from __future__ import annotations

from app.engine.strategies import get_strategy, list_strategies, strategy_spec
from app.engine.strategies.base import StrategyContext
from app.models import Position, PositionSide
from app.schemas import Candle


def make_candles(closes: list[float]) -> list[Candle]:
    return [Candle(ts=i, open=c, high=c, low=c, close=c, volume=1.0) for i, c in enumerate(closes)]


def test_examples_are_registered() -> None:
    keys = {cls.key for cls in list_strategies()}
    assert {"sma_cross", "rsi_reversion"} <= keys


def test_param_specs_expose_defaults() -> None:
    spec = strategy_spec(get_strategy("sma_cross"))
    names = {param.name for param in spec.params}
    assert {"fast", "slow", "size"} == names
    fast = next(param for param in spec.params if param.name == "fast")
    assert fast.default == 10
    assert fast.type == "int"


def test_unknown_params_rejected() -> None:
    cls = get_strategy("sma_cross")
    import pytest

    with pytest.raises(ValueError):
        cls({"nope": 1})


def test_sma_cross_emits_enter_long() -> None:
    strategy = get_strategy("sma_cross")({"fast": 2, "slow": 4, "size": 0.5})
    ctx = StrategyContext(
        candles=make_candles([10, 10, 10, 10, 10, 11]),
        position=None,
        equity=1000,
        cash=1000,
    )
    strategy.on_candle(ctx)
    intents = ctx.take_intents()
    assert len(intents) == 1
    assert intents[0].action == "enter_long"
    assert intents[0].size == 0.5


def test_sma_cross_emits_close_on_cross_down() -> None:
    strategy = get_strategy("sma_cross")({"fast": 2, "slow": 4, "size": 0.5})
    position = Position(
        strategy_key="sma_cross",
        symbol="BTC/USDT",
        side=PositionSide.LONG,
        qty=1.0,
        entry_price=10.0,
    )
    ctx = StrategyContext(
        candles=make_candles([10, 10, 10, 10, 10, 11, 8]),
        position=position,
        equity=1000,
        cash=1000,
    )
    strategy.on_candle(ctx)
    intents = ctx.take_intents()
    assert len(intents) == 1
    assert intents[0].action == "close"