app.py

import os
import gradio as gr
import pandas as pd
import duckdb
import openai
from transformers import AutoTokenizer, AutoModelForSeq2SeqLM, pipeline
import openai.error

# — Load OpenAI key —
openai.api_key = os.getenv("OPENAI_API_KEY")

# — Prepare DuckDB —
df   = pd.read_csv("synthetic_profit.csv")
conn = duckdb.connect(":memory:"); conn.register("sap", df)
schema = ", ".join(df.columns)

# — Prepare HF fallback pipeline once —
HF_MODEL = "google/flan-t5-small"
hf_tok   = AutoTokenizer.from_pretrained(HF_MODEL)
hf_mod   = AutoModelForSeq2SeqLM.from_pretrained(HF_MODEL)
hf_gen   = pipeline("text2text-generation", model=hf_mod, tokenizer=hf_tok, device=-1)

def generate_sql(question: str) -> str:
    prompt = (
        f"You are an expert SQL generator for DuckDB table `sap` with columns: {schema}.\n"
        f"Translate the user’s question into a valid SQL query. Return ONLY the SQL."
    )
    try:
        resp = openai.chat.completions.create(
            model="gpt-3.5-turbo",
            messages=[
                {"role":"system","content":prompt},
                {"role":"user","content":question}
            ],
            temperature=0.0,
            max_tokens=150,
        )
        sql = resp.choices[0].message.content.strip()
    except openai.error.InvalidRequestError as e:
        # catch non-quota OpenAI errors here if you want
        raise
    except openai.error.RateLimitError as e:
        # 429 fallback to Hugging Face
        fallback_prompt = f"Translate to SQL over `sap({schema})`:\n{question}"
        sql = hf_gen(fallback_prompt, max_length=128)[0]["generated_text"]
    # strip ``` fences if present
    if sql.startswith("```") and sql.endswith("```"):
        sql = "\n".join(sql.splitlines()[1:-1])
    return sql

def answer_profitability(question: str) -> str:
    sql = generate_sql(question)
    try:
        out_df = conn.execute(sql).df()
    except Exception as e:
        return f"❌ SQL error:\n{e}\n\n```sql\n{sql}\n```"
    if out_df.empty:
        return f"No results.\n\n```sql\n{sql}\n```"
    if out_df.shape == (1,1):
        return str(out_df.iat[0,0])
    return out_df.to_markdown(index=False)

iface = gr.Interface(
    fn=answer_profitability,
    inputs=gr.Textbox(lines=2, label="Question"),
    outputs=gr.Textbox(lines=8, label="Answer"),
    title="SAP Profitability Q&A",
    description="Uses OpenAI → DuckDB, falling back to Flan-T5-Small on 429s.",
    allow_flagging="never",
)

if __name__=="__main__":
    iface.launch(server_name="0.0.0.0", server_port=7860)