app.py

import os
import gradio as gr
from dotenv import load_dotenv, find_dotenv
from langchain.utilities.sql_database import SQLDatabase
from langchain_google_genai import ChatGoogleGenerativeAI
from langchain.chat_models.anthropic import ChatAnthropic
from langchain_core.prompts import ChatPromptTemplate
from langchain.agents import create_sql_agent, AgentType
from langchain_core.output_parsers import StrOutputParser
from langchain_core.runnables import RunnablePassthrough
from langchain_core.tracers import ConsoleCallbackHandler
from langchain.agents.agent_toolkits.sql.toolkit import SQLDatabaseToolkit
from huggingface_hub import login
from langchain.globals import set_verbose
from sqlalchemy import create_engine
from prompts import agent_template, table_info
set_verbose(True)

# load_dotenv(find_dotenv(r".env"))

def load_model(model_id):
    if model_id == "gemini":
        return ChatGoogleGenerativeAI(
            model='gemini-pro',
            google_api_key=os.getenv("GOOGLE_API_KEY"),
            convert_system_message_to_human=True,
            temperature=0.05,
            verbose=True,
        )
    elif model_id == "claude":
        return ChatAnthropic(
            model_name="claude-2",
            anthropic_api_key=os.getenv("ANTHROPIC_API_KEY"),
            temperature=0.05,
            streaming=True,
            verbose=True,
        )
    else:
        print("only gemini and claude supported aofn")

def chain(db, llm):
    
    def get_schema(_):
        return db.get_table_info()
    def run_query(query):
        return db.run(query)
    
    template = """Based on the table schema below, write a MS SQL query that would answer the user's question:
    {schema}
    Question: {question}
    Query:"""
    
    prompt = ChatPromptTemplate.from_messages(
        [
            ("system", "Given an input question, convert it to a MSSQL query. No pre-amble."),
            ("human", template),
        ]
    )
        
    template = """Based on the table schema below, question, mssql query, and mssql response, write a natural language response:
    {schema}
        
    Question: {question}
    MS-SQL Query: {query}
    MS-SQL Response: {response}"""
        
    prompt_response = ChatPromptTemplate.from_messages(
        [
            ("system", "Given an input question and MS-SQL response, convert it to a natural language answer. No pre-amble."),
            ("human", template),
        ]
    )
        
    sql_response = (
        RunnablePassthrough.assign(schema=get_schema)
        | prompt
        | llm.bind(stop=["\nSQLResult:"])
        | StrOutputParser()
    )
    full_chain = (
        RunnablePassthrough.assign(query=sql_response)
        | RunnablePassthrough.assign(
            schema=get_schema,
            response=lambda x: db.run(x["query"]),
        )
        | prompt_response
        | llm
    )
    
    return full_chain

def main():
    gemini = load_model("gemini")
    agent_llm = load_model("claude")
    
    path = r"OPPI_shift.db"       # \OPPI_down.db"
    db1 = SQLDatabase.from_uri(f"sqlite:///{path}", include_tables=['ShiftDownTimeDetails'],sample_rows_in_table_info=0)
    db2 = SQLDatabase.from_uri(f"sqlite:///{path}", include_tables=['ShiftProductionDetails'],sample_rows_in_table_info=0)
    db3 = SQLDatabase.from_uri(f"sqlite:///{path}", include_tables=['ShiftDownTimeDetails','ShiftProductionDetails'],sample_rows_in_table_info=0)
    
    down_chain = chain(db=db1, llm=gemini)
    prod_chain = chain(db=db2, llm=gemini)
    
    def echo1(message, history):
        ans = down_chain.invoke({"question":message}, config={"callbacks": [ConsoleCallbackHandler()]})
        return str(ans)
    
    def echo2(message, history):
        ans = prod_chain.invoke({"question":message}, config={"callbacks": [ConsoleCallbackHandler()]})
        return str(ans)
    
    prompt_agent = ChatPromptTemplate.from_messages(
        [ 
            ("system", "Given an input question, create a syntactically correct MS-SQL query to run, then look at the results of the query and return the answer in natural language. No Pre-amble."+agent_template),
            ("human", "{question}"+table_info)
        ]
    )
    sql_toolkit = SQLDatabaseToolkit(db=db3, llm=agent_llm)
    agent = create_sql_agent(
        toolkit=sql_toolkit,
        llm=agent_llm,
        agent_type=AgentType.ZERO_SHOT_REACT_DESCRIPTION,
        verbose=True,
        agent_executor_kwargs={"handle_parsing_errors":True}
    )

    def echo3(message, history):
        answer = agent.invoke(prompt_agent.format_prompt(question=message))
        return answer['output']
    
    downtime = gr.ChatInterface(fn=echo1, title="SQL-Chatbot", description="Q/A on Downtime details table")
    production = gr.ChatInterface(fn=echo2, title="SQL-Chatbot", description="Q/A on Production details table")
    agent_tab = gr.ChatInterface(fn=echo3, title="SQL-Chatbot", description="General Chatbot with self-thinking capability, more robust to questions.")
    demo = gr.TabbedInterface([agent_tab, downtime, production], ['DB_bot-both tables','ShiftDownTimeDetails', 'ShiftProductionDetails'])
    demo.launch(debug=True)

if __name__ == "__main__":
    main()