"""4H box breakout retest strategy candidate.

The detector factor is not the strategy. This module wraps that factor with
market, freshness, entry-distance and risk semantics to produce a standard
StrategySignal.
"""

from __future__ import annotations

from app.core.factor_roles import ENTRY, RISK, TRIGGER
from app.core.strategy_contract import StrategySignal, current_strategy_version
from app.core.strategy_registry import BOX_RETEST_4H_STRATEGY


def _safe_float(value, default=0.0) -> float:
    try:
        if value is None or value == "":
            return default
        return float(value)
    except Exception:
        return default


def build_box_retest_signal(
    *,
    symbol: str,
    current_price: float,
    detection: dict,
    entry_plan: dict | None = None,
    market_regime: dict | None = None,
    decision_log: dict | None = None,
) -> StrategySignal | None:
    if not (detection or {}).get("detected"):
        return None
    entry_plan = entry_plan or {}
    market_regime = market_regime or {}
    risk_level = str(market_regime.get("risk_level") or "medium").lower()
    entry_zone = _safe_float(detection.get("entry_zone"))
    current_price = _safe_float(current_price)
    distance_pct = (current_price / entry_zone - 1) * 100 if entry_zone > 0 and current_price > 0 else 0
    age = int(detection.get("pullback_age_bars") or 999)
    quality = str(detection.get("quality") or "")
    status = "candidate"
    reasons = []
    if risk_level == "critical":
        status = "observe"
        reasons.append("全局风险 critical，仅观察")
    if age > 4:
        status = "observe"
        reasons.append(f"回踩已过去 {age} 根4H，时效偏旧")
    if quality not in {"良好", "优质"}:
        status = "observe"
        reasons.append(f"形态质量 {quality or '未知'}，不直接交易")
    if distance_pct > 8:
        status = "observe"
        reasons.append(f"当前价离箱体上沿 {distance_pct:.1f}%，禁止追高")

    score = _safe_float(detection.get("score"))
    confidence = min(100.0, max(0.0, score * 8))
    trigger = {
        "factor_code": "box_breakout_pullback_4h",
        "factor_label": "4H箱体突破回踩",
        "box_high": detection.get("box_high"),
        "box_low": detection.get("box_low"),
        "entry_zone": detection.get("entry_zone"),
        "stop_level": detection.get("stop_level"),
        "pullback_kind": detection.get("pullback_kind"),
        "pullback_age_bars": age,
        "quality": quality,
        "distance_to_entry_zone_pct": round(distance_pct, 4),
        "market_regime": market_regime.get("regime") or "",
        "risk_level": risk_level,
    }
    risk_plan = {
        "invalid_if": ["跌回箱体", "放量冲高回落", "回踩过久", "全局风险升为critical"],
        "stop_level": detection.get("stop_level"),
        "risk_reasons": reasons,
    }
    return StrategySignal(
        strategy_code=BOX_RETEST_4H_STRATEGY,
        strategy_version=current_strategy_version(),
        symbol=symbol,
        direction="long",
        status=status,
        confidence=confidence,
        score=score,
        trigger=trigger,
        factor_roles={
            "box_breakout_pullback_4h": TRIGGER,
            "pullback_15m_confirm": ENTRY,
            "trend_exhaustion": RISK,
            "false_breakout": RISK,
        },
        entry_plan=entry_plan,
        risk_plan=risk_plan,
        decision_log=decision_log or {
            "module": "box_retest_4h_v1",
            "decision": status,
            "reasons": reasons,
        },
    )