Twin Range Filter

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

//@version=5

strategy(title='Twin Range Filter', overlay=true)

source = input(defval=close, title='Source')

// Smooth Average Range

per1 = input.int(defval=27, minval=1, title='Fast period')
mult1 = input.float(defval=1.5, minval=0.1, title='Fast range')

per2 = input.int(defval=55, minval=1, title='Slow period')
mult2 = input.float(defval=2, minval=0.1, title='Slow range')

smoothrng(x, t, m) =>
    wper = t * 2 - 1
    avrng = ta.ema(math.abs(x - x[1]), t)
    smoothrng = ta.ema(avrng, wper) * m
    smoothrng
smrng1 = smoothrng(source, per1, mult1)
smrng2 = smoothrng(source, per2, mult2)
smrng = (smrng1 + smrng2) / 2

// Range Filter

rngfilt(x, r) =>
    rngfilt = x
    rngfilt := x > nz(rngfilt[1]) ? x - r < nz(rngfilt[1]) ? nz(rngfilt[1]) : x - r : x + r > nz(rngfilt[1]) ? nz(rngfilt[1]) : x + r
    rngfilt
filt = rngfilt(source, smrng)

upward = 0.0
upward := filt > filt[1] ? nz(upward[1]) + 1 : filt < filt[1] ? 0 : nz(upward[1])
downward = 0.0
downward := filt < filt[1] ? nz(downward[1]) + 1 : filt > filt[1] ? 0 : nz(downward[1])

hband = filt + smrng
lband = filt - smrng

longCond = bool(na)
shortCond = bool(na)
longCond := source > filt and source > source[1] and upward > 0 or source > filt and source < source[1] and upward > 0
shortCond := source < filt and source < source[1] and downward > 0 or source < filt and source > source[1] and downward > 0

CondIni = 0
CondIni := longCond ? 1 : shortCond ? -1 : CondIni[1]

long = longCond and CondIni[1] == -1
short = shortCond and CondIni[1] == 1

// Plotting

plotshape(long, title='Long', text='Long', style=shape.labelup, textcolor=color.new(color.black, 0), size=size.tiny, location=location.belowbar, color=color.new(color.lime, 0))
plotshape(short, title='Short', text='Short', style=shape.labeldown, textcolor=color.new(color.white, 0), size=size.tiny, location=location.abovebar, color=color.new(color.red, 0))

// Alerts

alertcondition(long, title='Long', message='Long')
alertcondition(short, title='Short', message='Short')

longstring = 'Input your custom alert message here. \n and put {{strategy.order.alert_message}} in Message box.'
shortstring = 'Input your custom alert message here. \n and put {{strategy.order.alert_message}} in Message box.'

ltos=input.text_area(title='Long Alert Message', defval='Long', confirm=false, group='Alert Messages', tooltip=longstring)
stol=input.text_area(title='Short Alert Message', defval='Short', confirm=false, group='Alert Messages', tooltip=shortstring)

if long
    alert(ltos)
if short
    alert(stol)