// Licensed under the Apache License, Version 2.0
// © mihakralj
//@version=6
indicator("Ease of Movement (EOM)", "EOM", overlay=false)

//@function Calculate Ease of Movement Volume
//@param i_length integer Length for box ratio calculation
//@param i_smoothing integer Smoothing length for EOM
//@returns float Ease of Movement value
//@optimized for performance and dirty data
eom(i_smoothing, i_vol_scale, i_high=high, i_low=low, i_volume=volume) =>
    var float oldMidPoint = na
    midPoint = (i_high + i_low) * 0.5
    midPointChange = midPoint - nz(oldMidPoint, midPoint)
    oldMidPoint := midPoint
    priceRange = i_high - i_low
    boxRatio = priceRange > 0 and i_volume > 0 ? (i_volume / i_vol_scale) / priceRange : na
    rawEom = not na(boxRatio) and boxRatio != 0 ? midPointChange / boxRatio : 0.0
    var array<float> buffer = array.new_float(i_smoothing, 0.0)
    var int head = 0
    var float sum = 0.0
    float oldest = array.get(buffer, head)
    if bar_index >= i_smoothing
        sum -= oldest
    currentValue = nz(rawEom)
    sum += currentValue
    array.set(buffer, head, currentValue)
    head := (head + 1) % i_smoothing
    average = bar_index < i_smoothing ? sum / (bar_index + 1) : sum / i_smoothing
    average


// ---------- Main loop ----------

// Inputs
i_length = input.int(14, "Period", minval=1)
i_smoothing = input.int(14, "Smoothing", minval=1)

// Calculation
eomValue = eom(i_length, i_smoothing)

// Plot
plot(eomValue, "EOM", color=color.yellow, linewidth=2)