Session Highlighter

//@version=6
indicator("Session Highlighter", overlay=true, max_boxes_count=500)

// === INPUTS ===
grp1 = "Asia Session"
asiaEnabled = input.bool(true, "Show Asia", group=grp1)
asiaStart   = input.session("0000-0900", "Asia Time", group=grp1)
asiaColor   = input.color(color.new(color.blue, 88), "Asia Color", group=grp1)

grp2 = "London Session"
londonEnabled = input.bool(true, "Show London", group=grp2)
londonStart   = input.session("0800-1630", "London Time", group=grp2)
londonColor   = input.color(color.new(color.green, 88), "London Color", group=grp2)

grp3 = "New York Session"
nyEnabled = input.bool(true, "Show New York", group=grp3)
nyStart   = input.session("1330-2200", "New York Time", group=grp3)
nyColor   = input.color(color.new(color.orange, 88), "New York Color", group=grp3)

grp4 = "General"
tz       = input.string("Europe/Berlin", "Timezone", group=grp4)
showLabels = input.bool(true, "Show Session Labels", group=grp4)
keepN    = input.int(30, "Keep N sessions", minval=1, maxval=100, group=grp4)

// === SESSION DETECTION ===
inAsia   = not na(time(timeframe.period, asiaStart, tz))
inLondon = not na(time(timeframe.period, londonStart, tz))
inNY     = not na(time(timeframe.period, nyStart, tz))

startAsia   = asiaEnabled and inAsia and not inAsia[1]
endAsia     = asiaEnabled and not inAsia and inAsia[1]
startLondon = londonEnabled and inLondon and not inLondon[1]
endLondon   = londonEnabled and not inLondon and inLondon[1]
startNY     = nyEnabled and inNY and not inNY[1]
endNY       = nyEnabled and not inNY and inNY[1]

// === RANGE TRACKING ===
var float asiaH = na, var float asiaL = na, var int asiaLeft = na
var float londonH = na, var float londonL = na, var int londonLeft = na
var float nyH = na, var float nyL = na, var int nyLeft = na

// Asia
if startAsia
    asiaH := high, asiaL := low, asiaLeft := time
if inAsia and asiaEnabled
    asiaH := math.max(nz(asiaH, high), high)
    asiaL := math.min(nz(asiaL, low), low)

// London
if startLondon
    londonH := high, londonL := low, londonLeft := time
if inLondon and londonEnabled
    londonH := math.max(nz(londonH, high), high)
    londonL := math.min(nz(londonL, low), low)

// New York
if startNY
    nyH := high, nyL := low, nyLeft := time
if inNY and nyEnabled
    nyH := math.max(nz(nyH, high), high)
    nyL := math.min(nz(nyL, low), low)

// === STORAGE ===
var array<box> asiaBoxes = array.new<box>()
var array<box> londonBoxes = array.new<box>()
var array<box> nyBoxes = array.new<box>()
var array<label> allLabels = array.new<label>()

// === BOX CREATION ===
createBox(condition, leftT, h, l, col, boxArr, lblText) =>
    if condition and not na(leftT) and not na(h) and not na(l)
        b = box.new(leftT, h, time, l, xloc=xloc.bar_time, bgcolor=col, border_color=color.new(col, 50), border_width=1)
        array.push(boxArr, b)
        if showLabels
            lbl = label.new(leftT, h, lblText, xloc=xloc.bar_time, style=label.style_label_down, color=color.new(col, 30), textcolor=color.white, size=size.tiny)
            array.push(allLabels, lbl)
        while array.size(boxArr) > keepN
            box.delete(array.shift(boxArr))
        while array.size(allLabels) > keepN * 3
            label.delete(array.shift(allLabels))

createBox(endAsia, asiaLeft, asiaH, asiaL, asiaColor, asiaBoxes, "Asia")
createBox(endLondon, londonLeft, londonH, londonL, londonColor, londonBoxes, "London")
createBox(endNY, nyLeft, nyH, nyL, nyColor, nyBoxes, "NY")

// === INFO TABLE ===
var table t = table.new(position.bottom_right, 2, 4, border_width=1)
if barstate.islast
    table.cell(t, 0, 0, "Session", text_color=color.gray, bgcolor=color.new(color.black, 70), text_size=size.tiny)
    table.cell(t, 1, 0, "Status", text_color=color.gray, bgcolor=color.new(color.black, 70), text_size=size.tiny)

    table.cell(t, 0, 1, "Asia", text_color=color.white, bgcolor=color.new(color.blue, 80), text_size=size.tiny)
    table.cell(t, 1, 1, inAsia and asiaEnabled ? "ACTIVE" : "closed", text_color=inAsia and asiaEnabled ? color.lime : color.gray, bgcolor=color.new(color.blue, 80), text_size=size.tiny)

    table.cell(t, 0, 2, "London", text_color=color.white, bgcolor=color.new(color.green, 80), text_size=size.tiny)
    table.cell(t, 1, 2, inLondon and londonEnabled ? "ACTIVE" : "closed", text_color=inLondon and londonEnabled ? color.lime : color.gray, bgcolor=color.new(color.green, 80), text_size=size.tiny)

    table.cell(t, 0, 3, "New York", text_color=color.white, bgcolor=color.new(color.orange, 80), text_size=size.tiny)
    table.cell(t, 1, 3, inNY and nyEnabled ? "ACTIVE" : "closed", text_color=inNY and nyEnabled ? color.lime : color.gray, bgcolor=color.new(color.orange, 80), text_size=size.tiny)