// SPDX-License-Identifier: LGPL-3.0-or-later
#include <algorithm>
#include <catch2/catch_test_macros.hpp>
#include <catch2/generators/catch_generators.hpp>
#include <catch2/generators/catch_generators_adapters.hpp>
#include <catch2/generators/catch_generators_random.hpp>

#include "util.h"

TEST_CASE("Transform Mirror") {
  // elementary operations
  REQUIRE(transform(TRANSFORM_MIRROR_X, 10, 20) == std::make_pair(10, -20));
  REQUIRE(transform(TRANSFORM_MIRROR_Y, 10, 20) == std::make_pair(-10, 20));

  // composite operations
  REQUIRE(transform(TRANSFORM_MIRROR_X | TRANSFORM_MIRROR_Y, 10, 20) ==
          std::make_pair(-10, -20));
}

TEST_CASE("Transform Rotate") {
  REQUIRE(transform(TRANSFORM_ROTATE_CW, 10, 20) ==
          std::make_pair(-20, 10)); // 4th quadrant
  REQUIRE(transform(TRANSFORM_ROTATE_CW, -20, 10) ==
          std::make_pair(-10, -20)); // 3rd quadrant
  REQUIRE(transform(TRANSFORM_ROTATE_CW, -10, -20) ==
          std::make_pair(20, -10)); // 2nd quadrant
  REQUIRE(transform(TRANSFORM_ROTATE_CW, 20, -10) ==
          std::make_pair(10, 20)); // 1st quadrant

  REQUIRE(transform(TRANSFORM_ROTATE_CCW, 20, -10) ==
          std::make_pair(-10, -20)); // 1nd quadrant
  REQUIRE(transform(TRANSFORM_ROTATE_CCW, -10, -20) ==
          std::make_pair(-20, 10)); // 2rd quadrant
  REQUIRE(transform(TRANSFORM_ROTATE_CCW, -20, 10) ==
          std::make_pair(10, 20)); // 3th quadrant
  REQUIRE(transform(TRANSFORM_ROTATE_CCW, 10, 20) ==
          std::make_pair(20, -10)); // 4st quadrant
}

TEST_CASE("Transform Rotate + Mirror") {
  REQUIRE(transform(TRANSFORM_ROTATE_CW | TRANSFORM_MIRROR_X, 10, 20) ==
          std::make_pair(-20, -10));
  REQUIRE(transform(TRANSFORM_ROTATE_CW | TRANSFORM_MIRROR_Y, 10, 20) ==
          std::make_pair(20, 10));
  REQUIRE(
      transform(TRANSFORM_ROTATE_CW | TRANSFORM_MIRROR_X | TRANSFORM_MIRROR_Y,
                10, 20) == std::make_pair(20, -10));

  REQUIRE(transform(TRANSFORM_ROTATE_CCW | TRANSFORM_MIRROR_X, 10, 20) ==
          std::make_pair(20, 10));
  REQUIRE(transform(TRANSFORM_ROTATE_CCW | TRANSFORM_MIRROR_Y, 10, 20) ==
          std::make_pair(-20, -10));
  REQUIRE(
      transform(TRANSFORM_ROTATE_CCW | TRANSFORM_MIRROR_X | TRANSFORM_MIRROR_Y,
                10, 20) == std::make_pair(-20, 10));
}

TEST_CASE("Transform = Inverse Transform ○ Transform") {
  int x = GENERATE(take(10, random(-100, 100)));
  int y = GENERATE(take(10, random(-100, 100)));
  // this iterates over all possible transformations,
  // even bogus ones (like rotating cw and ccw)
  for (Transformation transformation = 0; transformation < 0b10000;
       transformation++) {
    int xt, yt;
    std::tie(xt, yt) = transform(transformation, x, y);
    int xti, yti;
    std::tie(xti, yti) = transform_inv(transformation, xt, yt);
    REQUIRE(x == xti);
    REQUIRE(y == yti);
  }
}