Linear Regression Volume

// This Pine Script™ code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © Lyro RS

//@version=6
indicator("Linear Regression Volume | Lyro RS", "LR Volume | 𝓛𝔂𝓻𝓸 𝓡𝓢", overlay=true)

// Inputs
len = input.int(35, title="Regression Length")
mult = input.float(1.0, title="Deviation Multiplier")
typeMA = input.string("SMA", "Type", ["SMA", "RMA", "HMA", "ALMA"], tooltip = "Change to what suits your style")
upperBandCOL = #ff026f
lowerBandCOL = #40ed49


// Volume Weighted Linear Regression Input // 
vw_linregSM(src, len) =>
    ta.sma(src * volume, len) / ta.sma(volume, len)
vw_linregRM(src, len) =>
    ta.rma(src * volume, len) / ta.rma(volume, len)
vw_linregHM(src, len) =>
    ta.hma(src * volume, len) / ta.hma(volume, len)
vw_linregAL(src, len) =>
    ta.alma(src * volume, len, 0, 0) / ta.alma(volume, len, 0, 0)

vw_linregCho(src, len, typeMA) =>
    switch typeMA
        "SMA" =>  ta.sma(src * volume, len) / ta.sma(volume, len)
        "RMA" =>  ta.rma(src * volume, len) / ta.rma(volume, len)
        "HMA" =>  ta.hma(src * volume, len) / ta.hma(volume, len)
        "ALMA" => ta.alma(src * volume, len, 0, 0) / ta.alma(volume, len, 0, 0)


// Fair value baseline
vw_price = vw_linregCho(close, len, typeMA)
baseline = ta.linreg(vw_price, len, 0)
slope = baseline - baseline[1]

// Deviation (volatility)
dev = mult * ta.stdev(close, len)

// Trend color based on slope
bandColor = slope > 0 ? #40ed49 : slope < 0 ? #ff026f : color.gray

// Bands
upper1 = baseline + dev
lower1 = baseline - dev
upper2 = baseline + dev * 2
lower2 = baseline - dev * 2
upper3 = baseline + dev * 3
lower3 = baseline - dev * 3


// Plot baseline and bands
plot(baseline, title="Fair Value", color=bandColor, linewidth=2)
upper1Plot = plot(upper1, color=color.new(upperBandCOL, 100))
lower1Plot = plot(lower1, color=color.new(upperBandCOL, 100))
upper2Plot = plot(upper2, color=color.new(upperBandCOL, 100))
lower2Plot = plot(lower2, color=color.new(lowerBandCOL, 100))
upper3Plot = plot(upper3, color=color.new(upperBandCOL, 100))
lower3Plot = plot(lower3, color=color.new(lowerBandCOL, 100))


// Fills
fill(upper1Plot, lower1Plot, color=color.new(bandColor, 85))
fill(upper2Plot, lower2Plot, color=color.new(bandColor, 92))
fill(upper3Plot, lower3Plot, color=color.new(bandColor, 96))

// Alerts
alertcondition(slope > 0, "Linear Regression Volume - Long", "Linear Regression Volume is Long {{exchange}}:{{ticker}}")
alertcondition(slope < 0, "Linear Regression Volume - Short", "Linear Regression Volume is Short {{exchange}}:{{ticker}}")