/*
    * Grapht, an open source dependency injector.
    * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt)
    * Copyright 2010-2014 Regents of the University of Minnesota
    *
    * This program is free software; you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as
    * published by the Free Software Foundation; either version 2.1 of the
    * License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
   * details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc., 51
   * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  package org.grouplens.grapht.util;
  
  import org.junit.Test;
  
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import static org.hamcrest.Matchers.*;
  import static org.junit.Assert.assertThat;
  import static org.junit.Assert.fail;
  
  /**
   * @author <a href="http://www.grouplens.org">GroupLens Research</a>
   */
  public class AbstractChainTest {
      static class TestChain extends AbstractChain<String> {
          TestChain(AbstractChain<String> prev, String tv) {
              super(prev, tv);
          }
          public TestChain extend(String tok) {
              return new TestChain(this, tok);
          }
      }
  
      static TestChain singleton(String tok) {
          return new TestChain(null, tok);
      }
      static TestChain chain(String t1, String... toks) {
          TestChain chain = singleton(t1);
          for (String tok: toks) {
              chain = chain.extend(tok);
          }
          return chain;
      }
  
      @Test
      public void testSingletonBasicProps() throws Exception {
          TestChain chain = singleton("foo");
          assertThat(chain.size(), equalTo(1));
          assertThat(chain.isEmpty(), equalTo(false));
          assertThat(chain.contains("foo"), equalTo(true));
          assertThat(chain, contains("foo"));
      }
  
      @Test
      public void testSingletonsEqual() {
          TestChain foo1 = singleton("foo");
          TestChain foo2 = singleton("foo");
          TestChain bar = singleton("bar");
  
          assertThat(foo1.equals(foo1), equalTo(true));
          assertThat(foo1.equals(foo2), equalTo(true));
          assertThat(foo1.equals(bar), equalTo(false));
      }
  
      @Test
      public void testSingletonGet() {
          TestChain foo = singleton("foo");
  
          assertThat(foo.get(0), equalTo("foo"));
      }
  
      @Test
      public void testExtend() {
          TestChain foo = singleton("foo");
          TestChain foobar = foo.extend("bar");
  
          assertThat(foobar.size(), equalTo(2));
  
          Iterator<String> iter = foobar.iterator();
          assertThat(iter.next(), equalTo("foo"));
          assertThat(iter.next(), equalTo("bar"));
          assertThat(iter.hasNext(), equalTo(false));
  
          assertThat(foobar.get(1), equalTo("bar"));
          assertThat(foobar.get(0), equalTo("foo"));
      }
  
      @Test
      public void testReverseIteration() {
         TestChain chain = chain("foobie", "bletch", "forever");
         assertThat(chain, hasSize(3));
         assertThat(chain.reverse(), contains("forever", "bletch", "foobie"));
 
         Iterator<String> iter = chain.reverseIterator();
         iter.next();
         iter.next();
         iter.next();
         try {
             iter.next();
             fail("must throw NoSuchElement");
         } catch (Throwable th) {
             assertThat(th, instanceOf(NoSuchElementException.class));
         }
     }
 
     @Test
     public void testChainsEqual() {
         TestChain base = chain("foo", "bar", "blatz");
         TestChain copy = chain("foo", "bar", "blatz");
         TestChain chend = chain("foo", "bar", "blam");
         TestChain chstart = chain("f00", "bar", "blatz");
 
         assertThat(base.equals(base), equalTo(true));
         assertThat(base.equals(copy), equalTo(true));
         assertThat(base.equals(chend), equalTo(false));
         assertThat(base.equals(chstart), equalTo(false));
     }
 }