from __future__ import annotations

import json

from smolagents import tool

from market_data.providers import get_option_chain, list_option_expirations

from .builder import generate_volatility_strategies
from .payoff import strategy_summary


@tool
def build_volatility_strategy(
    symbol: str,
    volatility_view: str = "neutral",
    directional_view: str = "neutral",
    near_expiration: str = "",
    far_expiration: str = "",
) -> str:
    """Build candidate volatility option strategies from the current option chain.

    Args:
        symbol: Yahoo Finance ticker.
        volatility_view: long_vol, short_vol, vol_expansion, vol_compression, term_structure, or neutral.
        directional_view: bullish, bearish, neutral, or range_bound.
        near_expiration: Near option expiration in YYYY-MM-DD. Empty uses nearest expiration.
        far_expiration: Far option expiration for calendar spreads. Empty uses a later available expiration.
    """
    try:
        symbol = symbol.strip().upper()
        expirations = list_option_expirations(symbol)
        if not expirations:
            raise ValueError(f"No option expirations found for {symbol}.")
        near = near_expiration or expirations[0]
        far = far_expiration or (expirations[1] if len(expirations) > 1 else "")
        near_chain = get_option_chain(symbol, near)
        far_chain = get_option_chain(symbol, far) if far else None
        strategies = generate_volatility_strategies(
            near_chain=near_chain,
            volatility_view=volatility_view,
            directional_view=directional_view,
            far_chain=far_chain,
        )
        return json.dumps(
            {
                "status": "success",
                "symbol": symbol,
                "near_expiration": near,
                "far_expiration": far or None,
                "strategies": [
                    {
                        **strategy.to_dict(),
                        "payoff_summary": strategy_summary(strategy),
                    }
                    for strategy in strategies
                ],
                "risk_note": (
                    "This is research output, not a trade recommendation. "
                    "Validate quotes, liquidity, margin, assignment risk, and event risk before trading."
                ),
            },
            ensure_ascii=False,
            indent=2,
            default=str,
        )
    except Exception as exc:
        return json.dumps(
            {"status": "error", "symbol": symbol, "message": str(exc)},
            ensure_ascii=False,
            indent=2,
        )