// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

#pragma once

#include "../Graphics/Drawable.h"

namespace Urho3D
{

/// Custom geometry vertex.
/// @nocount
struct CustomGeometryVertex
{
    /// Position.
    Vector3 position_;
    /// Normal.
    Vector3 normal_;
    /// Color.
    color32 color_;
    /// Texture coordinates.
    Vector2 texCoord_;
    /// Tangent.
    Vector4 tangent_;
};

class VertexBuffer;

/// Custom geometry component.
class URHO3D_API CustomGeometry : public Drawable
{
    URHO3D_OBJECT(CustomGeometry, Drawable);

public:
    /// Construct.
    explicit CustomGeometry(Context* context);
    /// Destruct.
    ~CustomGeometry() override;
    /// Register object factory. Drawable must be registered first.
    /// @nobind
    static void RegisterObject(Context* context);

    /// Process octree raycast. May be called from a worker thread.
    void ProcessRayQuery(const RayOctreeQuery& query, Vector<RayQueryResult>& results) override;
    /// Return the geometry for a specific LOD level.
    Geometry* GetLodGeometry(i32 batchIndex, i32 level) override;
    /// Return number of occlusion geometry triangles.
    i32 GetNumOccluderTriangles() override;
    /// Draw to occlusion buffer. Return true if did not run out of triangles.
    bool DrawOcclusion(OcclusionBuffer* buffer) override;

    /// Clear all geometries.
    void Clear();
    /// Set number of geometries.
    /// @property
    void SetNumGeometries(unsigned num);
    /// Set vertex buffer dynamic mode. A dynamic buffer should be faster to update frequently. Effective at the next Commit() call.
    /// @property
    void SetDynamic(bool enable);
    /// Begin defining a geometry. Clears existing vertices in that index.
    void BeginGeometry(unsigned index, PrimitiveType type);
    /// Define a vertex position. This begins a new vertex.
    void DefineVertex(const Vector3& position);
    /// Define a vertex normal.
    void DefineNormal(const Vector3& normal);
    /// Define a vertex color.
    void DefineColor(const Color& color);
    /// Define a vertex UV coordinate.
    void DefineTexCoord(const Vector2& texCoord);
    /// Define a vertex tangent.
    void DefineTangent(const Vector4& tangent);
    /// Set the primitive type, number of vertices and elements in a geometry, after which the vertices can be edited with GetVertex(). An alternative to BeginGeometry() / DefineVertex().
    void DefineGeometry
        (unsigned index, PrimitiveType type, unsigned numVertices, bool hasNormals, bool hasColors, bool hasTexCoords,
            bool hasTangents);
    /// Update vertex buffer and calculate the bounding box. Call after finishing defining geometry.
    void Commit();
    /// Set material on all geometries.
    /// @property
    void SetMaterial(Material* material);
    /// Set material on one geometry. Return true if successful.
    /// @property{set_materials}
    bool SetMaterial(unsigned index, Material* material);

    /// Return number of geometries.
    /// @property
    unsigned GetNumGeometries() const { return geometries_.Size(); }

    /// Return number of vertices in a geometry.
    /// @property
    unsigned GetNumVertices(unsigned index) const;

    /// Return whether vertex buffer dynamic mode is enabled.
    /// @property
    bool IsDynamic() const { return dynamic_; }

    /// Return material by geometry index.
    /// @property{get_materials}
    Material* GetMaterial(unsigned index = 0) const;

    /// Return all vertices. These can be edited; calling Commit() updates the vertex buffer.
    Vector<Vector<CustomGeometryVertex>>& GetVertices() { return vertices_; }

    /// Return a vertex in a geometry for editing, or null if out of bounds. After the edits are finished, calling Commit() updates  the vertex buffer.
    CustomGeometryVertex* GetVertex(unsigned geometryIndex, unsigned vertexNum);

    /// Set geometry data attribute.
    void SetGeometryDataAttr(const Vector<byte>& value);
    /// Set materials attribute.
    void SetMaterialsAttr(const ResourceRefList& value);
    /// Return geometry data attribute.
    Vector<byte> GetGeometryDataAttr() const;
    /// Return materials attribute.
    const ResourceRefList& GetMaterialsAttr() const;

protected:
    /// Recalculate the world-space bounding box.
    void OnWorldBoundingBoxUpdate() override;

private:
    /// Primitive type per geometry.
    Vector<PrimitiveType> primitiveTypes_;
    /// Source vertices per geometry.
    Vector<Vector<CustomGeometryVertex>> vertices_;
    /// All geometries.
    Vector<SharedPtr<Geometry>> geometries_;
    /// Vertex buffer.
    SharedPtr<VertexBuffer> vertexBuffer_;
    /// Element mask used so far.
    VertexElements elementMask_;
    /// Current geometry being updated.
    unsigned geometryIndex_;
    /// Material list attribute.
    mutable ResourceRefList materialsAttr_;
    /// Vertex buffer dynamic flag.
    bool dynamic_;
};

}