G-Channel & EMA Strategy with ATR SL/TP

//@version=4
strategy("G-Channel & EMA Strategy with ATR SL/TP", shorttitle="G-EMA-ATR Strategy", overlay=true, pyramiding=5)

// G-Channel settings, modified length to 5
length = input(5, title="G-Channel Length")
src = close

a = 0.0
b = 0.0
a := max(src, nz(a[1])) - nz(a[1] - b[1]) / length
b := min(src, nz(b[1])) + nz(a[1] - b[1]) / length
avg = avg(a, b)

crossup = b[1] < close[1] and b > close
crossdn = a[1] > close[1] and a < close

// EMA settings, modified length to 200
emaLength = input(200, title="EMA Length")
ema = ema(close, emaLength)

// ATR settings for SL and TP
atrLength = input(14, title="ATR Length")
atrMultiplierSL = input(2, title="ATR Multiplier for SL")
atrMultiplierTP = input(4, title="ATR Multiplier for TP")
atr = atr(atrLength)

// Define buy and sell conditions
buyCondition = crossup and close < ema
sellCondition = crossdn and close > ema

// Calculate SL and TP levels
longSL = close - atrMultiplierSL * atr
longTP = close + atrMultiplierTP * atr

// Strategy execution
if (buyCondition)
    strategy.entry("Buy", strategy.long)
    strategy.exit("Take Profit / Stop Loss", "Buy", stop=longSL, limit=longTP)

// Plotting with updated transparency handling
plot(a, "Upper", color=color.new(color.red, 50))
plot(b, "Lower", color=color.new(color.green, 50))
plot(ema, "EMA", color=color.new(color.orange, 0))

// Plot buy and sell signals
plotshape(series=buyCondition, title="Buy Signal", location=location.belowbar, color=color.new(color.green, 0), style=shape.labelup, size=size.small, text="BUY")
plotshape(series=sellCondition, title="Sell Signal", location=location.abovebar, color=color.new(color.red, 0), style=shape.labeldown, size=size.small, text="SELL")