from datetime import date, timedelta
from decimal import Decimal

import pytest

from grid_trading.domain.models import Instrument, QuoteSnapshot, Trade, TradeGroup, TradeSide
from grid_trading.services.trading_service import TradingService


class FakeQuoteProvider:
    def fetch_quotes(self, instruments):
        return {
            "510300": QuoteSnapshot(
                symbol="sh510300",
                code="510300",
                name="沪深300ETF",
                price=Decimal("4.12"),
                source="tencent",
                quote_time="20260708150000",
            )
        }


def test_service_creates_default_account_and_computes_summary(tmp_path):
    service = TradingService(tmp_path / "grid.db")
    service.ensure_defaults()
    account = service.get_active_account()
    assert account.name == "默认账户"

    account = service.save_account(account.__class__(id=account.id, name="主账户", initial_cash=Decimal("100000")))
    instrument = service.add_instrument(
        Instrument(id=None, code="510300", name="沪深300ETF", market="ETF", manual_price=Decimal("4.00"))
    )
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 7),
            side=TradeSide.BUY,
            price=Decimal("3.90"),
            quantity=1000,
            commission=Decimal("5"),
            trade_group=TradeGroup.GRID,
        )
    )
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 8),
            side=TradeSide.SELL,
            price=Decimal("4.10"),
            quantity=500,
            commission=Decimal("5"),
            stamp_tax=Decimal("1.03"),
            trade_group=TradeGroup.GRID,
        )
    )

    positions = service.get_position_summaries(as_of=date(2026, 7, 8))
    summary = service.get_account_summary(as_of=date(2026, 7, 8))

    assert len(positions) == 1
    assert positions[0].total_quantity == 500
    assert positions[0].current_price is None
    assert positions[0].price_source == "missing"
    assert positions[0].grid_profit == Decimal("91.47")
    assert summary.cash == Decimal("98138.97")
    assert summary.market_value == Decimal("0.00")
    assert summary.total_assets == Decimal("98138.97")


def test_service_validates_lot_size_and_available_sell_quantity(tmp_path):
    service = TradingService(tmp_path / "grid.db")
    service.ensure_defaults()
    account = service.get_active_account()
    instrument = service.add_instrument(Instrument(id=None, code="600000", name="浦发银行"))

    with pytest.raises(ValueError, match="100"):
        service.save_trade(
            Trade(
                id=None,
                account_id=account.id,
                instrument_id=instrument.id,
                trade_date=date(2026, 7, 8),
                side=TradeSide.BUY,
                price=Decimal("10"),
                quantity=50,
                trade_group=TradeGroup.BASE,
            )
        )

    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 8),
            side=TradeSide.BUY,
            price=Decimal("10"),
            quantity=100,
            trade_group=TradeGroup.BASE,
        )
    )

    with pytest.raises(ValueError, match="T\\+1"):
        service.save_trade(
            Trade(
                id=None,
                account_id=account.id,
                instrument_id=instrument.id,
                trade_date=date(2026, 7, 8),
                side=TradeSide.SELL,
                price=Decimal("10.1"),
                quantity=100,
                trade_group=TradeGroup.BASE,
            )
        )

    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 8) - timedelta(days=1),
            side=TradeSide.BUY,
            price=Decimal("9.9"),
            quantity=100,
            trade_group=TradeGroup.BASE,
        )
    )
    saved_sell = service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 8),
            side=TradeSide.SELL,
            price=Decimal("10.1"),
            quantity=100,
            trade_group=TradeGroup.BASE,
        )
    )

    assert saved_sell.id is not None


def test_service_rejects_historical_changes_that_break_future_sells(tmp_path):
    service = TradingService(tmp_path / "grid.db")
    service.ensure_defaults()
    account = service.get_active_account()
    instrument = service.add_instrument(Instrument(id=None, code="159915", name="创业板ETF"))
    buy = service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 7),
            side=TradeSide.BUY,
            price=Decimal("2.00"),
            quantity=200,
            trade_group=TradeGroup.GRID,
        )
    )
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 8),
            side=TradeSide.SELL,
            price=Decimal("2.10"),
            quantity=200,
            trade_group=TradeGroup.GRID,
        )
    )

    with pytest.raises(ValueError, match="后续成交"):
        service.update_trade(
            Trade(
                id=buy.id,
                account_id=account.id,
                instrument_id=instrument.id,
                trade_date=date(2026, 7, 7),
                side=TradeSide.BUY,
                price=Decimal("2.00"),
                quantity=100,
                trade_group=TradeGroup.GRID,
            )
        )

    with pytest.raises(ValueError, match="后续成交"):
        service.delete_trade(buy.id)


def test_service_refresh_quotes_uses_realtime_price_in_summaries(tmp_path):
    service = TradingService(tmp_path / "grid.db", quote_provider=FakeQuoteProvider())
    service.ensure_defaults()
    account = service.get_active_account()
    instrument = service.add_instrument(
        Instrument(id=None, code="510300", name="沪深300ETF", market="ETF", manual_price=Decimal("3.90"))
    )
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 7),
            side=TradeSide.BUY,
            price=Decimal("4.00"),
            quantity=1000,
            trade_group=TradeGroup.BASE,
        )
    )

    quotes = service.refresh_quotes()
    [position] = service.get_position_summaries(as_of=date(2026, 7, 8))
    summary = service.get_account_summary(as_of=date(2026, 7, 8))

    assert quotes["510300"].price == Decimal("4.12")
    assert position.current_price == Decimal("4.12")
    assert position.price_source == "tencent"
    assert summary.market_value == Decimal("4120.00")


def test_service_generates_grid_level_suggestions_from_realtime_price(tmp_path):
    service = TradingService(tmp_path / "grid.db", quote_provider=FakeQuoteProvider())
    service.ensure_defaults()
    account = service.get_active_account()
    instrument = service.add_instrument(Instrument(id=None, code="510300", name="沪深300ETF", market="ETF"))
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 7),
            side=TradeSide.BUY,
            price=Decimal("4.00"),
            quantity=1000,
            trade_group=TradeGroup.BASE,
        )
    )
    service.refresh_quotes()

    levels = service.get_grid_level_suggestions(instrument.id, levels=2)

    assert [item.buy_price for item in levels] == [Decimal("4.00"), Decimal("3.88")]
    assert [item.sell_price for item in levels] == [Decimal("4.12"), Decimal("4.00")]
    assert [item.buy_amount for item in levels] == [Decimal("5000.00"), Decimal("5000.00")]
    assert [item.suggested_quantity for item in levels] == [1200, 1200]


def test_service_returns_empty_grid_levels_without_realtime_price(tmp_path):
    service = TradingService(tmp_path / "grid.db")
    service.ensure_defaults()
    instrument = service.add_instrument(Instrument(id=None, code="510300", name="沪深300ETF", market="ETF"))

    assert service.get_grid_level_suggestions(instrument.id, levels=10) == []


def test_service_returns_open_grid_lots_with_suggested_sell_price(tmp_path):
    service = TradingService(tmp_path / "grid.db", quote_provider=FakeQuoteProvider())
    service.ensure_defaults()
    account = service.get_active_account()
    instrument = service.add_instrument(Instrument(id=None, code="510300", name="沪深300ETF", market="ETF"))
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 7),
            side=TradeSide.BUY,
            price=Decimal("4.00"),
            quantity=1000,
            trade_group=TradeGroup.GRID,
        )
    )
    service.save_trade(
        Trade(
            id=None,
            account_id=account.id,
            instrument_id=instrument.id,
            trade_date=date(2026, 7, 8),
            side=TradeSide.SELL,
            price=Decimal("4.12"),
            quantity=400,
            trade_group=TradeGroup.GRID,
        )
    )
    service.refresh_quotes()

    [lot] = service.get_open_grid_lots(instrument.id, as_of=date(2026, 7, 9))

    assert lot.buy_price == Decimal("4.00")
    assert lot.remaining_quantity == 600
    assert lot.suggested_sell_price == Decimal("4.12")
    assert lot.current_price == Decimal("4.12")
    assert lot.status == "可卖"