package edd.util;

import static org.junit.Assert.*;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

import org.junit.Test;

public class ListsAndIteratorsTest {

    @Test
    public void testDuplicate() {
        List<Double> doubleList = new ArrayList<>();
        assertEquals("[]", ListsAndIterators.duplicate(doubleList).toString());

        List<Integer> integerList = Arrays.asList(4, 8, 15, 16, 23, 42);
        assertEquals("[4, 4, 8, 8, 15, 15, 16, 16, 23, 23, 42, 42]",
                ListsAndIterators.duplicate(integerList).toString());

        List<Character> characterList = Arrays.asList('a', 'b', 'c', 'd', 'e');
        assertEquals("[a, a, b, b, c, c, d, d, e, e]", ListsAndIterators
                .duplicate(characterList).toString());
    }

    @Test
    public void testConsecute() {
        List<Double> doubleList = new ArrayList<>();
        assertEquals("[]", ListsAndIterators.consecute(doubleList).toString());

        List<Integer> integerList = Arrays.asList(1, 2, 3, 4, 5);
        assertEquals("[1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5]",
                ListsAndIterators.consecute(integerList).toString());

        List<Character> characterList = Arrays.asList('a', 'b', 'c', 'd');
        assertEquals("[a, b, b, c, c, c, d, d, d, d]", ListsAndIterators
                .consecute(characterList).toString());
    }

    @Test
    public void testRemoveDuplicates() {
        List<Integer> integerList = new ArrayList<>();
        assertEquals("[]", ListsAndIterators.removeDuplicates(integerList)
                .toString());

        integerList = Arrays.asList(4, 1, 4, 2, 4, 3, 4, 1, 2, 3);
        assertEquals("[4, 1, 2, 3]",
                ListsAndIterators.removeDuplicates(integerList).toString());

        integerList = Arrays.asList(4, 1, 2, 3);
        assertEquals("[4, 1, 2, 3]",
                ListsAndIterators.removeDuplicates(integerList).toString());

        List<String> stringList = Arrays.asList("a", "b", "c", "a", "b", "c",
                "d", "a", "b", "c");
        assertEquals("[a, b, c, d]",
                ListsAndIterators.removeDuplicates(stringList).toString());
    }

    private void testIterators(Iterator<Integer> it, int[] expected) {
        try {
            it.remove();
            fail();
        } catch (UnsupportedOperationException e) {
        }
        for (int i = 0; i < expected.length; i++) {
            assertTrue(it.hasNext());
            assertEquals(expected[i], (int) it.next());
        }
        try {
            it.next();
            fail();
        } catch (NoSuchElementException e) {
        }
    }

    @Test
    public void testPow2() {
        testIterators(ListsAndIterators.pow2(4), new int[] { 1, 2, 4, 8 });
        testIterators(ListsAndIterators.pow2(10), new int[] { 1, 2, 4, 8, 16,
                32, 64, 128, 256, 512 });
        testIterators(ListsAndIterators.pow2(30), new int[] { 1, 2, 4, 8, 16,
                32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768,
                65536, 131072, 262144, 524288, 1048576, 2097152, 4194304,
                8388608, 16777216, 33554432, 67108864, 134217728, 268435456,
                536870912 });
    }

    @Test
    public void testPrimes() {
        testIterators(ListsAndIterators.primes(1), new int[] {});
        testIterators(ListsAndIterators.primes(2), new int[] { 2 });
        testIterators(ListsAndIterators.primes(5), new int[] { 2, 3, 5 });
        testIterators(ListsAndIterators.primes(10), new int[] { 2, 3, 5, 7 });
        testIterators(ListsAndIterators.primes(50), new int[] { 2, 3, 5, 7, 11,
                13, 17, 19, 23, 29, 31, 37, 41, 43, 47 });
        testIterators(ListsAndIterators.primes(1000), new int[] { 2, 3, 5, 7,
                11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,
                73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137,
                139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197,
                199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269,
                271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347,
                349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419,
                421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487,
                491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571,
                577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643,
                647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727,
                733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811,
                821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883,
                887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977,
                983, 991, 997 });
    }

    @Test
    public void testSquares() {
        testIterators(ListsAndIterators.squares(new int[] {}), new int[] {});
        testIterators(
                ListsAndIterators.squares(new int[] { 10, -1, 0, 4, -5 }),
                new int[] { 100, 1, 0, 16, 25 });
        testIterators(
                ListsAndIterators.squares(new int[] { -5, -4, -3, -2, -1, 0, 1,
                        2, 3, 4, 5 }), new int[] { 25, 16, 9, 4, 1, 0, 1, 4, 9,
                        16, 25 });
    }
}