// 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 "crypto/default/hasher.h"

#include <string>
#include <utility>

#include "absl/log/check.h"
#include "absl/status/status.h"
#include "absl/status/status_matchers.h"
#include "absl/strings/escaping.h"
#include "absl/strings/string_view.h"
#include "crypto/algorithms.h"
#include "crypto/hash.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace credentio {
namespace {

using ::absl_testing::StatusIs;
using ::testing::Eq;
using ::testing::IsFalse;
using ::testing::IsTrue;
using ::testing::NotNull;

std::string BytesFromHexOrDie(absl::string_view hex) {
  std::string bytes;
  CHECK(absl::HexStringToBytes(hex, &bytes));
  return bytes;
}

TEST(CreateHasherTest, SHA256) {
  auto hasher_or = CreateHasher("sha256");
  ASSERT_TRUE(hasher_or.ok());
  auto hasher = std::move(hasher_or).value();
  hasher->Update(absl::string_view("hello"));
  hasher->Update(absl::string_view("world"));
  EXPECT_THAT(
      absl::BytesToHexString(hasher->Digest()),
      "936a185caaa266bb9cbe981e9e05cb78cd732b0b3280eb944412bb6f8f8f07af");
}

TEST(CreateHasherTest, SHA384) {
  auto hasher_or = CreateHasher("sha384");
  ASSERT_TRUE(hasher_or.ok());
  auto hasher = std::move(hasher_or).value();
  hasher->Update(absl::string_view("hello"));
  hasher->Update(absl::string_view("world"));
  EXPECT_THAT(absl::BytesToHexString(hasher->Digest()),
              "97982a5b1414b9078103a1c008c4e3526c27b41cdbcf80790560a40f2a9bf2ed"
              "4427ab1428789915ed4b3dc07c454bd9");
}

TEST(CreateHasherTest, SHA512) {
  auto hasher_or = CreateHasher("sha512");
  ASSERT_TRUE(hasher_or.ok());
  auto hasher = std::move(hasher_or).value();
  hasher->Update(absl::string_view("hello"));
  hasher->Update(absl::string_view("world"));
  EXPECT_THAT(
      absl::BytesToHexString(hasher->Digest()),
      "1594244d52f2d8c12b142bb61f47bc2eaf503d6d9ca8480cae9fcf112f66e4967dc5e8fa"
      "98285e36db8af1b8ffa8b84cb15e0fbcf836c3deb803c13f37659a60");
}

TEST(CreateHasherTest, UnknownAlgorithm) {
  EXPECT_THAT(CreateHasher("blah"),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       "unrecognized hash algorithm name"));
}

TEST(HashCheckerTest, Valid) {
  auto checker_or = DefaultHashCheckerFactory().Create(HashAlgorithm::kSha256);
  ASSERT_TRUE(checker_or.ok());
  auto checker = std::move(checker_or).value();
  ASSERT_THAT(checker, NotNull());
  checker->Update("hello");
  checker->Update("world");
  EXPECT_THAT(
      checker->Check(BytesFromHexOrDie(
          "936a185caaa266bb9cbe981e9e05cb78cd732b0b3280eb944412bb6f8f8f07af")),
      IsTrue());
}

TEST(HashCheckerTest, Invalid) {
  auto checker_or = DefaultHashCheckerFactory().Create(HashAlgorithm::kSha256);
  ASSERT_TRUE(checker_or.ok());
  auto checker = std::move(checker_or).value();
  ASSERT_THAT(checker, NotNull());
  checker->Update("hello");
  checker->Update("world2");
  EXPECT_THAT(
      checker->Check(BytesFromHexOrDie(
          "936a185caaa266bb9cbe981e9e05cb78cd732b0b3280eb944412bb6f8f8f07af")),
      IsFalse());
}

TEST(CreateHasherTest, SHA256HashFactory) {
  Sha256HasherFactory factory;
  EXPECT_EQ(factory.algorithm(), HashAlgorithm::kSha256);

  auto hasher_or = factory.Create();
  ASSERT_TRUE(hasher_or.ok());
  auto hasher = std::move(hasher_or).value();
  hasher->Update(absl::string_view("hello"));
  hasher->Update(absl::string_view("world"));
  EXPECT_THAT(
      absl::BytesToHexString(hasher->Digest()),
      "936a185caaa266bb9cbe981e9e05cb78cd732b0b3280eb944412bb6f8f8f07af");
}

TEST(CreateHasherTest, SHA384HashFactory) {
  Sha384HasherFactory factory;
  EXPECT_EQ(factory.algorithm(), HashAlgorithm::kSha384);

  auto hasher_or = factory.Create();
  ASSERT_TRUE(hasher_or.ok());
  auto hasher = std::move(hasher_or).value();
  hasher->Update(absl::string_view("hello"));
  hasher->Update(absl::string_view("world"));
  EXPECT_THAT(absl::BytesToHexString(hasher->Digest()),
              "97982a5b1414b9078103a1c008c4e3526c27b41cdbcf80790560a40f2a9bf2ed"
              "4427ab1428789915ed4b3dc07c454bd9");
}

TEST(CreateHasherTest, SHA512HashFactory) {
  Sha512HasherFactory factory;
  EXPECT_EQ(factory.algorithm(), HashAlgorithm::kSha512);

  auto hasher_or = factory.Create();
  ASSERT_TRUE(hasher_or.ok());
  auto hasher = std::move(hasher_or).value();
  hasher->Update(absl::string_view("hello"));
  hasher->Update(absl::string_view("world"));
  EXPECT_THAT(
      absl::BytesToHexString(hasher->Digest()),
      "1594244d52f2d8c12b142bb61f47bc2eaf503d6d9ca8480cae9fcf112f66e4967dc5e8fa"
      "98285e36db8af1b8ffa8b84cb15e0fbcf836c3deb803c13f37659a60");
}

TEST(HasherFactoryTest, DefaultIsSha256) {
  const HasherFactory& factory = DefaultHasherFactory();
  EXPECT_THAT(factory.algorithm(), Eq(HashAlgorithm::kSha256));
}

TEST(HasherFactoryTest, DefaultIsSingleton) {
  const HasherFactory& factory1 = DefaultHasherFactory();
  const HasherFactory& factory2 = DefaultHasherFactory();
  EXPECT_THAT(&factory1, Eq(&factory2));
}

}  // namespace
}  // namespace credentio