if !System.get_env("EXERCISM_TEST_EXAMPLES") do
  Code.load_file("alphametics.exs", __DIR__)
end

ExUnit.start()
ExUnit.configure(exclude: :pending, trace: true)

defmodule AlphameticsTest do
  use ExUnit.Case

  # @tag :pending
  test "puzzle with three letters" do
    puzzle = "I + BB == ILL"

    solution = %{
      ?I => 1,
      ?B => 9,
      ?L => 0
    }

    assert Alphametics.solve(puzzle) == solution
  end

  @tag :pending
  test "solution must have unique value for each letter" do
    puzzle = "A == B"
    assert Alphametics.solve(puzzle) == nil
  end

  @tag :pending
  test "leading zero solution is invalid" do
    puzzle = "ACA + DD == BD"
    assert Alphametics.solve(puzzle) == nil
  end

  @tag :pending
  test "puzzle with four letters" do
    puzzle = "AS + A == MOM"

    solution = %{
      ?A => 9,
      ?S => 2,
      ?M => 1,
      ?O => 0
    }

    assert Alphametics.solve(puzzle) == solution
  end

  @tag :pending
  test "puzzle with six letters" do
    puzzle = "NO + NO + TOO == LATE"

    solution = %{
      ?N => 7,
      ?O => 4,
      ?T => 9,
      ?L => 1,
      ?A => 0,
      ?E => 2
    }

    assert Alphametics.solve(puzzle) == solution
  end

  @tag :pending
  test "puzzle with seven letters" do
    puzzle = "HE + SEES + THE == LIGHT"

    solution = %{
      ?E => 4,
      ?G => 2,
      ?H => 5,
      ?I => 0,
      ?L => 1,
      ?S => 9,
      ?T => 7
    }

    assert Alphametics.solve(puzzle) == solution
  end

  @tag :pending
  test "puzzle with eight letters" do
    puzzle = "SEND + MORE == MONEY"

    solution = %{
      ?S => 9,
      ?E => 5,
      ?N => 6,
      ?D => 7,
      ?M => 1,
      ?O => 0,
      ?R => 8,
      ?Y => 2
    }

    assert Alphametics.solve(puzzle) == solution
  end

  @tag :pending
  test "puzzle with ten letters" do
    puzzle = "AND + A + STRONG + OFFENSE + AS + A + GOOD == DEFENSE"

    solution = %{
      ?A => 5,
      ?D => 3,
      ?E => 4,
      ?F => 7,
      ?G => 8,
      ?N => 0,
      ?O => 2,
      ?R => 1,
      ?S => 6,
      ?T => 9
    }

    assert Alphametics.solve(puzzle) == solution
  end

  @tag :pending
  test "puzzle with ten letters and 199 addends" do
    puzzle =
      "THIS + A + FIRE + THEREFORE + FOR + ALL + HISTORIES + I + TELL + A + " <>
        "TALE + THAT + FALSIFIES + ITS + TITLE + TIS + A + LIE + THE + TALE + " <>
        "OF + THE + LAST + FIRE + HORSES + LATE + AFTER + THE + FIRST + " <>
        "FATHERS + FORESEE + THE + HORRORS + THE + LAST + FREE + TROLL + " <>
        "TERRIFIES + THE + HORSES + OF + FIRE + THE + TROLL + RESTS + AT + " <>
        "THE + HOLE + OF + LOSSES + IT + IS + THERE + THAT + SHE + STORES + " <>
        "ROLES + OF + LEATHERS + AFTER + SHE + SATISFIES + HER + HATE + OFF + " <>
        "THOSE + FEARS + A + TASTE + RISES + AS + SHE + HEARS + THE + LEAST + " <>
        "FAR + HORSE + THOSE + FAST + HORSES + THAT + FIRST + HEAR + THE + " <>
        "TROLL + FLEE + OFF + TO + THE + FOREST + THE + HORSES + THAT + " <>
        "ALERTS + RAISE + THE + STARES + OF + THE + OTHERS + AS + THE + " <>
        "TROLL + ASSAILS + AT + THE + TOTAL + SHIFT + HER + TEETH + TEAR + " <>
        "HOOF + OFF + TORSO + AS + THE + LAST + HORSE + FORFEITS + ITS + " <>
        "LIFE + THE + FIRST + FATHERS + HEAR + OF + THE + HORRORS + THEIR + " <>
        "FEARS + THAT + THE + FIRES + FOR + THEIR + FEASTS + ARREST + AS + " <>
        "THE + FIRST + FATHERS + RESETTLE + THE + LAST + OF + THE + FIRE + " <>
        "HORSES + THE + LAST + TROLL + HARASSES + THE + FOREST + HEART + " <>
        "FREE + AT + LAST + OF + THE + LAST + TROLL + ALL + OFFER + THEIR + " <>
        "FIRE + HEAT + TO + THE + ASSISTERS + FAR + OFF + THE + TROLL + " <>
        "FASTS + ITS + LIFE + SHORTER + AS + STARS + RISE + THE + HORSES + " <>
        "REST + SAFE + AFTER + ALL + SHARE + HOT + FISH + AS + THEIR + " <>
        "AFFILIATES + TAILOR + A + ROOFS + FOR + THEIR + SAFE == FORTRESSES"

    solution = %{
      ?A => 1,
      ?E => 0,
      ?F => 5,
      ?H => 8,
      ?I => 7,
      ?L => 2,
      ?O => 6,
      ?R => 3,
      ?S => 4,
      ?T => 9
    }

    assert Alphametics.solve(puzzle) == solution
  end
end