// Copyright 2025 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_OPTIMIZATION_GUIDE_CORE_MODEL_EXECUTION_VALUE_CONVERTER_H_
#define COMPONENTS_OPTIMIZATION_GUIDE_CORE_MODEL_EXECUTION_VALUE_CONVERTER_H_

#include <algorithm>
#include <cstdint>
#include <string_view>
#include <type_traits>

#include "base/types/expected.h"
#include "components/optimization_guide/core/model_execution/on_device_model_execution_proto_enum_templates.h"
#include "components/optimization_guide/core/model_execution/on_device_model_execution_proto_status.h"

namespace optimization_guide {

// This file defines a family of ValueConverter types providing utility
// functions for use by the generated
// on_device_model_execution_proto_descriptors.cc file in converting
// string-encoded values to proto field values of the appropriate type.

template <typename T>
struct ValueConverter {
  static base::expected<T, ProtoStatus> TryConvertFromString(
      std::string_view string) {
    static_assert(false, "No specialization is defined for type T");
  }
};

template <typename T>
  requires std::is_enum_v<T>
struct ValueConverter<T> {
  static base::expected<T, ProtoStatus> TryConvertFromString(
      std::string_view string) {
    const auto loc = std::ranges::find_if(
        EnumTraits<T>::values,
        [&string](const EnumNameAndValue<T>& enum_name_and_value) {
          return enum_name_and_value.name == string;
        });
    if (loc == EnumTraits<T>::values.end()) {
      return base::unexpected(ProtoStatus::kError);
    }
    return loc->value;
  }
};

template <>
struct ValueConverter<bool> {
  static base::expected<bool, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

template <>
struct ValueConverter<float> {
  static base::expected<float, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

template <>
struct ValueConverter<double> {
  static base::expected<double, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

template <>
struct ValueConverter<int32_t> {
  static base::expected<int32_t, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

template <>
struct ValueConverter<uint32_t> {
  static base::expected<uint32_t, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

template <>
struct ValueConverter<int64_t> {
  static base::expected<int64_t, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

template <>
struct ValueConverter<uint64_t> {
  static base::expected<uint64_t, ProtoStatus> TryConvertFromString(
      std::string_view string);
};

}  // namespace optimization_guide

#endif  // COMPONENTS_OPTIMIZATION_GUIDE_CORE_MODEL_EXECUTION_VALUE_CONVERTER_H_