main.py

from flask import Flask, render_template, request, jsonify
import os
import shutil
from llama_index.core import StorageContext, load_index_from_storage, VectorStoreIndex, SimpleDirectoryReader, ChatPromptTemplate, Settings
from llama_index.llms.huggingface import HuggingFaceInferenceAPI
from llama_index.embeddings.huggingface import HuggingFaceEmbedding
from huggingface_hub import InferenceClient
from transformers import AutoTokenizer, AutoModel

# Ensure HF_TOKEN is set  
HF_TOKEN = os.getenv("HF_TOKEN")  
if not HF_TOKEN:  
    raise ValueError("HF_TOKEN environment variable not set.")  

repo_id = "meta-llama/Meta-Llama-3-8B-Instruct"  
llm_client = InferenceClient(  
    model=repo_id,  
    token=HF_TOKEN,  
)  

# Configure Llama index settings  
Settings.llm = HuggingFaceInferenceAPI(  
    model_name=repo_id,  
    tokenizer_name=repo_id,  
    context_window=3000,  
    token=HF_TOKEN,  
    max_new_tokens=512,  
    generate_kwargs={"temperature": 0.1},  
)  

# Configure embedding model (XLM-RoBERTa model for multilingual support)
Settings.embed_model = HuggingFaceEmbedding(
    model_name="xlm-roberta-base"  # Multilingual support
)

# Configure tokenizer and model for multilingual responses
tokenizer = AutoTokenizer.from_pretrained("xlm-roberta-base")
model = AutoModel.from_pretrained("xlm-roberta-base")

PERSIST_DIR = "db"  
PDF_DIRECTORY = 'data'  

# Ensure directories exist  
os.makedirs(PDF_DIRECTORY, exist_ok=True)  
os.makedirs(PERSIST_DIR, exist_ok=True)  
chat_history = []  
current_chat_history = []  

# Data ingestion function
def data_ingestion_from_directory():  
    if os.path.exists(PERSIST_DIR):  
        shutil.rmtree(PERSIST_DIR)  # Remove the persist directory and its contents  
    
    os.makedirs(PERSIST_DIR, exist_ok=True)  
    new_documents = SimpleDirectoryReader(PDF_DIRECTORY).load_data()  
    index = VectorStoreIndex.from_documents(new_documents)  
    index.storage_context.persist(persist_dir=PERSIST_DIR)  

def handle_query(query, user_language):  
    context_str = ""  

    # Build context from current chat history  
    for past_query, response in reversed(current_chat_history):  
        if past_query.strip():  
            context_str += f"User asked: '{past_query}'\nBot answered: '{response}'\n"  
    
    # Define the chat response template based on selected language
    if user_language == 'te':  # Telugu
        response_template = """
            మీరు తాజ్ హోటల్ చాట్‌బాట్, తాజ్ హోటల్ సహాయకుడిగా పనిచేస్తున్నారు.
            **మీరు చేసే పాత్ర:**
            - వినియోగదారుడి ప్రాముఖ్యమైన భాష (ఆంగ్లం, తెలుగు, హిందీ) లో సమాధానాలు ఇవ్వండి.
            - హోటల్ యొక్క సేవలు, సదుపాయాలు మరియు విధానాలపై సమాచారం ఇవ్వండి.
            **సూచన:**
            - **ప్రసంగం:**  
              {context_str}
            - **వినియోగదారు ప్రశ్న:**  
              {query_str}
            **సమాధానం:** [మీ సమాధానం తెలుగులో ఇక్కడ]
        """
    elif user_language == 'hi':  # Hindi
        response_template = """
            आप ताज होटल के चैटबोट, ताज होटल हेल्पर हैं।
            **आपकी भूमिका:**
            - उपयोगकर्ता द्वारा चुनी गई भाषा (अंग्रेजी, हिंदी, या तेलुगु) में उत्तर दें।
            - होटल की सेवाओं, सुविधाओं और नीतियों के बारे में जानकारी प्रदान करें।
            **निर्देश:**
            - **संदर्भ:**  
              {context_str}
            - **उपयोगकर्ता का प्रश्न:**  
              {query_str}
            **उत्तर:** [आपका उत्तर हिंदी में यहाँ]
        """
    else:  # Default to English
        response_template = """
            You are the Taj Hotel chatbot, Taj Hotel Helper.
            **Your Role:**
            - Respond accurately and concisely in the user's preferred language (English, Telugu, or Hindi).
            - Provide information about the hotel’s services, amenities, and policies.
            **Instructions:**
            - **Context:**  
              {context_str}
            - **User's Question:**  
              {query_str}
            **Response:** [Your concise response here]
        """

    # Create a list of chat messages with the user query and response template
    chat_text_qa_msgs = [
        (
            "user",
            response_template.format(context_str=context_str, query_str=query)
        )
    ]

    # Use the defined chat template
    text_qa_template = ChatPromptTemplate.from_messages(chat_text_qa_msgs)  

    storage_context = StorageContext.from_defaults(persist_dir=PERSIST_DIR)  
    index = load_index_from_storage(storage_context)  

    # Query the index and retrieve the answer
    query_engine = index.as_query_engine(text_qa_template=text_qa_template, context_str=context_str)  
    print(f"Querying: {query}")  
    answer = query_engine.query(query)  

    # Extracting the response  
    if hasattr(answer, 'response'):  
        response = answer.response  
    elif isinstance(answer, dict) and 'response' in answer:  
        response = answer['response']  
    else:  
        response = "I'm sorry, I couldn't find an answer to that."  

    # Append to chat history  
    current_chat_history.append((query, response))  
    return response


app = Flask(__name__)  

# Data ingestion  
data_ingestion_from_directory()  

# Generate Response  
def generate_response(query, language):  
    try:  
        # Call the handle_query function to get the response  
        bot_response = handle_query(query, language)  
        return bot_response  
    except Exception as e:  
        return f"Error fetching the response: {str(e)}"  

# Route for the homepage  
@app.route('/')  
def index():  
    return render_template('index.html')  

# Route to handle chatbot messages  
@app.route('/chat', methods=['POST'])  
def chat():  
    try:  
        user_message = request.json.get("message")  
        selected_language = request.json.get("language")  # Get selected language from the request
        if not user_message:  
            return jsonify({"response": "Please say something!"})  

        if selected_language not in ['english', 'telugu', 'hindi']:  
            return jsonify({"response": "Invalid language selected."})  

        bot_response = generate_response(user_message, selected_language)  
        return jsonify({"response": bot_response})  
    except Exception as e:  
        return jsonify({"response": f"An error occurred: {str(e)}"})  

if __name__ == '__main__':  
    app.run(debug=True)