// Copyright 2026 Google LLC
//
// 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
//
//    https://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 "salt/random_salt_generator.h"

#include <string>
#include <utility>

#include "absl/container/flat_hash_set.h"
#include "absl/status/status_matchers.h"
#include "absl/status/statusor.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "salt/salt_generator.h"

namespace credentio {
namespace {

using ::absl_testing::IsOkAndHolds;
using ::testing::SizeIs;

TEST(RandomSaltGeneratorTest, GeneratesSaltOfDefaultLength) {
  RandomSaltGenerator salt_generator;

  EXPECT_THAT(salt_generator.Generate(),
              IsOkAndHolds(SizeIs(kDefaultSaltLength)));
}

TEST(RandomSaltGeneratorTest, DefaultReturnsSameInstance) {
  EXPECT_EQ(&RandomSaltGenerator::Default(), &RandomSaltGenerator::Default());
  EXPECT_THAT(RandomSaltGenerator::Default().Generate(),
              IsOkAndHolds(SizeIs(kDefaultSaltLength)));
}

TEST(RandomSaltGeneratorTest, GeneratesUniqueSalts) {
  constexpr int kNumSalts = 1000;
  RandomSaltGenerator salt_generator;

  absl::flat_hash_set<std::string> salts;
  for (int i = 0; i < kNumSalts; ++i) {
    absl::StatusOr<std::string> salt = salt_generator.Generate();
    ABSL_ASSERT_OK(salt);
    salts.insert(*std::move(salt));
  }

  EXPECT_THAT(salts, SizeIs(kNumSalts));
}

}  // namespace
}  // namespace credentio