Stocks Seasonality Gauge

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © jawauntb


//@version=5
indicator("Stocks Seasonality Gauge", overlay=false, shorttitle="SSG")

// Input Parameters
lookbackYears = input.int(5, title="Lookback Years")
emaLength = input.int(9, title="EMA Length for Current Month's Performance")

// Function to calculate monthly performance for specific month and year offsets
getReturn(monthOffset, yearOffset) =>
    startPrice = request.security(syminfo.tickerid, "M", close[12 * yearOffset + monthOffset])
    endPrice = request.security(syminfo.tickerid, "M", close[12 * yearOffset + monthOffset + 1])
    (endPrice - startPrice) / startPrice

// Calculate returns for the current month over past years
currentMonthReturns = array.new_float(lookbackYears)
monthOffset = month[0] - 1  // Current month offset from the start of the year

for i = 0 to lookbackYears - 1
    array.set(currentMonthReturns, i, getReturn(monthOffset, -i))

currentMonthAvg = array.avg(currentMonthReturns)

// Calculate returns for the current year
currentYearReturns = array.new_float(12)
for i = 0 to month[0] - 1
    array.set(currentYearReturns, i, getReturn(i, 0))
currentYearAvg = array.sum(currentYearReturns) / ta.max(month[0])

// Price change percentage function
getPriceChangePercentage(period) =>
    change = (close - close[period]) / close[period]
    change

// Calculate percentage changes
threeWeekChange = getPriceChangePercentage(21)
oneWeekChange = getPriceChangePercentage(7)

// EMA calculation
currentMonthEMA = (ta.ema(threeWeekChange, emaLength) + ta.ema(oneWeekChange, emaLength)) / 2

// Plotting
hline(0, "0% Change", color=color.rgb(237, 255, 170), linewidth=1, linestyle=hline.style_dashed)
plot(currentMonthAvg, color=color.rgb(241, 103, 106), linewidth=2, title="Avg Performance This Month Over Last 5 Years")
plot(currentYearAvg, color=color.rgb(79, 226, 101), linewidth=3, title="Avg Monthly Performance Year to Date")
plot(currentMonthEMA, color=color.rgb(55, 245, 255), linewidth=4, title="EMA of Current Months Performance")