package labs.graphs;

import static org.junit.jupiter.api.Assertions.*;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

/**
 * Partial Unit tests for ArrayGraph. This class only tests addEdge, removeEdge
 * and hasEdge.
 * 
 * @author Nathan Sprague
 *
 */
class ArrayGraphTest {

	@Test
	void testNumEdgesAfterAdd() {
		Graph<Integer> graph = new ArrayGraph<>(3);
		assertEquals(0, graph.numEdges());

		graph.addEdge(0, 1);
		assertEquals(1, graph.numEdges());

		graph.addEdge(1, 2);
		assertEquals(2, graph.numEdges());

		graph.addEdge(2, 0);
		assertEquals(3, graph.numEdges());
		
		graph.addEdge(2, 0);
        assertEquals(3, graph.numEdges());

		graph.addEdge(0, 0);
		assertEquals(3, graph.numEdges());

		graph.addEdge(0, 20000);
		assertEquals(3, graph.numEdges());
		
		graph.addEdge(-1, 0);
        assertEquals(3, graph.numEdges());
	}

	@Test
	void testNumEdgesAfterRemove() {
		Graph<Integer> graph = new ArrayGraph<>(3);
		graph.addEdge(0, 1);
		graph.addEdge(1, 2);
		graph.addEdge(2, 0);

		graph.removeEdge(2, 0);
		assertEquals(2, graph.numEdges());
		
		graph.removeEdge(2, 0);
        assertEquals(2, graph.numEdges());

		graph.removeEdge(1, 2);
		assertEquals(1, graph.numEdges());

		graph.removeEdge(0, 1);
		assertEquals(0, graph.numEdges());

		graph.removeEdge(0, 1);
		assertEquals(0, graph.numEdges());

		graph.removeEdge(0, 20000);
		assertEquals(0, graph.numEdges());
		
		graph.removeEdge(-1, 0);
        assertEquals(0, graph.numEdges());

	}

	@Test
	void testHasEdgeAfterAdd() {
		Graph<Integer> graph = new ArrayGraph<>(3);

		assertFalse(graph.hasEdge(0, 1));
		graph.addEdge(0, 1);
		assertTrue(graph.hasEdge(0, 1));

		assertFalse(graph.hasEdge(1, 2));
		graph.addEdge(1, 2);
		assertTrue(graph.hasEdge(1, 2));

		assertFalse(graph.hasEdge(2, 0));
		graph.addEdge(2, 0);
		assertTrue(graph.hasEdge(2, 0));

		assertFalse(graph.hasEdge(0, 0));
		graph.addEdge(0, 0);
		assertFalse(graph.hasEdge(0, 0));

		assertFalse(graph.hasEdge(0, 2000));
		graph.addEdge(0, 2000);
		assertFalse(graph.hasEdge(0, 2000));
	}

	@Test
	void testHasEdgeAfterRemove() {
		Graph<Integer> graph = new ArrayGraph<>(3);
		graph.addEdge(0, 1);
		graph.addEdge(1, 2);
		graph.addEdge(2, 0);

		assertTrue(graph.hasEdge(0, 1));
		graph.removeEdge(0, 1);
		assertFalse(graph.hasEdge(0, 1));

		assertTrue(graph.hasEdge(1, 2));
		graph.removeEdge(1, 2);
		assertFalse(graph.hasEdge(1, 2));

		assertTrue(graph.hasEdge(2, 0));
		graph.removeEdge(2, 0);
		assertFalse(graph.hasEdge(2, 0));

		assertFalse(graph.hasEdge(0, 0));
		graph.removeEdge(0, 0);
		assertFalse(graph.hasEdge(0, 0));

		assertFalse(graph.hasEdge(0, 2000));
		graph.removeEdge(0, 2000);
		assertFalse(graph.hasEdge(0, 2000));
	}

}