import pytest
import pytest_asyncio
from decimal import Decimal
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
from app.models.entities import Base, LedgerEntryType
from app.domains.ledger.service import LedgerService, InsufficientBalanceError

TEST_DATABASE_URL = "sqlite+aiosqlite:///:memory:"

@pytest_asyncio.fixture
async def test_session():
    engine = create_async_engine(TEST_DATABASE_URL, echo=False)
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)

    session_maker = async_sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
    async with session_maker() as session:
        yield session

    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
    await engine.dispose()

@pytest.mark.asyncio
async def test_ledger_deposit_flow(test_session: AsyncSession):
    ledger = LedgerService(test_session)
    user = "0x6cddF384792C77219fc25C454Cfe264757842830"

    # 1. 初始余额为 0
    bal = await ledger.get_or_create_balance(user)
    assert bal.available_balance == Decimal("0")

    # 2. 存入 1000 WUSD
    entry = await ledger.record_deposit(user, Decimal("1000"), "0xtx1")
    assert entry.entry_type == LedgerEntryType.DEPOSIT
    assert entry.amount == Decimal("1000")
    assert entry.balance_after == Decimal("1000")

    bal = await ledger.get_or_create_balance(user)
    assert bal.available_balance == Decimal("1000")

@pytest.mark.asyncio
async def test_ledger_trade_and_insufficient_balance(test_session: AsyncSession):
    ledger = LedgerService(test_session)
    user = "0x6cddF384792C77219fc25C454Cfe264757842830"

    # 充值 500 WUSD
    await ledger.record_deposit(user, Decimal("500"), "0xtx1")

    # 尝试买入 600 WUSD (超额报错)
    with pytest.raises(InsufficientBalanceError):
        await ledger.record_trade(
            address=user,
            market_address="0xmarket1",
            order_id="order_1",
            side="BUY",
            amount=Decimal("600"),
            fee=Decimal("3.6")
        )

    # 成功买入 100 WUSD (扣除 100 + 0.6 手续费)
    entry = await ledger.record_trade(
        address=user,
        market_address="0xmarket1",
        order_id="order_2",
        side="BUY",
        amount=Decimal("100"),
        fee=Decimal("0.6")
    )
    assert entry.entry_type == LedgerEntryType.TRADE_BUY
    assert entry.amount == Decimal("-100.6")
    assert entry.balance_after == Decimal("399.4")

    # 验证不可变流水历史条数
    history = await ledger.list_user_ledger(user)
    assert len(history) == 2