#ifndef MEDIAPIPE_FRAMEWORK_TOOL_OPTIONS_REGISTRY_H_
#define MEDIAPIPE_FRAMEWORK_TOOL_OPTIONS_REGISTRY_H_

#include <string>

#include "absl/container/flat_hash_map.h"
#include "mediapipe/framework/deps/registration.h"
#include "mediapipe/framework/port/advanced_proto_inc.h"
#include "mediapipe/framework/tool/field_data.pb.h"

namespace mediapipe {
namespace tool {

class Descriptor;
class FieldDescriptor;
using FieldType = mediapipe::proto_ns::internal::WireFormatLite::FieldType;
using mediapipe::FieldData;

// A static registry that stores descriptors for protobufs used in MediaPipe
// calculator options. Lite-proto builds do not normally include descriptors.
// These registered descriptors allow individual protobuf fields to be
// referenced and specified separately within CalculatorGraphConfigs.
class OptionsRegistry {
 public:
  // Registers the protobuf descriptors for a FileDescriptorSet.
  static RegistrationToken Register(const FieldData& file_descriptor_set);

  // Finds the descriptor for a protobuf.
  static const Descriptor* GetProtobufDescriptor(const std::string& type_name);

  // Returns all known proto2 extensions to a type.
  static void FindAllExtensions(absl::string_view extendee,
                                std::vector<const FieldDescriptor*>* result);

 private:
  // Registers protobuf descriptors for a message type and nested types.
  static void Register(const FieldData& message_type,
                       const std::string& parent_name);

  static absl::flat_hash_map<std::string, Descriptor>& descriptors();
  static absl::flat_hash_map<std::string, std::vector<FieldDescriptor>>&
  extensions();
  static absl::Mutex& mutex();

  // Registers the descriptors for each options protobuf type.
  template <class MessageT>
  static const RegistrationToken registration_token;
};

// A custom implementation proto_ns::Descriptor.  This implementation
// avoids a code size problem introduced by proto_ns::FieldDescriptor.
class Descriptor {
 public:
  Descriptor() = default;
  Descriptor(const std::string& full_name, const FieldData& descriptor_proto);
  Descriptor(const std::string& full_name,
             const std::vector<FieldDescriptor>& fields);
  const std::string& full_name() const;
  const FieldDescriptor* FindFieldByName(const std::string& name) const;

 private:
  std::string full_name_;
  absl::flat_hash_map<std::string, FieldDescriptor> fields_;
};

// A custom implementation proto_ns::FieldDescriptor.  This implementation
// avoids a code size problem introduced by proto_ns::FieldDescriptor.
class FieldDescriptor {
 public:
  FieldDescriptor() = default;
  FieldDescriptor(const FieldData& field_proto);
  FieldDescriptor(std::string name, int number, FieldType type,
                  std::string message_type);
  const std::string& name() const;
  int number() const;
  FieldType type() const;
  const Descriptor* message_type() const;

 private:
  std::string name_;
  int number_;
  FieldType type_;
  std::string message_type_;
};

}  // namespace tool
}  // namespace mediapipe

#endif  // MEDIAPIPE_FRAMEWORK_TOOL_OPTIONS_REGISTRY_H_