package ch.epfl.alpano;

import static ch.epfl.test.TestRandomizer.newRandom;
import static java.lang.Math.toRadians;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertSame;

import java.util.Random;

import org.junit.Test;

public class PanoramaTestP{
    private static PanoramaParameters PARAMS() {
        return new PanoramaParameters(
                new GeoPoint(toRadians(46), toRadians(6)),
                1000,
                toRadians(180),
                toRadians(60),
                100_000,
                9,
                7);
    }

    @Test(expected = NullPointerException.class)
    public void builderFailsWithNullParameters() {
        new Panorama.Builder(null);
    }

    @Test
    public void builderConstructorCorrectlyInitializesSamples() {
        Panorama p = new Panorama.Builder(PARAMS()).build();
        assertEquals(Float.POSITIVE_INFINITY, p.distanceAt(0, 0), 0);
        assertEquals(0, p.longitudeAt(0, 0), 0);
        assertEquals(0, p.latitudeAt(0, 0), 0);
        assertEquals(0, p.elevationAt(0, 0), 0);
        assertEquals(0, p.slopeAt(0, 0), 0);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void setDistanceAtFailsWithInvalidIndex() {
        Panorama.Builder b = new Panorama.Builder(PARAMS());
        b.setDistanceAt(10, 0, 1);
    }

    @Test
    public void setLongitudeAtReturnsThis() {
        Panorama.Builder b = new Panorama.Builder(PARAMS());
        assertSame(b, b.setLongitudeAt(0, 0, 1));
    }

    @Test(expected = IllegalStateException.class)
    public void setSlopeAtFailsAfterBuild() {
        Panorama.Builder b = new Panorama.Builder(PARAMS());
        b.build();
        b.setSlopeAt(0, 0, 0);
    }

    @Test(expected = IllegalStateException.class)
    public void buildFailsAfterBuild() {
        Panorama.Builder b = new Panorama.Builder(PARAMS());
        b.build();
        b.build();
    }

    @Test
    public void parametersReturnsParameters() {
        PanoramaParameters ps = PARAMS();
        Panorama p = new Panorama.Builder(ps).build();
        assertSame(ps, p.parameters());
    }

    @Test
    public void builderSettersWork() {
        PanoramaParameters ps = PARAMS();
        float[] values = new float[ps.width() * ps.height()];
        Random rng = newRandom();
        for (int i = 0; i < values.length; ++i)
            values[i] = rng.nextFloat() + 0.5f;

        Panorama.Builder b = new Panorama.Builder(ps);
        for (int x = 0; x < ps.width(); ++x) {
            for (int y = 0; y < ps.height(); ++y) {
                float v = values[y + x * ps.height()];
                b.setDistanceAt(x, y, v)
                .setElevationAt(x, y, v)
                .setLatitudeAt(x, y, v)
                .setLongitudeAt(x, y, v)
                .setSlopeAt(x, y, v);
            }
        }

        Panorama p = b.build();
        for (int x = 0; x < ps.width(); ++x) {
            for (int y = 0; y < ps.height(); ++y) {
                float v = values[y + x * ps.height()];
                assertEquals(v, p.distanceAt(x, y), 0);
                assertEquals(v, p.elevationAt(x, y), 0);
                assertEquals(v, p.latitudeAt(x, y), 0);
                assertEquals(v, p.longitudeAt(x, y), 0);
                assertEquals(v, p.slopeAt(x, y), 0);
            }
        }
    }
}