import gradio as gr
import PyPDF2
import chromadb
from openai import OpenAI
import numpy as np
from typing import List, Dict, Tuple
import json
import io
import os
from datetime import datetime
import pandas as pd

class RAGPipeline:
    def __init__(self):
        # Initialize local ChromaDB client using new configuration
        try:
            self.chroma_client = chromadb.PersistentClient(path="./chroma_db")
        except Exception as e:
            print(f"ChromaDB initialization error: {e}")
            self.chroma_client = None
        
        # OpenAI client (will be set through UI)
        self.openai_client = None
        self.openai_api_key = None
        
        # Collection for storing document chunks
        self.collection = None
        
        # Store document metadata and full text
        self.document_metadata = {}
        self.full_extracted_text = ""  # Store full text here
    
    def set_openai_key(self, openai_key: str):
        """Set OpenAI API key and create client"""
        self.openai_api_key = openai_key
        
        if openai_key:
            self.openai_client = OpenAI(api_key=openai_key)
        
    def get_openai_embedding(self, text: str) -> List[float]:
        """Generate embeddings using OpenAI's text-embedding-ada-002 model"""
        if not self.openai_client:
            raise ValueError("OpenAI client not initialized")
        
        try:
            response = self.openai_client.embeddings.create(
                model="text-embedding-ada-002",
                input=text
            )
            return response.data[0].embedding
        except Exception as e:
            raise Exception(f"OpenAI embedding generation failed: {str(e)}")
    
    def extract_text_from_pdf(self, pdf_file) -> Tuple[str, Dict]:
        """Extract text from uploaded PDF file"""
        try:
            # Handle different file types from Gradio
            if hasattr(pdf_file, 'name'):
                # If it's a file path, read the file
                with open(pdf_file.name, 'rb') as file:
                    pdf_content = file.read()
            elif isinstance(pdf_file, bytes):
                # If it's already bytes
                pdf_content = pdf_file
            else:
                # If it's a file-like object, read it
                pdf_content = pdf_file.read() if hasattr(pdf_file, 'read') else pdf_file
            
            # Read PDF file
            pdf_reader = PyPDF2.PdfReader(io.BytesIO(pdf_content))
            
            text = ""
            page_count = len(pdf_reader.pages)
            
            # Extract text from all pages
            for page_num, page in enumerate(pdf_reader.pages):
                page_text = page.extract_text()
                if page_text.strip():  # Only add non-empty pages
                    text += f"\n--- Page {page_num + 1} ---\n"
                    text += page_text + "\n"
            
            # Clean up the text
            text = text.strip()
            
            # Store the full text in the pipeline object
            self.full_extracted_text = text
            print(f"DEBUG: Stored full text length: {len(self.full_extracted_text)}")
            
            # Create extraction metadata
            metadata = {
                "total_pages": page_count,
                "total_characters": len(text),
                "extraction_timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
                "file_size_bytes": len(pdf_content),
                "pages_with_text": sum(1 for page in pdf_reader.pages if page.extract_text().strip()),
                "average_chars_per_page": len(text) // page_count if page_count > 0 else 0
            }
            
            return text, metadata
            
        except Exception as e:
            return f"Error extracting PDF: {str(e)}", {}
    
    def chunk_text(self, text: str, chunk_size: int = 1000, overlap: int = 200) -> Tuple[List[str], Dict]:
        """Split text into overlapping chunks"""
        if not text or len(text.strip()) == 0:
            return [], {"error": "No text provided for chunking"}
        
        # Clean the text first
        text = text.strip()
        
        chunks = []
        start = 0
        
        print(f"DEBUG: Starting chunking with text length: {len(text)}")
        print(f"DEBUG: Chunk size: {chunk_size}, Overlap: {overlap}")
        
        while start < len(text):
            end = start + chunk_size
            
            # If we're not at the end, try to break at a sentence or word boundary
            if end < len(text):
                # Look for sentence boundary
                last_period = text.rfind('.', start, end)
                last_newline = text.rfind('\n', start, end)
                last_space = text.rfind(' ', start, end)
                
                # Choose the best breaking point
                break_point = max(last_period, last_newline, last_space)
                if break_point > start:
                    end = break_point + 1
            
            chunk = text[start:end].strip()
            if chunk and len(chunk) > 50:  # Only add meaningful chunks
                chunks.append(chunk)
                print(f"DEBUG: Added chunk {len(chunks)}: length={len(chunk)}")
            
            # Move start position
            if end >= len(text):
                break
            start = end - overlap
            
            # Prevent infinite loop
            if start >= end:
                start = end
        
        print(f"DEBUG: Final chunks count: {len(chunks)}")
        
        # Create chunking metadata
        chunk_lengths = [len(chunk) for chunk in chunks]
        metadata = {
            "total_chunks": len(chunks),
            "chunk_size": chunk_size,
            "overlap": overlap,
            "avg_chunk_length": np.mean(chunk_lengths) if chunks else 0,
            "min_chunk_length": min(chunk_lengths) if chunks else 0,
            "max_chunk_length": max(chunk_lengths) if chunks else 0,
            "total_text_length": len(text),
            "chunking_timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        }
        
        return chunks, metadata
    
    def store_in_chromadb(self, chunks: List[str], document_name: str) -> Dict:
        """Store chunks in ChromaDB with OpenAI embeddings"""
        if not self.openai_client:
            return {"error": "OpenAI client not initialized for embedding generation"}
        
        try:
            # Create or get collection
            collection_name = f"financial_docs_{datetime.now().strftime('%Y%m%d_%H%M%S')}"
            
            try:
                self.chroma_client.delete_collection(collection_name)
            except:
                pass
                
            self.collection = self.chroma_client.create_collection(
                name=collection_name,
                metadata={"hnsw:space": "cosine"}
            )
            
            # Generate embeddings for chunks using OpenAI
            embeddings = []
            embedding_metadata = {
                "model_used": "text-embedding-ada-002",
                "total_chunks_processed": len(chunks),
                "embedding_start_time": datetime.now().isoformat()
            }
            
            for i, chunk in enumerate(chunks):
                try:
                    embedding = self.get_openai_embedding(chunk)
                    embeddings.append(embedding)
                except Exception as e:
                    return {"error": f"Failed to generate embedding for chunk {i}: {str(e)}"}
            
            embedding_metadata["embedding_end_time"] = datetime.now().isoformat()
            embedding_metadata["embedding_dimension"] = len(embeddings[0]) if embeddings else 0
            
            # Create unique IDs for each chunk
            ids = [f"chunk_{i}" for i in range(len(chunks))]
            
            # Create metadata for each chunk
            metadatas = [
                {
                    "chunk_id": i,
                    "document_name": document_name,
                    "chunk_length": len(chunk),
                    "created_at": datetime.now().isoformat(),
                    "embedding_model": "text-embedding-ada-002"
                }
                for i, chunk in enumerate(chunks)
            ]
            
            # Store in ChromaDB
            self.collection.add(
                embeddings=embeddings,
                documents=chunks,
                metadatas=metadatas,
                ids=ids
            )
            
            # Create storage metadata
            storage_metadata = {
                "collection_name": collection_name,
                "total_vectors_stored": len(chunks),
                "embedding_dimension": len(embeddings[0]) if embeddings else 0,
                "embedding_model": "text-embedding-ada-002",
                "storage_timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
                "database_status": "Successfully stored",
                "database_type": "ChromaDB Local",
                "database_path": "./chroma_db",
                "embedding_metadata": embedding_metadata
            }
            
            return storage_metadata
            
        except Exception as e:
            return {"error": f"Storage failed: {str(e)}"}
    
    def semantic_search(self, query: str, top_k: int = 5) -> Tuple[List[Dict], Dict]:
        """Perform semantic search using OpenAI embeddings and return top-k results"""
        if not self.collection:
            return [], {"error": "No collection available. Please upload and process a document first."}
        
        if not self.openai_client:
            return [], {"error": "OpenAI client not initialized for query embedding generation"}
        
        try:
            # Generate query embedding using OpenAI
            query_embedding = self.get_openai_embedding(query)
            
            # Search in ChromaDB
            results = self.collection.query(
                query_embeddings=[query_embedding],
                n_results=top_k,
                include=['documents', 'metadatas', 'distances']
            )
            
            # Format results
            search_results = []
            for i in range(len(results['documents'][0])):
                result = {
                    "chunk_id": results['metadatas'][0][i]['chunk_id'],
                    "similarity_score": 1 - results['distances'][0][i],  # Convert distance to similarity
                    "content": results['documents'][0][i][:500] + "..." if len(results['documents'][0][i]) > 500 else results['documents'][0][i],
                    "full_content": results['documents'][0][i],
                    "metadata": results['metadatas'][0][i]
                }
                search_results.append(result)
            
            # Create search metadata
            search_metadata = {
                "query": query,
                "results_found": len(search_results),
                "search_timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
                "top_similarity_score": max([r["similarity_score"] for r in search_results]) if search_results else 0,
                "query_embedding_model": "text-embedding-ada-002",
                "vector_database": "ChromaDB Local"
            }
            
            return search_results, search_metadata
            
        except Exception as e:
            return [], {"error": f"Search failed: {str(e)}"}
    
    def generate_llm_response(self, query: str, search_results: List[Dict]) -> Tuple[str, Dict]:
        """Generate final response using OpenAI LLM"""
        if not self.openai_client:
            return "OpenAI client not initialized for LLM response generation.", {}
        
        try:
            # Prepare context from search results
            context = "\n\n".join([
                f"Chunk {result['chunk_id']} (Similarity: {result['similarity_score']:.3f}):\n{result['full_content']}"
                for result in search_results
            ])
            
            # Create prompt
            prompt = f"""Based on the following financial document excerpts, please provide a comprehensive and accurate answer to the user's question.

Context from financial document:
{context}

User Question: {query}

Instructions:
1. Provide a detailed, well-structured answer based solely on the provided context
2. If the context doesn't contain enough information to fully answer the question, clearly state this
3. Include specific numbers, dates, and financial figures when available
4. Structure your response clearly with proper formatting
5. Cite which chunk(s) your information comes from when possible

Answer:"""

            # Generate response using OpenAI
            response = self.openai_client.chat.completions.create(
                model="gpt-3.5-turbo",
                messages=[
                    {"role": "system", "content": "You are a financial analyst AI assistant. Provide accurate, well-structured responses based on the given financial document context."},
                    {"role": "user", "content": prompt}
                ],
                max_tokens=1000,
                temperature=0.1
            )
            
            llm_response = response.choices[0].message.content
            
            # Create response metadata
            response_metadata = {
                "model_used": "gpt-3.5-turbo",
                "response_length": len(llm_response),
                "tokens_used": response.usage.total_tokens,
                "prompt_tokens": response.usage.prompt_tokens,
                "completion_tokens": response.usage.completion_tokens,
                "generation_timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
                "context_chunks_used": len(search_results),
                "temperature": 0.1,
                "max_tokens": 1000
            }
            
            return llm_response, response_metadata
            
        except Exception as e:
            return f"LLM Generation failed: {str(e)}", {"error": str(e)}

# Initialize RAG pipeline
rag_pipeline = RAGPipeline()

def configure_openai_api(openai_key):
    """Configure OpenAI API key"""
    try:
        # Set OpenAI API key
        rag_pipeline.set_openai_key(openai_key)
        
        # Test OpenAI connection
        if openai_key:
            try:
                # Test with a simple API call
                test_response = rag_pipeline.openai_client.models.list()
                openai_status = "✅ OpenAI API key validated successfully"
            except Exception as e:
                openai_status = f"❌ OpenAI API key validation failed: {str(e)}"
        else:
            openai_status = "❌ OpenAI API key required"
        
        # ChromaDB status (local setup)
        if rag_pipeline.chroma_client:
            chroma_status = "✅ ChromaDB Local database ready (./chroma_db)"
        else:
            chroma_status = "❌ ChromaDB Local database initialization failed"
        
        return f"{openai_status}\n{chroma_status}"
        
    except Exception as e:
        return f"❌ Configuration failed: {str(e)}"

# Remove the global variable since we're storing in the class
# extracted_text_store = ""

def process_pdf_upload(pdf_file):
    """Process uploaded PDF and extract text"""
    if pdf_file is None:
        return "No file uploaded", "{}"
    
    # Extract text using the updated method
    text, metadata = rag_pipeline.extract_text_from_pdf(pdf_file)
    
    if text.startswith("Error"):
        return text, json.dumps(metadata, indent=2)
    
    # Show more text in preview (first 3000 characters instead of 2000)
    preview_text = text[:3000] + f"...\n\n[SHOWING FIRST 3000 CHARACTERS OF {len(text)} TOTAL CHARACTERS]\n[FULL TEXT STORED FOR PROCESSING - Total Length: {len(rag_pipeline.full_extracted_text)} chars]" if len(text) > 3000 else text
    
    return preview_text, json.dumps(metadata, indent=2)

def process_chunking(text, chunk_size, overlap):
    """Process text chunking"""
    # Always use the full text stored in the pipeline object
    if not rag_pipeline.full_extracted_text:
        return "No text available for chunking. Please upload a PDF first.", "{}"
    
    full_text = rag_pipeline.full_extracted_text
    print(f"DEBUG: Using full text for chunking, length: {len(full_text)}")
    
    if len(full_text.strip()) == 0:
        return "No valid text available for chunking.", "{}"
    
    chunks, metadata = rag_pipeline.chunk_text(full_text, int(chunk_size), int(overlap))
    
    if not chunks:
        return "No chunks created. Please check your text and parameters.", json.dumps(metadata, indent=2)
    
    # Display first few chunks as preview
    preview = f"=== CHUNKING RESULTS ===\n"
    preview += f"Total chunks created: {len(chunks)}\n"
    preview += f"Full text length processed: {len(full_text)} characters\n\n"
    preview += "--- CHUNK PREVIEW ---\n\n"
    
    for i, chunk in enumerate(chunks[:3]):
        preview += f"Chunk {i+1} (Length: {len(chunk)} chars):\n"
        preview += f"{chunk[:200]}...\n\n"
        preview += "-" * 50 + "\n\n"
    
    if len(chunks) > 3:
        preview += f"... and {len(chunks)-3} more chunks\n"
        preview += f"Shortest chunk: {min(len(c) for c in chunks)} chars\n"
        preview += f"Longest chunk: {max(len(c) for c in chunks)} chars\n"
    
    return preview, json.dumps(metadata, indent=2)

def process_vector_storage(text, chunk_size, overlap, doc_name):
    """Process vector storage in local ChromaDB"""
    if not rag_pipeline.openai_client:
        return "Please configure OpenAI API key first in the Configuration tab", "{}"
    
    if not rag_pipeline.chroma_client:
        return "ChromaDB local database not available. Please restart the application.", "{}"
    
    # Always use the stored full text
    if not rag_pipeline.full_extracted_text:
        return "No valid text to store. Please upload a PDF first.", "{}"
    
    full_text = rag_pipeline.full_extracted_text
    print(f"DEBUG: Using full text for storage, length: {len(full_text)}")
    
    # Re-chunk the text using full text
    chunks, _ = rag_pipeline.chunk_text(full_text, int(chunk_size), int(overlap))
    
    if not chunks:
        return "No chunks to store", "{}"
    
    # Store in ChromaDB
    storage_metadata = rag_pipeline.store_in_chromadb(chunks, doc_name or "financial_document")
    
    if "error" in storage_metadata:
        return f"Storage failed: {storage_metadata['error']}", json.dumps(storage_metadata, indent=2)
    
    return f"Successfully stored {len(chunks)} chunks in ChromaDB Local using OpenAI embeddings\nFull text length: {len(full_text)} characters", json.dumps(storage_metadata, indent=2)

def process_semantic_search(query, top_k):
    """Process semantic search"""
    if not query.strip():
        return "Please enter a search query", "{}", ""
    
    search_results, search_metadata = rag_pipeline.semantic_search(query, int(top_k))
    
    if not search_results:
        return "No results found", json.dumps(search_metadata, indent=2), ""
    
    # Format results for display
    results_display = "=== TOP MATCHING CHUNKS ===\n\n"
    for i, result in enumerate(search_results, 1):
        results_display += f"RESULT {i}:\n"
        results_display += f"Chunk ID: {result['chunk_id']}\n"
        results_display += f"Similarity Score: {result['similarity_score']:.4f}\n"
        results_display += f"Content Preview: {result['content']}\n"
        results_display += "-" * 50 + "\n\n"
    
    # Create DataFrame for structured display
    df_data = []
    for result in search_results:
        df_data.append({
            "Chunk ID": result['chunk_id'],
            "Similarity Score": f"{result['similarity_score']:.4f}",
            "Content Length": len(result['full_content']),
            "Preview": result['content'][:100] + "..."
        })
    
    df = pd.DataFrame(df_data)
    
    return results_display, json.dumps(search_metadata, indent=2), df

def generate_final_response(query, top_k):
    """Generate final LLM response"""
    if not rag_pipeline.openai_client:
        return "Please configure OpenAI API key first in the Configuration tab", "{}"
    
    if not query.strip():
        return "Please enter a query first", "{}"
    
    # Get search results
    search_results, _ = rag_pipeline.semantic_search(query, int(top_k))
    
    if not search_results:
        return "No search results available for LLM generation", "{}"
    
    # Generate LLM response
    response, metadata = rag_pipeline.generate_llm_response(query, search_results)
    
    return response, json.dumps(metadata, indent=2)

def create_gradio_interface():
    """Create the Gradio interface"""
    
    with gr.Blocks(title="RAG Pipeline Demo - Financial Document Analysis", theme=gr.themes.Soft()) as demo:
        gr.Markdown("""
        # 🏦 RAG Pipeline Demo - Financial Document Analysis
        
        This demo shows a complete Retrieval-Augmented Generation (RAG) pipeline with full transparency.
        Each step is clearly displayed so you can understand exactly what's happening in the backend.
        
        **🔧 Start by configuring your API keys in the Configuration tab below.**
        """)
        
        # Configuration Tab - Simplified
        with gr.Tab("⚙️ Configuration"):
            gr.Markdown("### API Configuration")
            gr.Markdown("Configure your OpenAI API key. ChromaDB will run locally and store data in `./chroma_db` folder.")
            
            with gr.Row():
                with gr.Column():
                    gr.Markdown("#### OpenAI API Key")
                    gr.Markdown("Required for both embeddings generation and LLM response generation")
                    openai_key_input = gr.Textbox(
                        label="OpenAI API Key", 
                        type="password", 
                        placeholder="sk-...",
                        info="Get your API key from: https://platform.openai.com/api-keys"
                    )
                    
                with gr.Column():
                    gr.Markdown("#### ChromaDB Status")
                    gr.Markdown("✅ **Local ChromaDB**: Data will be stored locally in `./chroma_db`")
                    gr.Markdown("📁 **Storage Location**: Current directory/chroma_db")
                    gr.Markdown("🔄 **Persistence**: Data persists between sessions")
            
            config_btn = gr.Button("Save OpenAI Configuration", variant="primary", size="lg")
            config_status = gr.Textbox(label="Configuration Status", lines=3)
        
        # Step 1: Document Upload
        with gr.Tab("1️⃣ Document Upload"):
            gr.Markdown("### Step 1: Upload Your Financial PDF Document")
            
            with gr.Row():
                with gr.Column():
                    pdf_input = gr.File(label="Upload PDF Document", file_types=[".pdf"])
                    upload_btn = gr.Button("Extract Text from PDF", variant="primary")
                    
                with gr.Column():
                    extraction_output = gr.Textbox(label="Extracted Text Preview", lines=15, max_lines=20)
                    extraction_metadata = gr.JSON(label="Extraction Metadata")
        
        # Step 2: Text Chunking
        with gr.Tab("2️⃣ Text Chunking"):
            gr.Markdown("### Step 2: Split Text into Manageable Chunks")
            
            with gr.Row():
                with gr.Column():
                    chunk_size = gr.Slider(minimum=200, maximum=2000, value=1000, label="Chunk Size (characters)")
                    overlap = gr.Slider(minimum=0, maximum=500, value=200, label="Overlap (characters)")
                    chunk_btn = gr.Button("Create Chunks", variant="primary")
                    
                with gr.Column():
                    chunks_output = gr.Textbox(label="Chunks Preview", lines=15, max_lines=20)
                    chunking_metadata = gr.JSON(label="Chunking Metadata")
        
        # Step 3: Vector Storage
        with gr.Tab("3️⃣ Vector Storage"):
            gr.Markdown("### Step 3: Store Chunks in ChromaDB Vector Database")
            
            with gr.Row():
                with gr.Column():
                    doc_name = gr.Textbox(label="Document Name", value="financial_report", placeholder="Enter document name")
                    storage_btn = gr.Button("Store in ChromaDB", variant="primary")
                    
                with gr.Column():
                    storage_output = gr.Textbox(label="Storage Status", lines=5)
                    storage_metadata = gr.JSON(label="Storage Metadata")
        
        # Step 4: Semantic Search
        with gr.Tab("4️⃣ Semantic Search"):
            gr.Markdown("### Step 4: Search for Relevant Information")
            
            with gr.Row():
                with gr.Column():
                    search_query = gr.Textbox(label="Enter your question", placeholder="e.g., What was the revenue growth in Q4?")
                    top_k = gr.Slider(minimum=1, maximum=10, value=5, label="Number of results to retrieve")
                    search_btn = gr.Button("Search Vector Database", variant="primary")
                    
                with gr.Column():
                    search_results_text = gr.Textbox(label="Search Results", lines=15, max_lines=20)
                    search_metadata = gr.JSON(label="Search Metadata")
            
            # Results table
            results_table = gr.DataFrame(label="Top Matching Chunks - Structured View")
        
        # Step 5: LLM Response Generation
        with gr.Tab("5️⃣ LLM Response"):
            gr.Markdown("### Step 5: Generate Final Answer using OpenAI")
            gr.Markdown("*Note: OpenAI API key must be configured in the Configuration tab*")
            
            with gr.Row():
                with gr.Column():
                    generate_btn = gr.Button("Generate Final Response", variant="primary")
                    gr.Markdown("**Current Query:** Will use the query from Step 4")
                    
                with gr.Column():
                    final_response = gr.Textbox(label="AI Generated Response", lines=15, max_lines=20)
                    response_metadata = gr.JSON(label="Response Metadata")
        
        # Complete Pipeline Tab
        with gr.Tab("🚀 Complete Pipeline"):
            gr.Markdown("### Run the Complete RAG Pipeline")
            gr.Markdown("*Note: Make sure to configure API keys in the Configuration tab first*")
            
            with gr.Row():
                with gr.Column():
                    complete_pdf = gr.File(label="Upload PDF", file_types=[".pdf"])
                    complete_query = gr.Textbox(label="Your Question", placeholder="Ask about the financial document")
                    
                with gr.Column():
                    complete_chunk_size = gr.Slider(minimum=200, maximum=2000, value=1000, label="Chunk Size")
                    complete_overlap = gr.Slider(minimum=0, maximum=500, value=200, label="Overlap")
                    complete_top_k = gr.Slider(minimum=1, maximum=10, value=5, label="Top K Results")
            
            complete_btn = gr.Button("Run Complete Pipeline", variant="primary", size="lg")
            
            with gr.Row():
                pipeline_status = gr.Textbox(label="Pipeline Status", lines=10)
                pipeline_response = gr.Textbox(label="Final Answer", lines=10)
        
        # Event handlers
        config_btn.click(
            configure_openai_api,
            inputs=[openai_key_input],
            outputs=[config_status]
        )
        
        upload_btn.click(
            process_pdf_upload,
            inputs=[pdf_input],
            outputs=[extraction_output, extraction_metadata]
        )
        
        chunk_btn.click(
            process_chunking,
            inputs=[extraction_output, chunk_size, overlap],
            outputs=[chunks_output, chunking_metadata]
        )
        
        storage_btn.click(
            process_vector_storage,
            inputs=[extraction_output, chunk_size, overlap, doc_name],
            outputs=[storage_output, storage_metadata]
        )
        
        search_btn.click(
            process_semantic_search,
            inputs=[search_query, top_k],
            outputs=[search_results_text, search_metadata, results_table]
        )
        
        generate_btn.click(
            generate_final_response,
            inputs=[search_query, top_k],
            outputs=[final_response, response_metadata]
        )
        
        # Complete pipeline function
        def run_complete_pipeline(pdf_file, query, chunk_size, overlap, top_k):
            if not pdf_file or not query:
                return "Please provide PDF file and query", ""
            
            if not rag_pipeline.openai_client:
                return "Please configure OpenAI API key in the Configuration tab first", ""
            
            if not rag_pipeline.chroma_client:
                return "ChromaDB local database not available. Please restart the application.", ""
            
            status = "Starting RAG Pipeline...\n\n"
            status += "Using: ChromaDB Local + OpenAI API\n"
            status += "Storage: ./chroma_db directory\n\n"
            
            try:
                # Step 1: Extract text
                status += "Step 1: Extracting text from PDF...\n"
                text, _ = rag_pipeline.extract_text_from_pdf(pdf_file)
                if text.startswith("Error"):
                    return status + f"Failed: {text}", ""
                status += "✅ Text extraction completed\n\n"
                
                # Step 2: Chunk text
                status += "Step 2: Chunking text...\n"
                chunks, _ = rag_pipeline.chunk_text(text, chunk_size, overlap)
                status += f"✅ Created {len(chunks)} chunks\n\n"
                
                # Step 3: Store in vector DB
                status += f"Step 3: Generating OpenAI embeddings and storing in ChromaDB Local...\n"
                storage_result = rag_pipeline.store_in_chromadb(chunks, "complete_pipeline_doc")
                if "error" in storage_result:
                    return status + f"Failed: {storage_result['error']}", ""
                status += f"✅ Vectors stored in ChromaDB Local using OpenAI embeddings\n\n"
                
                # Step 4: Search
                status += "Step 4: Performing semantic search with OpenAI embeddings...\n"
                search_results, _ = rag_pipeline.semantic_search(query, top_k)
                if not search_results:
                    return status + "❌ No search results found", ""
                status += f"✅ Found {len(search_results)} relevant chunks\n\n"
                
                # Step 5: Generate response
                status += "Step 5: Generating LLM response...\n"
                response, _ = rag_pipeline.generate_llm_response(query, search_results)
                if response.startswith("LLM Generation failed"):
                    return status + f"Failed: {response}", ""
                status += "✅ Final response generated successfully!"
                
                return status, response
                
            except Exception as e:
                return status + f"❌ Pipeline failed: {str(e)}", ""
        
        complete_btn.click(
            run_complete_pipeline,
            inputs=[complete_pdf, complete_query, complete_chunk_size, complete_overlap, complete_top_k],
            outputs=[pipeline_status, pipeline_response]
        )
    
    return demo

# Launch the application
if __name__ == "__main__":
    # Install required packages
    print("Starting RAG Pipeline Demo...")
    print("Make sure you have installed the required packages:")
    print("pip install gradio PyPDF2 chromadb openai pandas numpy")
    print("\nConfiguration:")
    print("✅ ChromaDB: Local storage (./chroma_db directory)")
    print("🔑 OpenAI: API key required for embeddings + LLM")
    print("📁 Data persistence: Enabled across sessions")
    
    # Create and launch the Gradio interface
    demo = create_gradio_interface()
    demo.launch()