use eframe::egui;

pub fn drag_value_with_scroll<T>(
    ui: &mut egui::Ui,
    value: &mut T,
    range: std::ops::RangeInclusive<T>,
    speed_drag: f64,
    speed_scroll: f64,
) -> egui::Response 
where
    T: egui::emath::Numeric + std::ops::Add<Output = T>  + std::fmt::Debug
{
    let drag = egui::DragValue::new(value)
        .speed(speed_drag)
        .range(range.clone());

    let response = ui.add(drag);

    if response.hovered() {
        let scroll_diff = ui.input(|i| i.smooth_scroll_delta.y);

        const THRESHOLD: f32 = 10.0;
        if scroll_diff > THRESHOLD {
            *value = clamp_partial(*value + T::from_f64(speed_scroll), *range.start(), *range.end());
        } else if scroll_diff < -THRESHOLD {
            *value = clamp_partial(*value + T::from_f64(-speed_scroll), *range.start(), *range.end());
        }
    }

    response
}

// literally why is this not given in the emath::Numeric definition
fn clamp_partial<T: PartialOrd + Copy + std::fmt::Debug>(val: T, min: T, max: T) -> T {
    if val < min { min }
    else if val > max { max }
    else { val }
}