Market Structure Break (MSB) Indicator

describe_indicator('Market Structure Break (MSB) Detector');

// Input parameters for customization
const swingLookback = input.number('Swing Lookback', 3, { min: 2 });
const bullishColor = input.color('Bullish MSB Color', '#00FF00');
const bearishColor = input.color('Bearish MSB Color', '#FF0000');
const lineLength = input.number('MSB Line Length (bars)', 20, { min: 10, max: 200 });
const msbLookback = input.number('MSB Lookback Period', 100, { min: 1, max: 1000 });

// Function to detect swing highs and lows
const detectSwings = (high, low, lookback) => {
    const swingHighs = series_of(null);
    const swingLows = series_of(null);
    for (let i = lookback; i < high.length - lookback; i++) {
        let isSwingHigh = true;
        let isSwingLow = true;
        for (let j = 1; j <= lookback; j++) {
            if (high[i - j] >= high[i] || high[i + j] >= high[i]) {
                isSwingHigh = false;
            }
            if (low[i - j] <= low[i] || low[i + j] <= low[i]) {
                isSwingLow = false;
            }
        }
        if (isSwingHigh) {
            swingHighs[i] = high[i];
        }
        if (isSwingLow) {
            swingLows[i] = low[i];
        }
    }
    return { swingHighs, swingLows };
};

// Detect swings
const { swingHighs, swingLows } = detectSwings(high, low, swingLookback);

// Detect Market Structure Breaks
const bullishMSB = series_of(null);
const bearishMSB = series_of(null);
const bullishMSBLines = [];
const bearishMSBLines = [];
let lastSwingHighIndex = null;
let lastSwingLowIndex = null;

for (let i = swingLookback; i < close.length; i++) {
    if (swingHighs[i] !== null) {
        lastSwingHighIndex = i;
    }
    if (swingLows[i] !== null) {
        lastSwingLowIndex = i;
    }
    
    if (lastSwingHighIndex !== null && close[i] > high[lastSwingHighIndex]) {
        bullishMSB[i] = high[lastSwingHighIndex];
        bullishMSBLines.push({
            startIndex: lastSwingHighIndex,
            breakIndex: i,
            value: high[lastSwingHighIndex]
        });
        lastSwingHighIndex = null;
    }
    
    if (lastSwingLowIndex !== null && close[i] < low[lastSwingLowIndex]) {
        bearishMSB[i] = low[lastSwingLowIndex];
        bearishMSBLines.push({
            startIndex: lastSwingLowIndex,
            breakIndex: i,
            value: low[lastSwingLowIndex]
        });
        lastSwingLowIndex = null;
    }
}

// Function to create a line
const createLine = (startIndex, breakIndex, value, color, isBullish, lineIndex) => {
    const lineData = series_of(null);
    const endIndex = Math.min(breakIndex + lineLength, close.length);
    for (let i = startIndex; i < endIndex; i++) {
        lineData[i] = value;
    }
    const paintedLine = paint(lineData, {
        color: color,
        name: `${isBullish ? 'Bullish' : 'Bearish'} MSB ${lineIndex}`
    });
    
    // Place label at the swing high/low candle
    const labelIndex = isBullish ? startIndex : startIndex;
    paint_label_at_line(paintedLine, labelIndex, 'MSB', {
        color: color,
        vertical_align: isBullish ? 'top' : 'bottom'
    });
};

// Paint MSB lines and labels
const currentIndex = close.length - 1;
const msbLookbackStartIndex = Math.max(0, currentIndex - msbLookback);
bullishMSBLines.filter(line => line.breakIndex >= msbLookbackStartIndex).forEach((line, index) => {
    createLine(line.startIndex, line.breakIndex, line.value, bullishColor, true, index);
});
bearishMSBLines.filter(line => line.breakIndex >= msbLookbackStartIndex).forEach((line, index) => {
    createLine(line.startIndex, line.breakIndex, line.value, bearishColor, false, index);
});