from dataclasses import dataclass


DEFAULT_SYMBOL = "/ES"


@dataclass(frozen=True)
class Instrument:
    id: str
    yahoo_symbol: str
    schwab_symbol: str
    tick: float
    decimals: int = 2
    session: str = "globex_18_17"
    rth: str = "spy_rth"

    def snap(self, price: float) -> float:
        return round(round(price / self.tick) * self.tick, self.decimals)

    def payload(self) -> dict:
        return {
            "id": self.id,
            "yahoo_symbol": self.yahoo_symbol,
            "schwab_symbol": self.schwab_symbol,
            "tick": self.tick,
            "decimals": self.decimals,
            "session": self.session,
            "rth": self.rth,
        }


INSTRUMENTS = {
    "es": Instrument("es", "ES=F", "/ES", 0.25, rth="spy_rth"),
    "nq": Instrument("nq", "NQ=F", "/NQ", 0.25, rth="spy_rth"),
    "gc": Instrument("gc", "GC=F", "/GC", 0.10, rth="none"),
    "cl": Instrument("cl", "CL=F", "/CL", 0.01, rth="nymex_day"),
}


def get_instrument(instrument_id: str) -> Instrument:
    try:
        return INSTRUMENTS[instrument_id]
    except KeyError:
        raise ValueError(f"Unknown instrument: {instrument_id}") from None


def instrument_for_symbol(symbol: str) -> Instrument:
    for instrument in INSTRUMENTS.values():
        if symbol in (instrument.id, instrument.schwab_symbol, instrument.yahoo_symbol):
            return instrument
    return INSTRUMENTS["es"]