            "results": enhanced_results,
            "snippet_extended": True
        }
    
    async def search_with_full_content(
        self,
        query: str,
        num_results: int = 5,
        language: str = None,
        country: str = None
    ) -> Dict:
        """검색 후 각 결과의 전체 내용 가져오기"""
        # 먼저 일반 검색 수행
        search_results = await self.search_with_custom_api(
            query, num_results, language, country
        )
        
        if "error" in search_results:
            return search_results
        
        # 각 결과의 전체 내용 가져오기
        enhanced_results = []
        for result in search_results.get("results", [])[:num_results]:
            # 원본 검색 결과 복사
            enhanced_result = result.copy()
            
            # 페이지 내용 가져오기
            if result.get("link"):
                content_data = await self.fetch_page_content(result["link"])
                enhanced_result["full_content"] = content_data
            
            enhanced_results.append(enhanced_result)
        
        return {
            **search_results,
            "results": enhanced_results,
            "content_fetched": True
        }
    
    async def get_trending_searches(self, country: str = None) -> Dict:
        """트렌딩 검색어 가져오기"""
        # Google Trends 비공식 API 사용
        url = f"https://trends.google.com/trends/api/dailytrends"
        params = {
            "geo": country or settings.default_country.upper()
        }
        
        async with httpx.AsyncClient() as client:
            try:
                response = await client.get(url, params=params)
                # Google Trends API는 ")]}',\n"로 시작하는 응답을 반환
                json_data = response.text[6:]
                data = json.loads(json_data)
                
                trending = []
                for date_data in data.get("default", {}).get("trendingSearchesDays", []):
                    for search in date_data.get("trendingSearches", []):
                        trending.append({
                            "title": search.get("title", {}).get("query"),
                            "traffic": search.get("formattedTraffic"),
                            "articles": [
                                {
                                    "title": article.get("title"),
                                    "url": article.get("url"),
                                    "source": article.get("source")
                                }
                                for article in search.get("articles", [])[:3]
                            ]
                        })
                
                return {
                    "country": country or settings.default_country,
                    "trending": trending[:10],
                    "timestamp": datetime.utcnow().isoformat()
                }
                
            except Exception as e:
                return {
                    "error": str(e),
                    "trending": []
                }