# ============================================================================
# Structure Flow Strategy v1.1
# 纯价格结构策略 — 零技术指标，价格行为学驱动
#
# 版本变化 v1.0 → v1.1:
#   - 主时间框架：5M → 1H（匹配用户实际交易尺度）
#   - 信息时间框架：D1 → 4H → 1H
#   - 启用做空（can_short=True），适配无杠杆合约交易
#   - 硬止损改为结构失效点 + 1% 缓冲（不再用固定百分比）
#   - 修复 custom_stoploss 动态跟踪结构位
#
# 设计哲学:
#   趋势由 HH/HL 定义，支撑阻力由 Swing Point 定义，
#   止损由结构失效点定义，出场由结构反转定义。
#
# 多时间框架:
#   D1  → 宏观结构方向
#   4H  → 中期结构位 + 入场区域判定
#   1H  → K线形态确认入场时机
# ============================================================================

from datetime import datetime
import numpy as np
import pandas as pd
from pandas import DataFrame
from freqtrade.strategy import IStrategy, IntParameter, DecimalParameter, informative
from freqtrade.persistence import Trade


class StructureFlowStrategy(IStrategy):
    """
    Structure Flow Strategy v1.1 — 纯价格结构策略

    不使用任何技术指标（无 EMA、ATR、RSI、MACD、布林带等）。
    一切信号来源于价格本身的 OHLC 数据和由此推导的结构信息。

    趋势判断:
        HH + HL → 上升趋势（Bullish Structure）
        LH + LL → 下降趋势（Bearish Structure）

    入场逻辑:
        做多: D1上升结构 + 价格在4H Swing区间下半区 + 1H看涨K线形态
        做空: D1下降结构 + 价格在4H Swing区间上半区 + 1H看跌K线形态

    止损逻辑:
        初始止损: 4H 最近 Swing Low（做多）/ Swing High（做空）+ 1% 缓冲
        动态止损: custom_stoploss 随新 Swing Point 形成而跟踪
    """

    # ── 基础配置 ──────────────────────────────────────────

    timeframe = "1h"
    can_short = True  # v1.1 启用做空，适配无杠杆合约
    stoploss = -0.05  # 硬止损 5%，实际由 custom_stoploss 动态管理
    use_custom_stoploss = True
    minimal_roi = {"0": 100}  # 不设时间止盈，出场由结构决定
    max_open_trades = 1

    # 回测参数
    startup_candle_count = 40  # 需要更多历史数据（1H 级别）

    # ── 可调参数 ──────────────────────────────────────────

    swing_lookback_d1 = IntParameter(
        2, 10, default=5, space="buy",
    )
    swing_lookback_h4 = IntParameter(
        2, 10, default=5, space="buy",
    )

    # Pin Bar 确认强度：影线至少是实体的 N 倍
    pin_bar_wick_ratio = DecimalParameter(
        1.5, 4.0, default=2.0, space="buy",
    )

    # 结构止损缓冲（%）：止损设在结构位之外一点，避免被噪音扫损
    sl_buffer_pct = DecimalParameter(
        0.005, 0.03, default=0.01, space="sell",
        optimize=True,
    )

    # ================================================================
    #  工具函数 — 纯价格计算，不依赖任何技术指标
    # ================================================================

    @staticmethod
    def _detect_swing_points(
        high: pd.Series,
        low: pd.Series,
        lookback: int,
    ) -> tuple[pd.Series, pd.Series]:
        """
        检测 Swing High 和 Swing Low。

        纯价格比较：
        - Swing High: 当前高点 > 左右各 lookback 根K线的所有高点
        - Swing Low:  当前低点 < 左右各 lookback 根K线的所有低点
        """
        n = len(high)
        is_swing_high = np.full(n, False)
        is_swing_low = np.full(n, False)

        for i in range(lookback, n - lookback):
            window_high = high.iloc[i - lookback : i + lookback + 1]
            window_low = low.iloc[i - lookback : i + lookback + 1]

            if high.iloc[i] == window_high.max():
                is_swing_high[i] = True
            if low.iloc[i] == window_low.min():
                is_swing_low[i] = True

        return (
            pd.Series(is_swing_high, index=high.index),
            pd.Series(is_swing_low, index=low.index),
        )

    @staticmethod
    def _build_structure(
        high: pd.Series,
        low: pd.Series,
        close: pd.Series,
        swing_high: pd.Series,
        swing_low: pd.Series,
    ) -> DataFrame:
        """
        从 Swing Points 构建市场结构信息。

        返回值包含:
          trend_up / trend_down：当前处于上升/下降结构
          support：最近 Swing Low 价格
          resistance：最近 Swing High 价格
          in_demand：价格在下半区（做多区域）
          in_supply：价格在上半区（做空区域）
        """
        n = len(high)

        trend_up_arr = np.full(n, False)
        trend_down_arr = np.full(n, False)
        nearest_support = np.full(n, np.nan)
        nearest_resistance = np.full(n, np.nan)
        in_demand_zone = np.full(n, False)
        in_supply_zone = np.full(n, False)

        sh_prices: list[float] = []
        sl_prices: list[float] = []

        for i in range(n):
            # ── 更新 Swing Point 队列 ──
            if swing_high.iloc[i] and not np.isnan(high.iloc[i]):
                sh_prices.append(high.iloc[i])
                if len(sh_prices) > 4:
                    sh_prices.pop(0)

            if swing_low.iloc[i] and not np.isnan(low.iloc[i]):
                sl_prices.append(low.iloc[i])
                if len(sl_prices) > 4:
                    sl_prices.pop(0)

            # ── 趋势判断 ──
            if len(sh_prices) >= 2 and len(sl_prices) >= 2:
                latest_sh, prev_sh = sh_prices[-1], sh_prices[-2]
                latest_sl, prev_sl = sl_prices[-1], sl_prices[-2]

                if latest_sh > prev_sh and latest_sl > prev_sl:
                    trend_up_arr[i] = True
                    trend_down_arr[i] = False
                elif latest_sh < prev_sh and latest_sl < prev_sl:
                    trend_up_arr[i] = False
                    trend_down_arr[i] = True
                else:
                    if i > 0:
                        trend_up_arr[i] = trend_up_arr[i - 1]
                        trend_down_arr[i] = trend_down_arr[i - 1]
            elif i > 0:
                trend_up_arr[i] = trend_up_arr[i - 1]
                trend_down_arr[i] = trend_down_arr[i - 1]

            # ── 最近支撑/阻力 ──
            if sl_prices:
                nearest_support[i] = sl_prices[-1]
            elif i > 0:
                nearest_support[i] = nearest_support[i - 1]

            if sh_prices:
                nearest_resistance[i] = sh_prices[-1]
            elif i > 0:
                nearest_resistance[i] = nearest_resistance[i - 1]

            # ── 入场区域：用 Swing 区间中点划分 ──
            if (
                not np.isnan(nearest_support[i])
                and not np.isnan(nearest_resistance[i])
                and nearest_resistance[i] > nearest_support[i]
            ):
                mid = (nearest_support[i] + nearest_resistance[i]) / 2.0
                in_demand_zone[i] = low.iloc[i] <= mid
                in_supply_zone[i] = high.iloc[i] >= mid
            elif i > 0:
                in_demand_zone[i] = in_demand_zone[i - 1]
                in_supply_zone[i] = in_supply_zone[i - 1]

        result = DataFrame(
            {
                "trend_up": trend_up_arr,
                "trend_down": trend_down_arr,
                "support": nearest_support,
                "resistance": nearest_resistance,
                "in_demand": in_demand_zone,
                "in_supply": in_supply_zone,
            },
            index=high.index,
        )
        return result

    @staticmethod
    def _detect_candle_patterns(
        o: pd.Series,
        h: pd.Series,
        l: pd.Series,
        c: pd.Series,
        pin_ratio: float,
    ) -> tuple[pd.Series, pd.Series, pd.Series, pd.Series]:
        """
        检测 K 线形态 — 纯 OHLC 计算。
        """
        body = abs(c - o)
        upper_wick = h - np.maximum(o, c)
        lower_wick = np.minimum(o, c) - l
        total_range = h - l

        valid_range = total_range > 0
        valid_body = body > 0

        bullish_pin = (
            valid_range
            & valid_body
            & (lower_wick >= pin_ratio * body)
            & (upper_wick <= 0.5 * body)
        )

        bearish_pin = (
            valid_range
            & valid_body
            & (upper_wick >= pin_ratio * body)
            & (lower_wick <= 0.5 * body)
        )

        prev_body = body.shift(1)
        prev_o = o.shift(1)
        prev_c = c.shift(1)

        bullish_engulf = (
            (c > o)
            & (prev_c < prev_o)
            & (body > prev_body)
        )

        bearish_engulf = (
            (c < o)
            & (prev_c > prev_o)
            & (body > prev_body)
        )

        return (
            pd.Series(bullish_pin, index=c.index),
            pd.Series(bearish_pin, index=c.index),
            pd.Series(bullish_engulf, index=c.index),
            pd.Series(bearish_engulf, index=c.index),
        )

    # ================================================================
    #  信息时间框架 — D1 宏观结构
    # ================================================================

    @informative("1d")
    def populate_indicators_1d(
        self, dataframe: DataFrame, metadata: dict
    ) -> DataFrame:
        sh, sl = self._detect_swing_points(
            dataframe["high"], dataframe["low"],
            self.swing_lookback_d1.value,
        )

        structure = self._build_structure(
            dataframe["high"], dataframe["low"], dataframe["close"],
            sh, sl,
        )

        dataframe["trend_up"] = structure["trend_up"]
        dataframe["trend_down"] = structure["trend_down"]

        return dataframe

    # ================================================================
    #  信息时间框架 — 4H 中期结构
    # ================================================================

    @informative("4h")
    def populate_indicators_4h(
        self, dataframe: DataFrame, metadata: dict
    ) -> DataFrame:
        sh, sl = self._detect_swing_points(
            dataframe["high"], dataframe["low"],
            self.swing_lookback_h4.value,
        )

        structure = self._build_structure(
            dataframe["high"], dataframe["low"], dataframe["close"],
            sh, sl,
        )

        dataframe["trend_up"] = structure["trend_up"]
        dataframe["trend_down"] = structure["trend_down"]
        dataframe["support"] = structure["support"]
        dataframe["resistance"] = structure["resistance"]
        dataframe["in_demand"] = structure["in_demand"]
        dataframe["in_supply"] = structure["in_supply"]

        return dataframe

    # ================================================================
    #  主时间框架 — 1H K线形态
    # ================================================================

    def populate_indicators(
        self, dataframe: DataFrame, metadata: dict
    ) -> DataFrame:
        """
        1H 一小时线：检测 K 线形态。
        """
        bullish_pin, bearish_pin, bullish_engulf, bearish_engulf = (
            self._detect_candle_patterns(
                dataframe["open"],
                dataframe["high"],
                dataframe["low"],
                dataframe["close"],
                self.pin_bar_wick_ratio.value,
            )
        )

        dataframe["bullish_pinbar"] = bullish_pin
        dataframe["bearish_pinbar"] = bearish_pin
        dataframe["bullish_engulfing"] = bullish_engulf
        dataframe["bearish_engulfing"] = bearish_engulf

        dataframe["bullish_signal"] = bullish_pin | bullish_engulf
        dataframe["bearish_signal"] = bearish_pin | bearish_engulf

        return dataframe

    # ================================================================
    #  入场信号
    # ================================================================

    def populate_entry_trend(
        self, dataframe: DataFrame, metadata: dict
    ) -> DataFrame:
        """
        入场逻辑（1H 时间框架）。

        做多条件:
          1. D1 上升结构（trend_up_1d）
          2. 4H 下半区 / 需求区域（in_demand_4h）
          3. 1H 看涨 K 线形态（bullish_signal）

        做空条件:
          1. D1 下降结构（trend_down_1d）
          2. 4H 上半区 / 供给区域（in_supply_4h）
          3. 1H 看跌 K 线形态（bearish_signal）
        """

        # ── NaN 安全处理 ──
        bool_cols = [
            "trend_up_1d", "trend_down_1d",
            "trend_up_4h", "trend_down_4h",
            "in_demand_4h", "in_supply_4h",
            "bullish_signal", "bearish_signal",
        ]
        for col in bool_cols:
            if col in dataframe.columns:
                dataframe[col] = dataframe[col].fillna(False).infer_objects(copy=False)

        # ── 做多 ──
        long_conditions = (
            dataframe["trend_up_1d"]
            & dataframe["in_demand_4h"]
            & dataframe["bullish_signal"]
        )
        dataframe.loc[long_conditions, "enter_long"] = 1

        # ── 做空 ──
        short_conditions = (
            dataframe["trend_down_1d"]
            & dataframe["in_supply_4h"]
            & dataframe["bearish_signal"]
        )
        dataframe.loc[short_conditions, "enter_short"] = 1

        return dataframe

    # ================================================================
    #  出场信号
    # ================================================================

    def populate_exit_trend(
        self, dataframe: DataFrame, metadata: dict
    ) -> DataFrame:
        """
        出场逻辑 — 由结构反转触发。
        """

        # 做多出场：D1 不再上升 或 4H 不再上升
        exit_long = (
            ~dataframe["trend_up_1d"].fillna(True)
        )
        dataframe.loc[exit_long, "exit_long"] = 1

        # 做空出场：D1 不再下降 或 4H 不再下降
        exit_short = (
            dataframe["trend_up_1d"].fillna(False)
        )
        dataframe.loc[exit_short, "exit_short"] = 1

        return dataframe

    # ================================================================
    #  动态止损 — 基于结构失效
    # ================================================================

    def custom_stoploss(
        self,
        pair: str,
        trade: Trade,
        current_time: datetime,
        current_rate: float,
        current_profit: float,
        after_fill: bool,
        **kwargs,
    ) -> float | None:
        """
        结构止损：止损位设在最近的 4H Swing Low（做多）或 Swing High（做空），
        加上缓冲距离（sl_buffer_pct）。

        随着行情发展，新的 Swing Point 形成，止损自动跟随。
        """
        dataframe, _ = self.dp.get_analyzed_dataframe(pair, self.timeframe)
        if dataframe is None or len(dataframe) == 0:
            return None

        last = dataframe.iloc[-1]
        buffer = self.sl_buffer_pct.value

        if trade.is_short:
            resistance = last.get("resistance_4h")
            if resistance is not None and not (isinstance(resistance, float) and np.isnan(resistance)):
                # 做空止损：resistance × (1 + buffer)，在当前价格上方
                sl_price = float(resistance) * (1 + buffer)
                sl_ratio = (current_rate - sl_price) / current_rate
                if sl_ratio < 0:  # 止损在当前价格上方（做空方向正确）
                    return max(sl_ratio, -0.25)  # 不超过 25%
        else:
            support = last.get("support_4h")
            if support is not None and not (isinstance(support, float) and np.isnan(support)):
                # 做多止损：support × (1 - buffer)，在当前价格下方
                sl_price = float(support) * (1 - buffer)
                sl_ratio = (sl_price - current_rate) / current_rate
                if sl_ratio < 0:  # 止损在当前价格下方（做多方向正确）
                    return max(sl_ratio, -0.25)

        return None