// Licensed under the Apache License, Version 2.0
// © mihakralj
//@version=6
indicator("Min-Max Normalization (NORMALIZE)", "NORMALIZE", overlay=false, precision=6)

//@function Normalizes a source series to the fixed range [0, 1] using Min-Max scaling over a lookback period.
//@param src The source series to normalize.
//@param len The lookback period to determine min and max values. Must be >= 1.
//@returns The normalized series (scaled to [0, 1]).
normalize(series float src, simple int len) =>
    float min_val_in_period = src
    float max_val_in_period = src
    for i = 1 to len - 1 
        current_val = src[i]
        if na(current_val)
            continue
        if current_val < min_val_in_period
            min_val_in_period := current_val
        if current_val > max_val_in_period
            max_val_in_period := current_val
    range_val = max_val_in_period - min_val_in_period
    normalized_value = 0.0 
    if range_val != 0.0 and not na(range_val) 
        normalized_value := (src - min_val_in_period) / range_val
    normalized_value

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

// Inputs
i_source = input.source(close, "Source")
i_length = input.int(200, "Lookback Length", minval=1, tooltip="Lookback period for finding min/max. Must be >= 1.")

// Calculation
normalizedValue = normalize(i_source, i_length)

// Plot
plot(normalizedValue, "Normalized Value [0,1]", color=color.yellow, linewidth=2)