Elders Force Index with MA/BB [TradingView Custom Indicator]

//
// @author LazyBear
// If you use this code in its original / modified form, do drop me a note. Thx.
//
study(title="Elder's Force Index [LazyBear]", shorttitle="EFI_LB")
length = input(13, minval=1)
lengthMA=input(8)
efi = sma(change(close) * volume, length)
s=sma(efi, lengthMA)

hline(0, title="Zero")
plot(efi, color=green, title="EFI", linewidth=2)
plot(s, color=orange)

// Draw BB on indices
BBEnabled=input(false,title="BB Enabled?", type=bool)
mult=input(2.5)
length_bb=input(20, title="BB Length")
HighlightBreaches=input(false, type=bool)

bb_s = s
basis = sma(bb_s, length)
dev = (mult * stdev(bb_s, length))
upper = (basis + dev)
lower = (basis - dev)

plot(BBEnabled ? basis : na, color=gray, style=cross)
p1_bb = plot(BBEnabled ? upper:na, color=gray)
p2_bb = plot(BBEnabled ? lower:na , color=gray)
fill(p1_bb, p2_bb, silver)

b_color = (bb_s > upper) ? red : (bb_s < lower) ? green : na
offset = (bb_s > upper) ? 6 : (bb_s < lower ? -6 : 0)
Breached=(bb_s > upper) or (bb_s < lower)
plot((BBEnabled and HighlightBreaches and Breached) ? bb_s+offset : na, style=cross, color=b_color,linewidth=2)