adaq-talib 0.2.0

//! # 形态识别 · 第 1 批（验证批）/ Pattern Recognition · Batch 1 (validation batch)
//!
//! 本批为 `CandleAvg` 助手与蜡烛原语的**验证批**，覆盖全部助手特性：
//! 1-candle 运行和（`cdl_doji` / `cdl_marubozu`）、`OFF=1` 的 `Near`（`cdl_hammer`）、
//! 影线非常长（`avgPeriod=0`，`cdl_highwave`）、纯 2-candle 比较（`cdl_engulfing` /
//! `cdl_shootingstar`）、`OFF=1` 的 2-candle（`cdl_harami`）、`OFF=2` 的 3-candle 多根
//! （`cdl_2crows`）。全部与 TA-Lib 0.7.1 黄金向量逐项 1:1。
//!
//! This is the **validation batch** for the [`CandleAvg`](super::CandleAvg) helper and candle
//! primitives, exercising every helper feature: 1-candle running-sum (`cdl_doji` /
//! `cdl_marubozu`), `OFF=1` `Near` (`cdl_hammer`), very-long shadow (`avgPeriod=0`,
//! `cdl_highwave`), pure 2-candle comparison (`cdl_engulfing` / `cdl_shootingstar`),
//! `OFF=1` 2-candle (`cdl_harami`), and `OFF=2` 3-candle multi-bar (`cdl_2crows`). All
//! bit-identical to TA-Lib 0.7.1 golden vectors.

use super::*;
use crate::error::TaError;
use crate::indicator::indicator;

// ===========================================================================
// cdl_doji — Doji（十字星）
// ===========================================================================

indicator! {
    /// Doji（十字星）：开盘价 ≈ 收盘价（实体极小）。
    ///
    /// `outInteger` 恒为 `100`（十字星表示犹豫，本身不判多空）。
    /// 对应 C 源 `ta_CDLDOJI.c`：`realBody(i) <= CANDLEAVERAGE(BodyDoji, i)`。
    ///
    /// Doji: open ≈ close (very small real body). Output is always `100`.
    fn cdl_doji(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_doji_with_output init zero;
}

/// `cdl_doji` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_doji`]。
/// Zero-copy variant of [`cdl_doji`]: writes results into `out` (length must equal input length).
pub fn cdl_doji_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_doji_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_doji")?;
    let n = open.len();
    let lookback = BODY_DOJI.avg_period; // 10
    if n <= lookback {
        return Ok(());
    }
    let mut sum_avg = {
        let mut s = lookback - 0 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += high_low_range(high[s], low[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg = lookback - 0 - 10;
    let mut i = lookback;
    while i < n {
        let cur_avg = high_low_range(high[i], low[i]);
        let val_avg = sum_avg / 10 as f64 * 0.1;
        out[i] = if real_body(open[i], close[i]) <= val_avg {
            100.0
        } else {
            0.0
        };
        sum_avg += cur_avg - high_low_range(high[trail_avg], low[trail_avg]);
        trail_avg += 1;
        i += 1;
    }

    Ok(())
}

// ===========================================================================
// cdl_marubozu — Marubozu（光头光脚）
// ===========================================================================

indicator! {
    /// Marubozu（光头光脚）：长实体、无/极短影线。
    ///
    /// 阳线（close ≥ open）输出 `+100`，阴线输出 `−100`；否则 `0`。
    /// 对应 C 源 `ta_CDLMARUBOZU.c`：`lookback = max(BodyLong, ShadowVeryShort)`。
    ///
    /// Marubozu: long real body with no/very-short shadows. Bullish → `+100`, bearish → `−100`.
    fn cdl_marubozu(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_marubozu_with_output init zero;
}

/// `cdl_marubozu` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_marubozu`]。
/// Zero-copy variant of [`cdl_marubozu`]: writes results into `out` (length must equal input length).
pub fn cdl_marubozu_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_marubozu_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_marubozu")?;
    let n = open.len();
    let lookback = BODY_LONG.avg_period.max(SHADOW_VERY_SHORT.avg_period); // max(10,10)=10
    if n <= lookback {
        return Ok(());
    }
    let mut sum_avg_body = {
        let mut s = lookback - 0 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += real_body(open[s], close[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_body = lookback - 0 - 10;
    let mut sum_avg_shadow = {
        let mut s = lookback - 0 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += high_low_range(high[s], low[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_shadow = lookback - 0 - 10;
    let mut i = lookback;
    while i < n {
        let cur_avg_body = real_body(open[i], close[i]);
        let val_avg_body = sum_avg_body / 10 as f64 * 1.0;
        let cur_avg_shadow = high_low_range(high[i], low[i]);
        let val_avg_shadow = sum_avg_shadow / 10 as f64 * 0.1;
        out[i] = if cur_avg_body > val_avg_body
            && upper_shadow(open[i], high[i], close[i]) < val_avg_shadow
            && lower_shadow(open[i], low[i], close[i]) < val_avg_shadow
        {
            candle_color(open[i], close[i]) * 100.0
        } else {
            0.0
        };
        sum_avg_body += cur_avg_body - real_body(open[trail_avg_body], close[trail_avg_body]);
        trail_avg_body += 1;
        sum_avg_shadow +=
            cur_avg_shadow - high_low_range(high[trail_avg_shadow], low[trail_avg_shadow]);
        trail_avg_shadow += 1;
        i += 1;
    }

    Ok(())
}

// ===========================================================================
// cdl_hammer — Hammer（锤头）
// ===========================================================================

indicator! {
    /// Hammer（锤头）：小实体、长下影线、无/极短上影线，且实体靠近前一根最低价附近。
    ///
    /// 锤头恒为看涨（`+100`）。`Near` 设置使用 `OFF=1`，引用 `i−1`
    /// （见 `ta_CDLHAMMER.c`）。`lookback = max(max(max(BodyShort, ShadowLong), ShadowVeryShort), Near) + 1 = 11`。
    ///
    /// Hammer: small body, long lower shadow, no/very-short upper shadow, body near prior low.
    /// Always bullish (`+100`). `Near` uses `OFF=1` (references `i−1`), `lookback = 11`.
    fn cdl_hammer(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_hammer_with_output init zero;
}

/// `cdl_hammer` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_hammer`]。
/// Zero-copy variant of [`cdl_hammer`]: writes results into `out` (length must equal input length).
pub fn cdl_hammer_with_output(
    open: &[f64], high: &[f64], low: &[f64], close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam("cdl_hammer_with_output: out length must equal input length".into()));
    }

    check_ohlc(open, high, low, close, "cdl_hammer")?;
    let n = open.len();
    // lookback = max(BODY_SHORT, SHADOW_LONG, SHADOW_VERY_SHORT, NEAR) + 1 = 10 + 1 = 11.
    let lookback = 11usize;
    if n <= lookback {
        return Ok(());
    }
    // 优化（数值与 CandleAvg 逐项一致 / parity-preserving）：
    // 原实现为每个 K 线调用 4 个 `CandleAvg` 的 `value()`+`advance()`，每调用都从原始
    // OHLC 切片重新 `range_of` 并带边界检查，约 12 次冗余求值/方法调用/bar。
    // 此处像 C 源那样每根 K 线把蜡烛原语算一次进局部变量，并以内联滚动和累加器推进
    // （与 `CandleAvg::value/advance` 完全相同的 `+= range(i) - range(trailing)` 递推），
    // 算术逐位一致，故黄金向量 1:1 不变。bounds-check 因索引可证在界内而被 LLVM 消除。
    // BODY_SHORT (RealBody, p=10, off=0): 种子窗口 [1, 11)。
    let mut sum_body = 0.0_f64;
    let mut s = 1usize;
    while s < lookback {
        sum_body += real_body(open[s], close[s]);
        s += 1;
    }
    let mut t_body = 1usize; // trailing = begin = lookback - off - p = 1
    // SHADOW_VERY_SHORT (HighLow, p=10, off=0): 种子窗口 [1, 11)。
    let mut sum_hl = 0.0_f64;
    let mut s = 1usize;
    while s < lookback {
        sum_hl += high_low_range(high[s], low[s]);
        s += 1;
    }
    let mut t_hl = 1usize;
    // NEAR (HighLow, p=5, off=1): 种子窗口 [5, 10)（i=11 时即 (i-1-5)..(i-1-1)）。
    let near_begin = lookback - 1 - 5; // 5
    let near_end = lookback - 1; // 10
    let mut sum_near = 0.0_f64;
    let mut s = near_begin;
    while s < near_end {
        sum_near += high_low_range(high[s], low[s]);
        s += 1;
    }
    let mut t_near = near_begin;
    let mut i = lookback;
    while i < n {
        let rb = real_body(open[i], close[i]);
        let ls = lower_shadow(open[i], low[i], close[i]);
        let us = upper_shadow(open[i], high[i], close[i]);
        // 与 CandleAvg::value 完全相同的表达式顺序（保证 FP 逐位一致）。
        let body_avg = (sum_body / 10.0) * 1.0; // BODY_SHORT
        let shadow_long = rb; // SHADOW_LONG (avg_period 0) = 当前实体
        let hl_avg = (sum_hl / 10.0) * 0.1; // SHADOW_VERY_SHORT
        let near_val = (sum_near / 5.0) * 0.2; // NEAR (引用 i-1)
        if rb < body_avg
            && ls > shadow_long
            && us < hl_avg
            && open[i].min(close[i]) <= low[i - 1] + near_val
        {
            out[i] = 100.0;
        } else {
            out[i] = 0.0;
        }
        // 推进滚动窗口（与 CandleAvg::advance 同递推）。
        sum_body += rb - real_body(open[t_body], close[t_body]);
        t_body += 1;
        sum_hl += high_low_range(high[i], low[i]) - high_low_range(high[t_hl], low[t_hl]);
        t_hl += 1;
        let ni = i - 1;
        sum_near += high_low_range(high[ni], low[ni]) - high_low_range(high[t_near], low[t_near]);
        t_near += 1;
        i += 1;
    }
    Ok(())
}

// ===========================================================================
// cdl_shootingstar — Shooting Star（射击之星）
// ===========================================================================

indicator! {
    /// Shooting Star（射击之星）：小实体、长上影线、无/极短下影线，且相对前一根实体向上跳空。
    ///
    /// 射击之星恒为看跌（`−100`）。`lookback = max(max(BodyShort, ShadowLong), ShadowVeryShort) = 10`。
    ///
    /// Shooting Star: small body, long upper shadow, no/very-short lower shadow, gap up from prior body.
    /// Always bearish (`−100`), `lookback = 10`.
    fn cdl_shootingstar(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_shootingstar_with_output init zero;
}

/// `cdl_shootingstar` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_shootingstar`]。
/// Zero-copy variant of [`cdl_shootingstar`]: writes results into `out` (length must equal input length).
pub fn cdl_shootingstar_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_shootingstar_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_shootingstar")?;
    let n = open.len();
    let lookback = [
        BODY_SHORT.avg_period,
        SHADOW_LONG.avg_period,
        SHADOW_VERY_SHORT.avg_period,
    ]
    .iter()
    .max()
    .copied()
    .unwrap()
        + 1; // 11: TA-Lib pads one extra leading candle (the evaluated bar sits at `lookback`).
    if n <= lookback {
        return Ok(());
    }
    let mut sum_avg_body = {
        let mut s = lookback - 0 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += real_body(open[s], close[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_body = lookback - 0 - 10;
    let mut sum_avg_shadow_long = {
        let mut s = lookback - 0 - 0;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += real_body(open[s], close[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_shadow_long = lookback - 0 - 0;
    let mut sum_avg_shadow_vshort = {
        let mut s = lookback - 0 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += high_low_range(high[s], low[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_shadow_vshort = lookback - 0 - 10;
    let mut i = lookback;
    while i < n {
        let cur_avg_body = real_body(open[i], close[i]);
        let val_avg_body = sum_avg_body / 10 as f64 * 1.0;
        let cur_avg_shadow_long = real_body(open[i], close[i]);
        let val_avg_shadow_long = cur_avg_shadow_long * 1.0;
        let cur_avg_shadow_vshort = high_low_range(high[i], low[i]);
        let val_avg_shadow_vshort = sum_avg_shadow_vshort / 10 as f64 * 0.1;
        out[i] = if real_body(open[i], close[i]) < val_avg_body
            && upper_shadow(open[i], high[i], close[i]) > val_avg_shadow_long
            && lower_shadow(open[i], low[i], close[i]) < val_avg_shadow_vshort
            && real_body_gap_up(open[i], close[i], open[i - 1], close[i - 1])
        {
            -100.0
        } else {
            0.0
        };
        sum_avg_body += cur_avg_body - real_body(open[trail_avg_body], close[trail_avg_body]);
        trail_avg_body += 1;
        sum_avg_shadow_long += cur_avg_shadow_long
            - real_body(open[trail_avg_shadow_long], close[trail_avg_shadow_long]);
        trail_avg_shadow_long += 1;
        sum_avg_shadow_vshort += cur_avg_shadow_vshort
            - high_low_range(high[trail_avg_shadow_vshort], low[trail_avg_shadow_vshort]);
        trail_avg_shadow_vshort += 1;
        i += 1;
    }

    Ok(())
}

// ===========================================================================
// cdl_engulfing — Engulfing Pattern（吞没形态）
// ===========================================================================

indicator! {
    /// Engulfing Pattern（吞没形态）：第 2 根实体吞没第 1 根实体。
    ///
    /// 与已安装的 TA-Lib 0.7.1 dylib 一致（见 ADR 0005），采用**两级**输出：
    /// - 完全吞没（`open[i] < close[i-1]`，bull；`open[i] > close[i-1]`，bear）→ `±100`；
    /// - 边界弱吞没（`open[i] == close[i-1]`，即第 2 根开盘恰等于前收）→ `±80`。
    ///
    /// 此为 dylib 修订版行为（上游 C 源 `ta_CDLENGULFING.c` 仅返回 `±100`）；黄金向量由 dylib
    /// 生成，本实现严格对齐 dylib。纯 2-candle 比较，无蜡烛设置，`lookback = 2`。
    ///
    /// Engulfing with the installed TA-Lib 0.7.1 dylib's **two-tier** output (ADR 0005):
    /// full engulf → `±100`; boundary weak engulf (`open[i] == close[i-1]`) → `±80`.
    /// Pure 2-candle comparison, no candle settings, `lookback = 2`.
    fn cdl_engulfing(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_engulfing_with_output init zero;
}

/// `cdl_engulfing` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_engulfing`]。
/// Zero-copy variant of [`cdl_engulfing`]: writes results into `out` (length must equal input length).
pub fn cdl_engulfing_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_engulfing_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_engulfing")?;
    let n = open.len();
    let lookback = 2; // TA_CDLENGULFING_Lookback() returns 2（见 ta_CDLENGULFING.c）
    if n <= lookback {
        return Ok(());
    }
    // 缓存前一根蜡烛的 open/close/color，避免每轮重复读取 open[i-1]/close[i-1] 与
    // 重复调用 `candle_color`，同时帮助编译器消除边界检查（P3-4，ADR 0005 零偏差）。
    // 循环自 `i = lookback = 2` 起，故首轮比较的"前一根"是第 1 根（索引 1）。
    let mut prev_open = open[1];
    let mut prev_close = close[1];
    let mut prev_color = candle_color(prev_open, prev_close);
    for i in lookback..n {
        let cur_open = open[i];
        let cur_close = close[i];
        let cur_color = candle_color(cur_open, cur_close);
        let bull = cur_color == 1.0 && prev_color == -1.0 && cur_close > prev_open;
        let bear = cur_color == -1.0 && prev_color == 1.0 && cur_close < prev_open;
        out[i] = if bull {
            if cur_open < prev_close {
                100.0
            } else if cur_open <= prev_close {
                80.0
            } else {
                0.0
            }
        } else if bear {
            if cur_open > prev_close {
                -100.0
            } else if cur_open >= prev_close {
                -80.0
            } else {
                0.0
            }
        } else {
            0.0
        };
        prev_open = cur_open;
        prev_close = cur_close;
        prev_color = cur_color;
    }
    Ok(())
}

// ===========================================================================
// cdl_harami — Harami Pattern（孕线形态）
// ===========================================================================

indicator! {
    /// Harami Pattern（孕线形态）：第 1 根长实体，第 2 根短实体完全被第 1 根实体包裹。
    ///
    /// 第 1 根为阳线则看跌（`−100`），为阴线则看涨（`+100`）。`BodyLong` 使用 `OFF=1`
    /// （引用 `i−1`），`lookback = max(BodyLong, BodyShort) + 1 = 11`。对应 `ta_CDLHARAMI.c`。
    ///
    /// Harami: 1st a long real body, 2nd a short body totally engulfed by the 1st.
    /// `BodyLong` uses `OFF=1` (references `i−1`), `lookback = 11`.
    fn cdl_harami(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_harami_with_output init zero;
}

/// `cdl_harami` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_harami`]。
/// Zero-copy variant of [`cdl_harami`]: writes results into `out` (length must equal input length).
pub fn cdl_harami_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_harami_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_harami")?;
    let n = open.len();
    let lookback = BODY_LONG.avg_period.max(BODY_SHORT.avg_period) + 1; // 11
    if n <= lookback {
        return Ok(());
    }
    // 两个蜡烛均值滚动窗口（BODY_LONG off=1 引用 i−1；BODY_SHORT off=0 引用 i），
    // 复用共享的 CandleAvg 内核（与手写滑动窗口逐项 1:1；但 `advance` 内部每根只算一次
    // `real_body`，消除原内联版在条件与推进处各算一次的冗余）。
    let mut avg_body_long = CandleAvg::new(BODY_LONG, open, high, low, close, lookback, 1);
    let mut avg_body_short = CandleAvg::new(BODY_SHORT, open, high, low, close, lookback, 0);
    let mut i = lookback;
    while i < n {
        let val_avg_body_long = avg_body_long.value(i, open, high, low, close);
        let val_avg_body_short = avg_body_short.value(i, open, high, low, close);
        out[i] = if real_body(open[i - 1], close[i - 1]) > val_avg_body_long
            && real_body(open[i], close[i]) <= val_avg_body_short
            && open[i].max(close[i]) < open[i - 1].max(close[i - 1])
            && open[i].min(close[i]) > open[i - 1].min(close[i - 1])
        {
            -candle_color(open[i - 1], close[i - 1]) * 100.0
        } else {
            0.0
        };
        avg_body_long.advance(i, open, high, low, close);
        avg_body_short.advance(i, open, high, low, close);
        i += 1;
    }

    Ok(())
}

// ===========================================================================
// cdl_highwave — High-Wave（高空浪）
// ===========================================================================

indicator! {
    /// High-Wave（高空浪）：短实体、极长上下影线。
    ///
    /// 阳线输出 `+100`，阴线输出 `−100`（不判多空）。`ShadowVeryLong` 为 `avgPeriod=0`
    /// （直接用当前 K 线范围）。`lookback = max(BodyShort, ShadowVeryLong) = 10`。对应 `ta_CDLHIGHWAVE.c`。
    ///
    /// High-Wave: short body, very long upper & lower shadows. White → `+100`, black → `−100`.
    /// `ShadowVeryLong` has `avgPeriod=0`; `lookback = 10`.
    fn cdl_highwave(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_highwave_with_output init zero;
}

/// `cdl_highwave` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_highwave`]。
/// Zero-copy variant of [`cdl_highwave`]: writes results into `out` (length must equal input length).
pub fn cdl_highwave_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_highwave_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_highwave")?;
    let n = open.len();
    let lookback = BODY_SHORT.avg_period.max(SHADOW_VERY_LONG.avg_period); // max(10,0)=10
    if n <= lookback {
        return Ok(());
    }
    let mut sum_avg_body = {
        let mut s = lookback - 0 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += real_body(open[s], close[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_body = lookback - 0 - 10;
    let mut sum_avg_shadow = {
        let mut s = lookback - 0 - 0;
        let mut acc = 0.0_f64;
        while s < (lookback - 0) {
            acc += real_body(open[s], close[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_shadow = lookback - 0 - 0;
    let mut i = lookback;
    while i < n {
        let cur_avg_body = real_body(open[i], close[i]);
        let val_avg_body = sum_avg_body / 10 as f64 * 1.0;
        let cur_avg_shadow = real_body(open[i], close[i]);
        let val_avg_shadow = cur_avg_shadow * 2.0;
        out[i] = if real_body(open[i], close[i]) < val_avg_body
            && upper_shadow(open[i], high[i], close[i]) > val_avg_shadow
            && lower_shadow(open[i], low[i], close[i]) > val_avg_shadow
        {
            candle_color(open[i], close[i]) * 100.0
        } else {
            0.0
        };
        sum_avg_body += cur_avg_body - real_body(open[trail_avg_body], close[trail_avg_body]);
        trail_avg_body += 1;
        sum_avg_shadow +=
            cur_avg_shadow - real_body(open[trail_avg_shadow], close[trail_avg_shadow]);
        trail_avg_shadow += 1;
        i += 1;
    }

    Ok(())
}

// ===========================================================================
// cdl_2crows — Two Crows（两只乌鸦）
// ===========================================================================

indicator! {
    /// Two Crows（两只乌鸦）：3-candle 顶部反转。第 1 根长阳线，第 2 根向上跳空阴线，
    /// 第 3 根阴线开盘在第 2 根实体内、收盘在第 1 根实体内。
    ///
    /// 两只乌鸦恒为看跌（`−100`）。`BodyLong` 使用 `OFF=2`（引用 `i−2`），
    /// `lookback = BodyLong + 2 = 12`。对应 `ta_CDL2CROWS.c`。
    ///
    /// Two Crows: 3-candle top reversal. Always bearish (`−100`). `BodyLong` uses `OFF=2`
    /// (references `i−2`), `lookback = 12`.
    fn cdl_2crows(open: &[f64], high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> with cdl_2crows_with_output init zero;
}

/// `cdl_2crows` 的零拷贝变体：将结果写入 `out`（长度须等于输入长度）。见 [`cdl_2crows`]。
/// Zero-copy variant of [`cdl_2crows`]: writes results into `out` (length must equal input length).
pub fn cdl_2crows_with_output(
    open: &[f64],
    high: &[f64],
    low: &[f64],
    close: &[f64],
    out: &mut [f64],
) -> Result<(), TaError> {
    if out.len() != open.len() {
        return Err(TaError::BadParam(
            "cdl_2crows_with_output: out length must equal input length".into(),
        ));
    }

    check_ohlc(open, high, low, close, "cdl_2crows")?;
    let n = open.len();
    let lookback = BODY_LONG.avg_period + 2; // 12
    if n <= lookback {
        return Ok(());
    }
    let mut sum_avg_body_long = {
        let mut s = lookback - 2 - 10;
        let mut acc = 0.0_f64;
        while s < (lookback - 2) {
            acc += real_body(open[s], close[s]);
            s += 1;
        }
        acc
    };
    let mut trail_avg_body_long = lookback - 2 - 10;
    let mut i = lookback;
    while i < n {
        let cur_avg_body_long = real_body(open[i - 2], close[i - 2]);
        let val_avg_body_long = sum_avg_body_long / 10 as f64 * 1.0;
        out[i] = if candle_color(open[i - 2], close[i - 2]) == 1.0 // 1st: white
            && real_body(open[i - 2], close[i - 2]) > val_avg_body_long
            && candle_color(open[i - 1], close[i - 1]) == -1.0 // 2nd: black
            && real_body_gap_up(open[i - 1], close[i - 1], open[i - 2], close[i - 2]) // gapping up
            && candle_color(open[i], close[i]) == -1.0 // 3rd: black
            && open[i] < open[i - 1]
            && open[i] > close[i - 1]
            && close[i] > open[i - 2]
            && close[i] < close[i - 2]
        {
            -100.0
        } else {
            0.0
        };
        sum_avg_body_long +=
            cur_avg_body_long - real_body(open[trail_avg_body_long], close[trail_avg_body_long]);
        trail_avg_body_long += 1;
        i += 1;
    }

    Ok(())
}