# Creating Custom Strategies

This guide explains how to create custom trading strategies for Crypto Trader.

## Strategy Framework

All strategies inherit from `BaseStrategy` and implement a standardized interface. This allows the trading engine to execute any strategy uniformly.

## Basic Strategy Structure

```python
from src.strategies.base import BaseStrategy, StrategyRegistry
from src.data.indicators import get_indicators
import pandas as pd
from typing import Dict, Any

class MyCustomStrategy(BaseStrategy):
    """My custom trading strategy."""
    
    def __init__(self, strategy_id: int, name: str, symbol: str, timeframe: str, parameters: Dict[str, Any]):
        super().__init__(strategy_id, name, symbol, timeframe, parameters)
        # Initialize strategy-specific parameters
        self.my_param = parameters.get("my_param", 10)
    
    async def on_data(self, new_data: pd.DataFrame):
        """Called when new data is available."""
        # Update internal data
        self.current_data = pd.concat([self.current_data, new_data])
        
        # Generate signal if enough data
        if len(self.current_data) >= self.my_param:
            signal = await self.generate_signal()
            if signal["signal"] != "hold":
                # Signal generated - will be handled by trading engine
                pass
    
    async def generate_signal(self) -> Dict[str, Any]:
        """Generate trading signal."""
        # Calculate indicators
        indicators = get_indicators()
        rsi = indicators.rsi(self.current_data['close'], period=14)
        
        # Generate signal based on strategy logic
        current_rsi = rsi.iloc[-1]
        current_price = self.current_data['close'].iloc[-1]
        
        if current_rsi < 30:
            return {"signal": "buy", "price": current_price}
        elif current_rsi > 70:
            return {"signal": "sell", "price": current_price}
        else:
            return {"signal": "hold", "price": current_price}
    
    async def calculate_position_size(self, capital: float, risk_percentage: float) -> float:
        """Calculate position size."""
        return capital * risk_percentage

# Register strategy
StrategyRegistry.register_strategy("my_custom", MyCustomStrategy)
```

## Required Methods

### `on_data(new_data: pd.DataFrame)`

Called when new OHLCV data is available for the strategy's timeframe.

**Responsibilities**:
- Update internal data storage
- Calculate indicators
- Generate signals when conditions are met

### `generate_signal() -> Dict[str, Any]`

Analyzes current data and generates a trading signal.

**Returns**:
```python
{
    "signal": "buy" | "sell" | "hold",
    "price": float,  # Optional, current price
    "confidence": float,  # Optional, 0.0 to 1.0
}
```

### `calculate_position_size(capital: float, risk_percentage: float) -> float`

Calculates the appropriate position size based on capital and risk.

**Parameters**:
- `capital`: Available trading capital
- `risk_percentage`: Percentage of capital to risk (0.0 to 1.0)

**Returns**: Position size in base currency

## Using Technical Indicators

Access indicators through the indicators library:

```python
from src.data.indicators import get_indicators

indicators = get_indicators()

# Calculate indicators
sma = indicators.sma(data['close'], period=20)
ema = indicators.ema(data['close'], period=20)
rsi = indicators.rsi(data['close'], period=14)
macd_result = indicators.macd(data['close'], fast=12, slow=26, signal=9)
bbands = indicators.bollinger_bands(data['close'], period=20, std_dev=2)
```

## Multi-Timeframe Strategies

Strategies can use multiple timeframes:

```python
from src.strategies.timeframe_manager import get_timeframe_manager

timeframe_manager = get_timeframe_manager()

# Get data from different timeframes
primary_data = timeframe_manager.get_data(self.symbol, self.timeframe)
higher_tf_data = timeframe_manager.get_data(self.symbol, "1d")  # Daily for trend

# Use higher timeframe for trend confirmation
if higher_tf_data is not None and len(higher_tf_data) > 0:
    daily_trend = higher_tf_data['close'].iloc[-1] > higher_tf_data['close'].iloc[-20]
    if daily_trend:
        # Only trade in direction of higher timeframe trend
        pass
```

## Strategy Parameters

Define configurable parameters:

```python
def __init__(self, strategy_id: int, name: str, symbol: str, timeframe: str, parameters: Dict[str, Any]):
    super().__init__(strategy_id, name, symbol, timeframe, parameters)
    
    # Required parameters with defaults
    self.rsi_period = parameters.get("rsi_period", 14)
    self.overbought = parameters.get("overbought", 70)
    self.oversold = parameters.get("oversold", 30)
    
    # Validate parameters
    if not (0 < self.oversold < self.overbought < 100):
        raise ValueError("Invalid RSI thresholds")
```

## Strategy Registration

Register your strategy so it can be used:

```python
from src.strategies.base import StrategyRegistry

StrategyRegistry.register_strategy("my_strategy", MyCustomStrategy)
```

## Strategy Lifecycle

1. **Initialization**: Strategy is created with parameters
2. **Start**: `start()` is called when strategy is activated
3. **Data Updates**: `on_data()` is called with new candles
4. **Signal Generation**: `generate_signal()` is called when conditions are met
5. **Order Execution**: Trading engine executes signals
6. **Stop**: `stop()` is called when strategy is deactivated

## Best Practices

1. **Parameter Validation**: Validate all parameters in `__init__`
2. **Error Handling**: Handle missing data and calculation errors
3. **Logging**: Use strategy logger for important events
4. **Testing**: Write unit tests for your strategy
5. **Documentation**: Document strategy logic and parameters
6. **Backtesting**: Always backtest before live trading

## Example: Complete Strategy

See `src/strategies/technical/rsi_strategy.py` for a complete example.

## Available Strategy Examples

The codebase includes several advanced strategy implementations that serve as examples:

### Multi-Indicator Confirmation

See `src/strategies/technical/confirmed_strategy.py` for an example of combining multiple indicators.

### Divergence Detection

See `src/strategies/technical/divergence_strategy.py` for an example of divergence detection using the indicators API.

### Ensemble Methods

See `src/strategies/ensemble/consensus_strategy.py` for an example of combining multiple strategies with weighted voting.

### Trend Filtering

All strategies can use the optional trend filter method from BaseStrategy:

```python
signal = strategy.apply_trend_filter(signal, ohlcv_data, adx_period=14, min_adx=25.0)
```

## Testing Your Strategy

```python
import pytest
from src.strategies.my_strategy import MyCustomStrategy

def test_strategy_signal_generation():
    """Test strategy signal generation."""
    strategy = MyCustomStrategy(
        strategy_id=1,
        name="Test Strategy",
        symbol="BTC/USD",
        timeframe="1h",
        parameters={"rsi_period": 14}
    )
    
    # Create test data
    test_data = pd.DataFrame({
        'close': [100, 101, 102, 103, 104]
    })
    
    # Test signal generation
    signal = await strategy.generate_signal()
    assert signal["signal"] in ["buy", "sell", "hold"]
```