package org.plt;

import org.plt.types.*;
import org.plt.Kernel;
import org.junit.Test;
import static org.junit.Assert.*;

public class TestMath {
	@Test
	public void testAdd() {
		Rational half = new Rational(1, 2);
		assertEquals(new Rational(1, 1), half.numericPlus(half));
	}

	@Test
	public void testSymbol() {
		assertEquals(Symbol.makeInstance("x"), Symbol.makeInstance("x"));
	}

	@Test
	public void testNegativeModulo() {
		// In Scheme, modulo is positive regardless of the dividend.
		assertEquals(new Rational(-5, 1).modulo(new Rational(2, 1)),
				new Rational(1, 1));
	}

	@Test
	public void testModuloMore() {
		assertEquals(new Rational(5, 1).modulo(new Rational(5, 1)),
				new Rational(0, 1));

		assertEquals(new Rational(5, 1).modulo(new Rational(2, 1)),
				new Rational(1, 1));

		assertTrue(new Rational(5, 1).modulo(new Rational(1, 1)).isZero());

		assertEquals(new Rational(2, 1).modulo(new Rational(3, 1)),
				new Rational(2, 1));

		assertEquals(new Rational(1, 1).modulo(new Rational(2, 1)),
				new Rational(1, 1));

	}

	@Test
	public void testAddition() {
		assertEquals(Rational.ONE.numericPlus(Rational.ONE), new Rational(2, 1));
	}

	@Test
	public void testCeiling() {
		// ceiling(1/2) ==> 1
		assertEquals(new Rational(1, 1), new Rational(1, 2).ceiling());

		// ceiling(1) ==> 1
		assertEquals(new Rational(1, 1), new Rational(1, 1).ceiling());

		// ceiling(-1/2) ==> 0
		assertEquals(new Rational(0, 1), new Rational(-1, 2).ceiling());

		// ceiling(-1) ==> -1
		assertEquals(new Rational(-1, 1), new Rational(-1, 1).ceiling());

		// ceiling(5/3) ==> 2
		assertEquals(new Rational(2, 1), new Rational(5, 3).ceiling());

	}

	@Test
	public void testFloor() {
		// floor(1/2) ==> 0
		assertEquals(new Rational(0, 1), new Rational(1, 2).floor());

		// floor(1) ==> 1
		assertEquals(new Rational(1, 1), new Rational(1, 1).floor());

		// floor(-1/2) ==> -1
		assertEquals(new Rational(-1, 1), new Rational(-1, 2).floor());

		// floor(-1) ==> -1
		assertEquals(new Rational(-1, 1), new Rational(-1, 1).floor());

		// floor(5/3) ==> 1
		assertEquals(Rational.ONE, new Rational(5, 3).floor());
	}

	@Test
	public void testAbs() {
		assertEquals(new Rational(5, 4), new Rational(5, 4).abs());

		assertEquals(new Rational(5, 4), new Rational(-5, 4).abs());

		assertEquals(FloatPoint.fromString("3.2"), FloatPoint.fromString("3.2")
				.abs());

		assertEquals(FloatPoint.fromString("3.2"), FloatPoint
				.fromString("-3.2").abs());
	}

	@Test
	public void testAcos() {
		assertEquals(new Rational(0, 1), Rational.ONE.acos());
		assertEquals(FloatPoint.PI, new Rational(-1, 1).acos());
	}

	@Test
	public void testAsin() {
		assertEquals(new Rational(0, 1), Rational.ZERO.asin());
		assertEquals(NumberTower.divide(FloatPoint.PI, new Rational(-2, 1)),
			     new Rational(-1, 1).asin());
		assertEquals(NumberTower.divide(FloatPoint.PI, Kernel.TWO), new Rational(1,
				1).asin());
	}

	@Test
	public void testAtan() {
		assertEquals(new Rational(0, 1), Rational.ZERO.atan());
	}

}