agent.py

# agent.py

import os
from dotenv import load_dotenv
from langgraph.graph import START, StateGraph, MessagesState
from langgraph.prebuilt import tools_condition
from langchain_google_genai import ChatGoogleGenerativeAI
from langchain_groq import ChatGroq
from langchain_huggingface import ChatHuggingFace, HuggingFaceEndpoint, HuggingFaceEmbeddings
from langchain_community.tools.tavily_search import TavilySearchResults
from langchain_community.document_loaders import WikipediaLoader
from langchain_community.utilities import WikipediaAPIWrapper
from langchain_community.document_loaders import ArxivLoader
from langchain_core.messages import SystemMessage, HumanMessage
from langchain_core.tools import tool
from langchain.tools.retriever import create_retriever_tool
from supabase.client import Client, create_client
from sentence_transformers import SentenceTransformer
from langchain.embeddings.base import Embeddings
from typing import List
import numpy as np
import yaml

import pandas as pd
import uuid
import requests
import json
from langchain_core.documents import Document
from langchain_community.vectorstores import FAISS

#from langchain.embeddings import BERTEmbeddings
#from langchain_community.embeddings import HuggingFaceEmbeddings


from youtube_transcript_api import YouTubeTranscriptApi
from youtube_transcript_api._errors import TranscriptsDisabled, VideoUnavailable
import re

from langchain_community.document_loaders import TextLoader, PyMuPDFLoader
from docx import Document as DocxDocument
import openpyxl
from io import StringIO

from transformers import BertTokenizer, BertModel
import torch
import torch.nn.functional as F
from langchain_community.chat_models import ChatOpenAI
from langchain_community.tools import Tool
import time
from huggingface_hub import InferenceClient
from langchain_community.llms import HuggingFaceHub
from langchain.prompts import PromptTemplate
from langchain.chains import LLMChain
from transformers import AutoTokenizer, AutoModelForCausalLM, pipeline
from huggingface_hub import login
from transformers import AutoTokenizer, AutoModelForCausalLM, pipeline, BitsAndBytesConfig
from langchain_huggingface import HuggingFaceEndpoint
#from langchain.agents import initialize_agent
#from langchain.agents import AgentType
from typing import Union, List
from functools import reduce
import operator
from typing import Union
from functools import reduce
from youtube_transcript_api import YouTubeTranscriptApi
from youtube_transcript_api._errors import TranscriptsDisabled, VideoUnavailable
from langchain_community.vectorstores import FAISS
from langchain.schema import Document


load_dotenv()




@tool
def calculator(inputs: Union[str, dict]):
    """
    Perform mathematical operations based on the operation provided.
    Supports both binary (a, b) operations and list operations.
    """

    # If input is a JSON string, parse it
    if isinstance(inputs, str):
        try:
            import json
            inputs = json.loads(inputs)
        except Exception as e:
            return f"Invalid input format: {e}"

    # Handle list-based operations like SUM
    if "list" in inputs:
        nums = inputs.get("list", [])
        op = inputs.get("operation", "").lower()

        if not isinstance(nums, list) or not all(isinstance(n, (int, float)) for n in nums):
            return "Invalid list input. Must be a list of numbers."

        if op == "sum":
            return sum(nums)
        elif op == "multiply":
            return reduce(operator.mul, nums, 1)
        else:
            return f"Unsupported list operation: {op}"

    # Handle basic two-number operations
    a = inputs.get("a")
    b = inputs.get("b")
    operation = inputs.get("operation", "").lower()

    if a is None or b is None or not isinstance(a, (int, float)) or not isinstance(b, (int, float)):
        return "Both 'a' and 'b' must be numbers."

    if operation == "add":
        return a + b
    elif operation == "subtract":
        return a - b
    elif operation == "multiply":
        return a * b
    elif operation == "divide":
        if b == 0:
            return "Error: Division by zero"
        return a / b
    elif operation == "modulus":
        return a % b
    else:
        return f"Unknown operation: {operation}"


@tool
def wiki_search(query: str) -> str:
    """Search Wikipedia for a query and return up to 2 results."""
    search_docs = WikipediaLoader(query=query, load_max_docs=2).load()

    formatted_search_docs = "\n\n---\n\n".join(
        [
            f'<Document source="{doc.metadata.get("source", "Wikipedia")}" page="{doc.metadata.get("page", "")}"/>\n{doc.page_content}\n</Document>'
            for doc in search_docs
        ]
    )
    return formatted_search_docs
    
    
@tool
def wikidata_query(query: str) -> str:
    """
    Run a SPARQL query on Wikidata and return results.
    """
    endpoint_url = "https://query.wikidata.org/sparql"
    headers = {
        "Accept": "application/sparql-results+json"
    }
    response = requests.get(endpoint_url, headers=headers, params={"query": query})
    data = response.json()
    return json.dumps(data, indent=2)


@tool
def web_search(query: str) -> str:
    """Search Tavily for a query and return up to 3 results."""
    tavily_key = os.getenv("TAVILY_API_KEY")
    
    if not tavily_key:
        return "Error: Tavily API key not set."

    search_tool = TavilySearchResults(tavily_api_key=tavily_key, max_results=3)
    search_docs = search_tool.invoke(query=query)
    
    formatted_search_docs = "\n\n---\n\n".join(
        [
            f'<Document source="{doc.metadata["source"]}" page="{doc.metadata.get("page", "")}"/>\n{doc.page_content}\n</Document>'
            for doc in search_docs
        ])
    
    return formatted_search_docs


@tool
def arxiv_search(query: str) -> str:
    """Search Arxiv for a query and return maximum 3 result.
    
    Args:
        query: The search query."""
    search_docs = ArxivLoader(query=query, load_max_docs=3).load()
    formatted_search_docs = "\n\n---\n\n".join(
        [
            f'<Document source="{doc.metadata["source"]}" page="{doc.metadata.get("page", "")}"/>\n{doc.page_content[:1000]}\n</Document>'
            for doc in search_docs
        ])
    return formatted_search_docs



@tool
def analyze_attachment(file_path: str) -> str:
    """
    Analyzes attachments including PY, PDF, TXT, DOCX, and XLSX files and returns text content.

    Args:
        file_path: Local path to the attachment.
    """
    if not os.path.exists(file_path):
        return f"File not found: {file_path}"

    try:
        ext = file_path.lower()

        if ext.endswith(".pdf"):
            loader = PyMuPDFLoader(file_path)
            documents = loader.load()
            content = "\n\n".join([doc.page_content for doc in documents])

        elif ext.endswith(".txt") or ext.endswith(".py"):
            # Both .txt and .py are plain text files
            with open(file_path, "r", encoding="utf-8") as file:
                content = file.read()

        elif ext.endswith(".docx"):
            doc = DocxDocument(file_path)
            content = "\n".join([para.text for para in doc.paragraphs])

        elif ext.endswith(".xlsx"):
            wb = openpyxl.load_workbook(file_path, data_only=True)
            content = ""
            for sheet in wb:
                content += f"Sheet: {sheet.title}\n"
                for row in sheet.iter_rows(values_only=True):
                    content += "\t".join([str(cell) if cell is not None else "" for cell in row]) + "\n"

        else:
            return "Unsupported file format. Please use PY, PDF, TXT, DOCX, or XLSX."

        return content[:3000]  # Limit output size for readability

    except Exception as e:
        return f"An error occurred while processing the file: {str(e)}"


@tool
def get_youtube_transcript(url: str) -> str:
    """
    Fetch transcript text from a YouTube video.
    
    Args:
        url (str): Full YouTube video URL.
    
    Returns:
        str: Transcript text as a single string.
    
    Raises:
        ValueError: If no transcript is available or URL is invalid.
    """
    try:
        # Extract video ID
        video_id = extract_video_id(url)
        transcript = YouTubeTranscriptApi.get_transcript(video_id)

        # Combine all transcript text
        full_text = " ".join([entry['text'] for entry in transcript])
        return full_text

    except (TranscriptsDisabled, VideoUnavailable) as e:
        raise ValueError(f"Transcript not available: {e}")
    except Exception as e:
        raise ValueError(f"Failed to fetch transcript: {e}")



@tool
def extract_video_id(url: str) -> str:
    """
    Extract the video ID from a YouTube URL.
    """
    match = re.search(r"(?:v=|youtu\.be/)([A-Za-z0-9_-]{11})", url)
    if not match:
        raise ValueError("Invalid YouTube URL")
    return match.group(1)




# -----------------------------
# Load configuration from YAML
# -----------------------------
with open("config.yaml", "r") as f:
    config = yaml.safe_load(f)

provider = config["provider"]
model_config = config["models"][provider]

#prompt_path = config["system_prompt_path"]
enabled_tool_names = config["tools"]


# -----------------------------
# Load system prompt
# -----------------------------
# load the system prompt from the file
with open("system_prompt.txt", "r", encoding="utf-8") as f:
    system_prompt = f.read()

# System message
sys_msg = SystemMessage(content=system_prompt)


# -----------------------------
# Map tool names to functions
# -----------------------------
tool_map = {
    "math": calculator,
    "wiki_search": wiki_search,
    "web_search": web_search,
    "arxiv_search": arxiv_search,
    "get_youtube_transcript": get_youtube_transcript,
    "extract_video_id": extract_video_id,
    "analyze_attachment": analyze_attachment,
    "wikidata_query": wikidata_query
}

# Then define which tools you want enabled
enabled_tool_names = [
    "math",
    "wiki_search",
    "web_search",
    "arxiv_search",
    "get_youtube_transcript",
    "extract_video_id",
    "analyze_attachment",
    "wikidata_query"
]


tools = [tool_map[name] for name in enabled_tool_names]


# Safe version
tools = []
for name in enabled_tool_names:
    if name not in tool_map:
        print(f"❌ Tool not found: {name}")
        continue
    tools.append(tool_map[name])

    
# -----------------------------
# Create FAISS Vector Store
# -----------------------------
import faiss
class MyVectorStore:
    def __init__(self, index: faiss.Index):
        self.index = index

    def save_local(self, path: str):
        # Save the FAISS index to the specified file
        faiss.write_index(self.index, path)
        print(f"Index saved to {path}") 
    
    @classmethod
    def load_local(cls, path: str):
        # Load the FAISS index from the specified file
        index = faiss.read_index(path)
        return cls(index)

# -----------------------------
# Prepare Documents
# -----------------------------
# Define the URL where the JSON file is hosted

import json
from langchain.schema import Document

def reverse_text(text: str) -> str:
    return text[::-1].replace("\\", "")  # Handle escaped quotes

# Load the JSON file
with open("https://huggingface.co/spaces/wt002/Final_Assignment_Project/blob/main/questions.json", "r", encoding="utf-8") as f:
    data = json.load(f)

# Convert each question into a Document
docs = [
    Document(
        page_content=(
            str(reverse_text(item["question"])) 
            if isinstance(item["question"], (list, bytes)) 
            else reverse_text(item["question"]) 
            if item["question"].startswith(('.', ',')) 
            else item["question"]
        ),
        metadata={
            "task_id": item["task_id"],
            "level": item["Level"],
            "file_name": item["file_name"]  # Added from your URL example
        }
    )
    for item in data 
    if "question" in item and item["question"]  # Skip empty questions
]


# Now extract texts
texts = [doc.page_content for doc in docs]

# Initialize the embedding model
embedding_model = HuggingFaceEmbeddings(model_name="sentence-transformers/all-MiniLM-L6-v2")

docs = [Document(page_content=texts, metadata={"task_id": item["task_id"]}) for item in data]

# Create the FAISS index
#vector_store = FAISS.from_documents(docs, embedding_model)
vector_store = FAISS.from_texts(texts = text_chunks, embedding = embeddings)

# Save the FAISS index
vector_store = MyVectorStore(index)

# Assuming you already have a FAISS index
index = faiss.IndexFlatL2(768)  # Or whatever dimensionality your embeddings have
vector_store = MyVectorStore(index)

# Save
vector_store.save_local("/home/wendy/Downloads/faiss_index.index")

# Load
loaded_store = MyVectorStore.load_local("/home/wendy/Downloads/faiss_index.index")




# -----------------------------
# Create LangChain Retriever Tool
# -----------------------------

retriever = FAISS.load_local("faiss_index.index", embedding_model).as_retriever()

question_retriever_tool = create_retriever_tool(
    retriever=retriever,
    name="Question_Search",
    description="A tool to retrieve documents related to a user's question."
)



# Define the LLM before using it
#llm = ChatOpenAI(temperature=0, model="gpt-3.5-turbo") # or "gpt-3.5-turbo" "gpt-4"
#llm = ChatMistralAI(model="mistral-7b-instruct-v0.1")


# Get the Hugging Face API token from the environment variable
#hf_token = os.getenv("HF_TOKEN")


llm = HuggingFaceEndpoint(
    repo_id="HuggingFaceH4/zephyr-7b-beta",
    task="text-generation",
    huggingfacehub_api_token=os.getenv("HF_TOKEN"),
    temperature=0.7,
    max_new_tokens=512
)



# -------------------------------
# Step 8: Use the Planner, Classifier, and Decision Logic
# -------------------------------

def process_question(question):
    # Step 1: Planner generates the task sequence
    tasks = planner(question)
    print(f"Tasks to perform: {tasks}")

    # Step 2: Classify the task (based on question)
    task_type = task_classifier(question)
    print(f"Task type: {task_type}")

    # Step 3: Use the classifier and planner to decide on the next task or node
    state = {"question": question, "last_response": ""}
    next_task = decide_task(state)
    print(f"Next task: {next_task}")

    # Step 4: Use node skipper logic (skip if needed)
    skip = node_skipper(state)
    if skip:
        print(f"Skipping to {skip}")
        return skip  # Or move directly to generating answer

    # Step 5: Execute task (with error handling)
    try:
        if task_type == "wiki_search":
            response = wiki_search(question)
        elif task_type == "math":
            response = calculator(question)
        else:
            response = "Default answer logic"
        
        # Step 6: Final response formatting
        final_response = final_answer_tool(state, {'wiki_search': response})
        return final_response
    
    except Exception as e:
        print(f"Error executing task: {e}")
        return "Sorry, I encountered an error processing your request."


# Run the process
#question = "How many albums did Mercedes Sosa release between 2000 and 2009?"
#response = agent.invoke(question)
#print("Final Response:", response)




from langchain.schema import HumanMessage

def retriever(state: MessagesState, k: int = 4):
    """
    Retrieves documents from the vector store using similarity scores, 
    applies a dynamic threshold filter, and returns updated message state.

    Args:
        state (MessagesState): Current message state including the user's query.
        k (int): Number of top results to retrieve from the vector store.

    Returns:
        dict: Updated messages state including relevant documents or fallback message.
    """
    query = state["messages"][0].content.strip()
    results = vector_store.similarity_search_with_score(query, k=k)

    # Determine dynamic similarity threshold
    if any(keyword in query.lower() for keyword in ["who", "what", "where", "when", "why", "how"]):
        threshold = 0.75
    else:
        threshold = 0.8

    filtered = [doc for doc, score in results if score < threshold]

    if not filtered:
        response_msg = HumanMessage(content="No relevant documents found.")
    else:
        content = "\n\n".join(doc.page_content for doc in filtered)
        response_msg = HumanMessage(content=f"Here are relevant reference documents:\n\n{content}")

    return {"messages": [sys_msg] + state["messages"] + [response_msg]}




# ----------------------------------------------------------------
# LLM Loader
# ----------------------------------------------------------------
def get_llm(provider: str, config: dict):
    if provider == "google":
        from langchain_google_genai import ChatGoogleGenerativeAI
        return ChatGoogleGenerativeAI(
            model=config.get("model"),
            temperature=config.get("temperature", 0.7),
            google_api_key=config.get("api_key")  # Optional: if needed
        )

    elif provider == "groq":
        from langchain_groq import ChatGroq
        return ChatGroq(
            model=config.get("model"),
            temperature=config.get("temperature", 0.7),
            groq_api_key=config.get("api_key")  # Optional: if needed
        )

    elif provider == "huggingface":
        from langchain_huggingface import ChatHuggingFace
        from langchain_huggingface import HuggingFaceEndpoint
        return ChatHuggingFace(
            llm=HuggingFaceEndpoint(
                endpoint_url=config.get("url"),
                temperature=config.get("temperature", 0.7),
                huggingfacehub_api_token=config.get("api_key")  # Optional
            )
        )

    else:
        raise ValueError(f"Invalid provider: {provider}")



# ----------------------------------------------------------------
# Planning & Execution Logic
# ----------------------------------------------------------------
def planner(question: str, tools: list) -> tuple:
    """
    Select the best-matching tool(s) for a question based on keyword-based intent detection and tool metadata.
    Returns the detected intent and matched tools.
    """
    question = question.lower().strip()

    # Define intent-based keywords
    intent_keywords = {
        "math": ["calculate", "evaluate", "add", "subtract", "multiply", "divide", "modulus", "plus", "minus", "times"],
        "wiki_search": ["who is", "what is", "define", "explain", "tell me about", "overview of"],
        "web_search": ["search", "find", "look up", "google", "latest news", "current info"],
        "arxiv_search": ["arxiv", "research paper", "scientific paper", "preprint"],
        "get_youtube_transcript": ["youtube", "watch", "play video", "show me a video"],
        "extract_video_id": ["analyze video", "summarize video", "video content"],
        "data_analysis": ["analyze", "plot", "graph", "data", "visualize"],
        "wikidata_query": ["wikidata", "sparql", "run sparql", "query wikidata"],
        "default": ["why", "how", "difference between", "compare", "what happens", "reason for", "cause of", "effect of"]
    }



    # Step 1: Identify intent
    detected_intent = None
    for intent, keywords in intent_keywords.items():
        if any(keyword in question for keyword in keywords):
            detected_intent = intent
            break

    # Step 2: Match tools by intent
    matched_tools = []
    if detected_intent:
        for tool in tools:
            name = getattr(tool, "name", "").lower()
            description = getattr(tool, "description", "").lower()
            if detected_intent in name or detected_intent in description:
                matched_tools.append(tool)

    # Step 3: Fallback to general-purpose/default tools if no match found
    if not matched_tools:
        matched_tools = [
            tool for tool in tools
            if "default" in getattr(tool, "name", "").lower()
            or "qa" in getattr(tool, "description", "").lower()
        ]

    return detected_intent, matched_tools if matched_tools else [tools[0]]




def task_classifier(question: str) -> str:
    """
    Classifies the question into one of the predefined task categories.
    """
    question = question.lower().strip()

    # Context-aware intent patterns
    if any(phrase in question for phrase in [
        "calculate", "how much is", "what is the result of", "evaluate", "solve"
    ]) or any(op in question for op in ["add", "subtract", "multiply", "divide", "modulus", "plus", "minus", "times"]):
        return "math"

    elif any(phrase in question for phrase in [
        "who is", "what is", "define", "explain", "tell me about", "give me an overview of"
    ]):
        return "wiki_search"

    elif any(phrase in question for phrase in [
        "search", "find", "look up", "google", "get the latest", "current news", "trending"
    ]):
        return "web_search"

    elif any(phrase in question for phrase in [
        "arxiv", "latest research", "scientific paper", "research paper", "preprint"
    ]):
        return "arxiv_search"

    elif any(phrase in question for phrase in [
        "youtube", "watch", "play the video", "show me a video"
    ]):
        return "get_youtube_transcript"

    elif any(phrase in question for phrase in [
        "analyze video", "summarize video", "what happens in the video", "video content"
    ]):
        return "video_analysis"

    elif any(phrase in question for phrase in [
        "analyze", "visualize", "plot", "graph", "inspect data", "explore dataset"
    ]):
        return "data_analysis"

    elif any(phrase in question for phrase in [
        "sparql", "wikidata", "query wikidata", "run sparql", "wikidata query"
    ]):
        return "wikidata_query"

    return "default"


def select_tool_and_run(question: str, tools: dict):
    # Step 1: Classify intent
    intent = task_classifier(question)  # assuming task_classifier maps the question to intent

    # Map intent to tool names
    intent_tool_map = {
        "math": "calculator",                                # maps to tools["math"] → calculator
        "wiki_search": "wiki_search",                        # → wiki_search
        "web_search": "web_search",                          # → web_search
        "arxiv_search": "arxiv_search",                      # → arxiv_search (spelling fixed)
        "get_youtube_transcript": "get_youtube_transcript",  # → get_youtube_transcript
        "extract_video_id": "extract_video_id",              # adjust based on your tools
        "analyze_attachment": "analyze_attachment",          # assuming analyze_attachment handles this
        "wikidata_query": "wikidata_query",                  # → wikidata_query
        "default": "default"                                 # → default_tool
    }

    # Get the corresponding tool name
    tool_name = intent_tool_map.get(intent, "default")  # Default to "default" if no match

    # Retrieve the tool from the tools dictionary
    tool_func = tools.get(tool_name)

    if not tool_func:
        return f"Tool not found for intent '{intent}'"

    # Step 2: Run the tool
    try:
        # If the tool needs JSON or structured data
        try:
            parsed_input = json.loads(question)
        except json.JSONDecodeError:
            parsed_input = question  # fallback to raw input if not JSON

        # Run the selected tool
        print(f"Running tool: {tool_name} with input: {parsed_input}")  # log the tool name and input
        return tool_func(parsed_input)
    except Exception as e:
        return f"Error while running tool '{tool_name}': {str(e)}"



# Function to extract math operation from the question

def extract_math_from_question(question: str):
    question = question.lower()

    # Map natural language to symbols
    ops = {
        "add": "+", "plus": "+",
        "subtract": "-", "minus": "-",
        "multiply": "*", "times": "*",
        "divide": "/", "divided by": "/",
        "modulus": "%", "mod": "%"
    }

    for word, symbol in ops.items():
        question = re.sub(rf"\b{word}\b", symbol, question)

    # Extract math expression like "12 + 5"
    match = re.search(r'(\d+)\s*([\+\-\*/%])\s*(\d+)', question)
    if match:
        num1 = int(match.group(1))
        operator = match.group(2)
        num2 = int(match.group(3))
        return {
            "a": num1,
            "b": num2,
            "operation": {
                "+": "add",
                "-": "subtract",
                "*": "multiply",
                "/": "divide",
                "%": "modulus"
            }[operator]
        }
    return None



# Example tool set (adjust these to match your actual tool names)
intent_tool_map = {
    "math": "math",                                      # maps to tools["math"] → calculator
    "wiki_search": "wiki_search",                        # → wiki_search
    "web_search": "web_search",                          # → web_search
    "arxiv_search": "arxiv_search",                      # → arxiv_search (spelling fixed)
    "get_youtube_transcript": "get_youtube_transcript",  # → get_youtube_transcript
    "extract_video_id": "extract_video_id",              # adjust based on your tools
    "analyze_attachment": "analyze_attachment",          # assuming analyze_attachment handles this
    "wikidata_query": "wikidata_query",                  # → wikidata_query
    "default": "default"                                 # → default_tool
}



# The task order can also include the tools for each task
priority_order = [
    {"task": "math", "tool": "math"},
    {"task": "wiki_search", "tool": "wiki_search"},
    {"task": "web_search", "tool": "web_search"},
    {"task": "arxiv_search", "tool": "arxiv_search"},
    {"task": "wikidata_query", "tool": "wikidata_query"},
    {"task": "retriever", "tool": "retriever"},
    {"task": "get_youtube_transcript", "tool": "get_youtube_transcript"},
    {"task": "extract_video_id", "tool": "extract_video_id"},
    {"task": "analyze_attachment", "tool": "analyze_attachment"},
    {"task": "default", "tool": "default"}  # Fallback
]

def decide_task(state: dict) -> str:
    """Decides which task to perform based on the current state."""
    
    # Get the list of tasks from the planner
    tasks = planner(state["question"])
    print(f"Available tasks: {tasks}")  # Debugging: show all possible tasks
    
    # Check if the tasks list is empty or invalid
    if not tasks:
        print("❌ No valid tasks were returned from the planner.")
        return "default"  # Return a default task if no tasks were generated

    # If there are multiple tasks, we can prioritize based on certain conditions
    task = tasks[0]  # Default to the first task in the list
    if len(tasks) > 1:
        print(f"⚠️ Multiple tasks found. Deciding based on priority.")
        # Example logic to prioritize tasks, adjust based on your use case
        task = prioritize_tasks(tasks)
    
    print(f"Decided on task: {task}")  # Debugging: show the final task
    return task


def prioritize_tasks(tasks: list) -> str:
    """Prioritize tasks based on certain conditions or criteria, including tools."""
    # Sort tasks based on priority_order mapping
    for priority in priority_order:
        # Check if any task matches the priority task type
        for task in tasks:
            if priority["task"] in task:
                print(f"✅ Prioritizing task: {task} with tool: {priority['tool']}")  # Debugging: show the chosen task and tool
                # Assign the correct tool based on the task
                tool = tools.get(priority["tool"], tools["default"])  # Default to 'default_tool' if not found
                return task, tool

    # If no priority task is found, return the first task with its default tool
    return tasks[0], tools["default"]


def process_question(question: str):
    """Process the question and route it to the appropriate tool."""
    # Get the tasks from the planner
    tasks = planner(question)
    print(f"Tasks to perform: {tasks}")

    task_type, tool = decide_task({"question": question})
    print(f"Next task: {task_type} with tool: {tool}")

    if node_skipper({"question": question}):
        print(f"Skipping task: {task_type}")
        return "Task skipped."

    try:
        # Execute the corresponding tool for the task type
        if task_type == "wiki_search":
            response = tool.run(question)  # Assuming tool is wiki_tool
        elif task_type == "math":
            response = tool.run(question)  # Assuming tool is calc_tool
        elif task_type == "retriever":
            response = tool.run(question)  # Assuming tool is retriever_tool
        else:
            response = tool.run(question)  # Default tool

        return generate_final_answer({"question": question}, {task_type: response})

    except Exception as e:
        print(f"❌ Error: {e}")
        return f"Sorry, I encountered an error: {str(e)}"




def call_llm(state):
    messages = state["messages"]
    response = llm.invoke(messages)
    return {"messages": messages + [response]}




from langchain.schema import AIMessage
from typing import TypedDict, List, Optional
from langchain_core.messages import BaseMessage

class AgentState(TypedDict):
    messages: List[BaseMessage]   # Chat history
    input: str                    # Original input
    intent: str                   # Derived or predicted intent
    result: Optional[str]         # Optional result


def tool_dispatcher(state: AgentState) -> AgentState:
    last_msg = state["messages"][-1]

    # Make sure it's an AI message with tool_calls
    if isinstance(last_msg, AIMessage) and last_msg.tool_calls:
        tool_call = last_msg.tool_calls[0]
        tool_name = tool_call["name"]
        tool_input = tool_call["args"]  # Adjust based on your actual schema

        tool_func = tool_map.get(tool_name, default_tool)

        # If args is a dict and your tool expects unpacked values:
        if isinstance(tool_input, dict):
            result = tool_func.invoke(tool_input) if hasattr(tool_func, "invoke") else tool_func(**tool_input)
        else:
            result = tool_func.invoke(tool_input) if hasattr(tool_func, "invoke") else tool_func(tool_input)

        # You can choose to append this to messages, or just save result
        return {
            **state,
            "result": result,
            # Optionally add: "messages": state["messages"] + [ToolMessage(...)]
        }

    # No tool call detected, return state unchanged
    return state

    


# Decide what to do next: if tool call → call_tool, else → end
def should_call_tool(state):
    last_msg = state["messages"][-1]
    if isinstance(last_msg, AIMessage) and last_msg.tool_calls:
        return "call_tool"
    return "end"
    

from typing import TypedDict, List, Optional, Union
from langchain.schema import BaseMessage

class AgentState(TypedDict):
    messages: List[BaseMessage]    # Chat history
    input: str                     # Original input
    intent: str                    # Derived or predicted intent
    result: Optional[str]          # Final or intermediate result






# To store previously asked questions and timestamps (simulating state persistence)
recent_questions = {}

def node_skipper(state: dict) -> bool:
    """
    Determines whether to skip the task based on the state.
    This could include:
    1. Repeated or similar questions
    2. Irrelevant or empty questions
    3. Tasks that have already been processed recently
    """
    question = state.get("question", "").strip()
    
    if not question:
        print("❌ Skipping: Empty or invalid question.")
        return True  # Skip if no valid question

    # 1. Skip if the question has already been asked recently (within a given time window)
    # Here, we're using a simple example with a 5-minute window (300 seconds).
    if question in recent_questions:
        last_asked_time = recent_questions[question]
        time_since_last_ask = time.time() - last_asked_time
        if time_since_last_ask < 300:  # 5-minute threshold
            print(f"❌ Skipping: The question has been asked recently. Time since last ask: {time_since_last_ask:.2f} seconds.")
            return True  # Skip if the question was asked within the last 5 minutes
    
    # 2. Skip if the question is irrelevant or not meaningful enough
    irrelevant_keywords = ["blah", "nothing", "invalid", "nonsense"]
    if any(keyword in question.lower() for keyword in irrelevant_keywords):
        print("❌ Skipping: Irrelevant or nonsense question.")
        return True  # Skip if the question contains irrelevant keywords

    # 3. Skip if the task has already been completed for this question (based on a unique task identifier)
    if "last_response" in state and state["last_response"]:
        print("❌ Skipping: Task has already been processed recently.")
        return True  # Skip if a response has already been given

    # 4. Skip based on a condition related to the task itself
    # Example: Skip math-related tasks if the result is already known or trivial
    if "math" in state.get("question", "").lower():
        # If math is trivial (like "What is 2+2?")
        trivial_math = ["2 + 2", "1 + 1", "3 + 3"]
        if any(trivial_question in question for trivial_question in trivial_math):
            print(f"❌ Skipping trivial math question: {question}")
            return True  # Skip if the math question is trivial
    
    # 5. Skip based on external factors (e.g., current time, system load, etc.)
    # Example: Avoid processing tasks at night if that's part of the business logic
    current_hour = time.localtime().tm_hour
    if current_hour >= 22 or current_hour < 6:
        print("❌ Skipping: It's night time, not processing tasks.")
        return True  # Skip tasks during night time (e.g., between 10 PM and 6 AM)

    # If none of the conditions matched, don't skip the task
    return False

# Update recent questions (for simulating repeated question check)
def update_recent_questions(question: str):
    """Update the recent questions dictionary with the current timestamp."""
    recent_questions[question] = time.time()



def generate_final_answer(state: dict, task_results: dict) -> str:
    """Generate a final answer based on the results of the task."""
    if "wiki_search" in task_results:
        return f"📚 Wiki Summary:\n{task_results['wiki_search']}"
    elif "math" in task_results:
        return f"🧮 Math Result: {task_results['math']}"
    elif "retriever" in task_results:
        return f"🔍 Retrieved Info: {task_results['retriever']}"
    else:
        return "🤖 Unable to generate a specific answer."


def answer_question(question: str) -> str:
    """Process a single question and return the answer."""
    print(f"Processing question: {question[:50]}...")  # Debugging: show first 50 chars

    # Wrap the question in a HumanMessage from langchain_core (assuming langchain is used)
    messages = [HumanMessage(content=question)]
    response = graph.invoke({"messages": messages})  # Assuming `graph` is defined elsewhere
    
    # Extract the answer from the response
    answer = response['messages'][-1].content
    return answer[14:]  # Assuming 'answer[14:]' is correct based on your example


def process_all_tasks(tasks: list):
    """Process a list of tasks."""
    results = {}

    for task in tasks:
        question = task.get("question", "").strip()
        if not question:
            print(f"Skipping task with missing or empty 'question': {task}")
            continue

        print(f"\n🟢 Processing Task: {task['task_id']} - Question: {question}")

        # Call the existing process_question logic
        response = process_question(question)
        
        print(f"✅ Response: {response}")
        results[task['task_id']] = response

    return results





## Langgraph

# Build graph function
vector_store = vector_store.save_local("faiss_index")

provider = "huggingface"

model_config = {
    "repo_id": "HuggingFaceH4/zephyr-7b-beta",
    "task": "text-generation",
    "temperature": 0.7,
    "max_new_tokens": 512,
    "huggingfacehub_api_token": os.getenv("HF_TOKEN")
}

# Get LLM
def get_llm(provider: str, config: dict):
    if provider == "huggingface":
        from langchain_huggingface import HuggingFaceEndpoint
        return HuggingFaceEndpoint(
            repo_id=config["repo_id"],
            task=config["task"],
            huggingfacehub_api_token=config["huggingfacehub_api_token"],
            temperature=config["temperature"],
            max_new_tokens=config["max_new_tokens"]
        )
    else:
        raise ValueError(f"Unsupported provider: {provider}")


def assistant(state: dict):
    return {
        "messages": [llm_with_tools.invoke(state["messages"])]
    }


def tools_condition(state: dict) -> str:
    if "use tool" in state["messages"][-1].content.lower():
        return "tools"
    else:
        return "END"

            

from langgraph.graph import StateGraph
from langchain_core.messages import SystemMessage
from langchain_core.runnables import RunnableLambda
def build_graph(vector_store, provider: str, model_config: dict) -> StateGraph:
    # Get LLM
    llm = get_llm(provider, model_config)

    # Define available tools
    tools = [
        wiki_search, calculator, web_search, arxiv_search,
        get_youtube_transcript, extract_video_id, analyze_attachment, wikidata_query
    ]

    # Tool mapping (global if needed elsewhere)
    global tool_map
    tool_map = {t.name: t for t in tools}

    # Bind tools only if LLM supports it
    if hasattr(llm, "bind_tools"):
        llm_with_tools = llm.bind_tools(tools)
    else:
        llm_with_tools = llm  # fallback for non-tool-aware models

    sys_msg = SystemMessage(content="You are a helpful assistant.")

    # Define nodes as runnables
    retriever = RunnableLambda(lambda state: {
        **state,
        "retrieved_docs": vector_store.similarity_search(state["input"])
    })

    assistant = RunnableLambda(lambda state: {
        **state,
        "messages": [sys_msg] + state["messages"]
    })

    call_llm = llm_with_tools  # already configured

    # Start building the graph
    builder = StateGraph(AgentState)
    builder.add_node("retriever", retriever)
    builder.add_node("assistant", assistant)
    builder.add_node("call_llm", call_llm)
    builder.add_node("call_tool", tool_dispatcher)
    builder.add_node("end", lambda state: state)  # Add explicit end node

    # Define graph flow
    builder.set_entry_point("retriever")
    builder.add_edge("retriever", "assistant")
    builder.add_edge("assistant", "call_llm")

    builder.add_conditional_edges("call_llm", should_call_tool, {
        "call_tool": "call_tool",
        "end": "end"  # ✅ fixed: must point to actual "end" node
    })

    builder.add_edge("call_tool", "call_llm")  # loop back after tool call

    return builder.compile()