// Copyright 2024 Google LLC

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "common/values/parsed_json_value.h"

#include <string>

#include <utility>

#include "absl/base/attributes.h"

#include "absl/base/nullability.h"

#include "absl/functional/overload.h"

#include "absl/status/status.h"

#include "absl/strings/cord.h"

#include "absl/strings/str_cat.h"

#include "absl/strings/string_view.h"

#include "absl/types/variant.h"

#include "common/allocator.h"

#include "common/memory.h"

#include "common/value.h"

#include "internal/well_known_types.h"

#include "google/protobuf/arena.h"

#include "google/protobuf/message.h"

namespace cel::common_internal {

namespace {

using ::cel::well_known_types::AsVariant;

using ::cel::well_known_types::GetValueReflectionOrDie;

google::protobuf::Arena* absl_nonnull MessageArenaOr(

    const google::protobuf::Message* absl_nonnull message,

    google::protobuf::Arena* absl_nonnull or_arena) {

  google::protobuf::Arena* absl_nullable arena = message->GetArena();

  if (arena == nullptr) {

    arena = or_arena;

  }

  return arena;

}

}  // namespace

Value ParsedJsonValue(const google::protobuf::Message* absl_nonnull message,

                      google::protobuf::Arena* absl_nonnull arena) {

  const auto reflection = GetValueReflectionOrDie(message->GetDescriptor());

  const auto kind_case = reflection.GetKindCase(*message);

  switch (kind_case) {

    case google::protobuf::Value::KIND_NOT_SET:

      ABSL_FALLTHROUGH_INTENDED;

    case google::protobuf::Value::kNullValue:

      return NullValue();

    case google::protobuf::Value::kBoolValue:

      return BoolValue(reflection.GetBoolValue(*message));

    case google::protobuf::Value::kNumberValue:

      return DoubleValue(reflection.GetNumberValue(*message));

    case google::protobuf::Value::kStringValue: {

      std::string scratch;

      return absl::visit(

          absl::Overload(

              [&](absl::string_view string) -> StringValue {

                if (string.empty()) {

                  return StringValue();

                }

                if (string.data() == scratch.data() &&

                    string.size() == scratch.size()) {

                  return StringValue(arena, std::move(scratch));

                } else {

                  return StringValue(

                      Borrower::Arena(MessageArenaOr(message, arena)), string);

                }

              },

              [&](absl::Cord&& cord) -> StringValue {

                if (cord.empty()) {

                  return StringValue();

                }

                return StringValue(std::move(cord));

              }),

          AsVariant(reflection.GetStringValue(*message, scratch)));

    }

    case google::protobuf::Value::kListValue:

      return ParsedJsonListValue(&reflection.GetListValue(*message),

                                 MessageArenaOr(message, arena));

    case google::protobuf::Value::kStructValue:

      return ParsedJsonMapValue(&reflection.GetStructValue(*message),

                                MessageArenaOr(message, arena));

    default:

      return ErrorValue(absl::InvalidArgumentError(

          absl::StrCat("unexpected value kind case: ", kind_case)));

  }

}

}  // namespace cel::common_internal