package MyGeometryLib;

import org.junit.jupiter.api.Test;

import java.util.Random;

import static org.junit.jupiter.api.Assertions.*;

class Vector3DTest {
    private final Random random = new Random();
    private final double DELTA = 1e-15;

    @Test
    void dimension() {
        Vector vector = new Vector3D(random.nextDouble(), random.nextDouble(), random.nextDouble());
        assertEquals(3, vector.dimension(), DELTA);
    }

    @Test
    void getComponent() {
        for (int i = 0; i < 100; i++) {
            double expectedX = random.nextDouble();
            double expectedY = random.nextDouble();
            double expectedZ = random.nextDouble();
            Vector vector = new Vector3D(expectedX, expectedY, expectedZ);

            double[] expectedCoord = new double[] {expectedX, expectedY, expectedZ};
            double[] actualCoord = new double[] {vector.getComponent(0), vector.getComponent(1), vector.getComponent(2)};

            assertArrayEquals(expectedCoord, actualCoord, DELTA);
        }
    }

    @Test
    void scalar() {
        for (int i = 0; i < 100; i++) {
            double vectorX = random.nextDouble();
            double vectorY = random.nextDouble();
            double vectorZ = random.nextDouble();

            double anVectorX = random.nextDouble();
            double anVectorY = random.nextDouble();
            double anVectorZ = random.nextDouble();

            Vector vector = new Vector3D(vectorX, vectorY, vectorZ);
            Vector anotherVector = new Vector3D(anVectorX, anVectorY, anVectorZ);
            double expectedScalar = vectorX*anVectorX + vectorY*anVectorY + vectorZ*anVectorZ;

            assertEquals(expectedScalar, vector.scalar(anotherVector), DELTA);
        }
    }

    @Test
    void len() {
        for (int i = 0; i < 100; i++) {
            double x = random.nextDouble();
            double y = random.nextDouble();
            double z = random.nextDouble();

            Vector vector = new Vector3D(x, y ,z);
            double expectedLength = Math.sqrt(x*x+y*y+z*z);

            assertEquals(expectedLength, vector.len(), DELTA);
        }

        assertEquals(0, new Vector3D(0, 0, 0).len(), DELTA);
    }

    @Test
    void multiply() {
        for (int i = 0; i < 100; i++) {
            double factor = random.nextDouble();
            double x = random.nextDouble();
            double y = random.nextDouble();
            double z = random.nextDouble();

            Vector vector = new Vector3D(x, y, z);
            Vector vectorMul = new Vector3D(factor*x, factor*y, factor*z);

            assertTrue(vector.multiply(factor).equals(vectorMul));
        }
    }

    @Test
    void add() {
        for (int i = 0; i < 100; i++) {
            double vectorX = random.nextDouble();
            double vectorY = random.nextDouble();
            double vectorZ = random.nextDouble();

            double anVectorX = random.nextDouble();
            double anVectorY = random.nextDouble();
            double anVectorZ = random.nextDouble();

            Vector vector = new Vector3D(vectorX, vectorY, vectorZ);
            Vector anotherVector = new Vector3D(anVectorX, anVectorY, anVectorZ);
            Vector vectorAdd = new Vector3D(vectorX+anVectorX, vectorY+anVectorY, vectorZ+anVectorZ);

            assertTrue(vector.add(anotherVector).equals(vectorAdd));
        }
    }

    @Test
    void sub() {
        for (int i = 0; i < 100; i++) {
            double vectorX = random.nextDouble();
            double vectorY = random.nextDouble();
            double vectorZ = random.nextDouble();

            double anVectorX = random.nextDouble();
            double anVectorY = random.nextDouble();
            double anVectorZ = random.nextDouble();

            Vector vector = new Vector3D(vectorX, vectorY, vectorZ);
            Vector anotherVector = new Vector3D(anVectorX, anVectorY, anVectorZ);
            Vector vectorSub = new Vector3D(vectorX-anVectorX, vectorY-anVectorY, vectorZ-anVectorZ);

            assertTrue(vector.sub(anotherVector).equals(vectorSub));
        }
    }
}