//
//  MeshPartPayload.h
//  interface/src/renderer
//
//  Created by Sam Gateau on 10/3/15.
//  Copyright 2015 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#ifndef hifi_MeshPartPayload_h
#define hifi_MeshPartPayload_h

#include <Interpolate.h>

#include <gpu/Batch.h>

#include <render/Scene.h>

#include <graphics/Geometry.h>

#include "Model.h"

class Model;

class MeshPartPayload {
public:
    MeshPartPayload() = default;
    MeshPartPayload(const std::shared_ptr<const graphics::Mesh>& mesh, int partIndex, graphics::MaterialPointer material);
    virtual ~MeshPartPayload() = default;

    typedef render::Payload<MeshPartPayload> Payload;
    typedef Payload::DataPointer Pointer;

    virtual void updateKey(const render::ItemKey& key);

    virtual void updateMeshPart(const std::shared_ptr<const graphics::Mesh>& drawMesh, int partIndex);

    virtual void notifyLocationChanged() {}
    void updateTransform(const Transform& transform, const Transform& offsetTransform);

    // Render Item interface
    virtual render::ItemKey getKey() const;
    virtual render::Item::Bound getBound() const;
    virtual render::ShapeKey getShapeKey() const; // shape interface
    virtual void render(RenderArgs* args);

    // ModelMeshPartPayload functions to perform render
    void drawCall(gpu::Batch& batch) const;
    virtual void bindMesh(gpu::Batch& batch);
    virtual void bindTransform(gpu::Batch& batch, RenderArgs::RenderMode renderMode) const;

    // Payload resource cached values
    Transform _drawTransform;
    Transform _transform;
    int _partIndex = 0;
    bool _hasColorAttrib { false };

    graphics::Box _localBound;
    graphics::Box _adjustedLocalBound;
    mutable graphics::Box _worldBound;
    std::shared_ptr<const graphics::Mesh> _drawMesh;

    graphics::MultiMaterial _drawMaterials;
    graphics::Mesh::Part _drawPart;

    size_t getVerticesCount() const { return _drawMesh ? _drawMesh->getNumVertices() : 0; }
    size_t getMaterialTextureSize() { return topMaterialExists() ? _drawMaterials.top().material->getTextureSize() : 0; }
    int getMaterialTextureCount() { return topMaterialExists() ? _drawMaterials.top().material->getTextureCount() : 0; }
    bool hasTextureInfo() const { return topMaterialExists() ? _drawMaterials.top().material->hasTextureInfo() : false; }

    void addMaterial(graphics::MaterialLayer material);
    void removeMaterial(graphics::MaterialPointer material);

protected:
    static const graphics::MaterialPointer DEFAULT_MATERIAL;
    render::ItemKey _itemKey{ render::ItemKey::Builder::opaqueShape().build() };

    bool topMaterialExists() const { return !_drawMaterials.empty() && _drawMaterials.top().material; }
};

namespace render {
    template <> const ItemKey payloadGetKey(const MeshPartPayload::Pointer& payload);
    template <> const Item::Bound payloadGetBound(const MeshPartPayload::Pointer& payload);
    template <> const ShapeKey shapeGetShapeKey(const MeshPartPayload::Pointer& payload);
    template <> void payloadRender(const MeshPartPayload::Pointer& payload, RenderArgs* args);
}

class ModelMeshPartPayload : public MeshPartPayload {
public:
    ModelMeshPartPayload(ModelPointer model, int meshIndex, int partIndex, int shapeIndex, const Transform& transform, const Transform& offsetTransform);

    typedef render::Payload<ModelMeshPartPayload> Payload;
    typedef Payload::DataPointer Pointer;

    void notifyLocationChanged() override;

    void updateKey(const render::ItemKey& key) override;

    // matrix palette skinning
    void updateClusterBuffer(const std::vector<glm::mat4>& clusterMatrices);

    // dual quaternion skinning
    void updateClusterBuffer(const std::vector<Model::TransformDualQuaternion>& clusterDualQuaternions);
    void updateTransformForSkinnedMesh(const Transform& renderTransform, const Transform& boundTransform);

    // Render Item interface
    render::ShapeKey getShapeKey() const override; // shape interface
    void render(RenderArgs* args) override;

    void setShapeKey(bool invalidateShapeKey, PrimitiveMode primitiveMode, bool useDualQuaternionSkinning);

    // ModelMeshPartPayload functions to perform render
    void bindMesh(gpu::Batch& batch) override;
    void bindTransform(gpu::Batch& batch, RenderArgs::RenderMode renderMode) const override;

    // matrix palette skinning
    void computeAdjustedLocalBound(const std::vector<glm::mat4>& clusterMatrices);

    // dual quaternion skinning
    void computeAdjustedLocalBound(const std::vector<Model::TransformDualQuaternion>& clusterDualQuaternions);

    gpu::BufferPointer _clusterBuffer;

    enum class ClusterBufferType { Matrices, DualQuaternions };
    ClusterBufferType _clusterBufferType { ClusterBufferType::Matrices };

    int _meshIndex;
    int _shapeID;

    bool _isSkinned{ false };
    bool _isBlendShaped { false };
    bool _hasTangents { false };

    void setBlendshapeBuffer(const std::unordered_map<int, gpu::BufferPointer>& blendshapeBuffers, const QVector<int>& blendedMeshSizes);

private:
    void initCache(const ModelPointer& model);

    gpu::BufferPointer _meshBlendshapeBuffer;
    int _meshNumVertices;
    render::ShapeKey _shapeKey { render::ShapeKey::Builder::invalid() };
};

namespace render {
    template <> const ItemKey payloadGetKey(const ModelMeshPartPayload::Pointer& payload);
    template <> const Item::Bound payloadGetBound(const ModelMeshPartPayload::Pointer& payload);
    template <> const ShapeKey shapeGetShapeKey(const ModelMeshPartPayload::Pointer& payload);
    template <> void payloadRender(const ModelMeshPartPayload::Pointer& payload, RenderArgs* args);
}

#endif // hifi_MeshPartPayload_h