"""
Phase 3: monitor 발화 + drawdown/past-leg tier (인과적).

매도는 monitor(sell_mtf_cross) 유지, tier만 drawdown·과거 leg 수익으로 강화합니다.
"""

from __future__ import annotations

from typing import Any

import pandas as pd

from config import (
    CAUSAL_GT_DD_LARGE_PCT,
    CAUSAL_GT_DD_MEDIUM_PCT,
    GT_BUY_PCT_LARGE_LEG,
    GT_BUY_PCT_MEDIUM_LEG,
    GT_BUY_PCT_SMALL_LEG,
    GT_INITIAL_CASH_KRW,
    SIM_TIER_CONVICTION_DD_PCT,
    TRADING_FEE_RATE,
)
from deepcoin.ground_truth.gt_allocation import (
    allocate_order_amounts_chronological,
    simulate_portfolio_summary,
)
from deepcoin.matching.portfolio_sim import sort_fires_chronological
from deepcoin.matching.position_sizing import enrich_sim_trades_with_gt_weights


def _deduped_ohlc(df: pd.DataFrame) -> pd.DataFrame:
    """
    DatetimeIndex 중복 제거·정렬 (drawdown lookup용).

    Args:
        df: OHLC DataFrame.

    Returns:
        index unique OHLC.
    """
    if df.empty:
        return df
    out = df.sort_index()
    if not out.index.is_unique:
        out = out[~out.index.duplicated(keep="last")]
    return out


def _close_series_from_df(df: pd.DataFrame) -> pd.Series:
    """
    OHLC DataFrame에서 종가 시리즈 추출 (positional index).

    Args:
        df: Open/Close 또는 open/close 컬럼을 가진 OHLC.

    Returns:
        float 종가 시리즈.
    """
    if df.empty:
        return pd.Series(dtype=float)
    frame = _deduped_ohlc(df)
    for col in ("close", "Close"):
        if col in frame.columns:
            return frame[col].astype(float).reset_index(drop=True)
    raise KeyError("OHLC DataFrame에 close/Close 컬럼이 없습니다.")


def _bar_index_at(df: pd.DataFrame, dt: str) -> int:
    """
    시각 dt에 대응하는 bar 위치 (인덱스 중복 시 nearest).

    Args:
        df: DatetimeIndex OHLC.
        dt: ISO 시각 문자열.

    Returns:
        정수 bar 위치 (0..n-1).
    """
    frame = _deduped_ohlc(df)
    if frame.empty:
        return 0
    try:
        ts = pd.to_datetime(dt)
    except (TypeError, ValueError):
        return 0
    pos = int(frame.index.get_indexer([ts], method="nearest")[0])
    return max(pos, 0)


def _drawdown_pct_at_index(closes: pd.Series, idx: int) -> float:
    """
    bar idx 시점 drawdown % (과거 rolling high 대비, 인과적).

    Args:
        closes: 종가 시리즈.
        idx: 봉 위치.

    Returns:
        drawdown % (0~100).
    """
    if idx < 0 or idx >= len(closes):
        return 0.0
    seg = closes.iloc[: idx + 1].astype(float)
    if seg.empty:
        return 0.0
    peak = float(seg.max())
    cur = float(seg.iloc[-1])
    if peak <= 0:
        return 0.0
    return max((peak - cur) / peak * 100.0, 0.0)


def hybrid_tier_scale(
    trade: dict[str, Any],
    *,
    completed_leg_ret: dict[int, float],
    enhanced: bool = False,
    dd_large_pct: float | None = None,
    dd_medium_pct: float | None = None,
) -> float:
    """
    과거 leg 수익 tier + drawdown tier (인과적).

    Args:
        trade: 매수 trade dict (drawdown_pct 포함).
        completed_leg_ret: 청산 완료 leg realized return %.
        enhanced: True면 medium tier·conviction 플래그 적용.
        dd_large_pct: drawdown large tier 임계(%). None이면 config.
        dd_medium_pct: drawdown medium tier 임계(%). None이면 config.

    Returns:
        asset_pct_scale.
    """
    from config import GT_LARGE_LEG_TOP_PCT
    from deepcoin.matching.position_sizing import (
        large_leg_ids_from_past_returns,
    )

    dd_large = float(dd_large_pct if dd_large_pct is not None else CAUSAL_GT_DD_LARGE_PCT)
    dd_medium = float(dd_medium_pct if dd_medium_pct is not None else CAUSAL_GT_DD_MEDIUM_PCT)

    lid = int(trade.get("leg_id", 0))
    large_past = large_leg_ids_from_past_returns(completed_leg_ret, GT_LARGE_LEG_TOP_PCT)
    dd = float(trade.get("drawdown_pct") or 0.0)

    if lid in large_past:
        if enhanced and dd >= SIM_TIER_CONVICTION_DD_PCT:
            trade["conviction_buy"] = True
        return float(GT_BUY_PCT_LARGE_LEG)

    if dd >= dd_large:
        if enhanced:
            trade["conviction_buy"] = True
        return float(GT_BUY_PCT_LARGE_LEG)
    if dd >= dd_medium:
        if enhanced and dd >= SIM_TIER_CONVICTION_DD_PCT:
            trade["conviction_buy"] = True
        return float(GT_BUY_PCT_MEDIUM_LEG) if enhanced else float(GT_BUY_PCT_LARGE_LEG) * 0.5
    return float(GT_BUY_PCT_SMALL_LEG)


def _monitor_rows_from_fires(fires: pd.DataFrame) -> list[dict[str, Any]]:
    """monitor 발화 DataFrame → trade dict 리스트."""
    rows: list[dict[str, Any]] = []
    for _, r in sort_fires_chronological(fires).iterrows():
        rows.append(
            {
                "dt": str(r["dt"]),
                "action": r["side"],
                "price": float(r["close"]),
                "rule_id": r.get("rule_id", ""),
            }
        )
    return rows


def build_monitor_hybrid_sized_trades(
    fires: pd.DataFrame,
    df: pd.DataFrame,
    *,
    enhanced: bool = False,
    initial_cash: float = GT_INITIAL_CASH_KRW,
    fee_rate: float = TRADING_FEE_RATE,
    dd_large_pct: float | None = None,
    dd_medium_pct: float | None = None,
) -> tuple[list[dict[str, Any]], dict[str, Any]]:
    """
    monitor 발화 → hybrid tier amount_krw 배분 (인과적).

    Args:
        fires: monitor rule 발화 (buy+sell).
        df: 3m OHLC (drawdown 계산).
        enhanced: conviction·medium tier 사용.
        initial_cash: 시작 현금.
        fee_rate: 수수료율.

    Returns:
        (amount_krw가 채워진 trade dict, alloc_stats).
    """
    from deepcoin.ground_truth.ground_truth import load_ground_truth, order_trades_chronological
    from deepcoin.paths import resolve_ground_truth_file

    if fires.empty:
        return [], {"buy_executed": 0, "buy_skipped": 0}

    gt_data = load_ground_truth(resolve_ground_truth_file()) or {}
    gt_trades = order_trades_chronological(gt_data.get("trades") or [])

    enriched = enrich_sim_trades_with_gt_weights(
        _monitor_rows_from_fires(fires),
        gt_trades,
        causal_legs=True,
    )
    enriched = _attach_drawdown_to_buys(enriched, df)

    def scale_fn(t: dict[str, Any], completed_leg_ret: dict[int, float]) -> float:
        return hybrid_tier_scale(
            t,
            completed_leg_ret=completed_leg_ret,
            enhanced=enhanced,
            dd_large_pct=dd_large_pct,
            dd_medium_pct=dd_medium_pct,
        )

    return allocate_order_amounts_chronological(
        enriched,
        initial_cash=initial_cash,
        fee_rate=fee_rate,
        causal_tier=False,
        asset_pct_scale_fn=scale_fn,
    )


def _simulate_monitor_tier_portfolio(
    fires: pd.DataFrame,
    df: pd.DataFrame,
    *,
    enhanced: bool = False,
    last_price: float | None = None,
    initial_cash: float = GT_INITIAL_CASH_KRW,
    fee_rate: float = TRADING_FEE_RATE,
    dd_large_pct: float | None = None,
    dd_medium_pct: float | None = None,
) -> dict[str, Any]:
    """
    monitor buy+sell + tier 복리 시뮬 (hybrid 또는 enhanced).

    Args:
        fires: monitor rule 발화 (buy+sell).
        df: 3m OHLC (drawdown 계산).
        enhanced: conviction·medium tier 사용.
        last_price: 미청산 평가가.
        initial_cash: 시작 현금.
        fee_rate: 수수료율.
        dd_large_pct: drawdown large tier 임계(%).
        dd_medium_pct: drawdown medium tier 임계(%).

    Returns:
        portfolio summary dict.
    """
    mode = "monitor_tier_enhanced" if enhanced else "monitor_dd_tier"
    if fires.empty:
        return {"pnl_pct": 0.0, "trade_count": 0, "sizing_mode": mode}

    sized, alloc_stats = build_monitor_hybrid_sized_trades(
        fires,
        df,
        enhanced=enhanced,
        initial_cash=initial_cash,
        fee_rate=fee_rate,
        dd_large_pct=dd_large_pct,
        dd_medium_pct=dd_medium_pct,
    )

    mark = last_price
    if mark is None and not df.empty:
        try:
            mark = float(_close_series_from_df(df).iloc[-1])
        except KeyError:
            mark = None

    result = simulate_portfolio_summary(
        sized,
        initial_cash=initial_cash,
        fee_rate=fee_rate,
        last_price=mark,
        use_amount_krw=True,
    )
    result["sizing_mode"] = mode
    if enhanced:
        result["sizing_note"] = (
            "monitor buy+sell + past-leg·drawdown tier + conviction (미래 미사용)"
        )
    else:
        result["sizing_note"] = (
            "monitor buy+sell + drawdown·past-leg tier (미래 미사용)"
        )
    result["alloc_stats"] = alloc_stats
    result["input_fires"] = int(len(fires))
    return result


def _attach_drawdown_to_buys(
    trades: list[dict[str, Any]],
    df: pd.DataFrame,
) -> list[dict[str, Any]]:
    """
    매수 trade에 bar drawdown % 부여 (인과적).

    Args:
        trades: enrich된 trade dict.
        df: 3m OHLC (DatetimeIndex).

    Returns:
        drawdown_pct가 추가된 trade dict.
    """
    if df.empty:
        return trades
    close_s = _close_series_from_df(df)
    out: list[dict[str, Any]] = []
    for t in trades:
        row = dict(t)
        if row.get("action") != "buy":
            out.append(row)
            continue
        bar_idx = _bar_index_at(df, str(row.get("dt", "")))
        row["drawdown_pct"] = round(_drawdown_pct_at_index(close_s, bar_idx), 2)
        out.append(row)
    return out


def simulate_monitor_dd_tier_portfolio(
    fires: pd.DataFrame,
    df: pd.DataFrame,
    *,
    last_price: float | None = None,
    initial_cash: float = GT_INITIAL_CASH_KRW,
    fee_rate: float = TRADING_FEE_RATE,
    dd_large_pct: float | None = None,
    dd_medium_pct: float | None = None,
) -> dict[str, Any]:
    """
    monitor buy+sell + drawdown/past-leg tier 복리 시뮬.

    Args:
        fires: monitor rule 발화 (buy+sell).
        df: 3m OHLC (drawdown 계산).
        last_price: 미청산 평가가.
        initial_cash: 시작 현금.
        fee_rate: 수수료율.
        dd_large_pct: drawdown large tier 임계(%).
        dd_medium_pct: drawdown medium tier 임계(%).

    Returns:
        portfolio summary dict.
    """
    return _simulate_monitor_tier_portfolio(
        fires,
        df,
        enhanced=False,
        last_price=last_price,
        initial_cash=initial_cash,
        fee_rate=fee_rate,
        dd_large_pct=dd_large_pct,
        dd_medium_pct=dd_medium_pct,
    )


def simulate_monitor_tier_enhanced_portfolio(
    fires: pd.DataFrame,
    df: pd.DataFrame,
    *,
    last_price: float | None = None,
    initial_cash: float = GT_INITIAL_CASH_KRW,
    fee_rate: float = TRADING_FEE_RATE,
) -> dict[str, Any]:
    """
    Phase 4: monitor + past-leg·drawdown tier + conviction (weight 분할 생략).

    Args:
        fires: monitor rule 발화 (buy+sell).
        df: 3m OHLC (drawdown 계산).
        last_price: 미청산 평가가.
        initial_cash: 시작 현금.
        fee_rate: 수수료율.

    Returns:
        portfolio summary dict.
    """
    return _simulate_monitor_tier_portfolio(
        fires,
        df,
        enhanced=True,
        last_price=last_price,
        initial_cash=initial_cash,
        fee_rate=fee_rate,
    )


def simulate_causal_gt_hybrid_portfolio(
    buy_fires: pd.DataFrame,
    df: pd.DataFrame,
    *,
    monitor_fires: pd.DataFrame | None = None,
    last_price: float | None = None,
    cg_params: dict[str, Any] | None = None,
    initial_cash: float = GT_INITIAL_CASH_KRW,
    fee_rate: float = TRADING_FEE_RATE,
    dd_large_pct: float | None = None,
    dd_medium_pct: float | None = None,
) -> dict[str, Any]:
    """
    Phase 3 하이브리드: monitor buy+sell + DD tier (권장).

    monitor_fires가 있으면 DD tier 경로, 없으면 구 peak-sell 경로(legacy).

    Args:
        buy_fires: buy 발화 (legacy peak-sell 경로용).
        df: 3m OHLCV.
        monitor_fires: monitor buy+sell (권장).
        last_price: 미청산 평가가.
        cg_params: legacy 파라미터.
        initial_cash: 시작 현금.
        fee_rate: 수수료율.
        dd_large_pct: drawdown large tier 임계(%).
        dd_medium_pct: drawdown medium tier 임계(%).

    Returns:
        portfolio summary dict.
    """
    if monitor_fires is not None and not monitor_fires.empty:
        return simulate_monitor_dd_tier_portfolio(
            monitor_fires,
            df,
            last_price=last_price,
            initial_cash=initial_cash,
            fee_rate=fee_rate,
            dd_large_pct=dd_large_pct,
            dd_medium_pct=dd_medium_pct,
        )

    return {
        "pnl_pct": 0.0,
        "trade_count": 0,
        "note": "monitor_fires required",
        "sizing_mode": "causal_gt_hybrid",
    }