#ifndef SRC_CRYPTO_CRYPTO_KEM_H_
#define SRC_CRYPTO_CRYPTO_KEM_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include "base_object.h"
#include "crypto/crypto_keys.h"
#include "crypto/crypto_util.h"
#include "env.h"
#include "memory_tracker.h"
#include "node_external_reference.h"

#if OPENSSL_WITH_KEM

namespace node {
namespace crypto {

enum class KEMMode { Encapsulate, Decapsulate };

struct KEMConfiguration final : public MemoryRetainer {
  KeyObjectData key;
  ByteSource ciphertext;

  KEMConfiguration() = default;
  explicit KEMConfiguration(KEMConfiguration&& other) noexcept;
  KEMConfiguration& operator=(KEMConfiguration&& other) noexcept;

  void MemoryInfo(MemoryTracker* tracker) const override;
  SET_MEMORY_INFO_NAME(KEMConfiguration)
  SET_SELF_SIZE(KEMConfiguration)
};

struct KEMEncapsulateTraits final {
  using AdditionalParameters = KEMConfiguration;
  static constexpr const char* JobName = "KEMEncapsulateJob";

  static constexpr AsyncWrap::ProviderType Provider =
      AsyncWrap::PROVIDER_DERIVEBITSREQUEST;

  static v8::Maybe<void> AdditionalConfig(
      CryptoJobMode mode,
      const v8::FunctionCallbackInfo<v8::Value>& args,
      unsigned int offset,
      KEMConfiguration* params);
};

class KEMEncapsulateJob final : public CryptoJob<KEMEncapsulateTraits> {
 public:
  using AdditionalParams = KEMEncapsulateTraits::AdditionalParameters;

  static void New(const v8::FunctionCallbackInfo<v8::Value>& args);
  static void Initialize(Environment* env, v8::Local<v8::Object> target);
  static void RegisterExternalReferences(ExternalReferenceRegistry* registry);

  KEMEncapsulateJob(Environment* env,
                    v8::Local<v8::Object> object,
                    CryptoJobMode mode,
                    AdditionalParams&& params);

  void DoThreadPoolWork() override;
  v8::Maybe<void> ToResult(v8::Local<v8::Value>* err,
                           v8::Local<v8::Value>* result) override;

  SET_SELF_SIZE(KEMEncapsulateJob)
  void MemoryInfo(MemoryTracker* tracker) const override;

 private:
  struct Output {
    ByteSource ciphertext;
    ByteSource shared_key;
  };

  std::optional<Output> out_;
};

struct KEMDecapsulateTraits final {
  using AdditionalParameters = KEMConfiguration;
  static constexpr const char* JobName = "KEMDecapsulateJob";

  static constexpr AsyncWrap::ProviderType Provider =
      AsyncWrap::PROVIDER_DERIVEBITSREQUEST;

  static v8::Maybe<void> AdditionalConfig(
      CryptoJobMode mode,
      const v8::FunctionCallbackInfo<v8::Value>& args,
      unsigned int offset,
      KEMConfiguration* params);

  static bool DeriveBits(Environment* env,
                         const KEMConfiguration& params,
                         ByteSource* out,
                         CryptoJobMode mode,
                         CryptoErrorStore* errors);

  static v8::MaybeLocal<v8::Value> EncodeOutput(Environment* env,
                                                const KEMConfiguration& params,
                                                ByteSource* out);
};

using KEMDecapsulateJob = DeriveBitsJob<KEMDecapsulateTraits>;

void InitializeKEM(Environment* env, v8::Local<v8::Object> target);
void RegisterKEMExternalReferences(ExternalReferenceRegistry* registry);

namespace KEM {
void Initialize(Environment* env, v8::Local<v8::Object> target);
void RegisterExternalReferences(ExternalReferenceRegistry* registry);
}  // namespace KEM

}  // namespace crypto
}  // namespace node

#else

// Provide stub implementations when KEM is unavailable.
namespace node {
namespace crypto {
namespace KEM {
inline void Initialize(Environment* env, v8::Local<v8::Object> target) {
  // No-op when KEM is unavailable.
}
inline void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
  // No-op when KEM is unavailable.
}
}  // namespace KEM
}  // namespace crypto
}  // namespace node

#endif
#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
#endif  // SRC_CRYPTO_CRYPTO_KEM_H_