defmodule CPSolverTest.Examples.GraphColoring do
  use ExUnit.Case, async: false

  alias CPSolver.Examples.GraphColoring

  test "P3" do
    test_graph("p3", 2, trials: 10)
  end

  test "P4" do
    test_graph("p4", 2, trials: 10)
  end

  test "Triangle" do
    test_graph("triangle", 6, trials: 10)
  end

  test "Square" do
    test_graph("square", 2, trials: 10)
  end

  test "Paw" do
    test_graph("paw", 12, timeout: 100, trials: 10)
  end

  test "Petersen" do
    test_graph("petersen", 120, timeout: 500, trials: 5)
  end

  test "gc_15_30_1" do
    test_graph("gc_15_30_1", 36)
  end

  @tag :slow
  test "gc_15_30_2" do
    test_graph("gc_15_30_2", 21408, timeout: 2000, trials: 1)
  end

  test "gc_15_30_3" do
    test_graph("gc_15_30_3", 12)
  end

  test "Multiple P4 runs" do
    test_graph("p4", 2, trials: 20)
  end

  test "Multiple P3 runs" do
    test_graph("p3", 2, trials: 20)
  end

  defp test_graph(graph_name, expected_solutions, opts \\ []) do
    opts =
      Keyword.merge([timeout: 100, trials: 5], opts)

    instance = "data/graph_coloring/#{graph_name}"

    Enum.each(1..opts[:trials], fn _ ->
      {:ok, result} = CPSolver.solve_sync(GraphColoring.model(instance), timeout: opts[:timeout])
      Enum.each(result.solutions, fn sol -> assert_solution(sol, instance) end)
      solution_count = result.statistics.solution_count

      assert solution_count == expected_solutions
    end)
  end

  defp assert_solution(solution, instance) do
    assert GraphColoring.check_solution(solution, instance)
  end
end