// Copyright 2021 https://github.com/tlepoint
//
// 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 "barrett.h"

#include "absl/numeric/int128.h"
#include "gtest/gtest.h"
#include "openssl/rand.h"

namespace {

template <typename Int>
class BarrettTest : public testing::Test {
 protected:
  void SetUp() {
    values_.resize(number_tests_);
    for (int i = 0; i < number_tests_; i++) {
      RAND_bytes(reinterpret_cast<uint8_t *>(&values_[i]), sizeof(values_[i]));
    }
  }
  std::vector<Int> values_;
  const int number_tests_ = 100;
};

typedef testing::Types<uint16_t, uint32_t, uint64_t> IntTypes;
TYPED_TEST_SUITE(BarrettTest, IntTypes);

TYPED_TEST(BarrettTest, Correctness) {
  for (TypeParam modulus :
       {static_cast<TypeParam>(1) << 2, static_cast<TypeParam>(1) << 8,
        (static_cast<TypeParam>(-1) >> 6)}) {
    Barrett<TypeParam> barrett(modulus);
    std::vector<TypeParam> out = barrett.Reduce(this->values_);

    for (int i = 0; i < this->number_tests_; i++) {
      ASSERT_EQ(out[i], (this->values_[i] % modulus));
    }
  }
}

}  // namespace

int main(int argc, char **argv) {
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}