//@version=5
indicator("Simple FVG", overlay=true, max_boxes_count=500)

boxLength = input.int(20, "Box Length", minval=1)
deleteFilled = input.bool(true, "Delete Filled FVGs")

var box[] bullBoxes = array.new_box()
var box[] bearBoxes = array.new_box()

// Bullish FVG
bullFVG = low > high[2]

// Bearish FVG
bearFVG = high < low[2]

if bullFVG
    b = box.new(
         left = bar_index - 2,
         top = low,
         right = bar_index + boxLength,
         bottom = high[2],
         bgcolor = color.new(color.green, 85),
         border_color = color.green)
    array.push(bullBoxes, b)

if bearFVG
    b = box.new(
         left = bar_index - 2,
         top = low[2],
         right = bar_index + boxLength,
         bottom = high,
         bgcolor = color.new(color.red, 85),
         border_color = color.red)
    array.push(bearBoxes, b)

// Manage bullish boxes
if array.size(bullBoxes) > 0
    for i = array.size(bullBoxes) - 1 to 0
        bx = array.get(bullBoxes, i)
        if close <= box.get_bottom(bx)
            if deleteFilled
                box.delete(bx)
                array.remove(bullBoxes, i)

// Manage bearish boxes
if array.size(bearBoxes) > 0
    for i = array.size(bearBoxes) - 1 to 0
        bx = array.get(bearBoxes, i)
        if close >= box.get_top(bx)
            if deleteFilled
                box.delete(bx)
                array.remove(bearBoxes, i)