/**
* Candlestick Pattern Detection
* detectCandlestickPatterns function
*/
export function detectCandlestickPatterns(historicalData, lookbackPeriod = 5) {
if (!historicalData || historicalData.length < lookbackPeriod) {
return {
patterns: []
};
}
const patterns = [];
const recentCandles = historicalData.slice(-lookbackPeriod);
for (let i = 1; i < recentCandles.length; i++) {
const current = recentCandles[i];
const previous = recentCandles[i - 1];
const bodySize = Math.abs(current.close - current.open);
const upperShadow = current.high - Math.max(current.open, current.close);
const lowerShadow = Math.min(current.open, current.close) - current.low;
const totalRange = current.high - current.low;
// Doji: Small body, long shadows
if (bodySize < totalRange * 0.1 && (upperShadow > totalRange * 0.3 || lowerShadow > totalRange * 0.3)) {
patterns.push({
type: 'doji',
index: i,
bullish: current.close > current.open
});
}
// Hammer: Small body at top, long lower shadow
if (bodySize < totalRange * 0.3 && lowerShadow > bodySize * 2 && upperShadow < bodySize * 0.5) {
patterns.push({
type: 'hammer',
index: i,
bullish: true
});
}
// Engulfing: Current candle engulfs previous
if (i > 0) {
const prevBodySize = Math.abs(previous.close - previous.open);
const currentBodySize = Math.abs(current.close - current.open);
// Bullish engulfing
if (previous.close < previous.open && current.close > current.open &&
current.open < previous.close && current.close > previous.open &&
currentBodySize > prevBodySize * 1.1) {
patterns.push({
type: 'bullish_engulfing',
index: i,
bullish: true
});
}
// Bearish engulfing
if (previous.close > previous.open && current.close < current.open &&
current.open > previous.close && current.close < previous.open &&
currentBodySize > prevBodySize * 1.1) {
patterns.push({
type: 'bearish_engulfing',
index: i,
bullish: false
});
}
}
}
return {
patterns: patterns
};
}
