package graph;

import graph.Graph.CycleException;
import junit.framework.TestCase;

public class GraphTest extends TestCase {
	
	public void testAddAndRemove() throws CycleException {
		Graph<Integer> g = new Graph<Integer>();
		g.addEdge(1,2);
		g.addEdge(2,3);
		g.addEdge(2,4);
		g.addEdge(4,5);
		assertEquals(true, g.containsVertex(5));
		assertEquals(true, g.containsEdge(1,2));
		assertEquals(false, g.containsEdge(2,1));
		
		
		g.visitDepthFirst(new Visitor<Integer>() {
			public void visit(Integer i) {
				System.out.println(i);
			}
		});
		
		g.addEdge(3,1); // create a cycle
		try {
			g.visitDepthFirst(new Visitor<Integer>() {
				public void visit(Integer i) {
					System.out.println(i);
				}
			});
			fail();  // should get an exception due to cycle
		} catch (CycleException cfe) {
			System.out.println(cfe);
		}
		
		g.removeEdge(3,1); // take out the cycle
		g.removeEdge(1,2);
		g.removeVertex(2);
		assertEquals(false, g.containsEdge(1,2));
		assertEquals(false, g.edgesTo(4).hasNext());
		g.removeEdge(4,5);
		assertEquals(false, g.containsEdge(4,5));
		assertEquals(true, g.containsVertex(5));
		for (int i : g)
			System.out.println(i);
	}

}