instrument_utils.py

import pandas as pd
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent
NSE_PATH = BASE_DIR / "instruments_nse.csv"
NFO_PATH = BASE_DIR / "instruments_nfo.csv"


def load_nse_instruments():
    if not NSE_PATH.exists():
        raise FileNotFoundError("instruments_nse.csv not found. Run main.py first.")
    return pd.read_csv(NSE_PATH)


def load_nfo_instruments():
    if not NFO_PATH.exists():
        raise FileNotFoundError("instruments_nfo.csv not found. Run main.py first.")
    return pd.read_csv(NFO_PATH)


def find_nse_symbol(symbol: str):
    df = load_nse_instruments()
    out = df[df["tradingsymbol"].astype(str).str.upper() == symbol.upper()].copy()
    return out


def find_nfo_by_name(name: str):
    df = load_nfo_instruments()
    out = df[df["name"].astype(str).str.upper() == name.upper()].copy()
    return out


def find_nearest_options(underlying: str, option_type: str = None):
    df = load_nfo_instruments().copy()

    df = df[df["name"].astype(str).str.upper() == underlying.upper()]
    df = df[df["instrument_type"].isin(["CE", "PE"])]

    if option_type:
        df = df[df["instrument_type"].astype(str).str.upper() == option_type.upper()]

    if df.empty:
        return df

    df["expiry"] = pd.to_datetime(df["expiry"], errors="coerce")
    df = df.sort_values(["expiry", "strike"])
    return df