from __future__ import annotations

import pytest

from app.engine.risk import RiskManager


def test_daily_loss_detects_and_halts() -> None:
    risk = RiskManager(max_daily_loss=100.0)
    risk.reset(10_000)
    assert risk.update(9_950) is None
    reason = risk.update(9_900)
    assert reason is not None and "daily loss" in reason
    assert risk.halted is False  # detection only; caller decides
    risk.halt(reason)
    assert risk.halted is True
    assert risk.can_enter() is False


def test_drawdown_halts() -> None:
    risk = RiskManager(max_drawdown_pct=10.0)
    risk.reset(10_000)
    risk.update(11_000)
    assert risk.update(10_000) is None
    reason = risk.update(9_850)
    assert reason is not None and "drawdown" in reason
    risk.halt(reason)
    assert risk.halted


def test_halt_is_sticky() -> None:
    risk = RiskManager(max_daily_loss=100.0)
    risk.reset(10_000)
    reason = risk.update(9_800)
    risk.halt(reason or "loss")
    assert risk.halted
    # A recovery must not silently resume trading.
    assert risk.update(10_500) is not None
    assert risk.halted


def test_max_trades_per_day() -> None:
    risk = RiskManager(max_trades_per_day=2)
    risk.reset(10_000)
    assert risk.can_enter()
    risk.record_entry()
    risk.record_entry()
    assert risk.can_enter() is False
    assert "max trades" in (risk.entry_block_reason() or "")


def test_clamp_size() -> None:
    risk = RiskManager(max_position_pct=0.25)
    assert risk.clamp_size(1.0) == pytest.approx(0.25)
    assert risk.clamp_size(0.1) == pytest.approx(0.1)
    assert risk.clamp_size(-1.0) == pytest.approx(0.0)


def test_disabled_limits_never_halt() -> None:
    risk = RiskManager()
    risk.reset(10_000)
    assert risk.update(1.0) is None
    assert risk.can_enter()