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

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

defmodule RobotSimulatorTest do
  use ExUnit.Case

  test "create has sensible defaults" do
    robot = RobotSimulator.create
    assert RobotSimulator.position(robot) == { 0, 0 }
    assert RobotSimulator.direction(robot) == :north
  end

  @tag :pending
  test "create works with valid arguments" do
    robot = RobotSimulator.create(:north, { 0, 0 })
    assert RobotSimulator.position(robot) == { 0, 0 }
    assert RobotSimulator.direction(robot) == :north

    robot = RobotSimulator.create(:south, { -10, 0 })
    assert RobotSimulator.position(robot) == { -10, 0 }
    assert RobotSimulator.direction(robot) == :south

    robot = RobotSimulator.create(:east, { 0, 10 })
    assert RobotSimulator.position(robot) == { 0, 10 }
    assert RobotSimulator.direction(robot) == :east

    robot = RobotSimulator.create(:west, { 100, -100 })
    assert RobotSimulator.position(robot) == { 100, -100 }
    assert RobotSimulator.direction(robot) == :west
  end

  @tag :pending
  test "create errors if invalid direction given" do
    position = {0, 0}
    invalid_direction = { :error, "invalid direction" }

    assert RobotSimulator.create(:invalid, position) == invalid_direction
    assert RobotSimulator.create(0, position) == invalid_direction
    assert RobotSimulator.create("east", position) == invalid_direction
  end

  @tag :pending
  test "create errors if invalid position given" do
    direction = :north
    invalid_position = { :error, "invalid position" }

    assert RobotSimulator.create(direction, { 0, 0, 0 }) == invalid_position
    assert RobotSimulator.create(direction, { 0, :invalid }) == invalid_position
    assert RobotSimulator.create(direction, { "0", 0 }) == invalid_position

    assert RobotSimulator.create(direction, "invalid") == invalid_position
    assert RobotSimulator.create(direction, 0 ) == invalid_position
    assert RobotSimulator.create(direction, [0, 0]) == invalid_position
    assert RobotSimulator.create(direction, nil) == invalid_position
  end

  @tag :pending
  test "simulate robots" do
    robot1 = RobotSimulator.create(:north, { 0, 0 }) |> RobotSimulator.simulate("LAAARALA")
    assert RobotSimulator.direction(robot1) == :west
    assert RobotSimulator.position(robot1) == { -4, 1 }

    robot2 = RobotSimulator.create(:east, { 2, -7 }) |> RobotSimulator.simulate("RRAAAAALA")
    assert RobotSimulator.direction(robot2) == :south
    assert RobotSimulator.position(robot2) == { -3, -8 }

    robot3 = RobotSimulator.create(:south, { 8, 4 }) |> RobotSimulator.simulate("LAAARRRALLLL")
    assert RobotSimulator.direction(robot3) == :north
    assert RobotSimulator.position(robot3) == { 11, 5 }
  end

  @tag :pending
  test "simulate errors on invalid instructions" do
    assert RobotSimulator.create |> RobotSimulator.simulate("UUDDLRLRBASTART") == { :error, "invalid instruction" }
  end
end