//@version=5
indicator("S Line",overlay = true )


tz = "America/New_York"  
market = time(timeframe.period,"0930-1600",tz)

var float mar_h = 0
var float mar_l = 0

if not na(market) and na(market[1])
    mar_h := high 
    mar_l := low   
    
if not na(market)
    if high>=mar_h
        mar_h := high
    if low<=mar_l
        mar_l := low 


mar_h_b = ta.valuewhen(ta.change(mar_h),bar_index,0)
mar_l_b = ta.valuewhen(ta.change(mar_l),bar_index,0)



// (0400-0930
pre = time(timeframe.period,"0400-0930",tz)

var float pre_h = 0
var float pre_l = 0

if not na(pre) and na(pre[1])
    pre_h := high 
    pre_l := low   
    
if not na(pre)
    if high>=pre_h
        pre_h := high
    if low<=pre_l
        pre_l := low 


pre_h_b = ta.valuewhen(ta.change(pre_h),bar_index,0)
pre_l_b = ta.valuewhen(ta.change(pre_l),bar_index,0)


mar_start = not na(market) and na(market[1])


high_on = input.bool(true,"Show High Lines")
low_on  = input.bool(true,"Show Low Lines")

var line high_l1 = na 
var line high_l2 = na 
var line low_l1 = na 
var line low_l2 = na 
if mar_start
    if high_on
        high_l1 := line.new(mar_h_b[1],mar_h[1],pre_h_b,pre_h,xloc.bar_index,extend.both,color.green )
        line.delete(high_l1[1])

        high_val_at_low = line.get_price(high_l1,mar_l_b[1])
        diff_hl = high_val_at_low-mar_l[1]

        high_l2 := line.new(mar_l_b[1],mar_l[1],pre_h_b,pre_h-diff_hl,xloc.bar_index,extend.both,color.green )
        line.delete(high_l2[1])


    if low_on
        low_l1 := line.new(mar_l_b[1],mar_l[1],pre_l_b,pre_l,xloc.bar_index,extend.both,color.red )
        line.delete(low_l1[1])

        low_val_at_high = line.get_price(low_l1,mar_h_b[1])
        diff_lh = mar_h[1] - low_val_at_high

        low_l2 := line.new(mar_h_b[1],mar_h[1],pre_l_b,pre_l+diff_lh,xloc.bar_index,extend.both,color.red )
        line.delete(low_l2[1])