module Test = (val Containers_testlib.make ~__FILE__ ())
open Test
open CCGraph;;

t @@ fun () ->
let l =
  let tbl = mk_table ~eq:CCInt.equal 128 in
  Traverse.Event.dfs ~tbl ~eq:CCInt.equal ~graph:divisors_graph
    (Iter.return 345614)
  |> Iter.to_list
in
let expected =
  [
    `Enter (345614, 0, []);
    `Edge (345614, (), 172807, `Forward);
    `Enter (172807, 1, [ 345614, (), 172807 ]);
    `Edge (172807, (), 1, `Forward);
    `Enter (1, 2, [ 172807, (), 1; 345614, (), 172807 ]);
    `Exit 1;
    `Exit 172807;
    `Edge (345614, (), 2, `Forward);
    `Enter (2, 3, [ 345614, (), 2 ]);
    `Edge (2, (), 1, `Cross);
    `Exit 2;
    `Edge (345614, (), 1, `Cross);
    `Exit 345614;
  ]
in
assert_equal expected l;
true
;;

t @@ fun () ->
let tbl = mk_table ~eq:CCInt.equal 128 in
let l = topo_sort ~eq:CCInt.equal ~tbl ~graph:divisors_graph (Iter.return 42) in
List.for_all
  (fun (i, j) ->
    let idx_i = CCList.find_idx (( = ) i) l |> CCOption.get_exn_or "" |> fst in
    let idx_j = CCList.find_idx (( = ) j) l |> CCOption.get_exn_or "" |> fst in
    idx_i < idx_j)
  [ 42, 21; 14, 2; 3, 1; 21, 7; 42, 3 ]
;;

t @@ fun () ->
let tbl = mk_table ~eq:CCInt.equal 128 in
let l =
  topo_sort ~eq:CCInt.equal ~rev:true ~tbl ~graph:divisors_graph
    (Iter.return 42)
in
List.for_all
  (fun (i, j) ->
    let idx_i = CCList.find_idx (( = ) i) l |> CCOption.get_exn_or "" |> fst in
    let idx_j = CCList.find_idx (( = ) j) l |> CCOption.get_exn_or "" |> fst in
    idx_i > idx_j)
  [ 42, 21; 14, 2; 3, 1; 21, 7; 42, 3 ]
;;

(* example from https://en.wikipedia.org/wiki/Strongly_connected_component *)
t @@ fun () ->
let set_eq ?(eq = ( = )) l1 l2 =
  CCList.subset ~eq l1 l2 && CCList.subset ~eq l2 l1
in
let graph =
  of_list ~eq:CCString.equal
    [
      "a", "b";
      "b", "e";
      "e", "a";
      "b", "f";
      "e", "f";
      "f", "g";
      "g", "f";
      "b", "c";
      "c", "g";
      "c", "d";
      "d", "c";
      "d", "h";
      "h", "d";
      "h", "g";
    ]
in
let tbl = mk_table ~eq:CCString.equal 128 in
let res = scc ~tbl ~graph (Iter.return "a") |> Iter.to_list in
assert_bool "scc"
  (set_eq ~eq:(set_eq ?eq:None) res
     [ [ "a"; "b"; "e" ]; [ "f"; "g" ]; [ "c"; "d"; "h" ] ]);
true