/*
 * 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 <Atom/RPI.Reflect/Model/ModelLodAsset.h>

#include <AzCore/Serialization/SerializeContext.h>

namespace AZ
{
    namespace RPI
    {
        const char* ModelLodAsset::DisplayName = "ModelLodAsset";
        const char* ModelLodAsset::Group = "Model";
        const char* ModelLodAsset::Extension = "azlod";

        void ModelLodAsset::Reflect(AZ::ReflectContext* context)
        {
            if (auto* serializeContext = azrtti_cast<AZ::SerializeContext*>(context))
            {
                serializeContext->Class<ModelLodAsset>()
                    ->Version(1)
                    ->Field("Meshes", &ModelLodAsset::m_meshes)
                    ->Field("Aabb", &ModelLodAsset::m_aabb)
                    ->Field("MaterialSlots", &ModelLodAsset::m_materialSlots)
                    ;
            }

            Mesh::Reflect(context);
        }
        
        void ModelLodAsset::Mesh::Reflect(AZ::ReflectContext* context)
        {
            if (auto* serializeContext = azrtti_cast<AZ::SerializeContext*>(context))
            {
                serializeContext->Class<ModelLodAsset::Mesh>()
                    ->Version(1)
                    ->Field("Name", &ModelLodAsset::Mesh::m_name)
                    ->Field("AABB", &ModelLodAsset::Mesh::m_aabb)
                    ->Field("MaterialSlotIndex", &ModelLodAsset::Mesh::m_materialSlotIndex)
                    ->Field("IndexBufferAssetView", &ModelLodAsset::Mesh::m_indexBufferAssetView)
                    ->Field("StreamBufferInfo", &ModelLodAsset::Mesh::m_streamBufferInfo)
                    ;
            }

            StreamBufferInfo::Reflect(context);
        }

        void ModelLodAsset::Mesh::StreamBufferInfo::Reflect(AZ::ReflectContext* context)
        {
            if (auto* serializeContext = azrtti_cast<AZ::SerializeContext*>(context))
            {
                serializeContext->Class<ModelLodAsset::Mesh::StreamBufferInfo>()
                    ->Version(1)
                    ->Field("Semantic", &ModelLodAsset::Mesh::StreamBufferInfo::m_semantic)
                    ->Field("CustomName", &ModelLodAsset::Mesh::StreamBufferInfo::m_customName)
                    ->Field("BufferAssetView", &ModelLodAsset::Mesh::StreamBufferInfo::m_bufferAssetView)
                    ;
            }
        }

        uint32_t ModelLodAsset::Mesh::GetVertexCount() const
        {
            // Index 0 here is not special. All stream buffer views owned by this mesh should
            // view the same number of vertices. It doesn't make sense to be viewing 30 positions
            // but only 20 normals since we're using an index buffer model. 
            return m_streamBufferInfo[0].m_bufferAssetView.GetBufferViewDescriptor().m_elementCount;
        }

        uint32_t ModelLodAsset::Mesh::GetIndexCount() const
        {
            return m_indexBufferAssetView.GetBufferViewDescriptor().m_elementCount;
        }

        size_t ModelLodAsset::Mesh::GetMaterialSlotIndex() const
        {
            return m_materialSlotIndex;
        }

        const AZ::Name& ModelLodAsset::Mesh::GetName() const
        {
            return m_name;
        }

        const AZ::Aabb& ModelLodAsset::Mesh::GetAabb() const
        {
            return m_aabb;
        }

        const BufferAssetView& ModelLodAsset::Mesh::GetIndexBufferAssetView() const
        {
            return m_indexBufferAssetView;
        }

        AZStd::array_view<ModelLodAsset::Mesh::StreamBufferInfo> ModelLodAsset::Mesh::GetStreamBufferInfoList() const
        {
            return AZStd::array_view<ModelLodAsset::Mesh::StreamBufferInfo>(m_streamBufferInfo);
        }

        void ModelLodAsset::AddMesh(const Mesh& mesh)
        {
            m_meshes.push_back(mesh);

            Aabb meshAabb = mesh.GetAabb();

            m_aabb.AddAabb(meshAabb);
        }

        AZStd::array_view<ModelLodAsset::Mesh> ModelLodAsset::GetMeshes() const
        {
            return AZStd::array_view<ModelLodAsset::Mesh>(m_meshes);
        }

        const AZ::Aabb& ModelLodAsset::GetAabb() const
        {
            return m_aabb;
        }
        
        AZStd::array_view<ModelMaterialSlot> ModelLodAsset::GetMaterialSlots() const
        {
            return m_materialSlots;
        }
            
        const ModelMaterialSlot& ModelLodAsset::GetMaterialSlot(size_t slotIndex) const
        {
            if (slotIndex < m_materialSlots.size())
            {
                return m_materialSlots[slotIndex];
            }
            else
            {
                AZ_Error("ModelAsset", false, "Material slot index %zu out of range. ModelAsset has %zu slots.", slotIndex, m_materialSlots.size());
                return m_fallbackSlot;
            }
        }
        
        const ModelMaterialSlot* ModelLodAsset::FindMaterialSlot(uint32_t stableId) const
        {
            auto iter = AZStd::find_if(m_materialSlots.begin(), m_materialSlots.end(), [&stableId](const ModelMaterialSlot& existingMaterialSlot)
                {
                    return existingMaterialSlot.m_stableId == stableId;
                });

            if (iter == m_materialSlots.end())
            {
                return nullptr;
            }
            else
            {
                return iter;
            }
        }

        const BufferAssetView* ModelLodAsset::Mesh::GetSemanticBufferAssetView(const AZ::Name& semantic) const
        {
            const AZStd::array_view<ModelLodAsset::Mesh::StreamBufferInfo>& streamBufferList = GetStreamBufferInfoList();

            for (const ModelLodAsset::Mesh::StreamBufferInfo& streamBufferInfo : streamBufferList)
            {
                if (streamBufferInfo.m_semantic.m_name == semantic)
                {
                    return &streamBufferInfo.m_bufferAssetView;
                }
            }

            return nullptr;
        }

        void ModelLodAsset::SetReady()
        {
            m_status = Data::AssetData::AssetStatus::Ready;
        }
    } // namespace RPI
} // namespace AZ