import tempfile
from datetime import datetime
from typing import List

import streamlit as st
from langchain_community.document_loaders import PyPDFLoader, WebBaseLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter

def process_pdf(file) -> List:
    """Process PDF file and add source metadata."""
    try:
        with tempfile.NamedTemporaryFile(delete=False, suffix='.pdf') as tmp_file:
            tmp_file.write(file.getvalue())
            loader = PyPDFLoader(tmp_file.name)
            documents = loader.load()
            
            # Add source metadata
            for doc in documents:
                doc.metadata.update({
                    "source_type": "pdf",
                    "file_name": file.name,
                    "timestamp": datetime.now().isoformat()
                })
                
            text_splitter = RecursiveCharacterTextSplitter(
                chunk_size=1000,
                chunk_overlap=200
            )
            return text_splitter.split_documents(documents)
    
    except Exception as e:
        st.error(f"📄 PDF processing error: {str(e)}")
        return []


def process_web(url: str) -> List:
    """Process web URL and add source metadata."""
    try:
        loader = WebBaseLoader(web_path=url)
        documents = loader.load()
        
        # Add source metadata
        for doc in documents:
            doc.metadata.update({
                "source_type": "url",
                "url": url,
                "timestamp": datetime.now().isoformat()
            })
            
        text_splitter = RecursiveCharacterTextSplitter(
            chunk_size=1000,
            chunk_overlap=200
        )
        return text_splitter.split_documents(documents)
    
    except Exception as e:
        st.error(f"🌐 Web processing error: {str(e)}")
        return []