"""Fee/tax policy tests (REQ-018 CHG-20260612-01, dcy-026, issue #24).

Validates the single fee/tax policy point (`calculate_fee`/`calculate_tax`)
and the paper broker carrying the policy-computed sell transaction tax — the
correction for the `tax=0.0` hardcoding that under-counted realized P&L.
"""
from __future__ import annotations

from trex_core.adapters.broker.paper import PaperBroker
from trex_core.application.broker_port import OrderRequest, calculate_fee, calculate_tax


# --- AC-6/AC-7: policy functions -------------------------------------------

def test_calculate_fee_same_rate_buy_and_sell():
    # 0.015 % commission on both sides (TREX_KIS_FEE_BPS=1.5 default)
    assert calculate_fee("buy", 1_000_000) == 150.0
    assert calculate_fee("sell", 1_000_000) == 150.0


def test_calculate_tax_sell_only():
    # 0.2 % securities transaction tax on sells (TREX_KRX_TAX_SELL_BPS=20.0)
    assert calculate_tax("sell", 1_000_000) == 2000.0
    # buys are tax-free (KR equities)
    assert calculate_tax("buy", 1_000_000) == 0.0


def test_fee_and_tax_zero_for_nonpositive_amount():
    assert calculate_fee("sell", 0) == 0.0
    assert calculate_fee("buy", -100) == 0.0
    assert calculate_tax("sell", 0) == 0.0
    assert calculate_tax("sell", -100) == 0.0


# --- AC-9: issue #24 four-fill regression (expected total 1,376.9원) --------

def test_issue_24_four_fill_regression():
    # (side, price) with qty=1 — from issue #24 evidence (2026-06-11).
    fills = [
        ("buy", 291_500),
        ("sell", 301_000),
        ("buy", 295_000),
        ("sell", 298_500),
    ]
    total_fee = sum(calculate_fee(side, amount) for side, amount in fills)
    total_tax = sum(calculate_tax(side, amount) for side, amount in fills)

    assert round(total_fee, 1) == 177.9
    assert round(total_tax, 1) == 1199.0
    assert round(total_fee + total_tax, 1) == 1376.9


# --- AC-7: paper broker carries policy tax (parity with KIS policy) ---------

def _fill(broker, *, side, symbol, qty, price):
    ack = broker.submit_order(
        OrderRequest(slot_id="s1", side=side, symbol=symbol, qty=qty, limit_price=price)
    )
    fs = broker.poll_fill(ack.broker_order_id, side=side, symbol=symbol)
    assert fs.is_filled
    return fs


def test_paper_sell_fill_carries_policy_tax():
    broker = PaperBroker(fill_after_polls=0)
    fs = _fill(broker, side="sell", symbol="005930", qty=1, price=301_000)
    assert fs.fee == calculate_fee("sell", 301_000)
    assert fs.tax == calculate_tax("sell", 301_000)
    assert fs.tax > 0.0  # the bug: previously hardcoded to 0.0


def test_paper_buy_fill_has_zero_tax():
    broker = PaperBroker(fill_after_polls=0)
    fs = _fill(broker, side="buy", symbol="005930", qty=1, price=291_500)
    assert fs.fee == calculate_fee("buy", 291_500)
    assert fs.tax == 0.0