feat: TA-Lib candlestick patterns — abandoned/advance/belt/break/counter (part 2 of 9) (#132)

* feat: add Abandoned Baby candlestick pattern (CDLABANDONEDBABY)

* feat: add Advance Block candlestick pattern (CDLADVANCEBLOCK)

* feat: add Belt Hold candlestick pattern (CDLBELTHOLD)

* feat: add Breakaway and Counterattack candlestick patterns (CDLBREAKAWAY, CDLCOUNTERATTACK)

Breakaway is a 5-bar reversal: a trend gaps away on the second bar, drifts
two more bars, then the fifth bar snaps back and closes inside the bar1/bar2
body gap (bullish +1, bearish -1). Counterattack is a 2-bar reversal where an
opposite-coloured long second bar closes level with the first (the counterattack
line; bullish +1, bearish -1).

Also suppress libtest's spanless `large_stack_arrays` false positive in
wickra-core test builds: the `#[test]` harness collects every test into a
compiler-generated array of references that crosses clippy's 16 KB threshold
once the suite passes ~2048 unit tests. The allow is scoped to `cfg(test)`, so
library code is still linted for genuinely large stack arrays.

* chore: sync indicator count to 254

---------

Co-authored-by: wickra-bot <wickra-bot@users.noreply.github.com>

crates/wickra-core/src/indicators/counterattack.rs

@@ -0,0 +1,245 @@
+//! Counterattack candlestick pattern.
+
+use crate::error::{Error, Result};
+use crate::ohlcv::Candle;
+use crate::traits::Indicator;
+
+/// Counterattack — a 2-bar reversal where the second bar storms back to close
+/// right where the first bar closed. A long candle runs with the trend, then an
+/// opposite-coloured long candle opens far in the trend direction and rallies (or
+/// sells off) all the way back to the prior close — the two closes meeting forms
+/// the "counterattack line".
+///
+/// ```text
+/// long bodies   = |close − open| >= 0.5 * (high − low)   (both bars)
+/// equal closes  = |close2 − close1| <= tol * mean(range1, range2)
+/// bullish (+1.0): bar1 black (down), bar2 white (up), equal closes
+/// bearish (−1.0): bar1 white (up),   bar2 black (down), equal closes
+/// ```
+///
+/// Output is `+1.0` bullish, `−1.0` bearish, and `0.0` when the bodies are short,
+/// the colours match, or the closes are not level. The first bar always returns
+/// `0.0` because the two-bar window is not yet filled. `equal_tolerance` defaults
+/// to `0.05` (TA-Lib's `CDLCOUNTERATTACK` "equal" factor — 5 % of the mean bar
+/// range) and must lie in `[0, 1)`. The body-length test uses a fixed half-range
+/// fraction rather than TA-Lib's rolling body average, matching the geometric
+/// house style of this pattern family. Pattern-shape check only — no trend filter
+/// is applied; combine with a trend indicator for actionable signals.
+///
+/// # Signed ±1 encoding
+///
+/// This detector emits the uniform candlestick sign convention shared across the
+/// pattern family — `+1.0` bullish, `−1.0` bearish, `0.0` no pattern — so it
+/// drops straight into a machine-learning feature matrix where the bullish and
+/// bearish variants occupy a single dimension.
+///
+/// # Example
+///
+/// ```
+/// use wickra_core::{Candle, Counterattack, Indicator};
+///
+/// let mut indicator = Counterattack::new();
+/// // Bullish: a long black bar, then a long white bar closing at the same level.
+/// indicator.update(Candle::new(20.0, 20.1, 14.9, 15.0, 1.0, 0).unwrap());
+/// let out = indicator
+///     .update(Candle::new(10.0, 15.1, 9.9, 15.0, 1.0, 1).unwrap());
+/// assert_eq!(out, Some(1.0));
+/// ```
+#[derive(Debug, Clone)]
+pub struct Counterattack {
+    equal_tolerance: f64,
+    prev: Option<Candle>,
+    has_emitted: bool,
+}
+
+impl Default for Counterattack {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Counterattack {
+    /// Construct a Counterattack detector with the default 5 % equal-close tolerance.
+    pub const fn new() -> Self {
+        Self {
+            equal_tolerance: 0.05,
+            prev: None,
+            has_emitted: false,
+        }
+    }
+
+    /// Construct a Counterattack detector with a custom equal-close tolerance.
+    ///
+    /// `equal_tolerance` is the fraction of the mean bar range within which the
+    /// two closes must agree and must lie in `[0, 1)`.
+    pub fn with_tolerance(equal_tolerance: f64) -> Result<Self> {
+        if !(0.0..1.0).contains(&equal_tolerance) {
+            return Err(Error::InvalidPeriod {
+                message: "counterattack equal tolerance must lie in [0, 1)",
+            });
+        }
+        Ok(Self {
+            equal_tolerance,
+            prev: None,
+            has_emitted: false,
+        })
+    }
+
+    /// Configured equal-close tolerance.
+    pub fn equal_tolerance(&self) -> f64 {
+        self.equal_tolerance
+    }
+}
+
+impl Indicator for Counterattack {
+    type Input = Candle;
+    type Output = f64;
+
+    fn update(&mut self, candle: Candle) -> Option<f64> {
+        self.has_emitted = true;
+        let prev = self.prev;
+        self.prev = Some(candle);
+        let Some(bar1) = prev else {
+            return Some(0.0);
+        };
+        let range1 = bar1.high - bar1.low;
+        let range2 = candle.high - candle.low;
+        let body1 = bar1.close - bar1.open;
+        let body2 = candle.close - candle.open;
+        let long1 = body1.abs() >= 0.5 * range1;
+        let long2 = body2.abs() >= 0.5 * range2;
+        let tol = self.equal_tolerance * 0.5 * (range1 + range2);
+        let equal_close = (candle.close - bar1.close).abs() <= tol;
+        if !(long1 && long2 && equal_close) {
+            return Some(0.0);
+        }
+        // Bullish: a long black bar met by a long white bar closing level.
+        if body1 < 0.0 && body2 > 0.0 {
+            return Some(1.0);
+        }
+        // Bearish: a long white bar met by a long black bar closing level.
+        if body1 > 0.0 && body2 < 0.0 {
+            return Some(-1.0);
+        }
+        Some(0.0)
+    }
+
+    fn reset(&mut self) {
+        self.prev = None;
+        self.has_emitted = false;
+    }
+
+    fn warmup_period(&self) -> usize {
+        2
+    }
+
+    fn is_ready(&self) -> bool {
+        self.has_emitted
+    }
+
+    fn name(&self) -> &'static str {
+        "Counterattack"
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::traits::BatchExt;
+
+    fn c(open: f64, high: f64, low: f64, close: f64, ts: i64) -> Candle {
+        Candle::new(open, high, low, close, 1.0, ts).unwrap()
+    }
+
+    #[test]
+    fn rejects_invalid_tolerance() {
+        assert!(Counterattack::with_tolerance(-0.01).is_err());
+        assert!(Counterattack::with_tolerance(1.0).is_err());
+    }
+
+    #[test]
+    fn accepts_valid_tolerance() {
+        let t = Counterattack::with_tolerance(0.0).unwrap();
+        assert!((t.equal_tolerance() - 0.0).abs() < 1e-12);
+    }
+
+    #[test]
+    fn accessors_and_metadata() {
+        let t = Counterattack::default();
+        assert_eq!(t.name(), "Counterattack");
+        assert_eq!(t.warmup_period(), 2);
+        assert!(!t.is_ready());
+        assert!((t.equal_tolerance() - 0.05).abs() < 1e-12);
+    }
+
+    #[test]
+    fn bullish_counterattack_is_plus_one() {
+        let mut t = Counterattack::new();
+        assert_eq!(t.update(c(20.0, 20.1, 14.9, 15.0, 0)), Some(0.0));
+        assert_eq!(t.update(c(10.0, 15.1, 9.9, 15.0, 1)), Some(1.0));
+    }
+
+    #[test]
+    fn bearish_counterattack_is_minus_one() {
+        let mut t = Counterattack::new();
+        assert_eq!(t.update(c(15.0, 20.1, 14.9, 20.0, 0)), Some(0.0));
+        assert_eq!(t.update(c(25.0, 25.1, 19.9, 20.0, 1)), Some(-1.0));
+    }
+
+    #[test]
+    fn unequal_close_yields_zero() {
+        let mut t = Counterattack::new();
+        t.update(c(20.0, 20.1, 14.9, 15.0, 0));
+        // Second close at 17.0 is far from the first close (15.0) -> not level.
+        assert_eq!(t.update(c(10.0, 17.1, 9.9, 17.0, 1)), Some(0.0));
+    }
+
+    #[test]
+    fn same_color_yields_zero() {
+        let mut t = Counterattack::new();
+        // Both bars black -> not opposite colours.
+        t.update(c(20.0, 20.1, 14.9, 15.0, 0));
+        assert_eq!(t.update(c(20.0, 20.1, 14.9, 15.0, 1)), Some(0.0));
+    }
+
+    #[test]
+    fn short_body_yields_zero() {
+        let mut t = Counterattack::new();
+        // Second bar has a tiny body relative to its range.
+        t.update(c(20.0, 20.1, 14.9, 15.0, 0));
+        assert_eq!(t.update(c(14.8, 20.0, 9.9, 15.2, 1)), Some(0.0));
+    }
+
+    #[test]
+    fn first_bar_returns_zero() {
+        let mut t = Counterattack::new();
+        assert_eq!(t.update(c(20.0, 20.1, 14.9, 15.0, 0)), Some(0.0));
+    }
+
+    #[test]
+    fn batch_equals_streaming() {
+        let candles: Vec<Candle> = (0..40)
+            .map(|i| {
+                let base = 100.0 + i as f64;
+                c(base, base + 2.0, base - 2.0, base + 1.5, i)
+            })
+            .collect();
+        let mut a = Counterattack::new();
+        let mut b = Counterattack::new();
+        assert_eq!(
+            a.batch(&candles),
+            candles.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
+        );
+    }
+
+    #[test]
+    fn reset_clears_state() {
+        let mut t = Counterattack::new();
+        t.update(c(20.0, 20.1, 14.9, 15.0, 0));
+        t.update(c(10.0, 15.1, 9.9, 15.0, 1));
+        assert!(t.is_ready());
+        t.reset();
+        assert!(!t.is_ready());
+        assert_eq!(t.update(c(20.0, 20.1, 14.9, 15.0, 0)), Some(0.0));
+    }
+}