// ----------------------------------------------------------------------------
// -                        Open3D: www.open3d.org                            -
// ----------------------------------------------------------------------------
// Copyright (c) 2018-2023 www.open3d.org
// SPDX-License-Identifier: MIT
// ----------------------------------------------------------------------------

#pragma once

#include <memory>
#include <numeric>

#include "open3d/visualization/rendering/View.h"

/// @cond
namespace filament {
class Engine;
class Scene;
class View;
class Viewport;
class ColorGrading;
}  // namespace filament
/// @endcond

namespace open3d {
namespace visualization {
namespace rendering {

class FilamentCamera;
class FilamentResourceManager;
class FilamentScene;

class FilamentView : public View {
public:
    static constexpr std::uint8_t kAllLayersMask =
            std::numeric_limits<std::uint8_t>::max();
    static constexpr std::uint8_t kMainLayer = 1;  // Default layer for objects

    FilamentView(filament::Engine& engine,
                 FilamentResourceManager& resource_mgr);
    FilamentView(filament::Engine& engine,
                 FilamentScene& scene,
                 FilamentResourceManager& resource_mgr);
    ~FilamentView() override;

    void SetDiscardBuffers(const TargetBuffers& buffers) override;
    Mode GetMode() const override;
    void SetMode(Mode mode) override;
    void SetWireframe(bool enable) override;

    void SetSampleCount(int n) override;
    int GetSampleCount() const override;

    void SetViewport(std::int32_t x,
                     std::int32_t y,
                     std::uint32_t w,
                     std::uint32_t h) override;
    std::array<int, 4> GetViewport() const override;

    void SetPostProcessing(bool enabled) override;
    void SetAmbientOcclusion(bool enabled, bool ssct_enabled = false) override;
    void SetBloom(bool enabled, float strength = 0.5f, int spread = 6) override;
    void SetAntiAliasing(bool enabled, bool temporal = false) override;
    void SetShadowing(bool enabled, ShadowType type) override;

    void SetColorGrading(const ColorGradingParams& color_grading) override;

    void ConfigureForColorPicking() override;

    void EnableViewCaching(bool enable) override;
    bool IsCached() const override;
    TextureHandle GetColorBuffer() override;

    Camera* GetCamera() const override;

    // Copies available settings for view and camera
    void CopySettingsFrom(const FilamentView& other);

    void SetScene(FilamentScene& scene);

    filament::View* GetNativeView() const { return view_; }

    void PreRender();
    void PostRender();

private:
    void SetRenderTarget(const RenderTargetHandle render_target);

    std::unique_ptr<FilamentCamera> camera_;
    Mode mode_ = Mode::Color;
    TargetBuffers discard_buffers_;
    bool caching_enabled_ = false;
    bool configured_for_picking_ = false;
    TextureHandle color_buffer_;
    TextureHandle depth_buffer_;
    RenderTargetHandle render_target_;

    filament::Engine& engine_;
    FilamentScene* scene_ = nullptr;
    FilamentResourceManager& resource_mgr_;
    filament::View* view_ = nullptr;
    filament::ColorGrading* color_grading_ = nullptr;
};

}  // namespace rendering
}  // namespace visualization
}  // namespace open3d