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

#include "open3d/visualization/visualizer/Visualizer.h"

#include <memory>

#include "open3d/geometry/TriangleMesh.h"

#if defined(__APPLE__) && defined(BUILD_GUI)
namespace bluegl {
int bind();
void unbind();
}  // namespace bluegl
#endif

namespace open3d {

namespace visualization {

/// \brief GLFW context, handled as a singleton.
class GLFWContext {
private:
    GLFWContext() {
        utility::LogDebug("GLFW init.");

#if defined(__APPLE__)
        // On macOS, GLFW changes the directory to the resource directory,
        // which will cause an unexpected change of directory if using a
        // framework build version of Python.
        glfwInitHint(GLFW_COCOA_CHDIR_RESOURCES, GLFW_FALSE);
#endif
        init_status_ = glfwInit();
    }

    GLFWContext(const GLFWContext &) = delete;
    GLFWContext &operator=(const GLFWContext &) = delete;

public:
    ~GLFWContext() {
        if (init_status_ == GLFW_TRUE) {
            glfwTerminate();
            utility::LogDebug("GLFW destruct.");
        }
    }

    /// \brief Get the glfwInit status.
    inline int InitStatus() const { return init_status_; }

    /// \brief Get a shared instance of the GLFW context.
    static std::shared_ptr<GLFWContext> GetInstance() {
        static std::weak_ptr<GLFWContext> singleton;

        auto res = singleton.lock();
        if (res == nullptr) {
            res = std::shared_ptr<GLFWContext>(new GLFWContext());
            singleton = res;
        }
        return res;
    }

    static void GLFWErrorCallback(int error, const char *description) {
        utility::LogWarning("GLFW Error: {}", description);
    }

private:
    /// \brief Status of the glfwInit call.
    int init_status_ = GLFW_FALSE;
};

Visualizer::Visualizer() {}

Visualizer::~Visualizer() {
    DestroyVisualizerWindow();

#if defined(__APPLE__) && defined(BUILD_GUI)
    bluegl::unbind();
#endif
}

bool Visualizer::CreateVisualizerWindow(
        const std::string &window_name /* = "Open3D"*/,
        const int width /* = 640*/,
        const int height /* = 480*/,
        const int left /* = 50*/,
        const int top /* = 50*/,
        const bool visible /* = true*/) {
    window_name_ = window_name;
    if (window_) {  // window already created
        utility::LogDebug("[Visualizer] Reusing window.");
        UpdateWindowTitle();
        glfwSetWindowPos(window_, left, top);
        glfwSetWindowSize(window_, width, height);
#ifdef __APPLE__
        glfwSetWindowSize(window_,
                          std::round(width * pixel_to_screen_coordinate_),
                          std::round(height * pixel_to_screen_coordinate_));
        glfwSetWindowPos(window_,
                         std::round(left * pixel_to_screen_coordinate_),
                         std::round(top * pixel_to_screen_coordinate_));
#endif  //__APPLE__
        return true;
    }

    utility::LogDebug("[Visualizer] Creating window.");
    glfwSetErrorCallback(GLFWContext::GLFWErrorCallback);
    glfw_context_ = GLFWContext::GetInstance();
    if (glfw_context_->InitStatus() != GLFW_TRUE) {
        utility::LogWarning("Failed to initialize GLFW");
        return false;
    }

    glfwWindowHint(GLFW_SAMPLES, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
#ifndef HEADLESS_RENDERING
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_VISIBLE, visible ? 1 : 0);

    window_ = glfwCreateWindow(width, height, window_name_.c_str(), NULL, NULL);
    if (!window_) {
        utility::LogWarning("Failed to create window");
        return false;
    }
    glfwSetWindowPos(window_, left, top);
    glfwSetWindowUserPointer(window_, this);

#ifdef __APPLE__
    // Some hacks to get pixel_to_screen_coordinate_
    glfwSetWindowSize(window_, 100, 100);
    glfwSetWindowPos(window_, 100, 100);
    int pixel_width_in_osx, pixel_height_in_osx;
    glfwGetFramebufferSize(window_, &pixel_width_in_osx, &pixel_height_in_osx);
    if (pixel_width_in_osx > 0) {
        pixel_to_screen_coordinate_ = 100.0 / (double)pixel_width_in_osx;
    } else {
        pixel_to_screen_coordinate_ = 1.0;
    }
    glfwSetWindowSize(window_, std::round(width * pixel_to_screen_coordinate_),
                      std::round(height * pixel_to_screen_coordinate_));
    glfwSetWindowPos(window_, std::round(left * pixel_to_screen_coordinate_),
                     std::round(top * pixel_to_screen_coordinate_));
#endif  //__APPLE__

    auto window_refresh_callback = [](GLFWwindow *window) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->WindowRefreshCallback(window);
    };
    glfwSetWindowRefreshCallback(window_, window_refresh_callback);

    auto window_resize_callback = [](GLFWwindow *window, int w, int h) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->WindowResizeCallback(window, w, h);
    };
    glfwSetFramebufferSizeCallback(window_, window_resize_callback);

    auto mouse_move_callback = [](GLFWwindow *window, double x, double y) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->MouseMoveCallback(window, x, y);
    };
    glfwSetCursorPosCallback(window_, mouse_move_callback);

    auto mouse_scroll_callback = [](GLFWwindow *window, double x, double y) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->MouseScrollCallback(window, x, y);
    };
    glfwSetScrollCallback(window_, mouse_scroll_callback);

    auto mouse_button_callback = [](GLFWwindow *window, int button, int action,
                                    int mods) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->MouseButtonCallback(window, button, action, mods);
    };
    glfwSetMouseButtonCallback(window_, mouse_button_callback);

    auto key_press_callback = [](GLFWwindow *window, int key, int scancode,
                                 int action, int mods) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->KeyPressCallback(window, key, scancode, action, mods);
    };
    glfwSetKeyCallback(window_, key_press_callback);

    auto window_close_callback = [](GLFWwindow *window) {
        static_cast<Visualizer *>(glfwGetWindowUserPointer(window))
                ->WindowCloseCallback(window);
    };
    glfwSetWindowCloseCallback(window_, window_close_callback);

    glfwMakeContextCurrent(window_);
    glfwSwapInterval(1);

    if (!InitOpenGL()) {
        return false;
    }

    if (!InitViewControl()) {
        return false;
    }

    if (!InitRenderOption()) {
        return false;
    }

    int window_width, window_height;
    glfwGetFramebufferSize(window_, &window_width, &window_height);
    WindowResizeCallback(window_, window_width, window_height);

    UpdateWindowTitle();

    is_initialized_ = true;
    return true;
}

void Visualizer::DestroyVisualizerWindow() {
    if (!is_initialized_) {
        return;
    }

    utility::LogDebug("[Visualizer] Destroying window.");
    is_initialized_ = false;
    glDeleteVertexArrays(1, &vao_id_);
    vao_id_ = 0;
    glfwDestroyWindow(window_);
    window_ = nullptr;
    glfw_context_.reset();
}

void Visualizer::RegisterAnimationCallback(
        std::function<bool(Visualizer *)> callback_func) {
    animation_callback_func_ = callback_func;
}

bool Visualizer::InitViewControl() {
    view_control_ptr_ = std::unique_ptr<ViewControl>(new ViewControl);
    ResetViewPoint();
    return true;
}

bool Visualizer::InitRenderOption() {
    render_option_ptr_ = std::unique_ptr<RenderOption>(new RenderOption);
    return true;
}

void Visualizer::UpdateWindowTitle() {
    if (window_ != NULL) {
        glfwSetWindowTitle(window_, window_name_.c_str());
    }
}

void Visualizer::BuildUtilities() {
    glfwMakeContextCurrent(window_);

    // 0. Build coordinate frame
    const auto boundingbox = GetViewControl().GetBoundingBox();
    double extent = std::max(0.01, boundingbox.GetMaxExtent() * 0.2);
    coordinate_frame_mesh_ptr_ = geometry::TriangleMesh::CreateCoordinateFrame(
            extent, boundingbox.min_bound_);
    coordinate_frame_mesh_renderer_ptr_ =
            std::make_shared<glsl::CoordinateFrameRenderer>();
    if (!coordinate_frame_mesh_renderer_ptr_->AddGeometry(
                coordinate_frame_mesh_ptr_)) {
        return;
    }
    utility_ptrs_.push_back(coordinate_frame_mesh_ptr_);
    utility_renderer_ptrs_.push_back(coordinate_frame_mesh_renderer_ptr_);
}

void Visualizer::Run() {
    BuildUtilities();
    UpdateWindowTitle();
    while (bool(animation_callback_func_) ? PollEvents() : WaitEvents()) {
        if (bool(animation_callback_func_in_loop_)) {
            if (animation_callback_func_in_loop_(this)) {
                UpdateGeometry();
            }
            // Set render flag as dirty anyways, because when we use callback
            // functions, we assume something has been changed in the callback
            // and the redraw event should be triggered.
            UpdateRender();
        }
    }
}

void Visualizer::Close() {
    glfwSetWindowShouldClose(window_, GL_TRUE);
    utility::LogDebug("[Visualizer] Window closing.");
}

bool Visualizer::WaitEvents() {
    if (!is_initialized_) {
        return false;
    }
    glfwMakeContextCurrent(window_);
    if (is_redraw_required_) {
        WindowRefreshCallback(window_);
    }
    animation_callback_func_in_loop_ = animation_callback_func_;
    glfwWaitEvents();
    return !glfwWindowShouldClose(window_);
}

bool Visualizer::PollEvents() {
    if (!is_initialized_) {
        return false;
    }
    glfwMakeContextCurrent(window_);
    if (is_redraw_required_) {
        WindowRefreshCallback(window_);
    }
    animation_callback_func_in_loop_ = animation_callback_func_;
    glfwPollEvents();
    return !glfwWindowShouldClose(window_);
}

bool Visualizer::AddGeometry(
        std::shared_ptr<const geometry::Geometry> geometry_ptr,
        bool reset_bounding_box) {
    if (!is_initialized_) {
        return false;
    }
    if (!geometry_ptr.get()) {
        utility::LogWarning(
                "[AddGeometry] Invalid pointer. Possibly a null pointer or "
                "None was passed in.");
        return false;
    }

    glfwMakeContextCurrent(window_);
    std::shared_ptr<glsl::GeometryRenderer> renderer_ptr;
    if (geometry_ptr->GetGeometryType() ==
        geometry::Geometry::GeometryType::Unspecified) {
        return false;
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::PointCloud) {
        renderer_ptr = std::make_shared<glsl::PointCloudRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::VoxelGrid) {
        renderer_ptr = std::make_shared<glsl::VoxelGridRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::Octree) {
        renderer_ptr = std::make_shared<glsl::OctreeRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::LineSet) {
        renderer_ptr = std::make_shared<glsl::LineSetRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
                       geometry::Geometry::GeometryType::TriangleMesh ||
               geometry_ptr->GetGeometryType() ==
                       geometry::Geometry::GeometryType::HalfEdgeTriangleMesh) {
        renderer_ptr = std::make_shared<glsl::TriangleMeshRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::Image) {
        renderer_ptr = std::make_shared<glsl::ImageRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::RGBDImage) {
        renderer_ptr = std::make_shared<glsl::RGBDImageRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::TetraMesh) {
        renderer_ptr = std::make_shared<glsl::TetraMeshRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::OrientedBoundingBox) {
        renderer_ptr = std::make_shared<glsl::OrientedBoundingBoxRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else if (geometry_ptr->GetGeometryType() ==
               geometry::Geometry::GeometryType::AxisAlignedBoundingBox) {
        renderer_ptr = std::make_shared<glsl::AxisAlignedBoundingBoxRenderer>();
        if (!renderer_ptr->AddGeometry(geometry_ptr)) {
            return false;
        }
    } else {
        return false;
    }
    geometry_renderer_ptrs_.insert(renderer_ptr);
    geometry_ptrs_.insert(geometry_ptr);
    if (reset_bounding_box) {
        view_control_ptr_->FitInGeometry(*geometry_ptr);
        ResetViewPoint();
    }
    utility::LogDebug(
            "Add geometry and update bounding box to {}",
            view_control_ptr_->GetBoundingBox().GetPrintInfo().c_str());
    return UpdateGeometry(geometry_ptr);
}

bool Visualizer::RemoveGeometry(
        std::shared_ptr<const geometry::Geometry> geometry_ptr,
        bool reset_bounding_box) {
    if (!is_initialized_) {
        return false;
    }
    glfwMakeContextCurrent(window_);
    std::shared_ptr<glsl::GeometryRenderer> geometry_renderer_delete = NULL;
    for (auto &geometry_renderer_ptr : geometry_renderer_ptrs_) {
        if (geometry_renderer_ptr->GetGeometry() == geometry_ptr)
            geometry_renderer_delete = geometry_renderer_ptr;
    }
    if (geometry_renderer_delete == NULL) return false;
    geometry_renderer_ptrs_.erase(geometry_renderer_delete);
    geometry_ptrs_.erase(geometry_ptr);
    if (reset_bounding_box) {
        ResetViewPoint(true);
    }
    utility::LogDebug(
            "Remove geometry and update bounding box to {}",
            view_control_ptr_->GetBoundingBox().GetPrintInfo().c_str());
    return UpdateGeometry(geometry_ptr);
}

bool Visualizer::ClearGeometries() {
    if (!is_initialized_) {
        return false;
    }
    glfwMakeContextCurrent(window_);
    geometry_renderer_ptrs_.clear();
    geometry_ptrs_.clear();
    return UpdateGeometry();
}

bool Visualizer::UpdateGeometry(
        std::shared_ptr<const geometry::Geometry> geometry_ptr) {
    glfwMakeContextCurrent(window_);
    bool success = true;
    for (const auto &renderer_ptr : geometry_renderer_ptrs_) {
        if (geometry_ptr == nullptr ||
            renderer_ptr->HasGeometry(geometry_ptr)) {
            success = (success && renderer_ptr->UpdateGeometry());
        }
    }
    UpdateRender();
    return success;
}

void Visualizer::UpdateRender() { is_redraw_required_ = true; }

bool Visualizer::HasGeometry() const { return !geometry_ptrs_.empty(); }

void Visualizer::SetFullScreen(bool fullscreen) {
    if (!fullscreen) {
        glfwSetWindowMonitor(window_, NULL, saved_window_pos_(0),
                             saved_window_pos_(1), saved_window_size_(0),
                             saved_window_size_(1), GLFW_DONT_CARE);
    } else {
        glfwGetWindowSize(window_, &saved_window_size_(0),
                          &saved_window_size_(1));
        glfwGetWindowPos(window_, &saved_window_pos_(0), &saved_window_pos_(1));
        GLFWmonitor *monitor = glfwGetPrimaryMonitor();
        if (const GLFWvidmode *mode = glfwGetVideoMode(monitor)) {
            glfwSetWindowMonitor(window_, monitor, 0, 0, mode->width,
                                 mode->height, mode->refreshRate);
        } else {
            utility::LogError(
                    "Internal error: glfwGetVideoMode returns nullptr.");
        }
    }
}

void Visualizer::ToggleFullScreen() {
    if (IsFullScreen()) {
        SetFullScreen(false);
    } else {
        SetFullScreen(true);
    }
}

bool Visualizer::IsFullScreen() {
    return glfwGetWindowMonitor(window_) != nullptr;
}

void Visualizer::PrintVisualizerHelp() {
    // clang-format off
    utility::LogInfo("  -- Mouse view control --");
    utility::LogInfo("    Left button + drag         : Rotate.");
    utility::LogInfo("    Ctrl + left button + drag  : Translate.");
    utility::LogInfo("    Wheel button + drag        : Translate.");
    utility::LogInfo("    Shift + left button + drag : Roll.");
    utility::LogInfo("    Wheel                      : Zoom in/out.");
    utility::LogInfo("");
    utility::LogInfo("  -- Keyboard view control --");
    utility::LogInfo("    [/]          : Increase/decrease field of view.");
    utility::LogInfo("    R            : Reset view point.");
    utility::LogInfo("    Ctrl/Cmd + C : Copy current view status into the clipboard.");
    utility::LogInfo("    Ctrl/Cmd + V : Paste view status from clipboard.");
    utility::LogInfo("");
    utility::LogInfo("  -- General control --");
    utility::LogInfo("    Q, Esc       : Exit window.");
    utility::LogInfo("    H            : Print help message.");
    utility::LogInfo("    P, PrtScn    : Take a screen capture.");
    utility::LogInfo("    D            : Take a depth capture.");
    utility::LogInfo("    O            : Take a capture of current rendering settings.");
    utility::LogInfo("    Alt + Enter  : Toggle between full screen and windowed mode.");
    utility::LogInfo("");
    utility::LogInfo("  -- Render mode control --");
    utility::LogInfo("    L            : Turn on/off lighting.");
    utility::LogInfo("    +/-          : Increase/decrease point size.");
    utility::LogInfo("    Ctrl + +/-   : Increase/decrease width of geometry::LineSet.");
    utility::LogInfo("    N            : Turn on/off point cloud normal rendering.");
    utility::LogInfo("    S            : Toggle between mesh flat shading and smooth shading.");
    utility::LogInfo("    W            : Turn on/off mesh wireframe.");
    utility::LogInfo("    B            : Turn on/off back face rendering.");
    utility::LogInfo("    I            : Turn on/off image zoom in interpolation.");
    utility::LogInfo("    T            : Toggle among image render:");
    utility::LogInfo("                   no stretch / keep ratio / freely stretch.");
    utility::LogInfo("");
    utility::LogInfo("  -- Color control --");
    utility::LogInfo("    0..4,9       : Set point cloud color option.");
    utility::LogInfo("                   0 - Default behavior, render point color.");
    utility::LogInfo("                   1 - Render point color.");
    utility::LogInfo("                   2 - x coordinate as color.");
    utility::LogInfo("                   3 - y coordinate as color.");
    utility::LogInfo("                   4 - z coordinate as color.");
    utility::LogInfo("                   9 - normal as color.");
    utility::LogInfo("    Ctrl + 0..4,9: Set mesh color option.");
    utility::LogInfo("                   0 - Default behavior, render uniform gray color.");
    utility::LogInfo("                   1 - Render point color.");
    utility::LogInfo("                   2 - x coordinate as color.");
    utility::LogInfo("                   3 - y coordinate as color.");
    utility::LogInfo("                   4 - z coordinate as color.");
    utility::LogInfo("                   9 - normal as color.");
    utility::LogInfo("    Shift + 0..4 : Color map options.");
    utility::LogInfo("                   0 - Gray scale color.");
    utility::LogInfo("                   1 - JET color map.");
    utility::LogInfo("                   2 - SUMMER color map.");
    utility::LogInfo("                   3 - WINTER color map.");
    utility::LogInfo("                   4 - HOT color map.");
    utility::LogInfo("");
    // clang-format on
}
}  // namespace visualization
}  // namespace open3d