package org.simantics.district.network.profile;

import java.awt.Color;

/**
 * @author Tuukka Lehtonen
 * @since 1.35.0
 */
public class Colors {

    private static class Cache implements ColorGradient {
        private final ColorGradient proxy;
        private final int discretization;
        private final Color[] cache;

        public Cache(ColorGradient proxy, int discretization) {
            this.proxy = proxy;
            this.discretization = discretization;
            this.cache = new Color[discretization+1];
        }

        private int discretize(double t) {
            return (int) (saturate(t) * discretization);
        }

        @Override
        public Color get(double t) {
            int d = discretize(t);
            Color cached = cache[d];
            if (cached != null)
                return cached;
            cached = cache[d] = proxy.get(t);
            return cached;
        }
    }

    public static final ColorGradient cached(ColorGradient cg) {
        return new Cache(cg, 2048);
    }

    public static final ColorGradient hsvGradient(float hue, float saturation) {
        return t -> {
            return Color.getHSBColor(hue, saturation, saturate((float) t));
        };
    }

    private static float saturate(float t) {
        return Math.max(0f, Math.min(t, 1f));
    }

    private static double saturate(double t) {
        return Math.max(0, Math.min(t, 1));
    }

}