/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */

#include <AzCore/Component/ComponentApplicationBus.h>
#include <AzCore/IO/FileIO.h>
#include <AzCore/IO/GenericStreams.h>
#include <AzCore/Serialization/Json/JsonSerialization.h>
#include <AzCore/Serialization/Json/JsonSerializationResult.h>
#include <AzCore/Serialization/Json/JsonUtils.h>
#include <AzCore/Serialization/SerializeContext.h>
#include <AzCore/Serialization/Utils.h>
#include <AzCore/Utils/Utils.h>
#include <AzCore/std/string/string_view.h>
#include <AzFramework/StringFunc/StringFunc.h>
#include <AzToolsFramework/API/EditorAssetSystemAPI.h>
#include <ScriptCanvas/Assets/ScriptCanvasFileHandling.h>
#include <ScriptCanvas/Bus/ScriptCanvasBus.h>
#include <ScriptCanvas/Components/EditorGraph.h>
#include <ScriptCanvas/Core/SerializationListener.h>

namespace ScriptCanvasFileHandlingCpp
{
    using namespace ScriptCanvas;

    void CollectNodes(const GraphData::NodeContainer& container, SerializationListeners& listeners)
    {
        for (auto& nodeEntity : container)
        {
            if (nodeEntity)
            {
                if (auto listener = azrtti_cast<SerializationListener*>(AZ::EntityUtils::FindFirstDerivedComponent<Node>(nodeEntity)))
                {
                    listeners.push_back(listener);
                }
            }
        }
    }
}

namespace ScriptCanvasEditor
{
    AZ::Outcome<void, AZStd::string> LoadDataFromJson
        ( ScriptCanvas::ScriptCanvasData& dataTarget
        , AZStd::string_view source
        , AZ::SerializeContext& serializeContext)
    {
        namespace JSRU = AZ::JsonSerializationUtils;
        using namespace ScriptCanvas;

        AZ::JsonDeserializerSettings settings;
        settings.m_serializeContext = &serializeContext;
        settings.m_metadata.Create<SerializationListeners>();

        auto loadResult = JSRU::LoadObjectFromStringByType
            ( &dataTarget
            , azrtti_typeid<ScriptCanvasData>()
            , source
            , &settings);

        if (!loadResult.IsSuccess())
        {
            return loadResult;
        }
                    
        if (auto graphData = dataTarget.ModGraph())
        {
            auto listeners = settings.m_metadata.Find<SerializationListeners>();
            AZ_Assert(listeners, "Failed to find SerializationListeners");

            ScriptCanvasFileHandlingCpp::CollectNodes(graphData->GetGraphData()->m_nodes, *listeners);

            for (auto listener : *listeners)
            {
                listener->OnDeserialize();
            }
        }
        else
        {
            return AZ::Failure(AZStd::string("Failed to find graph data after loading source"));
        }

        return AZ::Success();
    }

    AZ::Outcome<ScriptCanvasEditor::SourceHandle, AZStd::string> LoadFromFile(AZStd::string_view path)
    {
        namespace JSRU = AZ::JsonSerializationUtils;
        using namespace ScriptCanvas;

        auto fileStringOutcome = AZ::Utils::ReadFile<AZStd::string>(path);
        if (!fileStringOutcome)
        {
            return AZ::Failure(fileStringOutcome.TakeError());
        }

        const auto& asString = fileStringOutcome.GetValue();
        DataPtr scriptCanvasData = Graph::Create();
        
        AZ::SerializeContext* serializeContext = nullptr;
        AZ::ComponentApplicationBus::BroadcastResult(serializeContext, &AZ::ComponentApplicationRequests::GetSerializeContext);
        if (!serializeContext)
        {
            return AZ::Failure(AZStd::string("no serialize context available to properly parse source file"));
        }

        // attempt JSON deserialization...
        auto jsonResult = LoadDataFromJson(*scriptCanvasData, AZStd::string_view{ asString.begin(), asString.size() }, *serializeContext);
        if (!jsonResult.IsSuccess())
        {
            // ...try legacy xml as a failsafe
            AZ::IO::ByteContainerStream byteStream(&asString);
            if (!AZ::Utils::LoadObjectFromStreamInPlace
                ( byteStream
                , *scriptCanvasData
                , serializeContext
                , AZ::ObjectStream::FilterDescriptor(nullptr, AZ::ObjectStream::FILTERFLAG_IGNORE_UNKNOWN_CLASSES)))
            {
                return AZ::Failure(AZStd::string::format("XML and JSON load attempts failed: %s", jsonResult.GetError().c_str()));
            }
        }

        return AZ::Success(ScriptCanvasEditor::SourceHandle(scriptCanvasData, {}, path));
    }
}