from datetime import date, timedelta
from decimal import Decimal

import pytest

from grid_trading.domain.calculations import CalculationError, calculate_positions, estimate_fees
from grid_trading.domain.models import FeeRules, Instrument, Trade, TradeGroup, TradeSide


def make_trade(
    *,
    trade_id: int,
    instrument_id: int = 1,
    trade_date: date,
    side: TradeSide,
    price: str,
    quantity: int,
    commission: str = "0",
    stamp_tax: str = "0",
    transfer_fee: str = "0",
    trade_group: TradeGroup = TradeGroup.GRID,
) -> Trade:
    return Trade(
        id=trade_id,
        account_id=1,
        instrument_id=instrument_id,
        trade_date=trade_date,
        side=side,
        price=Decimal(price),
        quantity=quantity,
        commission=Decimal(commission),
        stamp_tax=Decimal(stamp_tax),
        transfer_fee=Decimal(transfer_fee),
        trade_group=trade_group,
    )


def test_buy_sell_grid_profit_and_breakeven():
    today = date(2026, 7, 8)
    instrument = Instrument(id=1, code="510300", name="沪深300ETF", manual_price=Decimal("9.50"))
    trades = [
        make_trade(
            trade_id=1,
            trade_date=today - timedelta(days=2),
            side=TradeSide.BUY,
            price="10",
            quantity=100,
            commission="1",
            trade_group=TradeGroup.GRID,
        ),
        make_trade(
            trade_id=2,
            trade_date=today - timedelta(days=1),
            side=TradeSide.SELL,
            price="11",
            quantity=100,
            commission="1",
            trade_group=TradeGroup.GRID,
        ),
        make_trade(
            trade_id=3,
            trade_date=today,
            side=TradeSide.BUY,
            price="9",
            quantity=100,
            commission="1",
            trade_group=TradeGroup.BASE,
        ),
    ]

    [summary] = calculate_positions([instrument], trades, as_of=today)

    assert summary.total_quantity == 100
    assert summary.base_quantity == 100
    assert summary.grid_quantity == 0
    assert summary.remaining_cost == Decimal("901.00")
    assert summary.realized_pnl == Decimal("98.00")
    assert summary.grid_profit == Decimal("98.00")
    assert summary.cost_price == Decimal("9.01")
    assert summary.position_breakeven_price == Decimal("8.03")
    assert summary.account_breakeven_price == Decimal("8.03")
    assert summary.market_value == Decimal("950.00")
    assert summary.floating_pnl == Decimal("49.00")


def test_t_plus_one_available_quantity_excludes_today_buys():
    today = date(2026, 7, 8)
    instrument = Instrument(id=1, code="600000", name="浦发银行", manual_price=Decimal("10"))
    trades = [
        make_trade(
            trade_id=1,
            trade_date=today - timedelta(days=1),
            side=TradeSide.BUY,
            price="10",
            quantity=200,
            trade_group=TradeGroup.BASE,
        ),
        make_trade(
            trade_id=2,
            trade_date=today,
            side=TradeSide.BUY,
            price="9.8",
            quantity=100,
            trade_group=TradeGroup.BASE,
        ),
    ]

    [summary] = calculate_positions([instrument], trades, as_of=today)

    assert summary.total_quantity == 300
    assert summary.available_quantity == 200


def test_sell_more_than_group_position_raises():
    today = date(2026, 7, 8)
    instrument = Instrument(id=1, code="159915", name="创业板ETF")
    trades = [
        make_trade(
            trade_id=1,
            trade_date=today - timedelta(days=1),
            side=TradeSide.BUY,
            price="2",
            quantity=100,
            trade_group=TradeGroup.GRID,
        ),
        make_trade(
            trade_id=2,
            trade_date=today,
            side=TradeSide.SELL,
            price="2.1",
            quantity=200,
            trade_group=TradeGroup.GRID,
        ),
    ]

    with pytest.raises(CalculationError, match="Insufficient grid position"):
        calculate_positions([instrument], trades, as_of=today)


def test_estimate_fees_uses_min_commission_and_sell_tax():
    rules = FeeRules(
        commission_rate=Decimal("0.00025"),
        min_commission=Decimal("5"),
        stamp_tax_rate=Decimal("0.0005"),
        transfer_fee_rate=Decimal("0.00001"),
    )

    buy_fees = estimate_fees(TradeSide.BUY, Decimal("10"), 100, rules)
    sell_fees = estimate_fees(TradeSide.SELL, Decimal("10"), 100, rules)

    assert buy_fees.commission == Decimal("5.00")
    assert buy_fees.stamp_tax == Decimal("0.00")
    assert buy_fees.transfer_fee == Decimal("0.01")
    assert sell_fees.commission == Decimal("5.00")
    assert sell_fees.stamp_tax == Decimal("0.50")
    assert sell_fees.transfer_fee == Decimal("0.01")