from datetime import date
from decimal import Decimal

from fastapi.testclient import TestClient
from sqlalchemy.orm import Session

from app.models.screening import ScreeningSignal
from app.models.stock import MarketIndex, Price, Sector, Stock


def _add_signal(
    db: Session,
    *,
    ticker: str,
    sector: str,
    trading_value: int,
    daily_return: Decimal,
    is_limit_up: bool = False,
) -> None:
    db.add(
        ScreeningSignal(
            screen_date=date(2026, 5, 22),
            ticker=ticker,
            name=f"{ticker} Corp",
            sector=sector,
            trading_value=trading_value,
            daily_return=daily_return,
            is_limit_up=is_limit_up,
            status="pending",
        )
    )


def _add_stock_with_sector(db: Session, ticker: str, name: str, sector: str) -> None:
    db.add(Stock(ticker=ticker, name=name, market="KOSPI", base_date=date(2026, 5, 22)))
    db.add(
        Sector(
            ticker=ticker,
            sector_code=f"S{ticker[-2:]}",
            company_name=name,
            sector_name=sector,
            base_date=date(2026, 5, 22),
        )
    )


def _add_price_series(
    db: Session,
    ticker: str,
    *,
    start_close: int,
    step: int,
    latest_volume: int,
) -> None:
    for offset in range(31):
        current_date = date(2026, 4, 22 + offset) if offset <= 8 else date(2026, 5, offset - 8)
        close = Decimal(start_close + (step * offset))
        volume = latest_volume if offset == 30 else 1_000_000
        db.add(
            Price(
                ticker=ticker,
                date=current_date,
                open=close - Decimal("10"),
                high=close + Decimal("20"),
                low=close - Decimal("20"),
                close=close,
                volume=volume,
                trading_value=int(close) * volume,
            )
        )


def _add_kospi_series(db: Session) -> None:
    for offset in range(31):
        current_date = date(2026, 4, 22 + offset) if offset <= 8 else date(2026, 5, offset - 8)
        close = Decimal(2500 + offset)
        db.add(
            MarketIndex(
                code="1001",
                date=current_date,
                name="KOSPI",
                open=close,
                high=close + Decimal("5"),
                low=close - Decimal("5"),
                close=close,
                volume=1_000_000,
                trading_value=100_000_000_000,
            )
        )


def test_sector_strongest_returns_top_signal_per_sector(
    client: TestClient,
    auth_headers: dict,
    db: Session,
):
    _add_signal(
        db,
        ticker="000001",
        sector="반도체",
        trading_value=250_000_000_000,
        daily_return=Decimal("0.0500"),
    )
    _add_signal(
        db,
        ticker="000002",
        sector="반도체",
        trading_value=400_000_000_000,
        daily_return=Decimal("0.0300"),
    )
    _add_signal(
        db,
        ticker="000003",
        sector="2차전지",
        trading_value=220_000_000_000,
        daily_return=Decimal("0.0100"),
    )
    _add_signal(
        db,
        ticker="000004",
        sector="2차전지",
        trading_value=210_000_000_000,
        daily_return=Decimal("0.3000"),
        is_limit_up=True,
    )
    db.commit()

    response = client.get(
        "/api/screening/sector-strongest?target_date=2026-05-22",
        headers=auth_headers,
    )

    assert response.status_code == 200
    data = response.json()
    assert len(data) == 2

    by_sector = {item["sector"]: item for item in data}
    assert by_sector["반도체"]["ticker"] == "000002"
    assert by_sector["반도체"]["signal_count"] == 2
    assert by_sector["2차전지"]["ticker"] == "000004"
    assert by_sector["2차전지"]["is_limit_up"] is True
    assert by_sector["2차전지"]["signal_strength"] > by_sector["반도체"]["signal_strength"]


def test_recent_sector_candidates_returns_stronger_same_sector_stocks(
    client: TestClient,
    auth_headers: dict,
    db: Session,
):
    _add_signal(
        db,
        ticker="000001",
        sector="반도체",
        trading_value=120_000_000_000,
        daily_return=Decimal("0.0200"),
    )
    _add_stock_with_sector(db, "000001", "기준전자", "반도체")
    _add_stock_with_sector(db, "000002", "강한전자", "반도체")
    _add_stock_with_sector(db, "000003", "약한전자", "반도체")
    _add_stock_with_sector(db, "000004", "다른섹터", "자동차")
    _add_kospi_series(db)
    _add_price_series(db, "000001", start_close=10000, step=5, latest_volume=1_000_000)
    _add_price_series(db, "000002", start_close=10000, step=250, latest_volume=8_000_000)
    _add_price_series(db, "000003", start_close=10000, step=-5, latest_volume=1_000_000)
    _add_price_series(db, "000004", start_close=10000, step=400, latest_volume=10_000_000)
    db.commit()

    response = client.get(
        "/api/screening/recent-sector-candidates?as_of=2026-05-22&window_days=30",
        headers=auth_headers,
    )

    assert response.status_code == 200
    data = response.json()
    assert len(data) == 1
    assert data[0]["ticker"] == "000001"
    assert data[0]["sector"] == "반도체"
    assert data[0]["stronger_count"] == 1
    assert data[0]["candidates"][0]["ticker"] == "000002"
    assert data[0]["candidates"][0]["is_stronger_than_source"] is True