import { Graph } from "graphlib";
import { normalizeRanks } from "../util";
import * as rankUtil from "./util";
const longestPath = rankUtil.longestPath;

describe("rank/util", function () {
  describe("longestPath", function () {
    let g: Graph;

    beforeEach(function () {
      g = new Graph()
        .setDefaultNodeLabel(function () {
          return {};
        })
        .setDefaultEdgeLabel(function () {
          return { minlen: 1 };
        });
    });

    it("can assign a rank to a single node graph", function () {
      g.setNode("a");
      longestPath(g);
      normalizeRanks(g);
      expect(g.node("a").rank).toBe(0);
    });

    it("can assign ranks to unconnected nodes", function () {
      g.setNode("a");
      g.setNode("b");
      longestPath(g);
      normalizeRanks(g);
      expect(g.node("a").rank).toBe(0);
      expect(g.node("b").rank).toBe(0);
    });

    it("can assign ranks to connected nodes", function () {
      g.setEdge("a", "b");
      longestPath(g);
      normalizeRanks(g);
      expect(g.node("a").rank).toBe(0);
      expect(g.node("b").rank).toBe(1);
    });

    it("can assign ranks for a diamond", function () {
      g.setPath(["a", "b", "d"]);
      g.setPath(["a", "c", "d"]);
      longestPath(g);
      normalizeRanks(g);
      expect(g.node("a").rank).toBe(0);
      expect(g.node("b").rank).toBe(1);
      expect(g.node("c").rank).toBe(1);
      expect(g.node("d").rank).toBe(2);
    });

    it("uses the minlen attribute on the edge", function () {
      g.setPath(["a", "b", "d"]);
      g.setEdge("a", "c");
      g.setEdge("c", "d", { minlen: 2 });
      longestPath(g);
      normalizeRanks(g);
      expect(g.node("a").rank).toBe(0);
      // longest path biases towards the lowest rank it can assign
      expect(g.node("b").rank).toBe(2);
      expect(g.node("c").rank).toBe(1);
      expect(g.node("d").rank).toBe(3);
    });
  });
});