Reversal finder

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © NS91 2020

//@version=4
study("Reversal finder", overlay=true)

// Inputs

lookback = input(20, "Lookback period for highs and lows")
malen = input(20, "SMA length for candles range")
avrange = sma((high-low), malen)
mult = input(1.5, "Range multiple", type=input.float)
rangethreshold = input(50, "Range threshold (% of candle range)", maxval=99)/100
barcol = input(false, "Highlight signal bars?", type=input.bool)
trackhilo = input(false, "Highlight highest high/lowest low?", type=input.bool)

// Signal conditions

longsig = (high-low)>=(avrange*mult) and ((low<lowest(low[1],lookback))) and (close>=(high-((high-low)*rangethreshold)))
shortsig = (high-low)>=(avrange*mult) and ((high>highest(high[1], lookback))) and (close<=(low+((high-low)*rangethreshold)))

// Plots for highest recent high/lowest recent low

hiplot = trackhilo ? highest(high[1], lookback) : na
loplot = trackhilo ? lowest(low[1],lookback) : na

plot(loplot, title="Lowest low", color=#FF0000, transp=99, trackprice=true)
plot(hiplot, title="Highest high", color=#00FF03, transp=99, trackprice=true)

// Plots for signal occurrences

plotshape(longsig, title="Long signal", style=shape.labelup, color=color.yellow, transp=1, location=location.belowbar, size=size.tiny)
plotshape(shortsig, title="Short signal", style=shape.labeldown, color=color.yellow, transp=1, location=location.abovebar, size=size.tiny)
plotshape((longsig and close>open), title="Long signal with up candle", style=shape.labelup, color=#00FF03, transp=1, location=location.belowbar, size=size.tiny)
plotshape((shortsig and close<open), title="Short signal with down candle", style=shape.labeldown, color=#FF0000, transp=1, location=location.abovebar, size=size.tiny)

// Bar colours for use with 'highlight signals' option

barcolor(barcol ? barcol and longsig ? #00FF03 : barcol and shortsig ? #FF0000 : #4F4F4F : na)

// Alert conditions

alertcondition(longsig, title="Long signal", message="Reversal finder long signal")
alertcondition(shortsig, title="Short signal", message="Reversal finder short signal")
alertcondition((longsig and close>open), title="Long signal with up candle", message="Reversal finder long signal with up candle")
alertcondition((shortsig and close<open), title="Short signal with down candle", message="Reversal finder short signal with down candle")
alertcondition((longsig or shortsig), title="Long or short signal", message="Reversal finder signal")