package com.ffbit.collectioins;

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

import java.util.Comparator;
import java.util.SortedSet;
import java.util.TreeSet;

import org.junit.Before;
import org.junit.Test;

public class SortedSetTest {
    private final String APPLE = "apple";
    private final String APRICOT = "apricot";
    private final String BERRY = "berry";
    private final String PLUM = "plum";
    private final String ZOO = "zoo";

    private SortedSet<String> sortedSet;

    @Before
    public void init() {
        sortedSet = new TreeSet<String>();
        fill(sortedSet, APPLE, APRICOT, BERRY, PLUM, ZOO);
    }

    @Test
    public void testComparator() {
        Comparator<?> comparator = sortedSet.comparator();
        assertNull(comparator);
    }

    @Test
    public void testFirst() {
        assertEquals(APPLE, sortedSet.first());
    }

    @Test
    public void testHeadSet() {
        SortedSet<String> headSet = new TreeSet<String>();
        fill(headSet, APPLE, APRICOT, BERRY);
        assertEquals(headSet, sortedSet.headSet(PLUM));
    }

    @Test
    public void testLast() {
        assertEquals(ZOO, sortedSet.last());
    }

    @Test
    public void testSubSet() {
        SortedSet<String> subSet = new TreeSet<String>();
        fill(subSet, APRICOT, BERRY, PLUM);
        assertEquals(subSet, sortedSet.subSet(APRICOT, ZOO));
    }

    @Test
    public void testTailSet() {
        SortedSet<String> tailSet = new TreeSet<String>();
        fill(tailSet, PLUM, ZOO);
        assertEquals(tailSet, sortedSet.tailSet(PLUM));
    }

    private <T> void fill(SortedSet<T> set, T...args) {
        for (T e : args) {
            set.add(e);
        }
    }

}