//
// Created by Marc Rousavy on 21.02.24.
//

#pragma once

#include "NitroDefines.hpp"
#include "NitroTypeInfo.hpp"
#include <fbjni/fbjni.h>
#include <memory>

namespace margelo::nitro {

using namespace facebook;

template <typename T>
struct GlobalRefDeleter {
  explicit GlobalRefDeleter(const jni::global_ref<typename T::javaobject>& ref) : _ref(ref) {}

  GlobalRefDeleter(const GlobalRefDeleter& copy) = delete;
  GlobalRefDeleter(GlobalRefDeleter&& move) = default;

  void operator()(T* /* cthis */) {
    // It's RAII - once `GlobalRefDeleter` goes out of scope, `jni::global_ref` will too.
    jni::ThreadScope::WithClassLoader([&] { _ref.reset(); });
  }

private:
  jni::global_ref<typename T::javaobject> _ref;
};

class JNISharedPtr final {
private:
  template <typename T, template <typename, typename...> class Base>
  struct is_base_template_of {
    template <typename U>
    static std::true_type test(Base<U>*) {}

    template <typename>
    static std::false_type test(...) {}

    static constexpr bool value = decltype(test<T>(nullptr))::value;
  };

public:
  JNISharedPtr() = delete;
  ~JNISharedPtr() = delete;

public:
  /**
   * Creates a new `std::shared_ptr<T>` from the given `jni::global_ref<T::javaobject>`.
   * Note: This does not perform any caching and will just re-create the shared_ptr control-block
   *       each time. It is not safe to call this multiple times if you use enable_shared_from_this.
   *       Instead, use HybridObject::shared().
   */
  template <typename T, typename std::enable_if<is_base_template_of<T, jni::HybridClass>::value, int>::type = 0>
  static std::shared_ptr<T> make_shared_from_jni(const jni::global_ref<typename T::javaobject>& ref) {
#ifdef NITRO_DEBUG
    if (ref == nullptr || ref->cthis() == nullptr) [[unlikely]] {
      std::string typeName = TypeInfo::getFriendlyTypename<T>(true);
      throw std::runtime_error("Failed to wrap jni::global_ref<" + typeName + "::javaobject> in std::shared_ptr<" + typeName +
                               "> - it's null!");
    }
#endif
    return std::shared_ptr<T>(ref->cthis(), GlobalRefDeleter<T>(ref));
  }
};

} // namespace margelo::nitro