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indicators/regime/
detector.rs

1//! Indicator-Based Regime Detector
2//!
3//! Combines multiple technical indicators (ADX, Bollinger Bands, ATR, EMA) to
4//! classify the current market regime as Trending, Mean-Reverting, Volatile, or Uncertain.
5//!
6//! This is the fastest regime detection method — purely rule-based with no statistical
7//! learning. It provides immediate classification once indicators are warmed up.
8//!
9
10use std::collections::{HashMap, VecDeque};
11
12use super::primitives::{ADX, ATR, BollingerBands, BollingerBandsValues, EMA};
13use super::types::{
14    MarketRegime, RecommendedStrategy, RegimeConfidence, RegimeConfig, TrendDirection,
15};
16
17use crate::error::IndicatorError;
18use crate::indicator::{Indicator, IndicatorOutput};
19use crate::registry::param_usize;
20use crate::types::Candle;
21
22// ── Indicator wrapper ─────────────────────────────────────────────────────────
23
24/// Batch `Indicator` adapter for [`RegimeDetector`].
25///
26/// Replays candles through the streaming detector and emits per-bar
27/// `confidence` (0–1) and `regime_id` (0=Uncertain, 1=MeanReverting,
28/// 2=Volatile, 3=TrendingBull, 4=TrendingBear).
29#[derive(Debug, Clone)]
30pub struct DetectorIndicator {
31    pub config: RegimeConfig,
32}
33
34impl DetectorIndicator {
35    pub fn new(config: RegimeConfig) -> Self {
36        Self { config }
37    }
38    pub fn with_defaults() -> Self {
39        Self::new(RegimeConfig::default())
40    }
41}
42
43fn regime_id(r: MarketRegime) -> f64 {
44    use super::types::TrendDirection;
45    match r {
46        MarketRegime::MeanReverting => 1.0,
47        MarketRegime::Volatile => 2.0,
48        MarketRegime::Trending(TrendDirection::Bullish) => 3.0,
49        MarketRegime::Trending(TrendDirection::Bearish) => 4.0,
50        MarketRegime::Uncertain => 0.0,
51    }
52}
53
54impl Indicator for DetectorIndicator {
55    fn name(&self) -> &'static str {
56        "RegimeDetector"
57    }
58    fn required_len(&self) -> usize {
59        // `is_ready()` gates on all constituent indicators — take the max so
60        // `check_len` never passes while the detector still emits all-NaN bars.
61        let adx_warmup = self.config.adx_period * 2 + self.config.regime_stability_bars;
62        let ema_warmup = self.config.ema_long_period;
63        let bb_warmup = self.config.bb_period;
64        adx_warmup.max(ema_warmup).max(bb_warmup)
65    }
66    fn required_columns(&self) -> &[&'static str] {
67        &["high", "low", "close"]
68    }
69
70    fn calculate(&self, candles: &[Candle]) -> Result<IndicatorOutput, IndicatorError> {
71        self.check_len(candles)?;
72        let mut det = RegimeDetector::new(self.config.clone());
73        let n = candles.len();
74        let mut conf = vec![f64::NAN; n];
75        let mut regime = vec![f64::NAN; n];
76        for (i, c) in candles.iter().enumerate() {
77            let rc = det.update(c.high, c.low, c.close);
78            conf[i] = rc.confidence;
79            regime[i] = regime_id(rc.regime);
80        }
81        Ok(IndicatorOutput::from_pairs([
82            ("regime_conf", conf),
83            ("regime_id", regime),
84        ]))
85    }
86}
87
88// ── Registry factory ──────────────────────────────────────────────────────────
89
90pub fn factory<S: ::std::hash::BuildHasher>(
91    params: &HashMap<String, String, S>,
92) -> Result<Box<dyn Indicator>, IndicatorError> {
93    let adx_period = param_usize(params, "adx_period", 14)?;
94    let bb_period = param_usize(params, "bb_period", 20)?;
95    let config = RegimeConfig {
96        adx_period,
97        bb_period,
98        ..RegimeConfig::default()
99    };
100    Ok(Box::new(DetectorIndicator::new(config)))
101}
102
103/// Main indicator-based regime detection engine.
104///
105/// Feeds OHLC bars through ADX, ATR, Bollinger Bands, and dual-EMA indicators,
106/// then scores each regime possibility to produce a classification with confidence.
107///
108/// Includes a stability filter to prevent regime whipsawing.
109///
110/// # Example
111///
112/// ```rust
113/// use indicators::{RegimeDetector, RegimeConfig, MarketRegime};
114///
115/// let mut detector = RegimeDetector::crypto_optimized();
116///
117/// // Feed OHLC bars
118/// for i in 0..300 {
119///     let price = 100.0 + i as f64 * 0.5;
120///     let result = detector.update(price + 1.0, price - 1.0, price);
121///     if detector.is_ready() {
122///         println!("Regime: {} (conf: {:.0}%)", result.regime, result.confidence * 100.0);
123///     }
124/// }
125/// ```
126#[derive(Debug)]
127pub struct RegimeDetector {
128    config: RegimeConfig,
129
130    // Indicators
131    adx: ADX,
132    atr: ATR,
133    atr_avg: EMA, // For measuring ATR expansion
134    bb: BollingerBands,
135    ema_short: EMA,
136    ema_long: EMA,
137
138    // State
139    current_regime: MarketRegime,
140    regime_history: VecDeque<MarketRegime>,
141    bars_in_regime: usize,
142
143    // For trend direction
144    last_close: Option<f64>,
145}
146
147impl RegimeDetector {
148    /// Create a new detector with the given configuration
149    pub fn new(config: RegimeConfig) -> Self {
150        Self {
151            adx: ADX::new(config.adx_period),
152            atr: ATR::new(config.atr_period),
153            atr_avg: EMA::new(50), // Longer-term ATR average
154            bb: BollingerBands::new(config.bb_period, config.bb_std_dev),
155            ema_short: EMA::new(config.ema_short_period),
156            ema_long: EMA::new(config.ema_long_period),
157            current_regime: MarketRegime::Uncertain,
158            regime_history: VecDeque::with_capacity(20),
159            bars_in_regime: 0,
160            last_close: None,
161            config,
162        }
163    }
164
165    /// Create with default config
166    pub fn default_config() -> Self {
167        Self::new(RegimeConfig::default())
168    }
169
170    /// Create optimized for crypto markets
171    pub fn crypto_optimized() -> Self {
172        Self::new(RegimeConfig::crypto_optimized())
173    }
174
175    /// Create with conservative config
176    pub fn conservative() -> Self {
177        Self::new(RegimeConfig::conservative())
178    }
179
180    /// Update with new OHLC bar and get the regime classification.
181    ///
182    /// Returns a `RegimeConfidence` with the detected regime, confidence score,
183    /// and supporting indicator metrics.
184    ///
185    /// The detector requires a warmup period (determined by the longest indicator
186    /// period) before it starts producing meaningful classifications. During
187    /// warmup, it returns `MarketRegime::Uncertain` with zero confidence.
188    pub fn update(&mut self, high: f64, low: f64, close: f64) -> RegimeConfidence {
189        // Update all indicators
190        let adx_value = self.adx.update(high, low, close);
191        let atr_value = self.atr.update(high, low, close);
192        let bb_values = self.bb.update(close);
193        let ema_short = self.ema_short.update(close);
194        let ema_long = self.ema_long.update(close);
195
196        // Update ATR average for expansion detection
197        if let Some(atr) = atr_value {
198            self.atr_avg.update(atr);
199        }
200
201        self.last_close = Some(close);
202
203        // Check if we have enough data. The destructure mirrors `is_ready()`
204        // but doesn't rely on it staying in sync — no panic path if an
205        // indicator reports ready while still returning None.
206        let (Some(adx_value), Some(atr_value), Some(bb_values), Some(ema_short), Some(ema_long)) = (
207            adx_value,
208            atr_value,
209            bb_values.as_ref(),
210            ema_short,
211            ema_long,
212        ) else {
213            return RegimeConfidence::new(MarketRegime::Uncertain, 0.0);
214        };
215        if !self.is_ready() {
216            return RegimeConfidence::new(MarketRegime::Uncertain, 0.0);
217        }
218
219        // Detect regime
220        let (new_regime, confidence) =
221            self.classify_regime(adx_value, atr_value, bb_values, ema_short, ema_long, close);
222
223        // Apply stability filter - avoid whipsawing
224        let stable_regime = self.apply_stability_filter(new_regime, confidence);
225
226        // Update state
227        if stable_regime != self.current_regime {
228            self.regime_history.push_back(self.current_regime);
229            if self.regime_history.len() > 20 {
230                self.regime_history.pop_front();
231            }
232            self.current_regime = stable_regime;
233            self.bars_in_regime = 0;
234        } else {
235            self.bars_in_regime += 1;
236        }
237
238        RegimeConfidence::with_metrics(
239            stable_regime,
240            confidence,
241            adx_value,
242            bb_values.width_percentile,
243            Self::calculate_trend_strength(ema_short, ema_long, close),
244        )
245    }
246
247    /// Classify regime based on indicator values.
248    ///
249    /// Scores each regime possibility across multiple indicator dimensions:
250    /// - ADX for trend strength vs ranging
251    /// - Bollinger Band width for volatility
252    /// - ATR expansion for volatility confirmation
253    /// - EMA alignment for trend direction
254    /// - Price position relative to EMAs
255    fn classify_regime(
256        &self,
257        adx: f64,
258        atr: f64,
259        bb: &BollingerBandsValues,
260        ema_short: f64,
261        ema_long: f64,
262        close: f64,
263    ) -> (MarketRegime, f64) {
264        // Calculate ATR expansion
265        let atr_expansion = if let Some(avg_atr) = self.atr_avg.value() {
266            atr / avg_atr
267        } else {
268            1.0
269        };
270
271        // Score each regime possibility
272        let mut trending_score: f64 = 0.0;
273        let mut ranging_score: f64 = 0.0;
274        let mut volatile_score: f64 = 0.0;
275
276        // ADX analysis
277        if adx >= self.config.adx_trending_threshold {
278            trending_score += 0.4;
279        } else if adx <= self.config.adx_ranging_threshold {
280            ranging_score += 0.3;
281        }
282
283        // Bollinger Band width analysis
284        if bb.is_high_volatility(self.config.bb_width_volatility_threshold) {
285            volatile_score += 0.3;
286        }
287        if bb.is_squeeze(25.0) {
288            ranging_score += 0.2; // Tight bands suggest range-bound
289        }
290
291        // ATR expansion
292        if atr_expansion >= self.config.atr_expansion_threshold {
293            volatile_score += 0.3;
294        } else if atr_expansion < 0.8 {
295            ranging_score += 0.2; // Low volatility suggests ranging
296        }
297
298        // EMA alignment for trend
299        let ema_diff_pct = ((ema_short - ema_long) / ema_long).abs() * 100.0;
300        if ema_diff_pct > 2.0 {
301            trending_score += 0.3;
302        } else if ema_diff_pct < 1.0 {
303            ranging_score += 0.2;
304        }
305
306        // Price position relative to EMAs
307        let price_above_both = close > ema_short && close > ema_long;
308        let price_below_both = close < ema_short && close < ema_long;
309        if price_above_both || price_below_both {
310            trending_score += 0.2;
311        } else {
312            ranging_score += 0.2; // Price between EMAs suggests consolidation
313        }
314
315        // Determine regime and direction
316        let max_score = trending_score.max(ranging_score).max(volatile_score);
317        let confidence = max_score / 1.2; // Normalize to 0-1 range
318
319        let regime = if volatile_score >= 0.5 && volatile_score >= trending_score {
320            MarketRegime::Volatile
321        } else if trending_score > ranging_score && trending_score > 0.3 {
322            // Determine trend direction
323            let direction = if ema_short > ema_long && close > ema_long {
324                TrendDirection::Bullish
325            } else if ema_short < ema_long && close < ema_long {
326                TrendDirection::Bearish
327            } else if let Some(dir) = self.adx.trend_direction() {
328                dir
329            } else {
330                TrendDirection::Bullish // Default
331            };
332            MarketRegime::Trending(direction)
333        } else if ranging_score > 0.3 {
334            MarketRegime::MeanReverting
335        } else {
336            MarketRegime::Uncertain
337        };
338
339        (regime, confidence.min(1.0))
340    }
341
342    /// Apply stability filter to avoid regime whipsawing.
343    ///
344    /// Prevents rapid switching between regimes by requiring:
345    /// - Minimum confidence threshold to change
346    /// - Minimum duration in current regime before switching
347    /// - Consistent signals in recent history
348    fn apply_stability_filter(&self, new_regime: MarketRegime, confidence: f64) -> MarketRegime {
349        // If confidence is low, stick with current regime
350        if confidence < 0.4 {
351            return self.current_regime;
352        }
353
354        // Require minimum duration in current regime before switching
355        if self.bars_in_regime < self.config.min_regime_duration
356            && new_regime != self.current_regime
357        {
358            // Only switch if new regime is strongly confirmed
359            if confidence < 0.7 {
360                return self.current_regime;
361            }
362        }
363
364        // Check recent history for stability
365        let recent_count = self
366            .regime_history
367            .iter()
368            .rev()
369            .take(self.config.regime_stability_bars)
370            .filter(|&&r| {
371                matches!(
372                    (&r, &new_regime),
373                    (MarketRegime::Trending(_), MarketRegime::Trending(_))
374                        | (MarketRegime::MeanReverting, MarketRegime::MeanReverting)
375                        | (MarketRegime::Volatile, MarketRegime::Volatile)
376                )
377            })
378            .count();
379
380        // If regime has been bouncing around, require stronger confirmation
381        if recent_count < self.config.regime_stability_bars / 2 && confidence < 0.6 {
382            return self.current_regime;
383        }
384
385        new_regime
386    }
387
388    /// Calculate trend strength from EMA alignment and price position
389    fn calculate_trend_strength(ema_short: f64, ema_long: f64, close: f64) -> f64 {
390        let ema_alignment = (ema_short - ema_long).abs() / ema_long * 100.0;
391        let price_position = if close > ema_short && close > ema_long {
392            1.0
393        } else if close < ema_short && close < ema_long {
394            0.7
395        } else {
396            0.5
397        };
398
399        (ema_alignment * price_position / 5.0).min(1.0) // Normalize
400    }
401
402    // ========================================================================
403    // Public Accessors
404    // ========================================================================
405
406    /// Check if detector has enough data to classify regime.
407    ///
408    /// All indicators must be warmed up before the detector can produce
409    /// meaningful results.
410    pub fn is_ready(&self) -> bool {
411        self.adx.is_ready()
412            && self.atr.is_ready()
413            && self.bb.is_ready()
414            && self.ema_short.is_ready()
415            && self.ema_long.is_ready()
416    }
417
418    /// Get current detected regime
419    pub fn current_regime(&self) -> MarketRegime {
420        self.current_regime
421    }
422
423    /// Get recommended strategy for current regime
424    pub fn recommended_strategy(&self) -> RecommendedStrategy {
425        RecommendedStrategy::from(&self.current_regime)
426    }
427
428    /// Get number of bars in current regime
429    pub fn bars_in_current_regime(&self) -> usize {
430        self.bars_in_regime
431    }
432
433    /// Get ADX value
434    pub fn adx_value(&self) -> Option<f64> {
435        self.adx.value()
436    }
437
438    /// Get ATR value
439    pub fn atr_value(&self) -> Option<f64> {
440        self.atr.value()
441    }
442
443    /// Get current config
444    pub fn config(&self) -> &RegimeConfig {
445        &self.config
446    }
447
448    /// Update config (resets internal state)
449    pub fn set_config(&mut self, config: RegimeConfig) {
450        *self = Self::new(config);
451    }
452
453    /// Get the regime history (most recent at the back)
454    pub fn regime_history(&self) -> &VecDeque<MarketRegime> {
455        &self.regime_history
456    }
457
458    /// Get the last close price
459    pub fn last_close(&self) -> Option<f64> {
460        self.last_close
461    }
462}
463
464// ============================================================================
465// Tests
466// ============================================================================
467
468#[cfg(test)]
469mod tests {
470    use super::*;
471
472    /// Generate synthetic trending data
473    fn generate_trending_data(
474        bars: usize,
475        start_price: f64,
476        trend_strength: f64,
477    ) -> Vec<(f64, f64, f64)> {
478        let mut data = Vec::new();
479        let mut price = start_price;
480
481        for _ in 0..bars {
482            let change = trend_strength * (1.0 + (rand::random::<f64>() - 0.5) * 0.2);
483            price += change;
484
485            let high = price + price * 0.005;
486            let low = price - price * 0.005;
487            let close = price;
488
489            data.push((high, low, close));
490        }
491
492        data
493    }
494
495    /// Generate synthetic ranging data
496    fn generate_ranging_data(
497        bars: usize,
498        center_price: f64,
499        range_pct: f64,
500    ) -> Vec<(f64, f64, f64)> {
501        let mut data = Vec::new();
502
503        for i in 0..bars {
504            let offset = (i as f64 * 0.5).sin() * center_price * range_pct / 100.0;
505            let price = center_price + offset;
506
507            let high = price + price * 0.002;
508            let low = price - price * 0.002;
509            let close = price;
510
511            data.push((high, low, close));
512        }
513
514        data
515    }
516
517    /// Generate volatile data with large swings
518    fn generate_volatile_data(bars: usize, center_price: f64) -> Vec<(f64, f64, f64)> {
519        let mut data = Vec::new();
520
521        for i in 0..bars {
522            let swing = if i % 2 == 0 { 1.05 } else { 0.95 };
523            let price = center_price * swing;
524
525            let high = price * 1.03;
526            let low = price * 0.97;
527            let close = price;
528
529            data.push((high, low, close));
530        }
531
532        data
533    }
534
535    #[test]
536    fn test_volatile_regime_detection() {
537        let mut detector = RegimeDetector::default_config();
538        // Warm up with enough bars
539        for (high, low, close) in generate_volatile_data(200, 100.0) {
540            detector.update(high, low, close);
541        }
542        // After sufficient volatile bars the detector should be ready and return a valid regime.
543        assert!(detector.is_ready());
544        let regime = detector.current_regime();
545        assert!(
546            matches!(
547                regime,
548                MarketRegime::Volatile
549                    | MarketRegime::Trending(_)
550                    | MarketRegime::MeanReverting
551                    | MarketRegime::Uncertain
552            ),
553            "Expected a valid regime variant, got: {regime:?}"
554        );
555    }
556
557    #[test]
558    fn test_detector_creation() {
559        let detector = RegimeDetector::default_config();
560        assert!(!detector.is_ready());
561        assert_eq!(detector.current_regime(), MarketRegime::Uncertain);
562        assert_eq!(detector.bars_in_current_regime(), 0);
563    }
564
565    #[test]
566    fn test_crypto_optimized_creation() {
567        let detector = RegimeDetector::crypto_optimized();
568        assert!(!detector.is_ready());
569        assert_eq!(detector.config().adx_trending_threshold, 20.0);
570        assert_eq!(detector.config().ema_short_period, 21);
571    }
572
573    #[test]
574    fn test_conservative_creation() {
575        let detector = RegimeDetector::conservative();
576        assert_eq!(detector.config().adx_trending_threshold, 30.0);
577        assert_eq!(detector.config().min_regime_duration, 10);
578    }
579
580    #[test]
581    fn test_warmup_returns_uncertain() {
582        let mut detector = RegimeDetector::default_config();
583
584        // Feed a few bars — not enough for warmup
585        for i in 0..10 {
586            let price = 100.0 + i as f64;
587            let result = detector.update(price + 1.0, price - 1.0, price);
588            assert_eq!(result.regime, MarketRegime::Uncertain);
589            assert_eq!(result.confidence, 0.0);
590        }
591
592        assert!(!detector.is_ready());
593    }
594
595    #[test]
596    fn test_trending_detection() {
597        let mut detector = RegimeDetector::default_config();
598
599        // Generate uptrending data
600        let data = generate_trending_data(300, 100.0, 0.5);
601
602        let mut last_regime = MarketRegime::Uncertain;
603        for (high, low, close) in data {
604            let result = detector.update(high, low, close);
605            if detector.is_ready() {
606                last_regime = result.regime;
607            }
608        }
609
610        assert!(
611            matches!(last_regime, MarketRegime::Trending(_)),
612            "Expected Trending regime, got: {last_regime:?}"
613        );
614    }
615
616    #[test]
617    fn test_trending_bullish_direction() {
618        let mut detector = RegimeDetector::default_config();
619
620        // Strong uptrend
621        let data = generate_trending_data(300, 100.0, 0.5);
622
623        let mut last_regime = MarketRegime::Uncertain;
624        for (high, low, close) in data {
625            let result = detector.update(high, low, close);
626            if detector.is_ready() {
627                last_regime = result.regime;
628            }
629        }
630
631        assert!(
632            matches!(last_regime, MarketRegime::Trending(TrendDirection::Bullish)),
633            "Expected Bullish trend, got: {last_regime:?}"
634        );
635    }
636
637    #[test]
638    fn test_trending_bearish_direction() {
639        let mut detector = RegimeDetector::default_config();
640
641        // Strong downtrend
642        let data = generate_trending_data(300, 200.0, -0.5);
643
644        let mut last_regime = MarketRegime::Uncertain;
645        for (high, low, close) in data {
646            let result = detector.update(high, low, close);
647            if detector.is_ready() {
648                last_regime = result.regime;
649            }
650        }
651
652        // Should be either Bearish trending or at least not Bullish
653        if matches!(last_regime, MarketRegime::Trending(_)) {
654            assert!(
655                matches!(last_regime, MarketRegime::Trending(TrendDirection::Bearish)),
656                "Expected Bearish trend, got: {last_regime:?}"
657            );
658        }
659    }
660
661    #[test]
662    fn test_ranging_detection() {
663        let mut detector = RegimeDetector::default_config();
664
665        // Generate ranging data
666        let data = generate_ranging_data(300, 100.0, 2.0);
667
668        let mut last_regime = MarketRegime::Uncertain;
669        for (high, low, close) in data {
670            let result = detector.update(high, low, close);
671            if detector.is_ready() {
672                last_regime = result.regime;
673            }
674        }
675
676        // Ranging data should produce MeanReverting or at least not strong Trending
677        assert!(
678            !matches!(last_regime, MarketRegime::Trending(TrendDirection::Bullish)),
679            "Ranging data shouldn't produce strong bullish trend, got: {last_regime:?}"
680        );
681    }
682
683    #[test]
684    fn test_confidence_range() {
685        let mut detector = RegimeDetector::default_config();
686
687        let data = generate_trending_data(300, 100.0, 0.5);
688
689        for (high, low, close) in data {
690            let result = detector.update(high, low, close);
691            assert!(
692                (0.0..=1.0).contains(&result.confidence),
693                "Confidence should be in [0, 1]: {}",
694                result.confidence
695            );
696        }
697    }
698
699    #[test]
700    fn test_regime_history_tracking() {
701        let mut detector = RegimeDetector::default_config();
702
703        // Feed enough data to produce some regime changes
704        let trend_data = generate_trending_data(200, 100.0, 0.5);
705        for (high, low, close) in trend_data {
706            detector.update(high, low, close);
707        }
708
709        let range_data = generate_ranging_data(200, 200.0, 1.0);
710        for (high, low, close) in range_data {
711            detector.update(high, low, close);
712        }
713
714        // History should have been populated
715        // (exact content depends on stability filter)
716        assert!(
717            detector.regime_history().len() <= 20,
718            "History should be bounded"
719        );
720    }
721
722    #[test]
723    fn test_recommended_strategy() {
724        let mut detector = RegimeDetector::default_config();
725
726        // Feed trending data
727        let data = generate_trending_data(300, 100.0, 0.5);
728        for (high, low, close) in data {
729            detector.update(high, low, close);
730        }
731
732        if matches!(detector.current_regime(), MarketRegime::Trending(_)) {
733            assert_eq!(
734                detector.recommended_strategy(),
735                RecommendedStrategy::TrendFollowing
736            );
737        }
738    }
739
740    #[test]
741    fn test_adx_atr_accessors() {
742        let mut detector = RegimeDetector::default_config();
743
744        // Before warmup
745        assert!(detector.adx_value().is_none());
746        assert!(detector.atr_value().is_none());
747
748        // Feed data
749        let data = generate_trending_data(300, 100.0, 0.5);
750        for (high, low, close) in data {
751            detector.update(high, low, close);
752        }
753
754        // After warmup
755        assert!(detector.adx_value().is_some());
756        assert!(detector.atr_value().is_some());
757    }
758
759    #[test]
760    fn test_set_config_resets_state() {
761        let mut detector = RegimeDetector::default_config();
762
763        // Feed data
764        let data = generate_trending_data(300, 100.0, 0.5);
765        for (high, low, close) in data {
766            detector.update(high, low, close);
767        }
768        assert!(detector.is_ready());
769
770        // Reset with new config
771        detector.set_config(RegimeConfig::crypto_optimized());
772        assert!(!detector.is_ready());
773        assert_eq!(detector.current_regime(), MarketRegime::Uncertain);
774        assert_eq!(detector.bars_in_current_regime(), 0);
775    }
776
777    #[test]
778    fn test_last_close_tracking() {
779        let mut detector = RegimeDetector::default_config();
780
781        assert!(detector.last_close().is_none());
782
783        detector.update(101.0, 99.0, 100.0);
784        assert_eq!(detector.last_close(), Some(100.0));
785
786        detector.update(106.0, 104.0, 105.0);
787        assert_eq!(detector.last_close(), Some(105.0));
788    }
789
790    #[test]
791    fn test_bars_in_regime_increments() {
792        let mut detector = RegimeDetector::default_config();
793
794        // Feed gently trending data so ADX can warm up (needs price movement)
795        for i in 0..300 {
796            let price = 100.0 + i as f64 * 0.3;
797            detector.update(price + 1.0, price - 1.0, price);
798        }
799
800        // After stabilization, bars_in_regime should be > 0
801        assert!(
802            detector.bars_in_current_regime() > 0,
803            "Should have been in current regime for multiple bars (regime: {:?})",
804            detector.current_regime()
805        );
806    }
807
808    #[test]
809    fn test_stability_filter_prevents_whipsaw() {
810        let mut detector = RegimeDetector::new(RegimeConfig {
811            min_regime_duration: 10,
812            regime_stability_bars: 5,
813            ..RegimeConfig::default()
814        });
815
816        // First establish a regime with trending data
817        let trend_data = generate_trending_data(300, 100.0, 0.5);
818        for (high, low, close) in trend_data {
819            detector.update(high, low, close);
820        }
821
822        let regime_before = detector.current_regime();
823
824        // Feed just 2-3 bars of ranging data — shouldn't immediately switch
825        for (high, low, close) in generate_ranging_data(3, 250.0, 1.0) {
826            detector.update(high, low, close);
827        }
828
829        let regime_after = detector.current_regime();
830
831        // The stability filter should prevent an immediate switch.
832        // We verify the detector didn't crash, both regimes are valid variants,
833        // and log the transition for debugging.
834        assert!(
835            matches!(
836                regime_before,
837                MarketRegime::Trending(_)
838                    | MarketRegime::MeanReverting
839                    | MarketRegime::Volatile
840                    | MarketRegime::Uncertain
841            ),
842            "regime_before should be a valid variant: {regime_before:?}"
843        );
844        assert!(
845            matches!(
846                regime_after,
847                MarketRegime::Trending(_)
848                    | MarketRegime::MeanReverting
849                    | MarketRegime::Volatile
850                    | MarketRegime::Uncertain
851            ),
852            "Regime should be a valid variant after ranging data: {regime_after:?}"
853        );
854    }
855
856    #[test]
857    fn test_metrics_populated_after_warmup() {
858        let mut detector = RegimeDetector::default_config();
859
860        let data = generate_trending_data(300, 100.0, 0.5);
861        let mut last_result = RegimeConfidence::default();
862
863        for (high, low, close) in data {
864            last_result = detector.update(high, low, close);
865        }
866
867        // After warmup, metrics should be populated
868        assert!(last_result.adx_value > 0.0, "ADX should be > 0");
869        assert!(
870            last_result.bb_width_percentile >= 0.0 && last_result.bb_width_percentile <= 100.0,
871            "BB width percentile should be in [0, 100]"
872        );
873        assert!(
874            last_result.trend_strength >= 0.0 && last_result.trend_strength <= 1.0,
875            "Trend strength should be in [0, 1]"
876        );
877    }
878}