import requests
from bs4 import BeautifulSoup
from typing import Optional
import PyPDF2
from docx import Document
import io

def extract_from_url(url: str) -> str:
    """Extract text content from URL (synchronous)"""
    try:
        headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36'
        }
        response = requests.get(url, headers=headers, timeout=10)
        response.raise_for_status()
        
        soup = BeautifulSoup(response.content, 'html.parser')
        
        # Remove script and style elements
        for script in soup(["script", "style", "nav", "footer", "header"]):
            script.decompose()
        
        # Get text
        text = soup.get_text(separator=' ', strip=True)
        
        # Clean up whitespace
        lines = (line.strip() for line in text.splitlines())
        chunks = (phrase.strip() for line in lines for phrase in line.split("  "))
        text = ' '.join(chunk for chunk in chunks if chunk)
        
        return text
    except Exception as e:
        print(f"Error extracting from URL: {e}")
        raise Exception(f"Failed to extract text from URL: {str(e)}")

def extract_from_document(content: bytes, file_extension: str) -> str:
    """Extract text from document (synchronous)"""
    try:
        if file_extension == ".pdf":
            return _extract_from_pdf(content)
        elif file_extension == ".docx":
            return _extract_from_docx(content)
        elif file_extension == ".txt":
            return content.decode('utf-8')
        else:
            raise ValueError(f"Unsupported file type: {file_extension}")
    except Exception as e:
        print(f"Error extracting from document: {e}")
        raise Exception(f"Failed to extract text from document: {str(e)}")

def _extract_from_pdf(content: bytes) -> str:
    """Extract text from PDF"""
    try:
        pdf_file = io.BytesIO(content)
        pdf_reader = PyPDF2.PdfReader(pdf_file)
        
        text = ""
        for page in pdf_reader.pages:
            text += page.extract_text() + "\n"
        
        return text.strip()
    except Exception as e:
        raise Exception(f"Error reading PDF: {str(e)}")

def _extract_from_docx(content: bytes) -> str:
    """Extract text from DOCX"""
    try:
        doc_file = io.BytesIO(content)
        doc = Document(doc_file)
        
        text = ""
        for paragraph in doc.paragraphs:
            text += paragraph.text + "\n"
        
        return text.strip()
    except Exception as e:
        raise Exception(f"Error reading DOCX: {str(e)}")