wickra_core/indicators/
cup_and_handle.rs

1//! Cup-and-Handle (and Inverse) continuation chart pattern.
2
3use crate::indicators::pattern_swing::{
4    approx_equal, SwingTracker, LEVEL_TOLERANCE, SWING_THRESHOLD,
5};
6use crate::ohlcv::Candle;
7use crate::traits::Indicator;
8
9/// Cup-and-Handle / Inverse — a rounded base (the cup) followed by a shallow
10/// pullback (the handle) near the rim, then a breakout in the cup's direction.
11///
12/// Built on confirmed swing pivots ([`SWING_THRESHOLD`] = 5%) and read from the
13/// last four pivots:
14///
15/// ```text
16/// cup-and-handle (bullish, +1):  Rim(high) , Cup(low) , Rim(high) , Handle(low)
17///   the two rims match (±3%) ; the handle low sits ABOVE the cup low (a shallow
18///   pullback) and below the right rim
19///
20/// inverse (bearish, -1):         Rim(low) , Cap(high) , Rim(low) , Handle(high)
21///   the two rims match ; the handle high sits BELOW the cap high and above the
22///   right rim
23/// ```
24///
25/// The shallow handle (closer to the rim than the cup extreme) is what
26/// distinguishes a cup-and-handle from a plain double bottom/top. Output is
27/// `+1.0` / `-1.0` / `0.0`; never `None`.
28#[derive(Debug, Clone)]
29pub struct CupAndHandle {
30    swing: SwingTracker,
31    has_emitted: bool,
32}
33
34impl CupAndHandle {
35    /// Construct a new Cup-and-Handle detector.
36    pub const fn new() -> Self {
37        Self {
38            swing: SwingTracker::new(SWING_THRESHOLD, 4),
39            has_emitted: false,
40        }
41    }
42}
43
44impl Default for CupAndHandle {
45    fn default() -> Self {
46        Self::new()
47    }
48}
49
50impl Indicator for CupAndHandle {
51    type Input = Candle;
52    type Output = f64;
53
54    fn update(&mut self, candle: Candle) -> Option<f64> {
55        self.has_emitted = true;
56        if !self.swing.update(candle) {
57            return Some(0.0);
58        }
59        let pivots = self.swing.pivots();
60        if pivots.len() < 4 {
61            return Some(0.0);
62        }
63        let n = pivots.len();
64        let rim_left = pivots[n - 4];
65        let extreme = pivots[n - 3];
66        let rim_right = pivots[n - 2];
67        let handle = pivots[n - 1];
68        let rims_match = approx_equal(rim_left.price, rim_right.price, LEVEL_TOLERANCE);
69
70        if handle.direction < 0.0 {
71            // Bullish cup-and-handle: rims are highs, cup is the low between them,
72            // handle is a shallow low above the cup but below the right rim.
73            if rims_match && handle.price > extreme.price && handle.price < rim_right.price {
74                return Some(1.0);
75            }
76        } else if rims_match && handle.price < extreme.price && handle.price > rim_right.price {
77            // Inverse: rims are lows, cap is the high, handle a shallow high.
78            return Some(-1.0);
79        }
80        Some(0.0)
81    }
82
83    fn reset(&mut self) {
84        self.swing.reset();
85        self.has_emitted = false;
86    }
87
88    fn warmup_period(&self) -> usize {
89        // Four confirmed pivots; the earliest confirmation of the fourth is bar 5.
90        5
91    }
92
93    fn is_ready(&self) -> bool {
94        self.has_emitted
95    }
96
97    fn name(&self) -> &'static str {
98        "CupAndHandle"
99    }
100}
101
102#[cfg(test)]
103mod tests {
104    use super::*;
105    use crate::indicators::pattern_swing::candles_for_pivots;
106    use crate::traits::BatchExt;
107
108    fn run(pivots: &[f64]) -> Vec<f64> {
109        let mut indicator = CupAndHandle::new();
110        candles_for_pivots(pivots)
111            .into_iter()
112            .map(|c| indicator.update(c).unwrap())
113            .collect()
114    }
115
116    #[test]
117    fn accessors_and_metadata() {
118        let indicator = CupAndHandle::new();
119        assert_eq!(indicator.name(), "CupAndHandle");
120        assert_eq!(indicator.warmup_period(), 5);
121        assert!(!indicator.is_ready());
122        assert!(!CupAndHandle::default().is_ready());
123    }
124
125    #[test]
126    fn cup_and_handle_is_plus_one() {
127        // Rims 120/121, cup 90 (deep), handle 110 (shallow, above the cup).
128        let out = run(&[120.0, 90.0, 121.0, 110.0]);
129        assert_eq!(*out.last().unwrap(), 1.0);
130    }
131
132    #[test]
133    fn inverse_cup_and_handle_is_minus_one() {
134        // Lead high then rims 100/101, cap 130, handle 110 (below cap, above rim).
135        let out = run(&[140.0, 100.0, 130.0, 101.0, 110.0]);
136        assert_eq!(*out.last().unwrap(), -1.0);
137    }
138
139    #[test]
140    fn deep_handle_is_not_cup_and_handle() {
141        // Handle (85) below the cup low (90) → a double bottom, not cup-and-handle.
142        let out = run(&[120.0, 90.0, 121.0, 85.0]);
143        assert_eq!(*out.last().unwrap(), 0.0);
144    }
145
146    #[test]
147    fn inverse_with_mismatched_rims_does_not_trigger() {
148        // Inverse shape (ends high) but the rims (100 / 90) diverge → enters the
149        // inverse branch yet reports no pattern.
150        let out = run(&[140.0, 100.0, 130.0, 90.0, 110.0]);
151        assert_eq!(*out.last().unwrap(), 0.0);
152    }
153
154    #[test]
155    fn reset_clears_state() {
156        let mut indicator = CupAndHandle::new();
157        for c in candles_for_pivots(&[120.0, 90.0, 121.0]) {
158            let _ = indicator.update(c);
159        }
160        indicator.reset();
161        assert!(!indicator.is_ready());
162        let c = Candle::new(99.5, 100.0, 99.5, 99.5, 1.0, 0).unwrap();
163        assert_eq!(indicator.update(c), Some(0.0));
164    }
165
166    #[test]
167    fn batch_equals_streaming() {
168        let candles = candles_for_pivots(&[120.0, 90.0, 121.0, 110.0]);
169        let mut a = CupAndHandle::new();
170        let mut b = CupAndHandle::new();
171        assert_eq!(
172            a.batch(&candles),
173            candles.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
174        );
175    }
176}
wickra_core/indicators/cup_and_handle.rs

wickra_core/indicators/
cup_and_handle.rs
