Create app.py

app.py

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+# This is my app.py
+
+import os
+import torch
+import re
+import warnings
+import time
+import json
+from transformers import AutoTokenizer, AutoModelForCausalLM, GenerationConfig
+from sentence_transformers import SentenceTransformer, util
+import gspread
+from google.auth import default
+from tqdm import tqdm
+from duckduckgo_search import DDGS
+import spacy
+from pathlib import Path
+import base64
+
+# Suppress warnings
+warnings.filterwarnings("ignore", category=UserWarning)
+
+# --- Configuration ---
+SHEET_ID = "19ipxC2vHYhpXCefpxpIkpeYdI43a1Ku2kYwecgUULIw" # Your Google Sheet ID
+HF_TOKEN = os.getenv("HF_TOKEN") # Get Hugging Face token from Space Secrets
+GOOGLE_SERVICE_ACCOUNT_KEY_BASE64 = os.getenv("GOOGLE_SERVICE_ACCOUNT_KEY_BASE64")
+
+# Changed model_id to Gemma 2B for CPU
+model_id = "google/gemma-2b" # Using Gemma 2B
+
+# --- Constants for Prompting and Validation ---
+SEARCH_MARKER = "ACTION: SEARCH:"
+BUSINESS_LOOKUP_MARKER = "ACTION: LOOKUP_BUSINESS_INFO:"
+ANSWER_DIRECTLY_MARKER = "ACTION: ANSWER_DIRECTLY:"
+BUSINESS_LOOKUP_VALIDATION_THRESHOLD = 0.6
+SEARCH_VALIDATION_THRESHOLD = 0.6
+PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD = 0.5
+
+# --- Global variables to load once ---
+tokenizer = None
+model = None
+nlp = None # SpaCy model
+embedder = None # Sentence Transformer
+data = [] # Google Sheet data
+descriptions = []
+embeddings = torch.tensor([]) # Google Sheet embeddings
+
+# --- Loading Functions (Run once on startup) ---
+
+def load_spacy_model():
+    """Loads or downloads the spaCy model."""
+    model_name = "en_core_web_sm"
+    try:
+        print(f"Loading spaCy model '{model_name}'...")
+        nlp_model = spacy.load(model_name)
+        print(f"SpaCy model '{model_name}' loaded.")
+        return nlp_model
+    except OSError:
+        print(f"SpaCy model '{model_name}' not found locally. Attempting download...")
+        # For HF Spaces, ensuring it's in requirements.txt is key.
+        # We'll assume requirements.txt handles installation, and try loading again.
+        print("Assuming 'en_core_web_sm' is installed via requirements.txt. Attempting to load...")
+        try:
+             nlp_model = spacy.load(model_name)
+             print(f"SpaCy model '{model_name}' loaded after assumed installation.")
+             return nlp_model
+        except Exception as e:
+             print(f"Failed to load spaCy model '{model_name}' after assumed installation: {e}")
+             print("SpaCy will not be available.")
+             return None # Return None if loading fails
+
+def load_sentence_transformer():
+    """Loads the Sentence Transformer model."""
+    print("Loading Sentence Transformer...")
+    try:
+        embedder_model = SentenceTransformer("all-MiniLM-L6-v2")
+        print("Sentence Transformer loaded.")
+        return embedder_model
+    except Exception as e:
+        print(f"Error loading Sentence Transformer: {e}")
+        return None
+
+def load_google_sheet_data(sheet_id, service_account_key_base64):
+    """Authenticates and loads data from Google Sheet."""
+    print(f"Attempting to load Google Sheet data from ID: {sheet_id}")
+    if not service_account_key_base64:
+        print("Warning: GOOGLE_SERVICE_ACCOUNT_KEY_BASE64 secret is not set. Cannot access Google Sheets.")
+        return [], [], torch.tensor([])
+
+    try:
+        # Decode the base64 key
+        key_bytes = base64.b64decode(service_account_key_base64)
+        key_dict = json.loads(key_bytes)
+
+        # Authenticate using the service account key
+        # Use service_account.Credentials.from_service_account_info directly
+        from google.oauth2 import service_account
+        creds = service_account.Credentials.from_service_account_info(key_dict)
+        client = gspread.authorize(creds)
+
+        sheet = client.open_by_key(sheet_id).sheet1
+        print(f"Successfully opened Google Sheet with ID: {sheet_id}")
+        sheet_data = sheet.get_all_records()
+
+        if not sheet_data:
+            print(f"Warning: No data records found in Google Sheet with ID: {sheet_id}")
+            return [], [], torch.tensor([])
+
+        filtered_data = [row for row in sheet_data if row.get('Service') and row.get('Description')]
+        if not filtered_data:
+            print("Warning: Filtered data is empty after checking for 'Service' and 'Description'.")
+            return [], [], torch.tensor([])
+
+        if not filtered_data or 'Service' not in filtered_data[0] or 'Description' not in filtered_data[0]:
+             print("Error: Filtered Google Sheet data must contain 'Service' and 'Description' columns.")
+             return [], [], torch.tensor([])
+
+        services = [row["Service"] for row in filtered_data]
+        descriptions = [row["Description"] for row in filtered_data]
+        print(f"Loaded {len(descriptions)} entries from Google Sheet for embedding.")
+
+        # embeddings will be encoded after embedder is loaded
+        return filtered_data, descriptions, None # Return descriptions, embeddings encoded later
+
+    except gspread.exceptions.SpreadsheetNotFound:
+        print(f"Error: Google Sheet with ID '{sheet_id}' not found.")
+        print("Please check the SHEET_ID and ensure the service account has access.")
+        return [], [], torch.tensor([])
+    except Exception as e:
+        print(f"An error occurred while accessing the Google Sheet: {e}")
+        return [], [], torch.tensor([])
+
+
+def load_llm_model(model_id, hf_token):
+    """Loads the LLM in full precision (for CPU).""" # Modified description
+    print(f"Loading model {model_id} in full precision...")
+    if not hf_token:
+        print("Error: HF_TOKEN secret is not set. Cannot load Hugging Face model.")
+        return None, None
+
+    try:
+        llm_tokenizer = AutoTokenizer.from_pretrained(model_id, token=hf_token)
+        if llm_tokenizer.pad_token is None:
+             llm_tokenizer.pad_token = llm_tokenizer.eos_token
+
+        # Load the model without quantization config
+        llm_model = AutoModelForCausalLM.from_pretrained(
+            model_id,
+            token=hf_token,
+            device_map="auto", # This will likely map to 'cpu'
+            # Removed quantization_config=bnb_config
+        )
+
+        print(f"Model {model_id} loaded in full precision.")
+        return llm_model, llm_tokenizer
+
+    except Exception as e:
+        print(f"Error loading model {model_id}: {e}")
+        # Removed specific bitsandbytes message
+        print("Please ensure transformers, trl, peft, and accelerate are installed.")
+        print("Check your Hugging Face token.")
+        # Do not raise, return None to allow app to start without LLM
+        return None, None
+
+# --- Load all assets on startup ---
+print("Loading assets...")
+nlp = load_spacy_model()
+embedder = load_sentence_transformer()
+data, descriptions, _ = load_google_sheet_data(SHEET_ID, GOOGLE_SERVICE_ACCOUNT_KEY_BASE64) # Load data and descriptions first
+
+if embedder and descriptions:
+    print("Encoding Google Sheet descriptions...")
+    try:
+        embeddings = embedder.encode(descriptions, convert_to_tensor=True)
+        print("Encoding complete.")
+    except Exception as e:
+        print(f"Error during embedding: {e}")
+        embeddings = torch.tensor([]) # Ensure embeddings is an empty tensor on error
+else:
+     print("Skipping embedding due to missing embedder or descriptions.")
+     embeddings = torch.tensor([]) # Ensure embeddings is an empty tensor if no descriptions
+
+model, tokenizer = load_llm_model(model_id, HF_TOKEN)
+
+# Check if essential components loaded
+if not model or not tokenizer or not embedder or not nlp:
+    print("\nERROR: Essential components failed to load. The application may not function correctly.")
+    if not model: print("- LLM Model failed to load.")
+    if not tokenizer: print("- LLM Tokenizer failed to load.")
+    if not embedder: print("- Sentence Embedder failed to load.")
+    if not nlp: print("- spaCy Model failed to load.")
+    # Continue, but the main inference function will need checks
+
+# --- Helper Functions (from your script) ---
+
+# Function to perform DuckDuckGo Search and return results with URLs
+def perform_duckduckgo_search(query, max_results=3):
+    """
+    Performs a search using DuckDuckGo and returns a list of dictionaries.
+    Includes a delay to avoid rate limits.
+    """
+    search_results_list = []
+    try:
+        time.sleep(1) # Add a delay before each search
+        with DDGS() as ddgs:
+            for r in ddgs.text(query, max_results=max_results):
+                search_results_list.append(r) # Append the dictionary directly
+    except Exception as e:
+        print(f"Error during DuckDuckgo search for '{query}': {e}")
+        return []
+    return search_results_list
+
+# Function to retrieve relevant business info
+def retrieve_business_info(query, data, embeddings, embedder, threshold=0.50):
+    """
+    Retrieves relevant business information based on query similarity.
+    Returns a dictionary if a match above threshold is found, otherwise None.
+    Also returns the similarity score.
+    Uses the global embedder, data, and embeddings.
+    """
+    if not data or (embeddings is None or embeddings.numel() == 0) or embedder is None:
+        print("Skipping business info retrieval: Data, embeddings or embedder not available.")
+        return None, 0.0
+
+    try:
+        user_embedding = embedder.encode(query, convert_to_tensor=True)
+        cos_scores = util.cos_sim(user_embedding, embeddings)[0]
+        best_score = cos_scores.max().item()
+
+        if best_score > threshold:
+            best_match_idx = cos_scores.argmax().item()
+            best_match = data[best_match_idx]
+            return best_match, best_score
+        else:
+            return None, best_score
+    except Exception as e:
+         print(f"Error during business information retrieval: {e}")
+         return None, 0.0
+
+# Function to split user query into potential sub-queries using spaCy
+def split_query(query):
+    """Splits a user query into potential sub-queries using spaCy."""
+    if nlp is None:
+        print("SpaCy model not loaded. Cannot split query.")
+        return [query] # Return original query if nlp is not available
+
+    try:
+        doc = nlp(query)
+        sentences = [sent.text.strip() for sent in doc.sents]
+        if len(sentences) == 1:
+            parts = re.split(r',| and (who|what|where|when|why|how|is|are|can|tell me about)|;', query, flags=re.IGNORECASE)
+            parts = [part.strip() for part in parts if part is not None and part.strip()]
+            if len(parts) <= 1:
+                 return [query]
+            return parts
+        return sentences
+    except Exception as e:
+        print(f"Error during query splitting: {e}")
+        return [query] # Return original query on error
+
+# --- Pass 1 System Prompt ---
+pass1_instructions_action = """You are a helpful assistant for a business. Your primary goal in this first step is to analyze the user's query and decide which actions are needed to answer it.
+
+You have analyzed the user's query and potentially broken it down into parts. For each part, a preliminary check was done to see if it matches known business information. The results of this check are provided below.
+
+{business_check_summary}
+
+Based on the user's query and the results of the business info check for each part, identify if you need to perform actions.
+
+Output one or more actions, each on a new line, in the format:
+ACTION: [ACTION_TYPE]: [Argument/Query for the action]
+
+Possible actions:
+1. **LOOKUP_BUSINESS_INFO**: If a part of the query asks about the business's services, prices, availability, or individuals mentioned in the business context, *and* the business info check for that part indicates a high relevance ({PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD:.2f} or higher). The argument should be the specific phrase or name to look up.
+2. **SEARCH**: If a part of the query asks for current external information (e.g., current events, real-time data, general facts not in business info), *or* if a part that seems like it could be business info did *not* have a high relevance score in the preliminary check (below {PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD:.2f}). The argument should be the precise search query.
+3. **ANSWER_DIRECTLY**: If the overall query is a simple greeting or can be answered from your general knowledge without lookup or search, *and* the business info check results indicate low relevance for all parts. The argument should be the direct answer here.
+
+**Crucially:**
+- **Prioritize LOOKUP_BUSINESS_INFO** for any part of the query where the preliminary business info check score was {PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD:.2f} or higher.
+- Use **SEARCH** for parts about external information or where the business info check score was below {PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD:.2f}.
+- If a part of the query is clearly external (like asking about current events or famous people) even if its business info score wasn't zero, you should likely use SEARCH for it.
+- Do NOT output any other text besides the ACTION lines.
+- If the results suggest a direct answer is sufficient, use ANSWER_DIRECTLY.
+
+Now, analyze the following user query, considering the business info check results provided above, and output the required actions:
+"""
+
+# --- Pass 2 System Prompt ---
+pass2_instructions_synthesize = """You are a helpful assistant for a business. You have been provided with the original user query, relevant Business Information (if found), and results from external searches (if performed).
+
+Your task is to synthesize ALL the provided information to answer the user's original question concisely and accurately.
+
+**Prioritize Business Information** for details about the business, its services, or individuals mentioned within that context.
+Use the Search Results for current external information that was requested.
+If information for a specific part of the question was not found in either Business Information or Search Results, use your general knowledge if possible, or state that the information could not be found.
+
+Synthesize the information into a natural language response. Do NOT copy and paste raw context or strings like 'Business Information:' or 'SEARCH RESULTS:' or 'ACTION:' or the raw user query.
+
+After your answer, generate a few concise follow-up questions that a user might ask based on the previous turn's conversation and your response. List these questions clearly at the end of your response.
+When search results were used to answer the question, list the URLs from the search results you used under a "Sources:" heading at the very end.
+"""
+
+# --- Main Inference Function for Gradio ---
+# This function will be called every time the user submits a query
+# chat_history is now a parameter managed by Gradio's State
+def respond(user_input, chat_history):
+    """
+    Processes user input, performs actions (lookup/search), and generates a response.
+    Manages chat history within Gradio state.
+    """
+    # Check if models loaded successfully
+    if model is None or tokenizer is None or embedder is None or nlp is None:
+        return "", chat_history + [(user_input, "Sorry, the application failed to load necessary components. Please try again later or contact the administrator.")] # Return empty string for input, updated history
+
+    original_user_input = user_input
+
+    # Initialize action results containers for this turn
+    search_results_dicts = []
+    business_lookup_results_formatted = []
+    response_pass1_raw = "" # To store the raw actions generated by Pass 1
+
+    # --- Pre-Pass 1: Programmatic Business Info Check for Query Parts ---
+    query_parts = split_query(original_user_input)
+    business_check_results = []
+    overall_pre_pass1_score = 0.0
+
+    print("\n--- Processing new user query ---")
+    print(f"User: {user_input}")
+    print("Performing programmatic business info check on query parts...")
+
+    if query_parts:
+        for i, part in enumerate(query_parts):
+            match, score = retrieve_business_info(part, data, embeddings, embedder, threshold=0.0)
+            business_check_results.append({"part": part, "score": score, "match": match})
+            print(f"- Part '{part}': Score {score:.4f}")
+            overall_pre_pass1_score = max(overall_pre_pass1_score, score)
+    else:
+        match, score = retrieve_business_info(original_user_input, data, embeddings, embedder, threshold=0.0)
+        business_check_results.append({"part": original_user_input, "score": score, "match": match})
+        print(f"- Part '{original_user_input}': Score {score:.4f}")
+        overall_pre_pass1_score = score
+
+    is_likely_direct_answer = overall_pre_pass1_score < PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD and len(query_parts) <= 2
+
+    # Format business check summary for Pass 1 prompt
+    business_check_summary = "Business Info Check Results for Query Parts:\n"
+    if business_check_results:
+        for result in business_check_results:
+            status = "High Relevance" if result['score'] >= PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD else "Low Relevance"
+            business_check_summary += f"- Part '{result['part']}': Score {result['score']:.4f} ({status})\n"
+    else:
+         business_check_summary += "- No parts identified or check skipped.\n"
+    business_check_summary += "\n"
+
+    # --- Pass 1: Action Identification (if not direct answer) ---
+    requested_actions = []
+    answer_directly_provided = None
+
+    if is_likely_direct_answer:
+        print("Programmatically determined likely direct answer.")
+        response_pass1_raw = f"ACTION: ANSWER_DIRECTLY: " # Signal Pass 2
+
+    else:
+        pass1_user_message_content = pass1_instructions_action.format(
+             business_check_summary=business_check_summary,
+             PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD=PRE_PASS1_BUSINESS_PART_LOOKUP_THRESHOLD # Pass threshold to prompt
+             ) + "\n\nUser Query: " + user_input
+
+        # Create a temporary history for Pass 1 focusing only on the current turn's user query and instructions
+        temp_chat_history_pass1 = [{"role": "user", "content": pass1_user_message_content}]
+
+        try:
+            prompt_pass1 = tokenizer.apply_chat_template(
+                temp_chat_history_pass1,
+                tokenize=False,
+                add_generation_prompt=True
+            )
+            # print("\n--- Pass 1 Prompt ---") # Debug print
+            # print(prompt_pass1)
+            # print("---------------------")
+
+            generation_config_pass1 = GenerationConfig(
+                max_new_tokens=200,
+                do_sample=False,
+                temperature=0.1,
+                eos_token_id=tokenizer.eos_token_id,
+                pad_token_id=tokenizer.pad_token_id,
+                use_cache=True
+            )
+
+            input_ids_pass1 = tokenizer(prompt_pass1, return_tensors="pt").input_ids # Removed .to(model.device) as device_map="auto" handles it
+            if model and input_ids_pass1.numel() > 0: # Added check for model
+                outputs_pass1 = model.generate(
+                    input_ids=input_ids_pass1,
+                    generation_config=generation_config_pass1,
+                )
+                prompt_length_pass1 = input_ids_pass1.shape[1]
+                if outputs_pass1.shape[1] > prompt_length_pass1:
+                    generated_tokens_pass1 = outputs_pass1[0, prompt_length_pass1:]
+                    response_pass1_raw = tokenizer.decode(generated_tokens_pass1, skip_special_tokens=True).strip()
+                else:
+                    response_pass1_raw = "" # No actions generated
+            else:
+                 response_pass1_raw = "" # Empty input or model not loaded
+
+            # print("\n--- Raw Pass 1 Response ---") # Debug print
+            # print(response_pass1_raw)
+            # print("--------------------------")
+
+
+        except Exception as e:
+            print(f"Error during Pass 1 (Action Identification): {e}")
+            # If Pass 1 fails, fallback to attempting a direct answer in Pass 2
+            response_pass1_raw = f"ACTION: ANSWER_DIRECTLY: Error in Pass 1 - {e}"
+
+
+    # --- Parse Model's Requested Actions with Validation ---
+    # Always parse even if flagged for direct answer to handle potential Pass 1 errors
+    if response_pass1_raw:
+        lines = response_pass1_raw.strip().split('\n')
+        for line in lines:
+            line = line.strip()
+            if line.startswith(SEARCH_MARKER):
+                query = line[len(SEARCH_MARKER):].strip()
+                if query:
+                     # Validate SEARCH Action
+                     _, score = retrieve_business_info(query, data, embeddings, embedder, threshold=0.0)
+                     if score < SEARCH_VALIDATION_THRESHOLD:
+                         requested_actions.append(("SEARCH", query))
+                         print(f"Validated Search Action for '{query}' (Score: {score:.4f})")
+                     else:
+                         print(f"Rejected Search Action for '{query}' (Score: {score:.4f}) - Too similar to business data.")
+            elif line.startswith(BUSINESS_LOOKUP_MARKER):
+                 query = line[len(BUSINESS_LOOKUP_MARKER):].strip()
+                 if query:
+                      # Validate Business Lookup Query
+                      match, score = retrieve_business_info(query, data, embeddings, embedder, threshold=0.0) # Use low threshold for scoring
+                      if score > BUSINESS_LOOKUP_VALIDATION_THRESHOLD:
+                           requested_actions.append(("LOOKUP_BUSINESS_INFO", query))
+                           print(f"Validated Business Lookup Action for '{query}' (Score: {score:.4f})")
+                      else:
+                           print(f"Rejected Business Lookup Action for '{query}' (Score: {score:.4f}) - Below validation threshold.")
+            elif line.startswith(ANSWER_DIRECTLY_MARKER):
+                 answer = line[len(ANSWER_DIRECTLY_MARKER):].strip()
+                 answer_directly_provided = answer if answer else original_user_input # Use explicit answer if provided, else original query hint
+                 requested_actions = [] # Clear other actions if DIRECT_ANSWER is given
+                 break # Exit action parsing loop
+
+    # --- Execute Actions (Search and Lookup) ---
+    # Only execute actions if ANSWER_DIRECTLY was NOT the primary outcome of Pass 1
+    # and there are validated requested actions.
+    context_for_pass2 = ""
+
+    if requested_actions:
+        print("Executing requested actions...")
+        for action_type, query in requested_actions:
+            if action_type == "SEARCH":
+                print(f"Performing search for: '{query}'")
+                results = perform_duckduckgo_search(query)
+                if results:
+                     search_results_dicts.extend(results)
+                     print(f"Found {len(results)} search results.")
+                else:
+                     print(f"No search results found for '{query}'.")
+
+            elif action_type == "LOOKUP_BUSINESS_INFO":
+                print(f"Performing business info lookup for: '{query}'")
+                match, score = retrieve_business_info(query, data, embeddings, embedder, threshold=retrieve_business_info.__defaults__[0]) # Use default threshold for retrieval
+                print(f"Actual lookup score for '{query}': {score:.4f} (Threshold: {retrieve_business_info.__defaults__[0]})")
+                if match:
+                     formatted_match = f"""Service: {match.get('Service', 'N/A')}
+Description: {match.get('Description', 'N/A')}
+Price: {match.get('Price', 'N/A')}
+Available: {match.get('Available', 'N/A')}"""
+                     business_lookup_results_formatted.append(formatted_match)
+                     print(f"Found business info match.")
+                else:
+                     print(f"No business info match found for '{query}' at threshold {retrieve_business_info.__defaults__[0]}.")
+
+        # --- Prepare Context for Pass 2 based on executed actions ---
+        if business_lookup_results_formatted:
+            context_for_pass2 += "Business Information (Use this for questions about the business):\n"
+            context_for_pass2 += "\n---\n".join(business_lookup_results_formatted)
+            context_for_pass2 += "\n\n"
+
+        if search_results_dicts:
+            context_for_pass2 += "SEARCH RESULTS (Use this for current external information):\n"
+            aggregated_search_results_formatted = []
+            for result in search_results_dicts:
+                 aggregated_search_results_formatted.append(f"Title: {result.get('title', 'N/A')}\nSnippet: {result.get('body', 'N/A')}\nURL: {result.get('href', 'N/A')}")
+            context_for_pass2 += "\n---\n".join(aggregated_search_results_formatted) + "\n\n"
+
+        if requested_actions and not business_lookup_results_formatted and not search_results_dicts:
+             context_for_pass2 = "Note: No relevant information was found in Business Information or via Search for your query."
+             print("Note: No results were found for the requested actions.")
+
+    # If ANSWER_DIRECTLY was determined (either programmatically or by Pass 1 model output)
+    if answer_directly_provided is not None:
+        print(f"Handling as direct answer: {answer_directly_provided}")
+        # Provide a simple context indicating it's a direct answer scenario
+        context_for_pass2 = "Note: This query is a simple request or greeting."
+        if answer_directly_provided != original_user_input and answer_directly_provided != "":
+             context_for_pass2 += f" Initial suggestion from action step: {answer_directly_provided}"
+        # Ensure no search/lookup results are included if it was flagged as direct answer
+        search_results_dicts = []
+        business_lookup_results_formatted = []
+
+
+    # If no actions were requested or direct answer flagged, and no results found...
+    # This handles cases where Pass 1 failed or generated nothing useful
+    if not requested_actions and answer_directly_provided is None:
+         if response_pass1_raw.strip():
+              print("Warning: Pass 1 did not result in valid actions or a direct answer.")
+              context_for_pass2 = f"Error: Could not determine actions from Pass 1 response: '{response_pass1_raw}'."
+         else:
+               print("Warning: Pass 1 generated an empty response.")
+               context_for_pass2 = "Error: Pass 1 generated an empty response."
+         # In this case, we will still try Pass 2 with the limited context
+
+
+    # --- Pass 2: Synthesize and Respond ---
+    final_response = "Sorry, I couldn't generate a response." # Default response on error
+
+    if model is not None and tokenizer is not None:
+        pass2_user_message_content = pass2_instructions_synthesize + "\n\nOriginal User Query: " + original_user_input + "\n\n" + context_for_pass2
+
+        # --- Chat History Management for Pass 2 ---
+        # Gradio's chat history state is [(User1, Bot1), (User2, Bot2), ...]
+        # We need to format the history correctly for the model template
+        # The Pass 2 prompt should build upon the *actual* conversation history, not just the Pass 2 context message.
+        # Let's build the chat history for the model template
+        model_chat_history = []
+        for user_msg, bot_msg in chat_history:
+            model_chat_history.append({"role": "user", "content": user_msg})
+            model_chat_history.append({"role": "assistant", "content": bot_msg})
+
+        # Add the *current* user query and the Pass 2 specific content as the latest turn
+        # The Pass 2 instructions and context are part of the *current* user turn's input to the model
+        model_chat_history.append({"role": "user", "content": pass2_user_message_content})
+
+        try:
+            prompt_pass2 = tokenizer.apply_chat_template(
+                model_chat_history,
+                tokenize=False,
+                add_generation_prompt=True # Add the assistant prompt token to start the response
+            )
+            # print("\n--- Pass 2 Prompt ---") # Debug print
+            # print(prompt_pass2)
+            # print("---------------------")
+
+
+            generation_config_pass2 = GenerationConfig(
+                max_new_tokens=1500, # Generate a longer response
+                do_sample=True,
+                temperature=0.7,
+                top_k=50,
+                top_p=0.95,
+                repetition_penalty=1.1,
+                eos_token_id=tokenizer.eos_token_id,
+                pad_token_id=tokenizer.pad_token_id,
+                use_cache=True
+            )
+
+            input_ids_pass2 = tokenizer(prompt_pass2, return_tensors="pt").input_ids # Removed .to(model.device)
+            if model and input_ids_pass2.numel() > 0: # Added check for model
+                outputs_pass2 = model.generate(
+                    input_ids=input_ids_pass2,
+                    generation_config=generation_config_pass2,
+                )
+
+                prompt_length_pass2 = input_ids_pass2.shape[1]
+                if outputs_pass2.shape[1] > prompt_length_pass2:
+                    generated_tokens_pass2 = outputs_pass2[0, prompt_length_pass2:]
+                    final_response = tokenizer.decode(generated_tokens_pass2, skip_special_tokens=True).strip()
+                else:
+                    final_response = "..." # Indicate potentially empty response
+            else:
+                final_response = "Error: Model or empty input for Pass 2." # Indicate model not loaded or empty input
+
+
+        except Exception as gen_error:
+             print(f"Error during model generation in Pass 2: {gen_error}")
+             final_response = "Error generating response in Pass 2."
+
+
+        # --- Post-process Final Response from Pass 2 ---
+        cleaned_response = final_response
+        # Filter out the Pass 2 instructions and context markers that might bleed through
+        lines = cleaned_response.split('\n')
+        cleaned_lines = [line for line in lines if not line.strip().lower().startswith("business information")
+                                                 and not line.strip().lower().startswith("search results")
+                                                 and not line.strip().startswith("---")
+                                                 and not line.strip().lower().startswith("original user query:")
+                                                 and not line.strip().lower().startswith("you are a helpful assistant for a business.")]
+
+        cleaned_response = "\n".join(cleaned_lines).strip()
+
+        # Extract and list URLs from the search results that were actually used
+        # This assumes the model uses the provided snippets with URLs
+        urls_to_list = [result.get('href') for result in search_results_dicts if result.get('href')]
+        urls_to_list = list(dict.fromkeys(urls_to_list)) # Remove duplicates
+
+        # Only add Sources if search was performed AND results were found
+        if search_results_dicts and urls_to_list:
+             cleaned_response += "\n\nSources:\n" + "\n".join(urls_to_list)
+
+        final_response = cleaned_response
+
+        # Check if the final response is empty or just whitespace after cleaning
+        if not final_response.strip():
+             final_response = "Sorry, I couldn't generate a meaningful response based on the information found."
+             print("Warning: Final response was empty after cleaning.")
+
+    else: # Model or tokenizer not loaded (this check is at the very beginning of the function)
+     final_response = "Sorry, the core language model is not available."
+     print("Error: LLM model or tokenizer not loaded for Pass 2.")
+
+
+    # --- Update Chat History for Gradio ---
+    # Append the user's original message and the final bot response to the history state
+    # The format is (user_input, bot_response)
+    updated_chat_history = chat_history + [(original_user_input, final_response)]
+
+    # Optional: Manage history length
+    max_history_pairs = 10 # Keep last 10 turns (20 messages total)
+    if len(updated_chat_history) > max_history_pairs:
+     updated_chat_history = updated_chat_history[-max_history_pairs:]
+    # print(f"History truncated. Keeping last {len(updated_chat_history)} turns.") # Debug print
+
+    # Return the updated history state and an empty string for the input box
+    return "", updated_chat_history