//@version=3
study(title='WH Median Renko Overlay', shorttitle='WH MRO', overlay=false)

ticksize = syminfo.mintick

boxsize = input(18) * ticksize * 10
reversalOffset = input(4)*ticksize

medrenko(S,B,R) =>
    rh = na
    rl = na
    ro = na
    rc = na

    rup = na
    rdown = na
    //reserval
    rreserval = na

    rup := nz(rup[1], S)
    rdown := nz(rdown[1], S)
    rreserval := nz(rreserval[1], S)

    rh := rup
    rc := rup
    rl := rdown
    ro := rdown

    if (S > rup[1] + B + R)
        rup := rup[1] + B
        rdown := rup[1] - B
        rreserval := rdown[1] - B


    if (S < rdown[1] - B - R)
        rdown := rdown[1] - B
        rup := rdown[1] + B
        rreserval := rup[1] + B


    if (S < rup[1] + B + R) and (S > rup[1] - B - R)
        rup := rup[1]
        rdown := rdown[1]
        rreserval := rreserval[1]

    if (rup > rup[1])
        rh:= rup
        rc:= rup
        ro:= rdown
        rl:= rdown

    if (rup < rup[1])
        rh:= rup
        ro:= rup
        rc:= rdown
        rl:= rdown

    if(rup == rup[1])
        rh:= rh[1]
        ro:= ro[1]
        rc:= rc[1]
        rl:= rl[1]


    [rh, rl, ro, rc, rup, rdown, rreserval]

[rh, rl, ro, rc, rup, rdown, rreserval] = medrenko(close,boxsize,reversalOffset)

palette = rreserval < rc ? lime : red
plotcandle(ro, rh, rl, rc, color = palette)
plot(close, color = black)

Change = change(rc)

bgc = Change > 0 ? green : Change < 0 ? red : na
bgcolor(bgc)

alertcondition(Change > 0, title='Renko Up', message='Buying Advice!')
alertcondition(Change < 0, title='Renko Down', message='Selling Advice!')