"""2026-10-09 db_worker 하드닝 회귀: DLQ 경보, 비차단 백오프/회로, 추가매수 remaining_pct 불변식."""
import asyncio
from types import SimpleNamespace

import pytest

import app.services.db_worker as dbw
from app.core import log_throttle


def _run(coro):
    return asyncio.run(coro)


@pytest.fixture(autouse=True)
def _iso(monkeypatch, tmp_path):
    log_throttle.reset_for_tests()
    monkeypatch.setattr(dbw, "DLQ_DIR", tmp_path / "dlq")
    monkeypatch.setattr(dbw, "_db_task_queue", None)
    yield
    log_throttle.reset_for_tests()


# ── 1. DLQ 텔레그램 ──────────────────────────────────────────────────────────
def test_save_to_dlq_sends_throttled_telegram(monkeypatch):
    sent = []

    async def fake_send(category, message):
        sent.append((category, message))

    monkeypatch.setattr(dbw, "_send_alert_impl", fake_send)

    async def go():
        await dbw._save_to_dlq({"type": "close_active_trade", "data": {}}, "boom")
        await dbw._save_to_dlq({"type": "close_active_trade", "data": {}}, "boom")
        await asyncio.sleep(0.05)

    _run(go())
    assert len(sent) == 1 and sent[0][0] == "DLQ"  # throttle
    assert len(list(dbw.DLQ_DIR.glob("*.json"))) == 2


def test_dlq_write_failure_alerts(monkeypatch):
    sent = []

    async def fake_send(category, message):
        sent.append(message)

    monkeypatch.setattr(dbw, "_send_alert_impl", fake_send)

    def bad(*a, **k):
        raise OSError("disk full")

    monkeypatch.setattr(dbw, "DLQ_DIR", type("P", (), {"mkdir": bad, "__truediv__": bad})())

    async def go():
        await dbw._save_to_dlq({"type": "upsert_stock_ban", "data": {}}, "x")
        await asyncio.sleep(0.05)

    _run(go())
    assert len(sent) == 1 and "유실" in sent[0]


# ── 2. 비차단 백오프 ─────────────────────────────────────────────────────────
def test_failed_task_does_not_block_following_tasks(monkeypatch):
    done = []

    async def fake_exec(task):
        if task["type"] == "bad":
            raise RuntimeError("db down")
        done.append(task["type"])

    monkeypatch.setattr(dbw, "_execute_db_task_impl", fake_exec)

    async def fake_dlq(task, err):
        return None

    monkeypatch.setattr(dbw, "_save_to_dlq", fake_dlq)
    monkeypatch.setattr(dbw, "CIRCUIT_OPEN_FAILURES", 999)

    async def go():
        q = dbw.get_db_task_queue()
        w = asyncio.ensure_future(dbw.db_writer_worker())
        await q.put({"type": "bad", "data": {}})
        await q.put({"type": "good1", "data": {}})
        await q.put({"type": "good2", "data": {}})
        await asyncio.sleep(0.2)  # 백오프 최소 1초 — 그 안에 정상 태스크는 처리돼야 한다
        snapshot = list(done)
        w.cancel()
        try:
            await w
        except asyncio.CancelledError:
            pass
        return snapshot

    assert _run(go()) == ["good1", "good2"]


def test_circuit_open_keeps_retry_count(monkeypatch):
    async def fake_exec(task):
        raise RuntimeError("db down")

    monkeypatch.setattr(dbw, "_execute_db_task_impl", fake_exec)
    monkeypatch.setattr(dbw, "CIRCUIT_OPEN_FAILURES", 2)
    monkeypatch.setattr(dbw, "CIRCUIT_RETRY_DELAY_SEC", 0.01)
    dropped = []

    async def fake_dlq(task, err):
        dropped.append(task)

    monkeypatch.setattr(dbw, "_save_to_dlq", fake_dlq)

    async def fake_one(task, started):  # 종료 drain 은 별개 — 여기서는 워커 루프 중 DLQ 만 본다
        return None

    monkeypatch.setattr(dbw, "_drain_one_impl", fake_one)

    async def go():
        q = dbw.get_db_task_queue()
        w = asyncio.ensure_future(dbw.db_writer_worker())
        t = {"type": "x", "data": {}}
        await q.put(t)
        await q.put({"type": "y", "data": {}})  # 연속 실패 2회 → 회로 열림
        await asyncio.sleep(0.3)
        rc = t.get("_retry_count", 0)
        state = dbw.get_worker_health_v2()
        w.cancel()
        try:
            await w
        except asyncio.CancelledError:
            pass
        return rc, state

    rc, state = _run(go())
    assert dropped == []            # 장애 구간에서 DLQ 로 조기 유실되지 않는다
    assert rc <= 1                  # 회로 열림 전 1회만 소모
    assert state["circuit_open"] is True


def test_cancel_during_backoff_drains_task(monkeypatch):
    drained = []

    async def fake_exec(task):
        raise RuntimeError("once")

    monkeypatch.setattr(dbw, "_execute_db_task_impl", fake_exec)
    monkeypatch.setattr(dbw, "CIRCUIT_OPEN_FAILURES", 999)

    async def fake_one(task, started):
        drained.append("drain:" + task["type"])

    monkeypatch.setattr(dbw, "_drain_one_impl", fake_one)

    async def go():
        q = dbw.get_db_task_queue()
        w = asyncio.ensure_future(dbw.db_writer_worker())
        await q.put({"type": "t", "data": {}})
        await asyncio.sleep(0.1)  # 백오프(1s) 대기 중
        w.cancel()
        try:
            await w
        except asyncio.CancelledError:
            pass

    _run(go())
    assert drained == ["drain:t"]


# ── 3. 추가매수 remaining_pct 불변식 ─────────────────────────────────────────
def _rec(**kw):
    base = dict(id=7, quantity=100, entry_price=10000.0, highest_since_entry=10500.0, remaining_pct=0.5)
    base.update(kw)
    return SimpleNamespace(**base)


def test_accumulate_after_partial_exit_keeps_held_invariant():
    r = _rec()  # 원본 100, 실보유 50
    data = {"accumulate_entry": True, "quantity": 50, "entry_price": 8000.0}
    dbw._apply_entry_price_adjustments_v2(r, data)
    assert r.quantity == 150
    assert r.quantity * r.remaining_pct == pytest.approx(100.0, abs=0.01)  # 실보유 100
    r2 = _rec()  # 재실행(종료 drain)도 같은 값
    dbw._apply_entry_price_adjustments_v2(r2, data)
    assert (r2.quantity, r2.remaining_pct) == (r.quantity, r.remaining_pct)


def test_accumulate_without_prior_exit_leaves_remaining_pct():
    r = _rec(remaining_pct=1.0)
    dbw._apply_entry_price_adjustments_v2(r, {"accumulate_entry": True, "quantity": 10, "entry_price": 9000.0})
    assert r.remaining_pct == 1.0 and r.quantity == 110


def test_accumulate_ignores_caller_remaining_pct():
    r = _rec()
    skip = dbw._apply_entry_price_adjustments_v2(
        r, {"accumulate_entry": True, "quantity": 50, "entry_price": 8000.0, "remaining_pct": 1.0})
    assert "remaining_pct" in skip


def test_fill_adjust_uses_held_quantity_as_denominator():
    # 실보유 100(원본150×2/3), 추가매수 50주가 주문가보다 100원 싸게 체결
    r = _rec(quantity=150, remaining_pct=100 / 150, entry_price=9000.0)
    d = {"entry_fill_adjust": {"order_price": 8000.0, "filled_price": 7900.0, "filled_qty": 50}}
    dbw._apply_entry_price_adjustments_v2(r, d)
    assert r.entry_price == pytest.approx(9000.0 - 100 * 50 / 100, abs=0.01)