package org.onlab.graph;

import org.junit.Test;

import java.util.Set;

import static org.junit.Assert.assertEquals;

/**
 * Test of the BFS and similar path search algorithms.
 */
public class BreadthFirstSearchTest extends AbstractGraphPathSearchTest {

    @Override
    protected AbstractGraphPathSearch<TestVertex, TestEdge> graphSearch() {
        return new BreadthFirstSearch<>();
    }

    @Test
    public void defaultGraphTest() {
        executeDefaultTest(7, 3, 8.0);
    }

    @Test
    public void defaultHopCountWeight() {
        weight = null;
        executeDefaultTest(7, 3, 3.0);
    }

    // Executes the default test
    protected void executeDefaultTest(int pathCount, int pathLength, double pathCost) {
        g = new AdjacencyListsGraph<>(vertices(), edges());

        GraphPathSearch<TestVertex, TestEdge> search = graphSearch();
        Set<Path<TestVertex, TestEdge>> paths = search.search(g, A, H, weight).paths();
        assertEquals("incorrect paths count", 1, paths.size());

        Path p = paths.iterator().next();
        assertEquals("incorrect src", A, p.src());
        assertEquals("incorrect dst", H, p.dst());
        assertEquals("incorrect path length", pathLength, p.edges().size());
        assertEquals("incorrect path cost", pathCost, p.cost(), 0.1);

        paths = search.search(g, A, null, weight).paths();
        printPaths(paths);
        assertEquals("incorrect paths count", pathCount, paths.size());
    }

    // Executes the search and validates its results.
    protected void executeSearch(GraphPathSearch<TestVertex, TestEdge> search,
                                 Graph<TestVertex, TestEdge> graph,
                                 TestVertex src, TestVertex dst,
                                 EdgeWeight<TestVertex, TestEdge> weight,
                                 int pathCount, double pathCost) {
        GraphPathSearch.Result<TestVertex, TestEdge> result =
                search.search(graph, src, dst, weight);
        Set<Path<TestVertex, TestEdge>> paths = result.paths();
        printPaths(paths);
        assertEquals("incorrect paths count", pathCount, paths.size());
        if (pathCount > 0) {
            Path<TestVertex, TestEdge> path = paths.iterator().next();
            assertEquals("incorrect path cost", pathCost, path.cost(), 0.1);
        }
    }

}