NYSE Tick Alert on Chart

//@version=5
// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © DocRR

indicator(title='NYSE Tick Alert on Chart', overlay=true)

user_input = input.float(minval = 600, step = 50, defval = 600, title='Level', tooltip="Min. Value = 600, step = 50")

string SIZE_LARGE  = "Large"
string SIZE_NORMAL = "Normal"
string SIZE_SMALL  = "Small"
string sizeInput = input.string(SIZE_NORMAL, "Size", options = [SIZE_LARGE, SIZE_NORMAL, SIZE_SMALL])
var bool plot = na

getSize(simple string userSize) =>
    result =
      switch userSize
        SIZE_LARGE  => size.large
        SIZE_NORMAL => size.normal
        SIZE_SMALL  => size.small
        => size.auto

neg_input = user_input * -1

[h, l, firstbar_check, lastbar_check] = request.security('USI:TICK', timeframe.period, [high, low, session.isfirstbar, session.islastbar])

plot := firstbar_check ? true : lastbar_check[1] ? false : plot
if not plot
    h := na
    l := na

if h >= user_input
    label.new(bar_index, na, yloc = yloc.abovebar, color = color.new(#ff8952, 0), style = label.style_triangledown, size = getSize(sizeInput))

if l <= neg_input
    label.new(bar_index, na, yloc = yloc.belowbar, color = color.new(#52a3ff, 0), style = label.style_triangleup, size = getSize(sizeInput))

alertcondition(h >= user_input == true, "NYSE Tick high!")
alertcondition(l <= neg_input == true, "NYSE Tick low!")