package graph;

import java.util.ArrayList;

public class Graph {
    private ArrayList<Node> nodes = new ArrayList<>();

    public ArrayList<Node> getNodes() {
        return nodes;
    }

    public Node getFirstNode() {
        return nodes.get(0);
    }

    public void addNode(Node n) {
        if (nodes.contains(n)) {
            throw new IllegalArgumentException();
        }
        nodes.add(n);
    }

    public ArrayList<Node> depthFirst(Node startNode) {
        unmarkAllNodes();
        final ArrayList<Node> collect = new ArrayList<>();
        search(startNode, collect);
        return collect;
    }

    private void search(Node node, ArrayList<Node> collect) {
        if (node.getMarked()) return;
        node.setMarked(true);
        collect.add(node);
        for (Edge e : node.getOut())
            search(e.getTarget(), collect);
    }

    public ArrayList<Node> breadthFirst(Node startNode) {
        unmarkAllNodes();
        final ArrayList<Node> collect = new ArrayList<>();
        startNode.setMarked(true);
        collect.add(startNode);
        // Die folgende For-Schleife kann nicht als foreach-loop
        // realisiert werden, weil sich collect laufend ändert
        for (int i = 0; i < collect.size(); i++)
            for (Edge edge : collect.get(i).getOut()) {
                final Node target = edge.getTarget();
                if (!target.getMarked()) {
                    target.setMarked(true);
                    collect.add(target);
                }
            }
        return collect;
    }

    private void unmarkAllNodes() {
        for (Node n : nodes)
            n.setMarked(false);
    }

    @Override
    public String toString() {
        StringBuilder str = new StringBuilder();
        str.append("Grap=\n");
        for (Node n : nodes) {
            str.append(n).append(";\n");
        }
        return str.toString();
    }
}