(*
This file is part of licht.

licht is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

licht is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with licht.  If not, see <http://www.gnu.org/licenses/>.
*)

open OUnit2

module Option = Tools.Option

let u = UTF8.from_utf8string

let catalog = Functions.C.compile @@ Functions.built_in Functions.C.empty

let _msg ~expected ~result = begin

  let get_string v = match v with
  | None -> "Undefined"
  | Some x -> UTF8.raw_encode @@ ScTypes.Result.show x
  in

    Printf.sprintf "Expected %s but got %s"
    (get_string expected)
    (get_string result)
end

let build_num value = ScTypes.Type.number @@ DataType.Num.of_int value

(** Test a simple references between two cells *)
let test_create_ref_1 ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=-1") (3,3) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=C3") (0,0) s;

  let _, result, _ = Sheet.get_cell (0, 0) s in
  let expected = Some (ScTypes.Result.Ok (build_num (-1))) in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

let test_create_ref_2 ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=C3") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1") (3,3) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"123") (1,1) s;

  let _, result, _ = Sheet.get_cell (2, 2) s in
  let expected = Some (ScTypes.Result.Ok (build_num 123)) in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

let test_create_direct_cycle ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=B2 + 1") (2,2) s;

  let _, result, _ = Sheet.get_cell (2, 2) s in
  let expected = Some (ScTypes.Result.Error Errors.TypeError) in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

(** Overide the value after a cycle. *)
let test_recover_from_cycle ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=B2 + 1") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=6") (2,2) s;

  let _, result, _ = Sheet.get_cell (2, 2) s in
  let expected = Some (ScTypes.Result.Ok (build_num (6))) in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

let test_create_indirect_cycle ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=2") (1,1) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=B2+1") (1,1) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1") (0,0) s;

  let _, result, _ = Sheet.get_cell (0, 0) s in
  let expected = Some (ScTypes.Result.Error Errors.Cycle) in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

let test_check_cycle3 ctx = begin

  let s = Sheet.create catalog in
  (* First set A1 to 3 *)
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=3") (1,1) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1") (1,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=B2") (5,5) s;
  (* A3 = A1 + A1 = 6 *)
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A2 + E5") (1,3) s;
  (* Then set A1 to 2 *)
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=2") (1,1) s;

  let _, result, _ = Sheet.get_cell (1, 3) s in
  (* A3 = A1 + A1 = 4 *)
  let expected = Some (ScTypes.Result.Ok (build_num 4)) in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

let test_delete ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=C3") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1") (3,3) s;
  ignore @@ Sheet.delete (Selection.create (2,2)) s;
  ignore @@ Sheet.delete (Selection.create (3,3)) s;
  let _, result, _ = Sheet.get_cell (3, 3) s in
  let expected = None in

  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result
end

let test_update_succs1 ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u" =1") (1,1) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A2") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1/1") (1,2) s;

  let result = Sheet.add ~history:false (Expression.load @@ u"=2") (1,1) s in

  (* All the cells are updated by the change *)
  let expected = Cell.Set.of_list [(1,1); (1, 2); (2,2)] in

  let msg = Printf.sprintf "Expected %s but got %s"
    (UTF8.raw_encode @@ Tools.String.print_buffer Cell.Set.printb expected)
    (UTF8.raw_encode @@ Tools.String.print_buffer Cell.Set.printb result) in

  assert_equal ~msg
    expected
    result
end

let test_update_succs2 ctx = begin

  let s = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=1") (1,1) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A2") (2,2) s;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=A1/0") (1,2) s;

  let result = Sheet.add ~history:false (Expression.load @@ u"=2") (1,1) s in

  (* Only (1, 1) is updated ; (2, 2) does not change, neither (2, 2) *)
  let expected = Cell.Set.of_list [(1,1)] in

  assert_equal
    expected
    result
end

let test_paste_undo ctx = begin

  (* The expected result for the whole test *)
  let expected = Some (ScTypes.Result.Ok (ScTypes.Type.number (DataType.Num.of_int 6))) in

  let sheet = Sheet.create catalog in
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=6") (2, 1) sheet;
  ignore @@ Sheet.add ~history:false (Expression.load @@ u"=B1") (1, 1) sheet;

  let _, result, _ = Sheet.get_cell (1, 1) sheet in

  (* Ensure the value is correctly evaluated *)
  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result;

  (* Copy the cell *)
  ignore @@ Sheet.yank (Selection.create (1, 1)) sheet;
  (* Paste it on another value *)
  ignore @@ Sheet.paste (2, 1) sheet;
  (* Undo the paste *)
  assert_equal true (Sheet.undo sheet);

  let _, result, _ = Sheet.get_cell (1, 1) sheet in

  (* The value should be the same as the first evaluation *)
  assert_equal
    ~msg:(_msg ~expected ~result)
    expected
    result

end

let tests = "sheet_test">::: [
  "test_ref1"           >:: test_create_ref_1;
  "test_ref2"           >:: test_create_ref_2;
  "test_cycle1"         >:: test_create_direct_cycle;
  "test_recover_cycle"  >:: test_recover_from_cycle;
  (*"test_cycle2"         >:: test_create_indirect_cycle;*)
  "test_cycle3"         >:: test_check_cycle3;
  "test_delete"         >:: test_delete;
  "test_update_succs1"  >:: test_update_succs1;
  (*"test_update_succs2"  >:: test_update_succs2;*)
  "test_paste_undo"     >:: test_paste_undo;
 ]