import static org.junit.Assert.*;

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

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;


public class Test2DTest {

  @Rule
  public ExpectedException exception = ExpectedException.none();

  @Test
  public void testLast() {
    final String[][] S =
      { {"a"},
        {"a", "b"},
        {"a", "b", "c"},
        {"a", "b", "c", "e", "f", "xyz"},
      };
    for (int i = 0; i < S.length; i++) {
      String[] strings = S[i];
      List<String> t = Arrays.asList(strings);
      assertEquals(strings[strings.length - 1], Test2D.last(t));
    }
  }

  @Test
  public void testSecondLast() {
    final String[][] S =
      { {"a", "b"},
        {"a", "b", "c"},
        {"a", "b", "c", "e", "f", "xyz"},
      };
    for (int i = 0; i < S.length; i++) {
      String[] strings = S[i];
      List<String> t = Arrays.asList(strings);
      assertEquals(strings[strings.length - 2], Test2D.secondLast(t));
    }
  }
  
  @Test
  public void testSecondLastThrows1() {
    exception.expect(IllegalArgumentException.class);
    Test2D.secondLast(new ArrayList<String>());    
  }
  
  @Test
  public void testSecondLastThrows2() {
    exception.expect(IllegalArgumentException.class);
    List<String> t = new ArrayList<String>();
    t.add("hello");
    Test2D.secondLast(t);    
  }
  
  

  @Test
  public void testConcat() {
    final String[][] S =
      { {},
        {"a"},
        {"a", "b"},
        {"a", "b", "c"},
        {"a", "b", "c", "e", "f", "xyz"}
      };
    final String[] EXP = {"", "a", "ab", "abc", "abcefxyz"};
    
    for (int i = 0; i < S.length; i++) {
      String[] strings = S[i];
      List<String> t = Arrays.asList(strings);
      assertEquals(EXP[i], Test2D.concat(t));
    }
  }

  @Test
  public void testSortByLength() {
    final String[][] S =
      { {},
        {"a"},
        {"a", "also"},
        {"also", "a"},
        {"bumblebee", "wizard", "been", "bat"},
        {"cold", "coat", "cat", "albatross", "cot", "cow" }
      };
    final String[][] EXP =
      { {},
        {"a"},
        {"a", "also"},
        {"a", "also"},
        {"bat", "been", "wizard", "bumblebee"},
        {"cat", "cot", "cow", "coat", "cold", "albatross"}
      };
    for (int i = 0; i < S.length; i++) {
      List<String> t = new ArrayList<String>(Arrays.asList(S[i]));
      Test2D.sortByLength(t);
      List<String> exp = Arrays.asList(EXP[i]);
      assertEquals(exp, t);
    }
  }

}