// Copyright 2021 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <string>

#include "gtest/gtest.h"

#include "fuzzers/tint_regex_fuzzer/wgsl_mutator.h"

namespace tint {
namespace fuzzers {
namespace regex_fuzzer {
namespace {

// Swaps two non-consecutive regions in the edge
TEST(SwapRegionsTest, SwapIntervalsEdgeNonConsecutive) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;";
  std::string all_regions = R1 + R2 + R3;

  // this call should swap R1 with R3.
  SwapIntervals(0, R1.length(), R1.length() + R2.length(), R3.length(),
                all_regions);

  ASSERT_EQ(R3 + R2 + R1, all_regions);
}

// Swaps two non-consecutive regions not in the edge
TEST(SwapRegionsTest, SwapIntervalsNonConsecutiveNonEdge) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // this call should swap R2 with R4.
  SwapIntervals(R1.length(), R2.length(),
                R1.length() + R2.length() + R3.length(), R4.length(),
                all_regions);

  ASSERT_EQ(R1 + R4 + R3 + R2 + R5, all_regions);
}

// Swaps two consecutive regions not in the edge (sorrounded by other
// regions)
TEST(SwapRegionsTest, SwapIntervalsConsecutiveEdge) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4;

  // this call should swap R2 with R3.
  SwapIntervals(R1.length(), R2.length(), R1.length() + R2.length(),
                R3.length(), all_regions);

  ASSERT_EQ(R1 + R3 + R2 + R4, all_regions);
}

// Swaps two consecutive regions not in the edge (not sorrounded by other
// regions)
TEST(SwapRegionsTest, SwapIntervalsConsecutiveNonEdge) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // this call should swap R4 with R5.
  SwapIntervals(R1.length() + R2.length() + R3.length(), R4.length(),
                R1.length() + R2.length() + R3.length() + R4.length(),
                R5.length(), all_regions);

  ASSERT_EQ(R1 + R2 + R3 + R5 + R4, all_regions);
}

// Deletes the first region.
TEST(DeleteRegionTest, DeleteFirstRegion) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // This call should delete R1.
  DeleteInterval(0, R1.length(), all_regions);

  ASSERT_EQ(";" + R2 + R3 + R4 + R5, all_regions);
}

// Deletes the last region.
TEST(DeleteRegionTest, DeleteLastRegion) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // This call should delete R5.
  DeleteInterval(R1.length() + R2.length() + R3.length() + R4.length(),
                 R5.length(), all_regions);

  ASSERT_EQ(R1 + R2 + R3 + R4 + ";", all_regions);
}

// Deletes the middle region.
TEST(DeleteRegionTest, DeleteMiddleRegion) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // This call should delete R3.
  DeleteInterval(R1.length() + R2.length(), R3.length(), all_regions);

  ASSERT_EQ(R1 + R2 + ";" + R4 + R5, all_regions);
}

TEST(InsertRegionTest, InsertRegionTest1) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // This call should insert R2 after R4.
  DuplicateInterval(R1.length(), R2.length(),
                    R1.length() + R2.length() + R3.length() + R4.length() - 1,
                    all_regions);

  ASSERT_EQ(R1 + R2 + R3 + R4 + R2.substr(1, R2.size() - 1) + R5, all_regions);
}

TEST(InsertRegionTest, InsertRegionTest2) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";

  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // This call should insert R3 after R1.
  DuplicateInterval(R1.length() + R2.length(), R3.length(), R1.length() - 1,
                    all_regions);

  ASSERT_EQ(R1 + R3.substr(1, R3.length() - 1) + R2 + R3 + R4 + R5,
            all_regions);
}

TEST(InsertRegionTest, InsertRegionTest3) {
  std::string R1 = ";region1;", R2 = ";regionregion2;",
              R3 = ";regionregionregion3;", R4 = ";regionregionregionregion4;",
              R5 = ";regionregionregionregionregion5;";

  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // This call should insert R2 after R5.
  DuplicateInterval(R1.length(), R2.length(), all_regions.length() - 1,
                    all_regions);

  ASSERT_EQ(R1 + R2 + R3 + R4 + R5 + R2.substr(1, R2.length() - 1),
            all_regions);
}

TEST(ReplaceIdentifierTest, ReplaceIdentifierTest1) {
  std::string R1 = "|region1|", R2 = "; region2;",
              R3 = "---------region3---------", R4 = "++region4++",
              R5 = "***region5***";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // Replaces R3 with R1.
  ReplaceRegion(0, R1.length(), R1.length() + R2.length(), R3.length(),
                all_regions);

  ASSERT_EQ(R1 + R2 + R1 + R4 + R5, all_regions);
}

TEST(ReplaceIdentifierTest, ReplaceIdentifierTest2) {
  std::string R1 = "|region1|", R2 = "; region2;",
              R3 = "---------region3---------", R4 = "++region4++",
              R5 = "***region5***";
  std::string all_regions = R1 + R2 + R3 + R4 + R5;

  // Replaces R5 with R3.
  ReplaceRegion(R1.length() + R2.length(), R3.length(),
                R1.length() + R2.length() + R3.length() + R4.length(),
                R5.length(), all_regions);

  ASSERT_EQ(R1 + R2 + R3 + R4 + R3, all_regions);
}

TEST(GetIdentifierTest, GetIdentifierTest1) {
  std::string wgsl_code =
      "fn clamp_0acf8f() {"
      "var res: vec2<f32> = clamp(vec2<f32>(), vec2<f32>(), vec2<f32>());}"
      "[[stage(vertex)]]"
      "fn vertex_main() -> [[builtin(position)]] vec4<f32> {"
      "  clamp_0acf8f();"
      "  return vec4<f32>();}"
      "[[stage(fragment)]]"
      "fn fragment_main() {"
      "  clamp_0acf8f();}"
      "[[stage(compute), workgroup_size(1)]]"
      "fn compute_main() {"
      "var<private> foo: f32 = 0.0;"
      "  clamp_0acf8f();}";

  std::vector<std::pair<size_t, size_t>> identifiers_pos =
      GetIdentifiers(wgsl_code);

  std::vector<std::pair<size_t, size_t>> ground_truth = {
      std::make_pair(3, 12),   std::make_pair(19, 3),  std::make_pair(28, 4),
      std::make_pair(40, 5),   std::make_pair(51, 3),  std::make_pair(59, 4),
      std::make_pair(72, 4),   std::make_pair(88, 5),  std::make_pair(103, 2),
      std::make_pair(113, 4),  std::make_pair(125, 7), std::make_pair(145, 4),
      std::make_pair(158, 12), std::make_pair(175, 6), std::make_pair(187, 3),
      std::make_pair(197, 5),  std::make_pair(214, 2), std::make_pair(226, 4),
      std::make_pair(236, 12), std::make_pair(254, 5), std::make_pair(270, 14),
      std::make_pair(289, 2),  std::make_pair(300, 4), std::make_pair(308, 3),
      std::make_pair(321, 3),  std::make_pair(326, 3), std::make_pair(338, 12)};

  ASSERT_EQ(ground_truth, identifiers_pos);
}

}  // namespace
}  // namespace regex_fuzzer
}  // namespace fuzzers
}  // namespace tint