app.py

from langchain_core.prompts import PromptTemplate
from langchain.chains import create_retrieval_chain
from langchain.chains.combine_documents import create_stuff_documents_chain
# import gradio as gr
import numpy as np
from langchain_ollama import OllamaLLM
from langchain_huggingface import HuggingFaceEmbeddings
# from langchain_community.llms import HuggingFacePipeline
from load_document import load_data
from split_document import split_docs
from embed_docs import embed_docs
from retrieve import retrieve
from datetime import datetime
from js import js
from theme import theme
import os
import glob
from fastapi import FastAPI, Query, Request
from pydantic import BaseModel
import uvicorn


app = FastAPI(title="Know The Law", description="A FastAPI application for legal assistance using AI.")



vector_store_path = "/home/user/VectorStoreDB"
index_name = "faiss_index"
full_index_path = os.path.join(vector_store_path, index_name)

# # Create the embedder with a specific model
embedder = HuggingFaceEmbeddings(model_name="sentence-transformers/all-MiniLM-L6-v2")

# # Initialize our speech pipeline
# transcriber = pipeline("automatic-speech-recognition", model="openai/whisper-base.en", device="cpu")




def fetch_doc():
    # Adjust the path as needed, e.g., './' for current directory
    pdf_files = glob.glob("*.pdf")

    return pdf_files

# # Define llm
#hf_token = os.environ.get("HF_TOKEN").strip()  # Ensure to set your Hugging Face token in the environment variable HF_TOKEN
llm = OllamaLLM(model="llama3.2", base_url="http://localhost:11434")

pdf_files = fetch_doc() #Fetch Dataset
chunks = None
loaded_docs = []
# just query if it exists
if not os.path.exists(full_index_path):
    for doc in pdf_files:
        print(f"Loading.....{doc}")
        docs = load_data(doc) #Load Dataset
        loaded_docs.append(docs)
    final_docs = [item for sublist in loaded_docs for item in sublist] # Flatten the list    
    chunks = split_docs(final_docs, embedder=embedder) #Split Document
saved_vector = embed_docs(chunks, embedder=embedder) #Embed Document
retrieved = retrieve(saved_vector) # Retrieve simimlar docs

# Define the prompt template
prompt = """
You are The Law Assistant, an AI trained to help Nigerians understand their legal rights and obligations. Using the provided context below, answer user questions related to Nigerian law.

Instructions:

1. Base your responses strictly on the given context or verified legal sources.

2. If the answer is not in the context and you're unsure, respond with: "I don't know based on the available information." Do not fabricate or speculate.

3. Keep your answers clear, concise, and jargon-free.

4. Always cite the legal source(s) or reference(s) you used (e.g., constitution section, legal act, court ruling).

Context: {context}
Question: {{question}}

Helpful Answer:"""


QA_CHAIN_PROMPT = PromptTemplate.from_template(template=prompt)

# Create document prompt
document_prompt = PromptTemplate(
    input_variables=["page_content", "source"],
    template="Context:\ncontent:{page_content}\nsource:{source}",
)

# Create the stuff documents chain
combine_docs_chain = create_stuff_documents_chain(
    llm,
    QA_CHAIN_PROMPT,
    document_prompt=document_prompt
)

# Create the retrieval chain
qa_chain = create_retrieval_chain(
    retriever=retrieved,
    combine_docs_chain=combine_docs_chain
)

class QueryRequest(BaseModel):
    question: str

@app.get("/")
def home():
    print("Testing Ollama LLM response...")
    try:
        response = llm.invoke("What is the capital of Nigeria?")
        print("Response:", response)
    except Exception as e:
        print("Failed to invoke model:", e)
    return {"message": "Welcome to the Know The Law API. Use POST /query to ask legal questions."}

@app.post("/query")
def respond(query: QueryRequest):
    question = query.question
    try:
        result = qa_chain.invoke({"input": question})
        return {"answer": result['answer']}
    except Exception as e:
        # Log the exception in detail
        import traceback
        traceback.print_exc()
        return {"error": str(e)}