import graphlib.edges.UndirectedEdge;
import graphlib.graphs.UndirectedGraph;
import graphlib.nodes.Node;
import org.junit.Assert;
import org.junit.Test;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

public class SimpleTest {

    Nightcrawler crawler = new BranchAndBoundCrawler();

    @Test
    public void testSingleton() {
        UndirectedGraph graph = new UndirectedGraph();
        Node a = graph.addNode("Alice");
        Set<Set<Node>> check = new HashSet<>();
        check.add(new HashSet<>(graph.getAllNodes()));
        Assert.assertEquals(check, crawler.minimalCoverage(graph, 1.0)
        );
    }

    @Test
    public void testSingleEdgeClose() {
        UndirectedGraph graph = new UndirectedGraph();
        Node a = graph.addNode("Alice"),
             b = graph.addNode("Bob");
        graph.addEdge(new UndirectedEdge(a, b, 5.0));

        Set<Set<Node>> check = new HashSet<>();
        check.add(Collections.singleton(a));
        check.add(Collections.singleton(b));

        Assert.assertEquals(check, crawler.minimalCoverage(graph, 10.0));
    }

    @Test
    public void testSingleEdgeFar() {
        UndirectedGraph graph = new UndirectedGraph();
        Node a = graph.addNode("Alice"),
             b = graph.addNode("Bob");
        graph.addEdge(new UndirectedEdge(a, b, 15.0));

        Set<Set<Node>> check = new HashSet<>();
        check.add(new HashSet<>(Arrays.asList(a, b)));

        Assert.assertEquals(check, crawler.minimalCoverage(graph, 10.0));
    }

    @Test
    public void testVShapeMiddle() {
        UndirectedGraph graph = new UndirectedGraph();
        Node a = graph.addNode("Alice"),
             b = graph.addNode("Bob"),
             m = graph.addNode("Mallory");
        graph.addEdge(new UndirectedEdge(a, m, 10.0));
        graph.addEdge(new UndirectedEdge(m, b, 10.0));

        Set<Set<Node>> check = new HashSet<>();
        check.add(Collections.singleton(m));

        Assert.assertEquals(check, crawler.minimalCoverage(graph, 10.0));
    }

    @Test
    public void testTriangleAny() {
        UndirectedGraph graph = new UndirectedGraph();
        Node a = graph.addNode("Alice"),
             b = graph.addNode("Bob"),
             c = graph.addNode("Carol");
        graph.addEdge(new UndirectedEdge(a, b, 5.0));
        graph.addEdge(new UndirectedEdge(b, c, 5.0));
        graph.addEdge(new UndirectedEdge(c, a, 5.0));

        Set<Set<Node>> check = new HashSet<>();
        check.add(Collections.singleton(a));
        check.add(Collections.singleton(b));
        check.add(Collections.singleton(c));

        Assert.assertEquals(check, crawler.minimalCoverage(graph, 10.0));
    }

    @Test
    public void testTriangleSingle() {
        UndirectedGraph graph = new UndirectedGraph();
        Node a = graph.addNode("Alice"),
             b = graph.addNode("Bob"),
             m = graph.addNode("Mallory");
        graph.addEdge(new UndirectedEdge(a, m, 5.0));
        graph.addEdge(new UndirectedEdge(m, b, 5.0));
        graph.addEdge(new UndirectedEdge(a, b, 10.0));

        Set<Set<Node>> check = new HashSet<>();
        check.add(Collections.singleton(m));

        Assert.assertEquals(check, crawler.minimalCoverage(graph, 10.0));
    }

}