src/tools/web_search_tool.py

#!/usr/bin/env python3
"""
Web Search Tool for GAIA Agent System
Handles web searches using Tavily API (primary) and Wikipedia (fallback)
"""

import re
import logging
import time
import os
from typing import Dict, List, Optional, Any
from urllib.parse import urlparse, urljoin
import requests
from bs4 import BeautifulSoup

from tools import BaseTool

logger = logging.getLogger(__name__)

class WebSearchResult:
    """Container for web search results"""
    
    def __init__(self, title: str, url: str, snippet: str, content: str = ""):
        self.title = title
        self.url = url
        self.snippet = snippet
        self.content = content
        
    def to_dict(self) -> Dict[str, str]:
        return {
            "title": self.title,
            "url": self.url,
            "snippet": self.snippet,
            "content": self.content[:1500] + "..." if len(self.content) > 1500 else self.content
        }

class WebSearchTool(BaseTool):
    """
    Web search tool using Tavily API (primary) and Wikipedia (fallback)
    Much more reliable than DuckDuckGo with no rate limiting issues
    """
    
    def __init__(self):
        super().__init__("web_search")
        
        # Configure requests session for web scraping
        self.session = requests.Session()
        self.session.headers.update({
            'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
        })
        self.session.timeout = 10
        
        # Initialize Tavily client if API key is available
        self.tavily_api_key = os.getenv("TAVILY_API_KEY")
        self.use_tavily = self.tavily_api_key is not None
        
        if self.use_tavily:
            logger.info("✅ Tavily API key found - using Tavily for web search")
        else:
            logger.info("ℹ️ No Tavily API key found - will use Wikipedia fallback only")
        
    def _execute_impl(self, input_data: Any, **kwargs) -> Dict[str, Any]:
        """
        Execute web search operations based on input type
        
        Args:
            input_data: Can be:
                - str: Search query or URL to extract content from
                - dict: {"query": str, "action": str, "limit": int, "extract_content": bool}
        """
        
        if isinstance(input_data, str):
            # Handle both search queries and URLs
            if self._is_url(input_data):
                return self._extract_content_from_url(input_data)
            else:
                return self._search_web(input_data)
                
        elif isinstance(input_data, dict):
            query = input_data.get("query", "")
            action = input_data.get("action", "search")
            limit = input_data.get("limit", 5)
            extract_content = input_data.get("extract_content", False)
            
            if action == "search":
                return self._search_web(query, limit, extract_content)
            elif action == "extract":
                return self._extract_content_from_url(query)
            else:
                raise ValueError(f"Unknown action: {action}")
        else:
            raise ValueError(f"Unsupported input type: {type(input_data)}")
    
    def _is_url(self, text: str) -> bool:
        """Check if text is a URL"""
        return bool(re.match(r'https?://', text))
    
    def _search_web(self, query: str, limit: int = 5, extract_content: bool = False) -> Dict[str, Any]:
        """
        Search the web using Tavily API (primary) or Wikipedia (fallback)
        """
        
        # Try Tavily first if API key is available
        if self.use_tavily:
            try:
                return self._search_with_tavily(query, limit, extract_content)
            except Exception as e:
                logger.warning(f"Tavily search failed, falling back to Wikipedia: {e}")
        
        # Fallback to Wikipedia search
        return self._search_with_wikipedia(query, limit)
    
    def _search_with_tavily(self, query: str, limit: int = 5, extract_content: bool = False) -> Dict[str, Any]:
        """
        Search using Tavily Search API - much more reliable than DuckDuckGo
        """
        try:
            logger.info(f"🔍 Tavily search for: {query}")
            
            # Prepare Tavily API request
            headers = {
                "Content-Type": "application/json"
            }
            
            payload = {
                "api_key": self.tavily_api_key,
                "query": query,
                "search_depth": "basic",
                "include_answer": False,
                "include_images": False,
                "include_raw_content": extract_content,
                "max_results": min(limit, 10)  # Tavily supports up to 10 results
            }
            
            # Make API request
            response = self.session.post(
                "https://api.tavily.com/search",
                json=payload,
                headers=headers,
                timeout=15
            )
            response.raise_for_status()
            
            tavily_data = response.json()
            
            # Process Tavily results
            results = []
            tavily_results = tavily_data.get('results', [])
            
            for result in tavily_results:
                web_result = WebSearchResult(
                    title=result.get('title', 'No title'),
                    url=result.get('url', ''),
                    snippet=result.get('content', 'No description'),
                    content=result.get('raw_content', '') if extract_content else ''
                )
                results.append(web_result.to_dict())
            
            if results:
                logger.info(f"✅ Tavily found {len(results)} results")
                return {
                    "query": query,
                    "found": True,
                    "results": results,
                    "total_results": len(results),
                    "message": f"Found {len(results)} results via Tavily Search API",
                    "search_engine": "tavily"
                }
            else:
                logger.warning("Tavily returned no results, trying Wikipedia fallback")
                return self._search_with_wikipedia(query, limit)
                
        except requests.exceptions.RequestException as e:
            logger.error(f"Tavily API request failed: {e}")
            # Fall back to Wikipedia
            return self._search_with_wikipedia(query, limit)
        except Exception as e:
            logger.error(f"Tavily search error: {e}")
            # Fall back to Wikipedia
            return self._search_with_wikipedia(query, limit)
    
    def _search_with_wikipedia(self, query: str, limit: int = 5) -> Dict[str, Any]:
        """
        Search using Wikipedia as fallback - very reliable and no rate limits
        """
        try:
            logger.info(f"📚 Wikipedia search for: {query}")
            
            # Try to import wikipedia library
            try:
                import wikipedia
            except ImportError:
                return {
                    "query": query,
                    "found": False,
                    "message": "❌ No search engines available. Install 'wikipedia' package or configure Tavily API key.",
                    "results": []
                }
            
            wikipedia.set_lang("en")
            
            # Clean up query for Wikipedia search
            search_terms = query.replace("site:", "").strip()
            
            # Search Wikipedia pages
            wiki_results = wikipedia.search(search_terms, results=min(limit * 2, 10))
            
            if not wiki_results:
                return {
                    "query": query,
                    "found": False,
                    "message": "No Wikipedia articles found for this query",
                    "results": [],
                    "search_engine": "wikipedia"
                }
            
            results = []
            processed = 0
            
            for page_title in wiki_results:
                if processed >= limit:
                    break
                    
                try:
                    page = wikipedia.page(page_title)
                    summary = page.summary[:300] + "..." if len(page.summary) > 300 else page.summary
                    
                    web_result = WebSearchResult(
                        title=f"{page_title} (Wikipedia)",
                        url=page.url,
                        snippet=summary,
                        content=page.summary[:1000] + "..." if len(page.summary) > 1000 else page.summary
                    )
                    results.append(web_result.to_dict())
                    processed += 1
                    
                except wikipedia.exceptions.DisambiguationError as e:
                    # Try the first suggestion from disambiguation
                    try:
                        if e.options:
                            page = wikipedia.page(e.options[0])
                            summary = page.summary[:300] + "..." if len(page.summary) > 300 else page.summary
                            
                            web_result = WebSearchResult(
                                title=f"{e.options[0]} (Wikipedia)",
                                url=page.url,
                                snippet=summary,
                                content=page.summary[:1000] + "..." if len(page.summary) > 1000 else page.summary
                            )
                            results.append(web_result.to_dict())
                            processed += 1
                    except:
                        continue
                        
                except wikipedia.exceptions.PageError:
                    # Page doesn't exist, skip
                    continue
                except Exception as e:
                    # Other Wikipedia errors, skip this page
                    logger.warning(f"Wikipedia page error for '{page_title}': {e}")
                    continue
            
            if results:
                logger.info(f"✅ Wikipedia found {len(results)} results")
                return {
                    "query": query,
                    "found": True,
                    "results": results,
                    "total_results": len(results),
                    "message": f"Found {len(results)} Wikipedia articles",
                    "search_engine": "wikipedia"
                }
            else:
                return {
                    "query": query,
                    "found": False,
                    "message": "No accessible Wikipedia articles found for this query",
                    "results": [],
                    "search_engine": "wikipedia"
                }
                
        except Exception as e:
            logger.error(f"Wikipedia search failed: {e}")
            return {
                "query": query,
                "found": False,
                "message": f"Search failed: {str(e)}",
                "results": [],
                "error_type": "search_failure"
            }
    
    def _extract_content_from_url(self, url: str) -> Dict[str, Any]:
        """
        Extract readable content from a web page
        """
        try:
            logger.info(f"Extracting content from: {url}")
            
            # Get page content
            response = self.session.get(url)
            response.raise_for_status()
            
            # Parse with BeautifulSoup
            soup = BeautifulSoup(response.content, 'html.parser')
            
            # Remove script and style elements
            for script in soup(["script", "style", "nav", "header", "footer", "aside"]):
                script.decompose()
            
            # Extract title
            title = soup.find('title')
            title_text = title.get_text().strip() if title else "No title"
            
            # Extract main content
            content = self._extract_main_content(soup)
            
            # Extract metadata
            meta_description = ""
            meta_desc = soup.find('meta', attrs={'name': 'description'})
            if meta_desc:
                meta_description = meta_desc.get('content', '')
            
            # Extract links
            links = []
            for link in soup.find_all('a', href=True)[:10]:  # First 10 links
                link_url = urljoin(url, link['href'])
                link_text = link.get_text().strip()
                if link_text and len(link_text) > 5:  # Filter out short/empty links
                    links.append({"text": link_text, "url": link_url})
            
            return {
                "url": url,
                "found": True,
                "title": title_text,
                "content": content,
                "meta_description": meta_description,
                "links": links,
                "content_length": len(content),
                "message": "Successfully extracted content from URL"
            }
            
        except requests.exceptions.RequestException as e:
            return {
                "url": url,
                "found": False,
                "message": f"Failed to fetch URL: {str(e)}",
                "error_type": "network_error"
            }
        except Exception as e:
            return {
                "url": url,
                "found": False,
                "message": f"Failed to extract content: {str(e)}",
                "error_type": "parsing_error"
            }
    
    def _extract_main_content(self, soup: BeautifulSoup) -> str:
        """
        Extract main content from HTML using various strategies
        """
        content_parts = []
        
        # Strategy 1: Look for article/main tags
        main_content = soup.find(['article', 'main'])
        if main_content:
            content_parts.append(main_content.get_text())
        
        # Strategy 2: Look for content in common div classes
        content_selectors = [
            'div.content',
            'div.article-content',
            'div.post-content',
            'div.entry-content',
            'div.main-content',
            'div#content',
            'div.text'
        ]
        
        for selector in content_selectors:
            elements = soup.select(selector)
            for element in elements:
                content_parts.append(element.get_text())
        
        # Strategy 3: Look for paragraphs in body
        if not content_parts:
            paragraphs = soup.find_all('p')
            for p in paragraphs[:20]:  # First 20 paragraphs
                text = p.get_text().strip()
                if len(text) > 50:  # Filter out short paragraphs
                    content_parts.append(text)
        
        # Clean and combine content
        combined_content = '\n\n'.join(content_parts)
        
        # Clean up whitespace and formatting
        combined_content = re.sub(r'\n\s*\n', '\n\n', combined_content)  # Multiple newlines
        combined_content = re.sub(r' +', ' ', combined_content)  # Multiple spaces
        
        return combined_content.strip()[:5000]  # Limit to 5000 characters
    
    def search_youtube_metadata(self, query: str) -> Dict[str, Any]:
        """
        Specialized search for YouTube video information
        """
        try:
            # Search specifically for YouTube videos
            youtube_query = f"site:youtube.com {query}"
            
            # Use the same search logic but filter for YouTube results
            search_result = self._search_web(youtube_query, limit=3)
            
            if not search_result.get('found'):
                return search_result
            
            youtube_results = []
            for result in search_result.get('results', []):
                if 'youtube.com/watch' in result.get('url', ''):
                    video_id = self._extract_youtube_id(result['url'])
                    
                    youtube_result = {
                        "title": result.get('title', 'No title'),
                        "url": result.get('url', ''),
                        "description": result.get('snippet', 'No description'),
                        "video_id": video_id
                    }
                    youtube_results.append(youtube_result)
            
            return {
                "query": query,
                "found": len(youtube_results) > 0,
                "results": youtube_results,
                "message": f"Found {len(youtube_results)} YouTube videos"
            }
            
        except Exception as e:
            raise Exception(f"YouTube search failed: {str(e)}")
    
    def _extract_youtube_id(self, url: str) -> str:
        """Extract YouTube video ID from URL"""
        patterns = [
            r'(?:v=|\/)([0-9A-Za-z_-]{11}).*',
            r'(?:embed\/)([0-9A-Za-z_-]{11})',
            r'(?:youtu\.be\/)([0-9A-Za-z_-]{11})'
        ]
        
        for pattern in patterns:
            match = re.search(pattern, url)
            if match:
                return match.group(1)
        return ""

def test_web_search_tool():
    """Test the web search tool with various queries"""
    tool = WebSearchTool()
    
    # Test cases
    test_cases = [
        "Python programming tutorial",
        "https://en.wikipedia.org/wiki/Machine_learning",
        {"query": "artificial intelligence news", "action": "search", "limit": 3},
        {"query": "https://www.python.org", "action": "extract"},
        {"query": "OpenAI ChatGPT", "action": "search", "limit": 2, "extract_content": True}
    ]
    
    print("🧪 Testing Web Search Tool...")
    
    for i, test_case in enumerate(test_cases, 1):
        print(f"\n--- Test {i}: {test_case} ---")
        try:
            result = tool.execute(test_case)
            
            if result.success:
                print(f"✅ Success: {result.result.get('message', 'No message')}")
                search_engine = result.result.get('search_engine', 'unknown')
                print(f"   Search engine: {search_engine}")
                
                if result.result.get('found'):
                    if 'results' in result.result:
                        print(f"   Found {len(result.result['results'])} results")
                        # Show first result details
                        if result.result['results']:
                            first_result = result.result['results'][0]
                            print(f"   First result: {first_result.get('title', 'No title')}")
                            print(f"   URL: {first_result.get('url', 'No URL')}")
                    elif 'content' in result.result:
                        print(f"   Extracted {len(result.result['content'])} characters")
                        print(f"   Title: {result.result.get('title', 'No title')}")
                else:
                    print(f"   Not found: {result.result.get('message', 'Unknown error')}")
            else:
                print(f"❌ Error: {result.error}")
            
            print(f"   Execution time: {result.execution_time:.2f}s")
            
        except Exception as e:
            print(f"❌ Exception: {str(e)}")

if __name__ == "__main__":
    # Test when run directly
    test_web_search_tool()