app.py

import os
import sqlite3
import requests
import openai
import gradio as gr
import asyncio
from langgraph import Graph, FunctionNode, RouterNode
from gtts import gTTS

def stt_agent(audio_path: str) -> str:
    """Convert speech to text using OpenAI Whisper API"""
    with open(audio_path, "rb") as afile:
        transcript = openai.audio.transcriptions.create(
            model="whisper-1",
            file=afile
        )
    return transcript.text.strip()

# Load API keys from environment
openai.api_key = os.getenv("OPENAI_API_KEY")

# --- Business Logic Functions ---
def db_agent(query: str) -> str:
    try:
        conn = sqlite3.connect("shop.db")
        cur = conn.cursor()
        if "max revenue" in query.lower():
            cur.execute(
                """
                SELECT product, SUM(amount) AS revenue
                FROM transactions
                WHERE date = date('now')
                GROUP BY product
                ORDER BY revenue DESC
                LIMIT 1
                """
            )
            row = cur.fetchone()
            if row:
                return f"Top product today: {row[0]} with ₹{row[1]:,.2f}"
            return "No transactions found for today."
        return None
    except sqlite3.OperationalError as e:
        return f"Database error: {e}. Please initialize 'transactions' table in shop.db."  

def web_search_agent(query: str) -> str:
    try:
        resp = requests.get(
            "https://serpapi.com/search",
            params={"q": query, "api_key": os.getenv("SERPAPI_KEY")}  
        )
        snippet = resp.json().get("organic_results", [{}])[0].get("snippet", "").strip()
        if snippet:
            return llm_agent(f"Summarize: {snippet}")
    except Exception:
        pass
    return llm_agent(query)

def llm_agent(query: str) -> str:
    response = openai.chat.completions.create(
        model="gpt-4o-mini",
        messages=[
            {"role": "system", "content": "You are a helpful assistant."},
            {"role": "user", "content": query},
        ],
        temperature=0.2,
    )
    return response.choices[0].message.content.strip()

# Text-to-Speech

def tts_agent(text: str, lang: str = 'en') -> str:
    """Convert text to speech mp3 and return filepath"""
    tts = gTTS(text=text, lang=lang)
    out_path = "response_audio.mp3"
    tts.save(out_path)
    return out_path

# --- LangGraph Multi-Agent Setup ---
router_node = RouterNode(
    name="router",
    routes=[
        (lambda q: any(k in q.lower() for k in ["max revenue", "revenue"]), "db"),
        (lambda q: any(k in q.lower() for k in ["who", "what", "when", "where"]), "web"),
        (lambda q: True, "llm"),
    ]
)

db_node = FunctionNode(func=db_agent, name="db")
web_node = FunctionNode(func=web_search_agent, name="web")
llm_node = FunctionNode(func=llm_agent, name="llm")

# Build Graph
graph = Graph("shop-assistant")
graph.add_nodes([router_node, db_node, web_node, llm_node])
graph.add_edge("router", "db", condition=lambda r: r == "db")
graph.add_edge("router", "web", condition=lambda r: r == "web")
graph.add_edge("router", "llm", condition=lambda r: r == "llm")

async def graph_handler(query: str) -> str:
    # If audio file path passed, convert to text first
    if query.startswith("audio://"):
        audio_path = query.replace("audio://", "")
        query = stt_agent(audio_path)
    text_resp = await graph.run(input=query, start_node="router")
    return text_resp

def handle_query(audio_or_text: str):
    # Determine output type
    is_audio = audio_or_text.endswith('.wav') or audio_or_text.endswith('.mp3')
    text_input = f"audio://{audio_or_text}" if is_audio else audio_or_text
    text_resp = asyncio.run(graph_handler(text_input))
    if is_audio:
        # Return both text and audio
        audio_path = tts_agent(text_resp)
        return text_resp, audio_path
    return text_resp

# --- Gradio UI ---
with gr.Blocks() as demo:
    gr.Markdown("## Shop Voice-Box Assistant (Speech In/Out)")
    inp = gr.Audio(source="microphone", type="filepath", label="Speak or type your question")
    out_text = gr.Textbox(label="Answer (text)")
    out_audio = gr.Audio(label="Answer (speech)")
    submit = gr.Button("Submit")
    # Examples
    gr.Examples(
        examples=[
            ["What is the max revenue product today?"],
            ["Who invented the light bulb?"],
            ["Tell me a joke about cats."],
        ],
        inputs=inp,
        outputs=[out_text, out_audio],
    )
    submit.click(fn=handle_query, inputs=inp, outputs=[out_text, out_audio])

if __name__ == "__main__":
    demo.launch(share=False, server_name="0.0.0.0", server_port=7860)