src/tools/web_search_tool.py

#!/usr/bin/env python3
"""
Web Search Tool for GAIA Agent System
Handles web searches using DuckDuckGo and content extraction from URLs
"""

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

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 DuckDuckGo
    Handles searches, URL content extraction, and result filtering
    """
    
    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
        
    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 DuckDuckGo
        """
        try:
            logger.info(f"Searching web for: {query}")
            
            # Perform DuckDuckGo search
            with DDGS() as ddgs:
                search_results = list(ddgs.text(
                    keywords=query,
                    max_results=limit,
                    region='us-en',
                    safesearch='moderate'
                ))
            
            if not search_results:
                return {
                    "query": query,
                    "found": False,
                    "message": "No web search results found",
                    "results": []
                }
            
            results = []
            for result in search_results:
                web_result = WebSearchResult(
                    title=result.get('title', 'No title'),
                    url=result.get('href', ''),
                    snippet=result.get('body', 'No description')
                )
                
                # Optionally extract full content from each URL
                if extract_content and web_result.url:
                    try:
                        content_result = self._extract_content_from_url(web_result.url)
                        if content_result.get('found'):
                            web_result.content = content_result['content'][:1000]  # Limit content size
                    except Exception as e:
                        logger.warning(f"Failed to extract content from {web_result.url}: {e}")
                
                results.append(web_result.to_dict())
            
            return {
                "query": query,
                "found": True,
                "results": results,
                "total_results": len(results),
                "message": f"Found {len(results)} web search results"
            }
            
        except Exception as e:
            raise Exception(f"Web search failed: {str(e)}")
    
    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}"
            
            with DDGS() as ddgs:
                search_results = list(ddgs.text(
                    keywords=youtube_query,
                    max_results=3,
                    region='us-en',
                    safesearch='moderate'
                ))
            
            youtube_results = []
            for result in search_results:
                if 'youtube.com/watch' in result.get('href', ''):
                    video_id = self._extract_youtube_id(result['href'])
                    
                    youtube_result = {
                        "title": result.get('title', 'No title'),
                        "url": result.get('href', ''),
                        "description": result.get('body', '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')}")
                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()