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

import java.util.HashMap;
import java.util.HashSet;
import java.util.stream.IntStream;


public class SimpleTest {

    private static GreedyColouring kleuring;

    @BeforeClass
    public static void init() {
        kleuring = new MyGreedyColouring();
    }

    @Test
    public void testDriehoek() {
        UndirectedGraph<Integer> graaf1 = new UndirectedGraph<>();
        graaf1.addNode(1);
        graaf1.addNode(2);
        graaf1.addNode(3);

        graaf1.addEdge(new UndirectedEdge<>(graaf1.getNode(1), graaf1.getNode(2)));
        graaf1.addEdge(new UndirectedEdge<>(graaf1.getNode(2), graaf1.getNode(3)));
        graaf1.addEdge(new UndirectedEdge<>(graaf1.getNode(1), graaf1.getNode(3)));

        HashMap<Node<Integer>, Integer> colouring = kleuring.greedyColouring(Graphs.unmodifiableUndirectedGraph(graaf1));
        Assert.assertEquals(3, coloursUsed(colouring));
    }


    @Test
    public void testCykel() {
        UndirectedGraph<Integer> graaf = new UndirectedGraph<>();
        graaf.addNode(1);
        graaf.addNode(2);
        graaf.addNode(3);
        graaf.addNode(4);
        graaf.addNode(5);
        graaf.addNode(6);

        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(1), graaf.getNode(3)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(3), graaf.getNode(4)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(4), graaf.getNode(2)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(2), graaf.getNode(5)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(5), graaf.getNode(6)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(1), graaf.getNode(6)));

        HashMap<Node<Integer>, Integer> colouring = kleuring.greedyColouring(Graphs.unmodifiableUndirectedGraph(graaf));
        Assert.assertEquals(2, coloursUsed(colouring));
    }

    @Test
    public void testCykel2() {
        UndirectedGraph<Integer> graaf = new UndirectedGraph<>();
        IntStream.range(0,10).forEach(graaf::addNode);
        for (int i = 0; i < 10; i++) {
            graaf.addEdge(graaf.getNode(3 * i % 10), graaf.getNode((3 * i + 3) % 10));
        }

        HashMap<Node<Integer>, Integer> colouring = kleuring.greedyColouring(Graphs.unmodifiableUndirectedGraph(graaf));
        Assert.assertEquals(2, coloursUsed(colouring));
    }

    @Test
    public void testGraaf3() {
        UndirectedGraph<Integer> graaf = new UndirectedGraph<>();
        graaf.addNode(1);
        graaf.addNode(2);
        graaf.addNode(3);
        graaf.addNode(4);
        graaf.addNode(5);
        graaf.addNode(6);
        graaf.addNode(7);

        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(1), graaf.getNode(2)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(1), graaf.getNode(3)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(1), graaf.getNode(4)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(1), graaf.getNode(5)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(2), graaf.getNode(3)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(2), graaf.getNode(6)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(2), graaf.getNode(4)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(3), graaf.getNode(6)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(4), graaf.getNode(6)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(4), graaf.getNode(7)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(5), graaf.getNode(6)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(5), graaf.getNode(7)));
        graaf.addEdge(new UndirectedEdge<>(graaf.getNode(6), graaf.getNode(7)));

        var colouring = kleuring.greedyColouring(Graphs.unmodifiableUndirectedGraph(graaf));
        Assert.assertEquals(3, coloursUsed(colouring));
    }

    @Test
    public void testGreedy(){
        UndirectedGraph<Integer> graph = new UndirectedGraph<>();
        IntStream.range(0,5).forEach(graph::addNode);
        graph.addEdge(new UndirectedEdge<>(graph.getNode(0), graph.getNode(1)));
        graph.addEdge(new UndirectedEdge<>(graph.getNode(2), graph.getNode(0)));
        graph.addEdge(new UndirectedEdge<>(graph.getNode(0), graph.getNode(3)));
        graph.addEdge(new UndirectedEdge<>(graph.getNode(0), graph.getNode(4)));
        graph.addEdge(new UndirectedEdge<>(graph.getNode(1), graph.getNode(3)));
        graph.addEdge(new UndirectedEdge<>(graph.getNode(3), graph.getNode(4)));
        graph.addEdge(new UndirectedEdge<>(graph.getNode(4), graph.getNode(2)));

        var colouring = kleuring.greedyColouring(Graphs.unmodifiableUndirectedGraph(graph));
        Assert.assertEquals(3, coloursUsed(colouring));
    }



    private int coloursUsed(HashMap<Node<Integer>, Integer> colouring){
        return new HashSet<>(colouring.values()).size();
    }
}