// =============================================
//  Aster: model_loader.h
//  Copyright (c) 2020-2024 Anish Bhobe
// =============================================

#pragma once

#include "buffer.h"
#include "global.h"
#include "image.h"

#include "render_resource_manager.h"

#include <tiny_gltf.h>

struct TextureHandle;
struct Texture;

constexpr auto GLTF_ASCII_FILE_EXTENSION = ".gltf";
constexpr auto GLTF_BINARY_FILE_EXTENSION = ".glb";

struct MeshPrimitive
{
    u32 m_VertexOffset;
    i32 m_NormalOffset;    // <0 for invalid
    i32 m_TexCoord0Offset; // <0 for invalid
    u32 m_FirstIndex;
    u32 m_IndexCount;
    i32 m_MaterialIdx; // <0 for invalid
};

struct Material
{
    vec4 m_AlbedoFactor;
    vec3 m_EmissionFactor;
    f32 m_MetalFactor;
    f32 m_RoughFactor;
    TextureHandle m_AlbedoTex;
    TextureHandle m_NormalTex;
    TextureHandle m_MetalRoughTex;
    TextureHandle m_OcclusionTex;
    TextureHandle m_EmissionTex;
};

struct Model
{
    RenderResourceManager *m_ResourceManager;

    eastl::vector<Texture> m_Textures;
    eastl::vector<TextureHandle> m_TextureHandles;

    StorageBuffer m_MaterialsBuffer;
    BufferHandle m_MaterialsHandle;

    StorageBuffer m_VertexPositions;
    BufferHandle m_VertexPositionHandle;

    StorageBuffer m_NormalVectors;
    BufferHandle m_NormalHandle;

    StorageBuffer m_TexCoord0;
    BufferHandle m_TexCoord0Handle;

    IndexBuffer m_IndexBuffer;
    eastl::vector<MeshPrimitive> m_MeshPrimitives;

    Model(RenderResourceManager *resourceManager, eastl::vector<Texture> &&textures,
          eastl::vector<TextureHandle> &&textureHandles, const StorageBuffer &materialsBuffer,
          BufferHandle materialsHandle, const StorageBuffer &vertexPosBuffer, BufferHandle vertexPosHandle,
          const StorageBuffer &normalBuffer, BufferHandle normalHandle, const StorageBuffer &uv0Buffer,
          BufferHandle uv0Handle, const IndexBuffer &indexBuffer, const eastl::vector<MeshPrimitive> &meshPrimitives);

    Model(Model &&other) noexcept;
    Model &operator=(Model &&other) noexcept;

    ~Model();

    DISALLOW_COPY_AND_ASSIGN(Model);
};

struct ModelLoader
{
    RenderResourceManager *const m_ResourceManager;
    vk::CommandPool m_CommandPool;
    vk::CommandBuffer m_CommandBuffer;
    vk::Queue m_TransferQueue;
    u32 m_TransferQueueIndex;
    u32 m_GraphicsQueueIndex;

    ModelLoader(RenderResourceManager *resourceManager, vk::Queue transferQueue, u32 transferQueueIndex,
                u32 graphicsQueueIndex);
    ~ModelLoader();

    TextureHandle LoadImage(vk::CommandBuffer commandBuffer, Texture *texture, StagingBuffer *stagingBuffer,
                            tinygltf::Image *image) const;
    Model LoadModel(cstr path, cstr name = nullptr, bool batched = false);

    constexpr static auto ANormal = "NORMAL";
    constexpr static auto APosition = "POSITION";
    constexpr static auto ATangent = "TANGENT";
    constexpr static auto ATexCoord0 = "TEXCOORD_0";
    constexpr static auto ATexCoord1 = "TEXCOORD_1";
    constexpr static auto AJoints0 = "JOINTS_0";
    constexpr static auto AWeights0 = "WEIGHTS_0";
};