// PineScript v6 reference for DSTOCH (Double Stochastic / Bressert DSS)
// Apply Stochastic formula twice with EMA smoothing between stages.

//@version=6
indicator("Double Stochastic (DSS Bressert)", shorttitle="DSTOCH", overlay=false)

period = input.int(21, "Period", minval=1)

// Stage 1: Raw %K
rawK = ta.stoch(close, high, low, period)

// Stage 1: EMA smooth rawK → smoothK
smoothK = ta.ema(rawK, period)

// Stage 2: Stochastic of smoothK
skHigh = ta.highest(smoothK, period)
skLow  = ta.lowest(smoothK, period)
skRange = skHigh - skLow
dsRaw = skRange > 0 ? 100.0 * (smoothK - skLow) / skRange : 0.0

// Stage 2: EMA smooth dsRaw → DSS output
dss = ta.ema(dsRaw, period)

plot(dss, "DSS", color=color.blue, linewidth=2)
hline(80, "Overbought", color=color.red, linestyle=hline.style_dotted)
hline(20, "Oversold", color=color.green, linestyle=hline.style_dotted)
hline(50, "Midline", color=color.gray, linestyle=hline.style_dotted)