o3de/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabDomUtils.cpp

/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/

#include <AzCore/Asset/AssetManager.h>
#include <AzCore/JSON/prettywriter.h>
#include <AzCore/Serialization/Json/JsonSerialization.h>
#include <AzToolsFramework/Entity/EditorEntityContextBus.h>
#include <AzToolsFramework/Prefab/PrefabDomUtils.h>
#include <AzToolsFramework/Prefab/Instance/Instance.h>
#include <AzToolsFramework/Prefab/Instance/InstanceEntityScrubber.h>
#include <AzToolsFramework/Prefab/Instance/InstanceEntityIdMapper.h>
#include <AzToolsFramework/Prefab/Instance/InstanceSerializer.h>

#include <QDebug>

namespace AzToolsFramework
{
    namespace Prefab
    {
        namespace PrefabDomUtils
        {
            PrefabDomValueReference FindPrefabDomValue(PrefabDomValue& parentValue, const char* valueName)
            {
                PrefabDomValue::MemberIterator valueIterator = parentValue.FindMember(valueName);
                if (valueIterator == parentValue.MemberEnd())
                {
                    return AZStd::nullopt;
                }

                return valueIterator->value;
            }

            PrefabDomValueConstReference FindPrefabDomValue(const PrefabDomValue& parentValue, const char* valueName)
            {
                PrefabDomValue::ConstMemberIterator valueIterator = parentValue.FindMember(valueName);
                if (valueIterator == parentValue.MemberEnd())
                {
                    return AZStd::nullopt;
                }

                return valueIterator->value;
            }

            bool StoreInstanceInPrefabDom(const Instance& instance, PrefabDom& prefabDom)
            {
                InstanceEntityIdMapper entityIdMapper;
                entityIdMapper.SetStoringInstance(instance);

                // Need to store the id mapper as both its type and its base type
                // Meta data is found by type id and we need access to both types at different levels (Instance, EntityId)
                AZ::JsonSerializerSettings settings;
                settings.m_metadata.Add(static_cast<AZ::JsonEntityIdSerializer::JsonEntityIdMapper*>(&entityIdMapper));
                settings.m_metadata.Add(&entityIdMapper);

                AZ::JsonSerializationResult::ResultCode result =
                    AZ::JsonSerialization::Store(prefabDom, prefabDom.GetAllocator(), instance, settings);

                if (result.GetProcessing() == AZ::JsonSerializationResult::Processing::Halted)
                {
                    AZ_Error("Prefab", false,
                        "Failed to serialize prefab instance with source path %s. "
                        "Unable to proceed.",
                        instance.GetTemplateSourcePath().c_str());

                    return false;
                }

                return true;
            }

            bool LoadInstanceFromPrefabDom(Instance& instance, const PrefabDom& prefabDom, LoadInstanceFlags flags)
            {
                // When entities are rebuilt they are first destroyed. As a result any assets they were exclusively holding on to will
                // be released and reloaded once the entities are built up again. By suspending asset release temporarily the asset reload
                // is avoided.
                AZ::Data::AssetManager::Instance().SuspendAssetRelease();

                InstanceEntityIdMapper entityIdMapper;
                entityIdMapper.SetLoadingInstance(instance);
                if ((flags & LoadInstanceFlags::AssignRandomEntityId) == LoadInstanceFlags::AssignRandomEntityId)
                {
                    entityIdMapper.SetEntityIdGenerationApproach(InstanceEntityIdMapper::EntityIdGenerationApproach::Random);
                }

                AZ::JsonDeserializerSettings settings;
                // The InstanceEntityIdMapper is registered twice because it's used in several places during deserialization where one is
                // specific for the InstanceEntityIdMapper and once for the generic JsonEntityIdMapper. Because the Json Serializer's meta
                // data has strict typing and doesn't look for inheritance both have to be explicitly added so they're found both locations.
                settings.m_metadata.Add(static_cast<AZ::JsonEntityIdSerializer::JsonEntityIdMapper*>(&entityIdMapper));
                settings.m_metadata.Add(&entityIdMapper);
                
                AZ::JsonSerializationResult::ResultCode result =
                    AZ::JsonSerialization::Load(instance, prefabDom, settings);

                AZ::Data::AssetManager::Instance().ResumeAssetRelease();

                if (result.GetProcessing() == AZ::JsonSerializationResult::Processing::Halted)
                {
                    AZ_Error("Prefab", false,
                        "Failed to de-serialize Prefab Instance from Prefab DOM. "
                        "Unable to proceed.");

                    return false;
                }

                return true;
            }

            bool LoadInstanceFromPrefabDom(
                Instance& instance, Instance::EntityList& newlyAddedEntities, const PrefabDom& prefabDom, LoadInstanceFlags flags)
            {
                // When entities are rebuilt they are first destroyed. As a result any assets they were exclusively holding on to will
                // be released and reloaded once the entities are built up again. By suspending asset release temporarily the asset reload
                // is avoided.
                AZ::Data::AssetManager::Instance().SuspendAssetRelease();

                InstanceEntityIdMapper entityIdMapper;
                entityIdMapper.SetLoadingInstance(instance);
                if ((flags & LoadInstanceFlags::AssignRandomEntityId) == LoadInstanceFlags::AssignRandomEntityId)
                {
                    entityIdMapper.SetEntityIdGenerationApproach(InstanceEntityIdMapper::EntityIdGenerationApproach::Random);
                }

                AZ::JsonDeserializerSettings settings;
                // The InstanceEntityIdMapper is registered twice because it's used in several places during deserialization where one is
                // specific for the InstanceEntityIdMapper and once for the generic JsonEntityIdMapper. Because the Json Serializer's meta
                // data has strict typing and doesn't look for inheritance both have to be explicitly added so they're found both locations.
                settings.m_metadata.Add(static_cast<AZ::JsonEntityIdSerializer::JsonEntityIdMapper*>(&entityIdMapper));
                settings.m_metadata.Add(&entityIdMapper);
                settings.m_metadata.Create<InstanceEntityScrubber>(newlyAddedEntities);

                AZ::JsonSerializationResult::ResultCode result = AZ::JsonSerialization::Load(instance, prefabDom, settings);

                AZ::Data::AssetManager::Instance().ResumeAssetRelease();

                if (result.GetProcessing() == AZ::JsonSerializationResult::Processing::Halted)
                {
                    AZ_Error(
                        "Prefab", false,
                        "Failed to de-serialize Prefab Instance from Prefab DOM. "
                        "Unable to proceed.");

                    return false;
                }

                return true;
            }

            void PrintPrefabDomValue(
                [[maybe_unused]] const AZStd::string_view printMessage,
                [[maybe_unused]] const PrefabDomValue& prefabDomValue)
            {
                rapidjson::StringBuffer prefabBuffer;
                rapidjson::PrettyWriter<rapidjson::StringBuffer> writer(prefabBuffer);
                prefabDomValue.Accept(writer);

                qDebug() << printMessage.data() << "\n" << prefabBuffer.GetString();
            }
        } // namespace PrefabDomUtils
    } // namespace Prefab
} // namespace AzToolsFramework