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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
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 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
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#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_CRYPTO_CRYPTO_RESULT_IMPL_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_CRYPTO_CRYPTO_RESULT_IMPL_H_

#include "third_party/blink/public/platform/web_crypto.h"
#include "third_party/blink/renderer/bindings/core/v8/script_promise.h"
#include "third_party/blink/renderer/bindings/core/v8/script_promise_resolver.h"
#include "third_party/blink/renderer/core/execution_context/execution_context.h"
#include "third_party/blink/renderer/core/execution_context/execution_context_lifecycle_observer.h"
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/platform/bindings/exception_code.h"
#include "third_party/blink/renderer/platform/crypto_result.h"
#include "third_party/blink/renderer/platform/wtf/forward.h"

namespace blink {

class CryptoKey;
class EncapsulatedKey;
class EncapsulatedBits;
class V8UnionCryptoKeyOrCryptoKeyPair;
class V8UnionArrayBufferOrJsonWebKey;

MODULES_EXPORT ExceptionCode WebCryptoErrorToExceptionCode(WebCryptoErrorType);

// Wrapper around a Promise to notify completion of the crypto operation.
//
// The thread on which CryptoResultImpl was created on is referred to as the
// "origin thread".
//
//  * At creation time there must be an active ExecutionContext.
//  * All methods of the CryptoResult implementation must be called from
//    the origin thread. The exception is that destruction may happen on
//    another thread.
//  * One of the CompleteWith***() functions must be called, or the
//    |resolver_| will be leaked until the ExecutionContext is destroyed.
class MODULES_EXPORT CryptoResultImpl final
    : public CryptoResult,
      public ExecutionContextLifecycleObserver {
 public:
  enum class DetailedResolverType {
    kArrayBuffer,
    kBoolean,
    kKey,
    kUnionCryptoKeyCryptoKeyPair,
    kUnionArrayBufferJsonWebKey,
    kEncapsulatedKey,
    kEncapsulatedBits
  };

  template <typename IDLType>
  CryptoResultImpl(ScriptState* script_state,
                   ScriptPromiseResolver<IDLType>* resolver)
      : ExecutionContextLifecycleObserver(ExecutionContext::From(script_state)),
        resolver_(resolver),
        detailed_type_(GetDetailedResolverType<IDLType>()),
        cancel_(base::MakeRefCounted<CryptoResultCancel>()) {
    // Sync cancellation state.
    if (ExecutionContext::From(script_state)->IsContextDestroyed()) {
      Cancel();
    }
  }
  ~CryptoResultImpl() override;

  void CompleteWithError(WebCryptoErrorType, const WebString&) override;
  void CompleteWithBuffer(base::span<const uint8_t> bytes) override;
  void CompleteWithJson(std::string_view utf8_data) override;
  void CompleteWithBoolean(bool) override;
  void CompleteWithKey(const WebCryptoKey&) override;
  void CompleteWithKeyForGenerateKey(const WebCryptoKey&) override;
  void CompleteWithKeyPairForGenerateKey(
      const WebCryptoKey& public_key,
      const WebCryptoKey& private_key) override;
  void CompleteWithEncapsulatedKey(
      const WebCryptoKey& shared_key,
      base::span<const uint8_t> ciphertext) override;
  void CompleteWithEncapsulatedBits(
      base::span<const uint8_t> shared_key,
      base::span<const uint8_t> ciphertext) override;
  WebCryptoWarningType GetWarning() override { return warning_code_; }
  void SetWarning(WebCryptoWarningType code) override { warning_code_ = code; }
  ExecutionContext* GetExecutionContext() const override {
    return resolver_ ? resolver_->GetExecutionContext() : nullptr;
  }

  WebCryptoResult Result() { return WebCryptoResult(this, cancel_.get()); }

  // ExecutionContextLifecycleObserver override:
  void ContextDestroyed() override { Cancel(); }

  void Trace(Visitor*) const override;

 private:
  void Cancel();
  void ClearResolver();

  template <typename...>
  static constexpr bool kAlwaysFalse = false;

  template <typename IDLType>
  static DetailedResolverType GetDetailedResolverType() {
    if constexpr (std::is_same_v<IDLType, DOMArrayBuffer>) {
      return DetailedResolverType::kArrayBuffer;
    } else if constexpr (std::is_same_v<IDLType, IDLBoolean>) {
      return DetailedResolverType::kBoolean;
    } else if constexpr (std::is_same_v<IDLType, CryptoKey>) {
      return DetailedResolverType::kKey;
    } else if constexpr (std::is_same_v<IDLType,
                                        V8UnionCryptoKeyOrCryptoKeyPair>) {
      return DetailedResolverType::kUnionCryptoKeyCryptoKeyPair;
    } else if constexpr (std::is_same_v<IDLType,
                                        V8UnionArrayBufferOrJsonWebKey>) {
      return DetailedResolverType::kUnionArrayBufferJsonWebKey;
    } else if constexpr (std::is_same_v<IDLType, EncapsulatedKey>) {
      return DetailedResolverType::kEncapsulatedKey;
    } else if constexpr (std::is_same_v<IDLType, EncapsulatedBits>) {
      return DetailedResolverType::kEncapsulatedBits;
    } else {
      NOTREACHED();
    }
  }

  // TODO(crbug.com/507066144): try to make resolver_ typed so we don't need to
  // use DowncastTo. If that doesn't work, pick either the detailed_type_
  // pattern or the CompleteWithKey/CompleteWithGenerateKey pattern and stick to
  // one of those.
  Member<ScriptPromiseResolverBase> resolver_;
  const DetailedResolverType detailed_type_;

  // Separately communicate cancellation to WebCryptoResults so as to
  // allow this result object, which will be on the Oilpan heap, to be
  // GCed and destructed as needed. That is, it may end being GCed while
  // the thread owning the heap is detached and shut down, which will
  // in some cases happen before corresponding webcrypto operations have
  // all been processed. Hence these webcrypto operations cannot reliably
  // check cancellation status via this result object. So, keep a separate
  // cancellation status object for the purpose, which will outlive the
  // result object and can be safely accessed by multiple threads.
  scoped_refptr<CryptoResultCancel> cancel_;

  WebCryptoWarningType warning_code_;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_CRYPTO_CRYPTO_RESULT_IMPL_H_