package com.evsuite.abrp;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import org.junit.Test;

public class MusicPulseTest {

    private static final float STEP = 0.04f;

    @Test
    public void noReadingAndSilenceLightNothing() {
        MusicPulse p = new MusicPulse();
        assertEquals(0f, p.update(null, STEP), 0f);
        assertEquals(0f, p.update(Float.NaN, STEP), 0f);
        assertEquals(0f, p.update(0f, STEP), 0f);
    }

    @Test
    public void aBeatLightsAndFadesSlowerThanItRises() {
        MusicPulse p = new MusicPulse();
        for (int i = 0; i < 50; i++) p.update(0.05f, STEP);
        float beat = p.update(0.5f, STEP);
        assertTrue("a beat lights it, got " + beat, beat > 0.8f);
        float after = p.update(0.05f, STEP);
        assertTrue("it fades, got " + after, after < beat);
        assertTrue("slowly, got " + after, after > beat * 0.7f);
    }

    @Test
    public void aSteadyHumSettlesAtNothing() {
        MusicPulse p = new MusicPulse();
        float last = 1f;
        for (int i = 0; i < 400; i++) last = p.update(0.3f, STEP);
        assertEquals(0f, last, 0f);
    }

    @Test
    public void aHeldBassNoteLightsOnlyItsStart() {
        MusicPulse p = new MusicPulse();
        for (int i = 0; i < 50; i++) p.update(0.05f, STEP);
        assertTrue(p.update(0.4f, STEP) > 0.8f);
        float last = 1f;
        for (int i = 0; i < 25; i++) last = p.update(0.4f, STEP);
        assertEquals(0f, last, 0f);
    }

    @Test
    public void aWobblingBassLineStaysDark() {
        MusicPulse p = new MusicPulse();
        for (int i = 0; i < 50; i++) p.update(0.3f, STEP);
        float top = 0f;
        for (int i = 0; i < 200; i++) top = Math.max(top, p.update(i % 3 == 0 ? 0.33f : 0.3f, STEP));
        assertEquals(0f, top, 0f);
    }

    @Test
    public void aSwellingNoteStaysDark() {
        MusicPulse p = new MusicPulse();
        for (int i = 0; i < 50; i++) p.update(0.1f, STEP);
        float top = 0f;
        for (int i = 0; i < 100; i++) top = Math.max(top, p.update(0.1f + i * 0.004f, STEP));
        assertEquals(0f, top, 0f);
    }

    @Test
    public void aKickOverABassLineLights() {
        MusicPulse p = new MusicPulse();
        float top = 0f;
        for (int i = 0; i < 300; i++) {
            float v = p.update(i % 12 == 0 ? 0.6f : (i % 3 == 0 ? 0.33f : 0.3f), STEP);
            if (i > 100) top = Math.max(top, v);
        }
        assertTrue("a kick lights it, got " + top, top > 0.8f);
    }

    @Test
    public void quietAndLoudSongsPulseAlike() {
        assertEquals(beatOf(0.5f), beatOf(0.05f), 0.02f);
    }

    private static float beatOf(float scale) {
        MusicPulse p = new MusicPulse();
        float top = 0f;
        for (int i = 0; i < 500; i++) {
            top = Math.max(top * 0.99f, p.update(i % 12 == 0 ? scale : scale * 0.2f, STEP));
        }
        return top;
    }

    @Test
    public void whenTheMusicStopsItGoesOut() {
        MusicPulse p = new MusicPulse();
        for (int i = 0; i < 100; i++) p.update(i % 12 == 0 ? 0.5f : 0.1f, STEP);
        float last = 1f;
        for (int i = 0; i < 100; i++) last = p.update(null, STEP);
        assertEquals(0f, last, 0f);
    }

    @Test
    public void itStaysBetweenZeroAndOne() {
        MusicPulse p = new MusicPulse();
        for (int i = 0; i < 2000; i++) {
            Float bass = i % 11 == 0 ? null : Float.valueOf(i % 7 == 0 ? 1f : 0.1f);
            float v = p.update(bass, i % 5 == 0 ? 2f : STEP);
            assertTrue(v >= 0f && v <= 1f);
        }
    }
}