// 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_message_value.h"

#include <cstdint>

#include <limits>

#include <string>

#include <type_traits>

#include <utility>

#include <vector>

#include "google/protobuf/empty.pb.h"

#include "absl/base/nullability.h"

#include "absl/base/optimization.h"

#include "absl/log/absl_check.h"

#include "absl/status/status.h"

#include "absl/status/statusor.h"

#include "absl/strings/str_cat.h"

#include "absl/strings/string_view.h"

#include "absl/types/optional.h"

#include "absl/types/span.h"

#include "base/attribute.h"

#include "common/memory.h"

#include "common/value.h"

#include "common/values/values.h"

#include "extensions/protobuf/internal/qualify.h"

#include "internal/empty_descriptors.h"

#include "internal/json.h"

#include "internal/message_equality.h"

#include "internal/status_macros.h"

#include "runtime/runtime_options.h"

#include "google/protobuf/arena.h"

#include "google/protobuf/descriptor.h"

#include "google/protobuf/io/zero_copy_stream.h"

#include "google/protobuf/message.h"

#include "google/protobuf/message_lite.h"

namespace cel {

namespace {

template <typename T>

std::enable_if_t<std::is_base_of_v<google::protobuf::Message, T>,

                 const google::protobuf::Message* absl_nonnull>

EmptyParsedMessageValue() {

  return &T::default_instance();

}

template <typename T>

std::enable_if_t<

    std::conjunction_v<std::is_base_of<google::protobuf::MessageLite, T>,

                       std::negation<std::is_base_of<google::protobuf::Message, T>>>,

    const google::protobuf::Message* absl_nonnull>

EmptyParsedMessageValue() {

  return internal::GetEmptyDefaultInstance();

}

}  // namespace

ParsedMessageValue::ParsedMessageValue()

    : value_(EmptyParsedMessageValue<google::protobuf::Empty>()),

      arena_(nullptr) {}

bool ParsedMessageValue::IsZeroValue() const {

  const auto* reflection = GetReflection();

  if (!reflection->GetUnknownFields(*value_).empty()) {

    return false;

  }

  std::vector<const google::protobuf::FieldDescriptor*> fields;

  reflection->ListFields(*value_, &fields);

  return fields.empty();

}

std::string ParsedMessageValue::DebugString() const {

  return absl::StrCat(*value_);

}

absl::Status ParsedMessageValue::SerializeTo(

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::io::ZeroCopyOutputStream* absl_nonnull output) const {

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(output != nullptr);

  if (!value_->SerializePartialToZeroCopyStream(output)) {

    return absl::UnknownError(

        absl::StrCat("failed to serialize message: ", value_->GetTypeName()));

  }

  return absl::OkStatus();

}

absl::Status ParsedMessageValue::ConvertToJson(

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Message* absl_nonnull json) const {

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(json != nullptr);

  ABSL_DCHECK_EQ(json->GetDescriptor()->well_known_type(),

                 google::protobuf::Descriptor::WELLKNOWNTYPE_VALUE);

  return internal::MessageToJson(*value_, descriptor_pool, message_factory,

                                 json);

}

absl::Status ParsedMessageValue::ConvertToJsonObject(

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Message* absl_nonnull json) const {

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(json != nullptr);

  ABSL_DCHECK_EQ(json->GetDescriptor()->well_known_type(),

                 google::protobuf::Descriptor::WELLKNOWNTYPE_STRUCT);

  return internal::MessageToJson(*value_, descriptor_pool, message_factory,

                                 json);

}

absl::Status ParsedMessageValue::Equal(

    const Value& other,

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Arena* absl_nonnull arena, Value* absl_nonnull result) const {

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(arena != nullptr);

  ABSL_DCHECK(result != nullptr);

  if (auto other_message = other.AsParsedMessage(); other_message) {

    CEL_ASSIGN_OR_RETURN(

        auto equal, internal::MessageEquals(*value_, **other_message,

                                            descriptor_pool, message_factory));

    *result = BoolValue(equal);

    return absl::OkStatus();

  }

  if (auto other_struct = other.AsStruct(); other_struct) {

    return common_internal::StructValueEqual(StructValue(*this), *other_struct,

                                             descriptor_pool, message_factory,

                                             arena, result);

  }

  *result = BoolValue(false);

  return absl::OkStatus();

}

ParsedMessageValue ParsedMessageValue::Clone(

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

  ABSL_DCHECK(arena != nullptr);

  if (arena_ == arena) {

    return *this;

  }

  auto* cloned = value_->New(arena);

  cloned->CopyFrom(*value_);

  return ParsedMessageValue(cloned, arena);

}

absl::Status ParsedMessageValue::GetFieldByName(

    absl::string_view name, ProtoWrapperTypeOptions unboxing_options,

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Arena* absl_nonnull arena, Value* absl_nonnull result) const {

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(arena != nullptr);

  ABSL_DCHECK(result != nullptr);

  const auto* descriptor = GetDescriptor();

  const auto* field = descriptor->FindFieldByName(name);

  if (field == nullptr) {

    field = descriptor->file()->pool()->FindExtensionByPrintableName(descriptor,

                                                                     name);

    if (field == nullptr) {

      *result = NoSuchFieldError(name, arena);

      return absl::OkStatus();

    }

  }

  return GetField(field, unboxing_options, descriptor_pool, message_factory,

                  arena, result);

}

absl::Status ParsedMessageValue::GetFieldByNumber(

    int64_t number, ProtoWrapperTypeOptions unboxing_options,

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Arena* absl_nonnull arena, Value* absl_nonnull result) const {

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(arena != nullptr);

  ABSL_DCHECK(result != nullptr);

  const auto* descriptor = GetDescriptor();

  if (number < std::numeric_limits<int32_t>::min() ||

      number > std::numeric_limits<int32_t>::max()) {

    *result = NoSuchFieldError(absl::StrCat(number), arena);

    return absl::OkStatus();

  }

  const auto* field = descriptor->FindFieldByNumber(static_cast<int>(number));

  if (field == nullptr) {

    *result = NoSuchFieldError(absl::StrCat(number), arena);

    return absl::OkStatus();

  }

  return GetField(field, unboxing_options, descriptor_pool, message_factory,

                  arena, result);

}

absl::StatusOr<bool> ParsedMessageValue::HasFieldByName(

    absl::string_view name) const {

  const auto* descriptor = GetDescriptor();

  const auto* field = descriptor->FindFieldByName(name);

  if (field == nullptr) {

    field = descriptor->file()->pool()->FindExtensionByPrintableName(descriptor,

                                                                     name);

    if (field == nullptr) {

      return common_internal::MakeNoSuchFieldError(name);

    }

  }

  return HasField(field);

}

absl::StatusOr<bool> ParsedMessageValue::HasFieldByNumber(

    int64_t number) const {

  const auto* descriptor = GetDescriptor();

  if (number < std::numeric_limits<int32_t>::min() ||

      number > std::numeric_limits<int32_t>::max()) {

    return common_internal::MakeNoSuchFieldError(absl::StrCat(number));

  }

  const auto* field = descriptor->FindFieldByNumber(static_cast<int>(number));

  if (field == nullptr) {

    return common_internal::MakeNoSuchFieldError(absl::StrCat(number));

  }

  return HasField(field);

}

absl::Status ParsedMessageValue::ForEachField(

    ForEachFieldCallback callback,

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

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

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(arena != nullptr);

  std::vector<const google::protobuf::FieldDescriptor*> fields;

  const auto* reflection = GetReflection();

  reflection->ListFields(*value_, &fields);

  for (const auto* field : fields) {

    auto value = Value::WrapField(value_, field, descriptor_pool,

                                  message_factory, arena);

    CEL_ASSIGN_OR_RETURN(auto ok, callback(field->name(), value));

    if (!ok) {

      break;

    }

  }

  return absl::OkStatus();

}

namespace {

class ParsedMessageValueQualifyState final

    : public extensions::protobuf_internal::ProtoQualifyState {

 public:

  ParsedMessageValueQualifyState(

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

      const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

      google::protobuf::MessageFactory* absl_nonnull message_factory,

      google::protobuf::Arena* absl_nonnull arena, bool unsafe)

      : ProtoQualifyState(message, message->GetDescriptor(),

                          message->GetReflection()),

        descriptor_pool_(descriptor_pool),

        message_factory_(message_factory),

        arena_(arena),

        unsafe_(unsafe) {}

  absl::optional<Value>& result() { return result_; }

 private:

  void SetResultFromError(absl::Status status, cel::MemoryManagerRef) override {

    result_ = ErrorValue::From(std::move(status), arena_);

  }

  void SetResultFromBool(bool value) override { result_ = BoolValue(value); }

  // When `unsafe_` is set, the qualified message is externally managed (see

  // `UnsafeParsedMessageValue()`), so borrow field values instead of copying

  // them onto `arena_`. This matches `ParsedMessageValue::GetField()`.

  absl::Status SetResultFromField(const google::protobuf::Message* message,

                                  const google::protobuf::FieldDescriptor* field,

                                  ProtoWrapperTypeOptions unboxing_option,

                                  cel::MemoryManagerRef) override {

    result_ =

        unsafe_

            ? Value::WrapFieldUnsafe(unboxing_option, message, field,

                                     descriptor_pool_, message_factory_, arena_)

            : Value::WrapField(unboxing_option, message, field,

                               descriptor_pool_, message_factory_, arena_);

    return absl::OkStatus();

  }

  absl::Status SetResultFromRepeatedField(const google::protobuf::Message* message,

                                          const google::protobuf::FieldDescriptor* field,

                                          int index,

                                          cel::MemoryManagerRef) override {

    result_ = unsafe_ ? Value::WrapRepeatedFieldUnsafe(index, message, field,

                                                       descriptor_pool_,

                                                       message_factory_, arena_)

                      : Value::WrapRepeatedField(index, message, field,

                                                 descriptor_pool_,

                                                 message_factory_, arena_);

    return absl::OkStatus();

  }

  absl::Status SetResultFromMapField(const google::protobuf::Message* message,

                                     const google::protobuf::FieldDescriptor* field,

                                     const google::protobuf::MapValueConstRef& value,

                                     cel::MemoryManagerRef) override {

    result_ = unsafe_ ? Value::WrapMapFieldValueUnsafe(value, message, field,

                                                       descriptor_pool_,

                                                       message_factory_, arena_)

                      : Value::WrapMapFieldValue(value, message, field,

                                                 descriptor_pool_,

                                                 message_factory_, arena_);

    return absl::OkStatus();

  }

  const google::protobuf::DescriptorPool* absl_nonnull const descriptor_pool_;

  google::protobuf::MessageFactory* absl_nonnull const message_factory_;

  google::protobuf::Arena* absl_nonnull const arena_;

  const bool unsafe_;

  absl::optional<Value> result_;

};

}  // namespace

absl::Status ParsedMessageValue::Qualify(

    absl::Span<const SelectQualifier> qualifiers, bool presence_test,

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Arena* absl_nonnull arena, Value* absl_nonnull result,

    int* absl_nonnull count) const {

  ABSL_DCHECK(!qualifiers.empty());

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(arena != nullptr);

  ABSL_DCHECK(result != nullptr);

  ABSL_DCHECK(count != nullptr);

  if (ABSL_PREDICT_FALSE(qualifiers.empty())) {

    return absl::InvalidArgumentError("invalid select qualifier path.");

  }

  ParsedMessageValueQualifyState qualify_state(

      value_, descriptor_pool, message_factory, arena, is_unsafe());

  for (int i = 0; i < qualifiers.size() - 1; i++) {

    const auto& qualifier = qualifiers[i];

    CEL_RETURN_IF_ERROR(qualify_state.ApplySelectQualifier(

        qualifier, MemoryManagerRef::Pooling(arena)));

    if (qualify_state.result().has_value()) {

      *result = std::move(qualify_state.result()).value();

      *count = result->Is<ErrorValue>() ? -1 : i + 1;

      return absl::OkStatus();

    }

  }

  const auto& last_qualifier = qualifiers.back();

  if (presence_test) {

    CEL_RETURN_IF_ERROR(qualify_state.ApplyLastQualifierHas(

        last_qualifier, MemoryManagerRef::Pooling(arena)));

  } else {

    CEL_RETURN_IF_ERROR(qualify_state.ApplyLastQualifierGet(

        last_qualifier, MemoryManagerRef::Pooling(arena)));

  }

  *result = std::move(qualify_state.result()).value();

  *count = -1;

  return absl::OkStatus();

}

absl::Status ParsedMessageValue::GetField(

    const google::protobuf::FieldDescriptor* absl_nonnull field,

    ProtoWrapperTypeOptions unboxing_options,

    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,

    google::protobuf::MessageFactory* absl_nonnull message_factory,

    google::protobuf::Arena* absl_nonnull arena, Value* absl_nonnull result) const {

  ABSL_DCHECK(field != nullptr);

  ABSL_DCHECK(descriptor_pool != nullptr);

  ABSL_DCHECK(message_factory != nullptr);

  ABSL_DCHECK(arena != nullptr);

  ABSL_DCHECK(result != nullptr);

  if (is_unsafe()) {

    *result = Value::WrapFieldUnsafe(unboxing_options, value_, field,

                                     descriptor_pool, message_factory, arena);

  } else {

    *result = Value::WrapField(unboxing_options, value_, field, descriptor_pool,

                               message_factory, arena);

  }

  return absl::OkStatus();

}

bool ParsedMessageValue::HasField(

    const google::protobuf::FieldDescriptor* absl_nonnull field) const {

  ABSL_DCHECK(field != nullptr);

  const auto* reflection = GetReflection();

  if (field->is_map() || field->is_repeated()) {

    return reflection->FieldSize(*value_, field) > 0;

  }

  return reflection->HasField(*value_, field);

}

}  // namespace cel