Taught to Trade - Configurable Stochastics

//@version=6
// =============================================================================
// Taught to Trade - Configurable Stochastics
// shorttitle: TT Stoch
// -----------------------------------------------------------------------------
// WHAT IT IS
//   A stochastic oscillator that exposes the parts most versions hide: it plots
//   fast %K, slow %K, and slow %D, and lets you pick the SMOOTHING method
//   (SMA / EMA / WMA / HMA) instead of forcing plain SMA. Same classic stochastic
//   math - more control over how it responds.
//
// HOW TO USE
//   Read overbought/oversold and %K/%D crosses as you would any stochastic. Faster
//   smoothing (HMA/WMA) reacts sooner but gives more false turns; slower (SMA) is
//   steadier but later. Set YOUR OWN alerts from the conditions provided - this
//   script does not send buy/sell signals.
//
// WHERE IT FAILS
//   - Stochastics whipsaw in strong trends (they stay "overbought" while price keeps
//     rising). Best as ranging/confirmation context, not a standalone trigger.
//   - Signals evaluate on close and can change intrabar.
//
// Educational tool only - not investment advice. (c) 2026 Taught to Trade.
// =============================================================================
indicator("Taught to Trade - Configurable Stochastics", shorttitle = "TT Stoch", overlay = false)

// ----- MA selector ----------------------------------------------------------
f_ma(series float src, simple int len, simple string t) =>
    switch t
        "SMA" => ta.sma(src, len)
        "EMA" => ta.ema(src, len)
        "WMA" => ta.wma(src, len)
        "HMA" => ta.hma(src, len)
        => ta.sma(src, len)

// ----- Inputs ---------------------------------------------------------------
grp = "Stochastic"
kLen    = input.int(14, "%K length",       minval = 1, group = grp)
kSmooth = input.int(3,  "%K smoothing",    minval = 1, group = grp)
dLen    = input.int(3,  "%D length",       minval = 1, group = grp)
maType  = input.string("SMA", "Smoothing method", options = ["SMA","EMA","WMA","HMA"], group = grp, tooltip = "How %K and %D are smoothed. HMA/WMA react faster; SMA is steadier.")
showFast= input.bool(true, "Show fast %K", group = grp)

grpL = "Levels"
obLvl = input.int(80, "Overbought", minval = 50, maxval = 100, group = grpL)
osLvl = input.int(20, "Oversold",   minval = 0,  maxval = 50,  group = grpL)

// ----- Calculations ---------------------------------------------------------
fastK = ta.stoch(close, high, low, kLen)     // raw %K, 0..100
slowK = f_ma(fastK, kSmooth, maType)
slowD = f_ma(slowK, dLen, maType)

// ----- Colors ---------------------------------------------------------------
cK = color.new(#2F6FED, 0)
cD = color.new(#E8A13C, 0)
cF = color.new(#8A8F98, 40)

// ----- Plots ----------------------------------------------------------------
plot(showFast ? fastK : na, "Fast %K", color = cF, linewidth = 1)
plot(slowK, "Slow %K", color = cK, linewidth = 2)
plot(slowD, "Slow %D", color = cD, linewidth = 2)
hline(obLvl, "Overbought", color = color.new(#C64545, 50), linestyle = hline.style_dashed)
hline(50,    "Mid",        color = color.new(#8A8F98, 70))
hline(osLvl, "Oversold",   color = color.new(#3F8F5F, 50), linestyle = hline.style_dashed)

// ----- Signals + user alerts (no pushed buy/sell) ---------------------------
bullCross = ta.crossover(slowK, slowD) and slowK < osLvl + 10
bearCross = ta.crossunder(slowK, slowD) and slowK > obLvl - 10

plotshape(bullCross, title = "K/D up in oversold",   style = shape.triangleup,   location = location.bottom, color = color.new(#3F8F5F,0), size = size.tiny)
plotshape(bearCross, title = "K/D down in overbought",style = shape.triangledown, location = location.top,    color = color.new(#C64545,0), size = size.tiny)

alertcondition(bullCross, "Stoch bullish cross (oversold)", "TT Stoch: %K crossed above %D from oversold on {{ticker}} ({{interval}}). Educational only - not a trade instruction.")
alertcondition(bearCross, "Stoch bearish cross (overbought)","TT Stoch: %K crossed below %D from overbought on {{ticker}} ({{interval}}). Educational only - not a trade instruction.")