# Trend Indicators

## Overview

Trend indicators help identify the direction and strength of market trends. IncrementalTrader provides Supertrend implementations that combine price action with volatility to generate clear trend signals.

## SupertrendState

Individual Supertrend indicator that tracks trend direction and provides support/resistance levels.

### Features
- **Trend Direction**: Clear bullish/bearish trend identification
- **Dynamic Support/Resistance**: Adaptive levels based on volatility
- **ATR-Based**: Uses Average True Range for volatility adjustment
- **Real-time Updates**: Incremental calculation for live trading

### Mathematical Formula

```
Basic Upper Band = (High + Low) / 2 + (Multiplier × ATR)
Basic Lower Band = (High + Low) / 2 - (Multiplier × ATR)

Final Upper Band = Basic Upper Band < Previous Final Upper Band OR Previous Close > Previous Final Upper Band 
                   ? Basic Upper Band : Previous Final Upper Band

Final Lower Band = Basic Lower Band > Previous Final Lower Band OR Previous Close < Previous Final Lower Band 
                   ? Basic Lower Band : Previous Final Lower Band

Supertrend = Close <= Final Lower Band ? Final Lower Band : Final Upper Band
Trend = Close <= Final Lower Band ? DOWN : UP
```

### Class Definition

```python
from IncrementalTrader.strategies.indicators import SupertrendState

class SupertrendState(OHLCIndicatorState):
    def __init__(self, period: int, multiplier: float):
        super().__init__(period)
        self.multiplier = multiplier
        self.atr = SimpleATRState(period)
        
        # Supertrend state
        self.supertrend_value = 0.0
        self.trend = 1  # 1 for up, -1 for down
        self.final_upper_band = 0.0
        self.final_lower_band = 0.0
        self.previous_close = 0.0
    
    def _process_ohlc_data(self, high: float, low: float, close: float):
        # Update ATR
        self.atr.update_ohlc(high, low, close)
        
        if not self.atr.is_ready():
            return
        
        # Calculate basic bands
        hl2 = (high + low) / 2.0
        atr_value = self.atr.get_value()
        
        basic_upper_band = hl2 + (self.multiplier * atr_value)
        basic_lower_band = hl2 - (self.multiplier * atr_value)
        
        # Calculate final bands
        if self.data_count == 1:
            self.final_upper_band = basic_upper_band
            self.final_lower_band = basic_lower_band
        else:
            # Final upper band logic
            if basic_upper_band < self.final_upper_band or self.previous_close > self.final_upper_band:
                self.final_upper_band = basic_upper_band
            
            # Final lower band logic
            if basic_lower_band > self.final_lower_band or self.previous_close < self.final_lower_band:
                self.final_lower_band = basic_lower_band
        
        # Determine trend and supertrend value
        if close <= self.final_lower_band:
            self.trend = -1  # Downtrend
            self.supertrend_value = self.final_lower_band
        else:
            self.trend = 1   # Uptrend
            self.supertrend_value = self.final_upper_band
        
        self.previous_close = close
    
    def get_value(self) -> float:
        return self.supertrend_value
    
    def get_trend(self) -> int:
        """Get current trend direction: 1 for up, -1 for down."""
        return self.trend
    
    def is_bullish(self) -> bool:
        """Check if current trend is bullish."""
        return self.trend == 1
    
    def is_bearish(self) -> bool:
        """Check if current trend is bearish."""
        return self.trend == -1
```

### Usage Examples

#### Basic Supertrend Usage
```python
# Create Supertrend with 10-period ATR and 3.0 multiplier
supertrend = SupertrendState(period=10, multiplier=3.0)

# OHLC data: (high, low, close)
ohlc_data = [
    (105.0, 102.0, 104.0),
    (106.0, 103.0, 105.5),
    (107.0, 104.0, 106.0),
    (108.0, 105.0, 107.5)
]

for high, low, close in ohlc_data:
    supertrend.update_ohlc(high, low, close)
    if supertrend.is_ready():
        trend_direction = "BULLISH" if supertrend.is_bullish() else "BEARISH"
        print(f"Supertrend: {supertrend.get_value():.2f}, Trend: {trend_direction}")
```

#### Trend Change Detection
```python
class SupertrendSignals:
    def __init__(self, period: int = 10, multiplier: float = 3.0):
        self.supertrend = SupertrendState(period, multiplier)
        self.previous_trend = None
    
    def update(self, high: float, low: float, close: float):
        self.supertrend.update_ohlc(high, low, close)
    
    def get_signal(self) -> str:
        if not self.supertrend.is_ready():
            return "HOLD"
        
        current_trend = self.supertrend.get_trend()
        
        # Check for trend change
        if self.previous_trend is not None and self.previous_trend != current_trend:
            if current_trend == 1:
                signal = "BUY"  # Trend changed to bullish
            else:
                signal = "SELL"  # Trend changed to bearish
        else:
            signal = "HOLD"
        
        self.previous_trend = current_trend
        return signal
    
    def get_support_resistance(self) -> float:
        """Get current support/resistance level."""
        return self.supertrend.get_value()

# Usage
signals = SupertrendSignals(period=10, multiplier=3.0)

for high, low, close in ohlc_data:
    signals.update(high, low, close)
    signal = signals.get_signal()
    support_resistance = signals.get_support_resistance()
    
    if signal != "HOLD":
        print(f"Signal: {signal} at {close:.2f}, S/R: {support_resistance:.2f}")
```

### Performance Characteristics
- **Time Complexity**: O(1) per update
- **Space Complexity**: O(ATR_period)
- **Memory Usage**: ~8 bytes per ATR period + constant overhead

## SupertrendCollection

Collection of multiple Supertrend indicators for meta-trend analysis.

### Features
- **Multiple Timeframes**: Combines different Supertrend configurations
- **Consensus Signals**: Requires agreement among multiple indicators
- **Trend Strength**: Measures trend strength through consensus
- **Flexible Configuration**: Customizable periods and multipliers

### Class Definition

```python
class SupertrendCollection:
    def __init__(self, configs: list):
        """
        Initialize with list of (period, multiplier) tuples.
        Example: [(10, 3.0), (14, 2.0), (21, 1.5)]
        """
        self.supertrendss = []
        for period, multiplier in configs:
            self.supertrendss.append(SupertrendState(period, multiplier))
        
        self.configs = configs
    
    def update_ohlc(self, high: float, low: float, close: float):
        """Update all Supertrend indicators."""
        for st in self.supertrendss:
            st.update_ohlc(high, low, close)
    
    def is_ready(self) -> bool:
        """Check if all indicators are ready."""
        return all(st.is_ready() for st in self.supertrendss)
    
    def get_consensus_trend(self) -> int:
        """Get consensus trend: 1 for bullish, -1 for bearish, 0 for mixed."""
        if not self.is_ready():
            return 0
        
        trends = [st.get_trend() for st in self.supertrendss]
        bullish_count = sum(1 for trend in trends if trend == 1)
        bearish_count = sum(1 for trend in trends if trend == -1)
        
        if bullish_count > bearish_count:
            return 1
        elif bearish_count > bullish_count:
            return -1
        else:
            return 0
    
    def get_trend_strength(self) -> float:
        """Get trend strength as percentage of indicators agreeing."""
        if not self.is_ready():
            return 0.0
        
        consensus_trend = self.get_consensus_trend()
        if consensus_trend == 0:
            return 0.0
        
        trends = [st.get_trend() for st in self.supertrendss]
        agreeing_count = sum(1 for trend in trends if trend == consensus_trend)
        
        return agreeing_count / len(trends)
    
    def get_supertrend_values(self) -> list:
        """Get all Supertrend values."""
        return [st.get_value() for st in self.supertrendss if st.is_ready()]
    
    def get_average_supertrend(self) -> float:
        """Get average Supertrend value."""
        values = self.get_supertrend_values()
        return sum(values) / len(values) if values else 0.0
```

### Usage Examples

#### Multi-Timeframe Trend Analysis
```python
# Create collection with different configurations
configs = [
    (10, 3.0),  # Fast Supertrend
    (14, 2.5),  # Medium Supertrend
    (21, 2.0)   # Slow Supertrend
]

supertrend_collection = SupertrendCollection(configs)

for high, low, close in ohlc_data:
    supertrend_collection.update_ohlc(high, low, close)
    
    if supertrend_collection.is_ready():
        consensus = supertrend_collection.get_consensus_trend()
        strength = supertrend_collection.get_trend_strength()
        avg_supertrend = supertrend_collection.get_average_supertrend()
        
        trend_name = {1: "BULLISH", -1: "BEARISH", 0: "MIXED"}[consensus]
        print(f"Consensus: {trend_name}, Strength: {strength:.1%}, Avg S/R: {avg_supertrend:.2f}")
```

#### Meta-Trend Strategy
```python
class MetaTrendStrategy:
    def __init__(self):
        # Multiple Supertrend configurations
        self.supertrend_collection = SupertrendCollection([
            (10, 3.0),  # Fast
            (14, 2.5),  # Medium
            (21, 2.0),  # Slow
            (28, 1.5)   # Very slow
        ])
        
        self.previous_consensus = None
    
    def update(self, high: float, low: float, close: float):
        self.supertrend_collection.update_ohlc(high, low, close)
    
    def get_meta_signal(self) -> dict:
        if not self.supertrend_collection.is_ready():
            return {"signal": "HOLD", "confidence": 0.0, "strength": 0.0}
        
        current_consensus = self.supertrend_collection.get_consensus_trend()
        strength = self.supertrend_collection.get_trend_strength()
        
        # Check for consensus change
        signal = "HOLD"
        if self.previous_consensus is not None and self.previous_consensus != current_consensus:
            if current_consensus == 1:
                signal = "BUY"
            elif current_consensus == -1:
                signal = "SELL"
        
        # Calculate confidence based on strength and consensus
        confidence = strength if current_consensus != 0 else 0.0
        
        self.previous_consensus = current_consensus
        
        return {
            "signal": signal,
            "confidence": confidence,
            "strength": strength,
            "consensus": current_consensus,
            "avg_supertrend": self.supertrend_collection.get_average_supertrend()
        }

# Usage
meta_strategy = MetaTrendStrategy()

for high, low, close in ohlc_data:
    meta_strategy.update(high, low, close)
    result = meta_strategy.get_meta_signal()
    
    if result["signal"] != "HOLD":
        print(f"Meta Signal: {result['signal']}, Confidence: {result['confidence']:.1%}")
```

### Performance Characteristics
- **Time Complexity**: O(n) per update (where n is number of Supertrends)
- **Space Complexity**: O(sum of all ATR periods)
- **Memory Usage**: Scales with number of indicators

## Advanced Usage Patterns

### Adaptive Supertrend
```python
class AdaptiveSupertrend:
    def __init__(self, base_period: int = 14, base_multiplier: float = 2.0):
        self.base_period = base_period
        self.base_multiplier = base_multiplier
        
        # Volatility measurement for adaptation
        self.atr_short = SimpleATRState(period=5)
        self.atr_long = SimpleATRState(period=20)
        
        # Current adaptive Supertrend
        self.current_supertrend = SupertrendState(base_period, base_multiplier)
        
        # Adaptation parameters
        self.min_multiplier = 1.0
        self.max_multiplier = 4.0
    
    def update_ohlc(self, high: float, low: float, close: float):
        # Update volatility measurements
        self.atr_short.update_ohlc(high, low, close)
        self.atr_long.update_ohlc(high, low, close)
        
        # Calculate adaptive multiplier
        if self.atr_long.is_ready() and self.atr_short.is_ready():
            volatility_ratio = self.atr_short.get_value() / self.atr_long.get_value()
            
            # Adjust multiplier based on volatility
            adaptive_multiplier = self.base_multiplier * volatility_ratio
            adaptive_multiplier = max(self.min_multiplier, min(self.max_multiplier, adaptive_multiplier))
            
            # Update Supertrend if multiplier changed significantly
            if abs(adaptive_multiplier - self.current_supertrend.multiplier) > 0.1:
                self.current_supertrend = SupertrendState(self.base_period, adaptive_multiplier)
        
        # Update current Supertrend
        self.current_supertrend.update_ohlc(high, low, close)
    
    def get_value(self) -> float:
        return self.current_supertrend.get_value()
    
    def get_trend(self) -> int:
        return self.current_supertrend.get_trend()
    
    def is_ready(self) -> bool:
        return self.current_supertrend.is_ready()
    
    def get_current_multiplier(self) -> float:
        return self.current_supertrend.multiplier

# Usage
adaptive_st = AdaptiveSupertrend(base_period=14, base_multiplier=2.0)

for high, low, close in ohlc_data:
    adaptive_st.update_ohlc(high, low, close)
    
    if adaptive_st.is_ready():
        trend = "BULLISH" if adaptive_st.get_trend() == 1 else "BEARISH"
        multiplier = adaptive_st.get_current_multiplier()
        print(f"Adaptive Supertrend: {adaptive_st.get_value():.2f}, "
              f"Trend: {trend}, Multiplier: {multiplier:.2f}")
```

### Supertrend with Stop Loss Management
```python
class SupertrendStopLoss:
    def __init__(self, period: int = 14, multiplier: float = 2.0, buffer_percent: float = 0.5):
        self.supertrend = SupertrendState(period, multiplier)
        self.buffer_percent = buffer_percent / 100.0
        
        self.current_position = None  # "LONG", "SHORT", or None
        self.entry_price = 0.0
        self.stop_loss = 0.0
    
    def update(self, high: float, low: float, close: float):
        previous_trend = self.supertrend.get_trend() if self.supertrend.is_ready() else None
        self.supertrend.update_ohlc(high, low, close)
        
        if not self.supertrend.is_ready():
            return
        
        current_trend = self.supertrend.get_trend()
        supertrend_value = self.supertrend.get_value()
        
        # Check for trend change (entry signal)
        if previous_trend is not None and previous_trend != current_trend:
            if current_trend == 1:  # Bullish trend
                self.enter_long(close, supertrend_value)
            else:  # Bearish trend
                self.enter_short(close, supertrend_value)
        
        # Update stop loss for existing position
        if self.current_position:
            self.update_stop_loss(supertrend_value)
    
    def enter_long(self, price: float, supertrend_value: float):
        self.current_position = "LONG"
        self.entry_price = price
        self.stop_loss = supertrend_value * (1 - self.buffer_percent)
        print(f"LONG entry at {price:.2f}, Stop: {self.stop_loss:.2f}")
    
    def enter_short(self, price: float, supertrend_value: float):
        self.current_position = "SHORT"
        self.entry_price = price
        self.stop_loss = supertrend_value * (1 + self.buffer_percent)
        print(f"SHORT entry at {price:.2f}, Stop: {self.stop_loss:.2f}")
    
    def update_stop_loss(self, supertrend_value: float):
        if self.current_position == "LONG":
            new_stop = supertrend_value * (1 - self.buffer_percent)
            if new_stop > self.stop_loss:  # Only move stop up
                self.stop_loss = new_stop
        elif self.current_position == "SHORT":
            new_stop = supertrend_value * (1 + self.buffer_percent)
            if new_stop < self.stop_loss:  # Only move stop down
                self.stop_loss = new_stop
    
    def check_stop_loss(self, current_price: float) -> bool:
        """Check if stop loss is hit."""
        if not self.current_position:
            return False
        
        if self.current_position == "LONG" and current_price <= self.stop_loss:
            print(f"LONG stop loss hit at {current_price:.2f}")
            self.current_position = None
            return True
        elif self.current_position == "SHORT" and current_price >= self.stop_loss:
            print(f"SHORT stop loss hit at {current_price:.2f}")
            self.current_position = None
            return True
        
        return False

# Usage
st_stop_loss = SupertrendStopLoss(period=14, multiplier=2.0, buffer_percent=0.5)

for high, low, close in ohlc_data:
    st_stop_loss.update(high, low, close)
    
    # Check stop loss on each update
    if st_stop_loss.check_stop_loss(close):
        print("Position closed due to stop loss")
```

## Integration with Strategies

### Supertrend Strategy Example
```python
class SupertrendStrategy(IncStrategyBase):
    def __init__(self, name: str, params: dict = None):
        super().__init__(name, params)
        
        # Initialize Supertrend collection
        configs = self.params.get('supertrend_configs', [(10, 3.0), (14, 2.5), (21, 2.0)])
        self.supertrend_collection = SupertrendCollection(configs)
        
        # Strategy parameters
        self.min_strength = self.params.get('min_strength', 0.75)
        self.previous_consensus = None
    
    def _process_aggregated_data(self, timestamp: int, ohlcv: tuple) -> IncStrategySignal:
        open_price, high, low, close, volume = ohlcv
        
        # Update Supertrend collection
        self.supertrend_collection.update_ohlc(high, low, close)
        
        # Wait for indicators to be ready
        if not self.supertrend_collection.is_ready():
            return IncStrategySignal.HOLD()
        
        # Get consensus and strength
        current_consensus = self.supertrend_collection.get_consensus_trend()
        strength = self.supertrend_collection.get_trend_strength()
        
        # Check for strong consensus change
        if (self.previous_consensus is not None and 
            self.previous_consensus != current_consensus and 
            strength >= self.min_strength):
            
            if current_consensus == 1:
                # Strong bullish consensus
                return IncStrategySignal.BUY(
                    confidence=strength,
                    metadata={
                        'consensus': current_consensus,
                        'strength': strength,
                        'avg_supertrend': self.supertrend_collection.get_average_supertrend()
                    }
                )
            elif current_consensus == -1:
                # Strong bearish consensus
                return IncStrategySignal.SELL(
                    confidence=strength,
                    metadata={
                        'consensus': current_consensus,
                        'strength': strength,
                        'avg_supertrend': self.supertrend_collection.get_average_supertrend()
                    }
                )
        
        self.previous_consensus = current_consensus
        return IncStrategySignal.HOLD()
```

## Performance Optimization Tips

### 1. Choose Appropriate Configurations
```python
# For fast signals (more noise)
fast_configs = [(7, 3.0), (10, 2.5)]

# For balanced signals
balanced_configs = [(10, 3.0), (14, 2.5), (21, 2.0)]

# For slow, reliable signals
slow_configs = [(14, 2.0), (21, 1.5), (28, 1.0)]
```

### 2. Optimize Memory Usage
```python
# Use SimpleATRState for memory efficiency
class MemoryEfficientSupertrend(SupertrendState):
    def __init__(self, period: int, multiplier: float):
        super().__init__(period, multiplier)
        # Replace ATRState with SimpleATRState
        self.atr = SimpleATRState(period)
```

### 3. Batch Processing
```python
def update_multiple_supertrends(supertrends: list, high: float, low: float, close: float):
    """Efficiently update multiple Supertrend indicators."""
    for st in supertrends:
        st.update_ohlc(high, low, close)
    
    return [(st.get_value(), st.get_trend()) for st in supertrends if st.is_ready()]
```

---

*Supertrend indicators provide clear trend direction and dynamic support/resistance levels. Use single Supertrend for simple trend following or SupertrendCollection for robust meta-trend analysis.*