Dual Moving Average Ribbon

//@version=6
indicator("Dual Moving Average Ribbon", shorttitle="Dual MA Ribbon", overlay=true)

// === INPUTS ===
// Fast MA Settings
grpFast = "Fast Moving Average"
fastLength = input.int(21, "Length", minval=1, group=grpFast)
fastType = input.string("SMA", "Type", options=["SMA", "EMA", "WMA", "VWMA", "RMA", "HMA", "ALMA", "SMMA", "LSMA", "DEMA", "TEMA"], group=grpFast)
fastSource = input.source(close, "Source", group=grpFast)

// Slow MA Settings
grpSlow = "Slow Moving Average"
slowLength = input.int(50, "Length", minval=1, group=grpSlow)
slowType = input.string("SMA", "Type", options=["SMA", "EMA", "WMA", "VWMA", "RMA", "HMA", "ALMA", "SMMA", "LSMA", "DEMA", "TEMA"], group=grpSlow)
slowSource = input.source(close, "Source", group=grpSlow)

// Colors (edit in Style tab)
bullColor = #089981
bearColor = #ef5350

// === MA CALCULATION FUNCTION ===
calcMA(src, len, maType) =>
    switch maType
        "SMA" => ta.sma(src, len)
        "EMA" => ta.ema(src, len)
        "WMA" => ta.wma(src, len)
        "VWMA" => ta.vwma(src, len)
        "RMA" => ta.rma(src, len)
        "HMA" => ta.hma(src, len)
        "ALMA" => ta.alma(src, len, 0.85, 6)
        "SMMA" =>
            smma = 0.0
            smma := na(smma[1]) ? ta.sma(src, len) : (smma[1] * (len - 1) + src) / len
            smma
        "LSMA" => ta.linreg(src, len, 0)
        "DEMA" =>
            ema1 = ta.ema(src, len)
            ema2 = ta.ema(ema1, len)
            2 * ema1 - ema2
        "TEMA" =>
            ema1 = ta.ema(src, len)
            ema2 = ta.ema(ema1, len)
            ema3 = ta.ema(ema2, len)
            3 * ema1 - 3 * ema2 + ema3
        => ta.sma(src, len)

// === CALCULATE MAs ===
fastMA = calcMA(fastSource, fastLength, fastType)
slowMA = calcMA(slowSource, slowLength, slowType)

// === PLOTTING ===
fastPlot = plot(fastMA, "Fast MA", color=color.new(bullColor, 35), linewidth=1)
slowPlot = plot(slowMA, "Slow MA", color=color.new(bearColor, 35), linewidth=1)

// Fill between MAs
fillColor = fastMA > slowMA ? color.new(bullColor, 85) : color.new(bearColor, 85)
fill(fastPlot, slowPlot, color=fillColor, title="MA Fill")

// === ALERT CONDITIONS ===
bullishCross = ta.crossover(fastMA, slowMA)
bearishCross = ta.crossunder(fastMA, slowMA)

alertcondition(bullishCross, title="Bullish Crossover", message="{{ticker}}: Fast MA crossed ABOVE Slow MA")
alertcondition(bearishCross, title="Bearish Crossover", message="{{ticker}}: Fast MA crossed BELOW Slow MA")