search_engine.py

from typing import Dict, List, Any
import requests
from bs4 import BeautifulSoup
from duckduckgo_search import ddg
from transformers import pipeline
from langchain.embeddings import HuggingFaceEmbeddings
import time
import json
import os
from urllib.parse import urlparse

class ModelManager:
    """Manages AI models for text processing"""
    def __init__(self):
        # Initialize with smaller, CPU-friendly models
        self.summarizer = pipeline(
            "summarization",
            model="facebook/bart-base",
            device=-1  # Use CPU
        )
        self.embeddings = HuggingFaceEmbeddings(
            model_name="sentence-transformers/all-MiniLM-L6-v2"
        )
    
    def generate_summary(self, text: str, max_length: int = 150) -> str:
        """Generate a concise summary of the text"""
        if not text or len(text.split()) < 50:
            return text
        
        try:
            summary = self.summarizer(
                text,
                max_length=max_length,
                min_length=30,
                do_sample=False
            )[0]['summary_text']
            return summary
        except Exception as e:
            print(f"Error in summarization: {e}")
            return text[:500] + "..."

class ContentProcessor:
    """Processes and analyzes different types of content"""
    def __init__(self):
        self.model_manager = ModelManager()
    
    def process_content(self, content: str) -> Dict[str, Any]:
        """Process content and generate insights"""
        if not content:
            return {"summary": "", "insights": []}
        
        try:
            summary = self.model_manager.generate_summary(content)
            return {
                "summary": summary,
                "insights": []  # Simplified for CPU deployment
            }
        except Exception as e:
            print(f"Error processing content: {e}")
            return {"summary": content[:500] + "...", "insights": []}

class WebSearchEngine:
    """Main search engine class"""
    def __init__(self):
        self.processor = ContentProcessor()
        self.session = requests.Session()
        self.request_delay = 1.0
        self.last_request_time = 0
    
    def is_valid_url(self, url: str) -> bool:
        """Check if URL is valid for crawling"""
        try:
            parsed = urlparse(url)
            return bool(parsed.netloc and parsed.scheme in ['http', 'https'])
        except:
            return False
    
    def get_metadata(self, soup: BeautifulSoup) -> Dict[str, str]:
        """Extract metadata from page"""
        metadata = {}
        
        # Get title
        title = soup.find('title')
        if title:
            metadata['title'] = title.text.strip()
        
        # Get meta description
        desc = soup.find('meta', attrs={'name': 'description'})
        if desc:
            metadata['description'] = desc.get('content', '')
        
        # Get publication date
        date = soup.find('meta', attrs={'property': 'article:published_time'})
        if date:
            metadata['published_date'] = date.get('content', '').split('T')[0]
        
        return metadata
    
    def process_url(self, url: str) -> Dict[str, Any]:
        """Process a single URL"""
        if not self.is_valid_url(url):
            return None
        
        try:
            # Rate limiting
            current_time = time.time()
            if current_time - self.last_request_time < self.request_delay:
                time.sleep(self.request_delay)
            
            response = self.session.get(url, timeout=10)
            self.last_request_time = time.time()
            
            if response.status_code != 200:
                return None
            
            soup = BeautifulSoup(response.text, 'lxml')
            metadata = self.get_metadata(soup)
            
            # Extract main content (simplified)
            content = ' '.join([p.text for p in soup.find_all('p')])
            processed = self.processor.process_content(content)
            
            return {
                'url': url,
                'title': metadata.get('title', url),
                'summary': processed['summary'],
                'published_date': metadata.get('published_date', '')
            }
        
        except Exception as e:
            print(f"Error processing URL {url}: {e}")
            return None
    
    def search(self, query: str, max_results: int = 5) -> List[Dict[str, Any]]:
        """Perform search and process results"""
        try:
            # Perform DuckDuckGo search
            search_results = ddg(query, max_results=max_results)
            
            results = []
            for result in search_results:
                processed = self.process_url(result['link'])
                if processed:
                    results.append(processed)
            
            return results[:max_results]
            
        except Exception as e:
            print(f"Error in search: {e}")
            return []

# Main search function
def search(query: str, max_results: int = 5) -> List[Dict[str, Any]]:
    """Main search function"""
    engine = WebSearchEngine()
    return engine.search(query, max_results)