src/tools/web_search_tool.py

#!/usr/bin/env python3
"""
Web Search Tool for GAIA Agent System
Handles web searches using DuckDuckGo (primary), Tavily API (secondary), 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 DuckDuckGo (primary), Tavily API (secondary), and Wikipedia (fallback)
    Provides multiple search engine options for reliability
    """
    
    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 search engines
        self.tavily_api_key = os.getenv("TAVILY_API_KEY")
        self.use_tavily = self.tavily_api_key is not None
        
        # Try to import DuckDuckGo
        try:
            from duckduckgo_search import DDGS
            self.ddgs = DDGS()
            self.use_duckduckgo = True
            logger.info("✅ DuckDuckGo search initialized")
        except ImportError:
            logger.warning("⚠️ DuckDuckGo search not available - install duckduckgo-search package")
            self.use_duckduckgo = False
        
        # Try to import Wikipedia
        try:
            import wikipedia
            self.wikipedia = wikipedia
            self.use_wikipedia = True
            logger.info("✅ Wikipedia search initialized")
        except ImportError:
            logger.warning("⚠️ Wikipedia search not available - install wikipedia package")
            self.use_wikipedia = False
        
        if self.use_tavily:
            logger.info("✅ Tavily API key found - using as secondary search")
        
        # Search engine priority: DuckDuckGo -> Tavily -> Wikipedia
        search_engines = []
        if self.use_duckduckgo:
            search_engines.append("DuckDuckGo")
        if self.use_tavily:
            search_engines.append("Tavily")
        if self.use_wikipedia:
            search_engines.append("Wikipedia")
            
        logger.info(f"🔍 Available search engines: {', '.join(search_engines)}")
        
    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 _extract_search_terms(self, query: str, max_length: int = 250) -> str:
        """
        Extract key search terms from a potentially long query
        """
        # If query is short enough, use as-is
        if len(query) <= max_length:
            return query
        
        # Remove common stop words and extract key terms
        stop_words = {
            'the', 'a', 'an', 'and', 'or', 'but', 'in', 'on', 'at', 'to', 'for', 'of', 'with', 'by',
            'is', 'are', 'was', 'were', 'be', 'been', 'being', 'have', 'has', 'had', 'do', 'does', 'did',
            'will', 'would', 'could', 'should', 'may', 'might', 'must', 'can', 'this', 'that', 'these', 'those',
            'i', 'you', 'he', 'she', 'it', 'we', 'they', 'me', 'him', 'her', 'us', 'them',
            'what', 'where', 'when', 'why', 'how', 'which', 'who', 'whose', 'whom',
            'please', 'could', 'you', 'tell', 'me', 'find', 'search', 'for', 'about'
        }
        
        # Split into words and filter
        words = re.findall(r'\b\w+\b', query.lower())
        key_words = [word for word in words if word not in stop_words and len(word) > 2]
        
        # Keep important phrases and entities
        # Look for quoted phrases, proper nouns, numbers, dates
        important_patterns = [
            r'"[^"]*"',  # Quoted phrases
            r'\b[A-Z][a-z]*(?:\s+[A-Z][a-z]*)*\b',  # Proper nouns
            r'\b\d{4}\b',  # Years
            r'\b\d+\b',   # Numbers
        ]
        
        important_terms = []
        for pattern in important_patterns:
            matches = re.findall(pattern, query)
            important_terms.extend(matches)
        
        # Combine key words and important terms
        search_terms = []
        
        # Add important terms first (they're usually more specific)
        for term in important_terms:
            if len(' '.join(search_terms + [term])) <= max_length:
                search_terms.append(term)
        
        # Add key words until we hit the limit
        for word in key_words:
            potential_query = ' '.join(search_terms + [word])
            if len(potential_query) <= max_length:
                search_terms.append(word)
            else:
                break
        
        result = ' '.join(search_terms)
        
        # If still too long, truncate
        if len(result) > max_length:
            result = result[:max_length].rsplit(' ', 1)[0]
        
        # If we ended up with nothing, use first part of original query
        if not result.strip():
            result = query[:max_length].rsplit(' ', 1)[0]
        
        if result != query:
            logger.info(f"📝 Extracted search terms: '{result}' from '{query[:100]}...'")
        
        return result
    
    def _search_web(self, query: str, limit: int = 5, extract_content: bool = False) -> Dict[str, Any]:
        """
        Search the web using available search engines in priority order
        """
        
        # Extract search terms to avoid length issues
        search_query = self._extract_search_terms(query, max_length=250)
        
        # Try DuckDuckGo first (most comprehensive for general web search)
        if self.use_duckduckgo:
            try:
                return self._search_with_duckduckgo(search_query, limit, extract_content)
            except Exception as e:
                logger.warning(f"DuckDuckGo search failed, trying Tavily: {e}")
        
        # Try Tavily if DuckDuckGo fails and API key is available
        if self.use_tavily:
            try:
                return self._search_with_tavily(search_query, limit, extract_content)
            except Exception as e:
                logger.warning(f"Tavily search failed, trying Wikipedia: {e}")
        
        # Fallback to Wikipedia search
        if self.use_wikipedia:
            return self._search_with_wikipedia(search_query, limit)
        
        # No search engines available
        return {
            "query": query,
            "found": False,
            "message": "❌ No search engines available. Please install required packages.",
            "results": []
        }
    
    def _search_with_duckduckgo(self, query: str, limit: int = 5, extract_content: bool = False) -> Dict[str, Any]:
        """
        Search using DuckDuckGo - primary search engine with improved error handling
        """
        try:
            logger.info(f"🦆 DuckDuckGo search for: {query}")
            
            # Use DuckDuckGo text search - fail fast if there are issues
            ddg_results = list(self.ddgs.text(query, max_results=min(limit, 10)))
            
            if not ddg_results:
                logger.warning("DuckDuckGo returned no results")
                return self._search_with_fallback(query, limit)
            
            # Process DuckDuckGo results
            results = []
            for result in ddg_results:
                web_result = WebSearchResult(
                    title=result.get('title', 'No title'),
                    url=result.get('href', ''),
                    snippet=result.get('body', 'No description'),
                    content=''  # DuckDuckGo doesn't provide full content
                )
                results.append(web_result.to_dict())
            
            # Extract content if requested
            if extract_content and results:
                for result in results[:2]:  # Only extract from first 2 results to save time
                    try:
                        content_result = self._extract_content_from_url(result['url'])
                        if content_result.get('found'):
                            result['content'] = content_result.get('content', '')[:1000]
                    except:
                        pass  # Skip content extraction errors
            
            logger.info(f"✅ DuckDuckGo found {len(results)} results")
            return {
                "query": query,
                "found": True,
                "results": results,
                "total_results": len(results),
                "message": f"Found {len(results)} results via DuckDuckGo",
                "search_engine": "duckduckgo"
            }
            
        except Exception as e:
            logger.warning(f"DuckDuckGo search failed: {str(e)[:100]}")
            # Fall back to other search engines immediately
            return self._search_with_fallback(query, limit)
    
    def _search_with_fallback(self, query: str, limit: int) -> Dict[str, Any]:
        """Try fallback search engines"""
        # Try Tavily if available
        if self.use_tavily:
            try:
                return self._search_with_tavily(query, limit, False)
            except Exception as e:
                logger.warning(f"Tavily fallback failed: {e}")
        
        # Try Wikipedia as last resort
        if self.use_wikipedia:
            return self._search_with_wikipedia(query, limit)
        
        return {
            "query": query,
            "found": False,
            "message": "All search engines failed",
            "results": []
        }
    
    def _search_with_tavily(self, query: str, limit: int = 5, extract_content: bool = False) -> Dict[str, Any]:
        """
        Search using Tavily Search API - secondary search engine
        """
        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)
            }
            
            # 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")
                # Fall back to Wikipedia
                if self.use_wikipedia:
                    return self._search_with_wikipedia(query, limit)
                
        except requests.exceptions.RequestException as e:
            logger.error(f"Tavily API request failed: {e}")
        except Exception as e:
            logger.error(f"Tavily search error: {e}")
        
        # Fall back to Wikipedia if Tavily fails
        if self.use_wikipedia:
            return self._search_with_wikipedia(query, limit)
        
        return {
            "query": query,
            "found": False,
            "message": "Tavily search failed and no fallback available",
            "results": []
        }
    
    def _search_with_wikipedia(self, query: str, limit: int = 5) -> Dict[str, Any]:
        """
        Search using Wikipedia - fallback search engine for factual information
        """
        try:
            logger.info(f"📚 Wikipedia search for: {query}")
            
            self.wikipedia.set_lang("en")
            
            # Clean up query for Wikipedia search and ensure it's not too long
            search_terms = self._extract_search_terms(query, max_length=100)  # Wikipedia has stricter limits
            
            # Search Wikipedia pages
            wiki_results = self.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 = self.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 self.wikipedia.exceptions.DisambiguationError as e:
                    # Try the first suggestion from disambiguation
                    try:
                        if e.options:
                            page = self.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 self.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"Wikipedia 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 test_web_search_tool():
    """Test the web search tool with various queries"""
    tool = WebSearchTool()
    
    # Test cases
    test_cases = [
        "Python programming tutorial",
        "Mercedes Sosa studio albums 2000 2009",
        "artificial intelligence recent developments",
        "climate change latest research",
        "https://en.wikipedia.org/wiki/Machine_learning"
    ]
    
    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()