Engine Singleton Interactions

// Standard singleton access pattern in GDExtension
#include <godot_cpp/classes/engine.hpp>
#include <godot_cpp/classes/input.hpp>
#include <godot_cpp/classes/os.hpp>
#include <godot_cpp/classes/rendering_server.hpp>

void example_singleton_access() {
    // Direct singleton access
    Engine *engine = Engine::get_singleton();
    Input *input = Input::get_singleton();
    OS *os = OS::get_singleton();
    RenderingServer *rs = RenderingServer::get_singleton();

    // All singletons are guaranteed to exist during runtime
    // No need for null checks in normal operation
}

// How singletons are implemented (conceptual)
class EngineSingleton : public Object {
    static EngineSingleton *singleton;

protected:
    EngineSingleton() {
        singleton = this;
    }

public:
    static EngineSingleton *get_singleton() {
        return singleton;
    }

    ~EngineSingleton() {
        singleton = nullptr;
    }
};

#include <godot_cpp/classes/engine.hpp>

class EngineInteraction : public Node {
    GDCLASS(EngineInteraction, Node)

public:
    void demonstrate_engine_singleton() {
        Engine *engine = Engine::get_singleton();

        // Version information
        Dictionary version = engine->get_version_info();
        String version_string = version["string"];
        int major = version["major"];
        int minor = version["minor"];
        int patch = version["patch"];
        print_line("Engine version: " + version_string);

        // Frame information
        int physics_fps = engine->get_physics_ticks_per_second();
        int max_fps = engine->get_max_fps();
        double physics_jitter = engine->get_physics_jitter_fix();
        print_line(vformat("Physics: %d Hz, Max FPS: %d", physics_fps, max_fps));

        // Performance metrics
        uint64_t physics_frames = engine->get_physics_frames();
        uint64_t process_frames = engine->get_process_frames();
        double time_scale = engine->get_time_scale();

        // Editor detection
        bool is_editor = engine->is_editor_hint();
        if (is_editor) {
            print_line("Running in editor");
        }

        // Time scale manipulation (slow motion/fast forward)
        engine->set_time_scale(0.5);  // Half speed

        // Physics interpolation
        engine->set_physics_jitter_fix(0.0);  // Disable jitter fix

        // Custom main loop (advanced)
        // engine->set_main_loop(custom_main_loop);
    }

    void check_features() {
        Engine *engine = Engine::get_singleton();

        // Check for debug build
        if (engine->is_in_physics_frame()) {
            print_line("Currently in physics frame");
        }

        // Get singleton list
        TypedArray<Dictionary> singletons = engine->get_singleton_list();
        for (int i = 0; i < singletons.size(); i++) {
            Dictionary singleton_info = singletons[i];
            print_line("Singleton: " + String(singleton_info["name"]));
        }

        // Register custom singleton
        Engine::Singleton my_singleton("MySingleton", get_singleton_instance());
        engine->register_singleton(my_singleton);
    }

private:
    Object *get_singleton_instance() {
        // Return your singleton instance
        return memnew(Object);
    }
};

#include <godot_cpp/classes/os.hpp>

class OSInteraction : public Node {
    GDCLASS(OSInteraction, Node)

public:
    void demonstrate_os_singleton() {
        OS *os = OS::get_singleton();

        // System information
        String os_name = os->get_name();  // "Windows", "Linux", "macOS", etc.
        String model_name = os->get_model_name();
        int processor_count = os->get_processor_count();
        String processor_name = os->get_processor_name();

        print_line(vformat("OS: %s, CPUs: %d", os_name, processor_count));

        // Memory information
        uint64_t static_memory = os->get_static_memory_usage();
        uint64_t static_memory_peak = os->get_static_memory_peak_usage();

        // Time and date
        Dictionary datetime = os->get_datetime();
        int year = datetime["year"];
        int month = datetime["month"];
        int day = datetime["day"];
        int hour = datetime["hour"];
        int minute = datetime["minute"];
        int second = datetime["second"];

        uint64_t unix_time = os->get_unix_time();
        uint64_t ticks_msec = os->get_ticks_msec();
        uint64_t ticks_usec = os->get_ticks_usec();

        // Environment variables
        String home = os->get_environment("HOME");
        os->set_environment("MY_VAR", "my_value");

        // System directories
        String user_data = os->get_user_data_dir();
        String config = os->get_config_dir();
        String cache = os->get_cache_dir();
        String data = os->get_data_dir();

        // Executable information
        String exe_path = os->get_executable_path();
        PackedStringArray cmd_args = os->get_cmdline_args();

        // Process management
        int pid = os->get_process_id();
        os->create_process("/usr/bin/ls", {"-la"});
        os->kill(pid);  // Kill process by PID

        // System features
        bool has_feature = os->has_feature("mobile");

        // Clipboard
        os->set_clipboard("Hello from GDExtension");
        String clipboard = os->get_clipboard();

        // Shell operations
        os->shell_open("https://godotengine.org");  // Open URL
        os->shell_open("file:///home/user/file.txt");  // Open file

        // Threading
        int thread_id = os->get_thread_caller_id();
        int main_thread_id = os->get_main_thread_id();

        // Alerts (blocking)
        // os->alert("Message", "Title");
    }

    void benchmark_example() {
        OS *os = OS::get_singleton();

        uint64_t start = os->get_ticks_usec();

        // Perform operation
        complex_operation();

        uint64_t elapsed = os->get_ticks_usec() - start;
        print_line(vformat("Operation took: %d microseconds", elapsed));
    }

private:
    void complex_operation() {
        // Some complex work
    }
};

#include <godot_cpp/classes/time.hpp>

class TimeInteraction : public Node {
    GDCLASS(TimeInteraction, Node)

public:
    void demonstrate_time_singleton() {
        Time *time = Time::get_singleton();

        // Current time
        Dictionary datetime = time->get_datetime_dict_from_system();
        String datetime_string = time->get_datetime_string_from_system();

        // Unix timestamp
        int64_t unix_timestamp = time->get_unix_time_from_system();

        // Time zone information
        Dictionary timezone = time->get_time_zone_from_system();
        int bias = timezone["bias"];  // Minutes from UTC
        String tz_name = timezone["name"];

        // Formatting
        String formatted = time->get_datetime_string_from_datetime_dict(datetime, false);

        // Parsing
        Dictionary parsed = time->get_datetime_dict_from_datetime_string("2024-01-15 14:30:00");

        // High precision timing
        int64_t ticks = time->get_ticks_msec();
        int64_t ticks_us = time->get_ticks_usec();

        print_line("Current time: " + datetime_string);
        print_line(vformat("Unix time: %d", unix_timestamp));
    }
};

#include <godot_cpp/classes/rendering_server.hpp>
#include <godot_cpp/classes/rendering_device.hpp>

class RenderingInteraction : public Node {
    GDCLASS(RenderingInteraction, Node)

private:
    RID viewport_rid;
    RID camera_rid;
    RID scenario_rid;
    RID instance_rid;
    RID mesh_rid;

public:
    void demonstrate_rendering_server() {
        RenderingServer *rs = RenderingServer::get_singleton();

        // Create viewport
        viewport_rid = rs->viewport_create();
        rs->viewport_set_size(viewport_rid, 1920, 1080);
        rs->viewport_set_active(viewport_rid, true);

        // Create scenario (3D world)
        scenario_rid = rs->scenario_create();
        rs->viewport_set_scenario(viewport_rid, scenario_rid);

        // Create camera
        camera_rid = rs->camera_create();
        rs->camera_set_perspective(camera_rid, 60.0, 0.1, 1000.0);
        rs->camera_set_transform(camera_rid,
            Transform3D(Basis(), Vector3(0, 5, 10)));
        rs->viewport_attach_camera(viewport_rid, camera_rid);

        // Create mesh
        create_custom_mesh();

        // Create instance
        instance_rid = rs->instance_create();
        rs->instance_set_base(instance_rid, mesh_rid);
        rs->instance_set_scenario(instance_rid, scenario_rid);
        rs->instance_set_transform(instance_rid, Transform3D());

        // Global rendering settings
        rs->set_default_clear_color(Color(0.1, 0.1, 0.2));

        // Performance settings
        rs->viewport_set_msaa_3d(viewport_rid,
            RenderingServer::VIEWPORT_MSAA_4X);
        rs->viewport_set_screen_space_aa(viewport_rid,
            RenderingServer::VIEWPORT_SCREEN_SPACE_AA_FXAA);

        // Debug visualization
        rs->viewport_set_debug_draw(viewport_rid,
            RenderingServer::VIEWPORT_DEBUG_DRAW_WIREFRAME);
    }

    void create_custom_mesh() {
        RenderingServer *rs = RenderingServer::get_singleton();

        // Create mesh
        mesh_rid = rs->mesh_create();

        // Define vertices
        PackedVector3Array vertices;
        vertices.push_back(Vector3(-1, 0, -1));
        vertices.push_back(Vector3(1, 0, -1));
        vertices.push_back(Vector3(1, 0, 1));
        vertices.push_back(Vector3(-1, 0, 1));

        // Define normals
        PackedVector3Array normals;
        for (int i = 0; i < 4; i++) {
            normals.push_back(Vector3(0, 1, 0));
        }

        // Define UVs
        PackedVector2Array uvs;
        uvs.push_back(Vector2(0, 0));
        uvs.push_back(Vector2(1, 0));
        uvs.push_back(Vector2(1, 1));
        uvs.push_back(Vector2(0, 1));

        // Define indices
        PackedInt32Array indices;
        indices.append_array({0, 1, 2, 0, 2, 3});

        // Create surface
        Array surface_array;
        surface_array.resize(RenderingServer::ARRAY_MAX);
        surface_array[RenderingServer::ARRAY_VERTEX] = vertices;
        surface_array[RenderingServer::ARRAY_NORMAL] = normals;
        surface_array[RenderingServer::ARRAY_TEX_UV] = uvs;
        surface_array[RenderingServer::ARRAY_INDEX] = indices;

        rs->mesh_add_surface_from_arrays(mesh_rid,
            RenderingServer::PRIMITIVE_TRIANGLES,
            surface_array);
    }

    void cleanup() {
        RenderingServer *rs = RenderingServer::get_singleton();

        // Free resources
        if (instance_rid.is_valid()) rs->free_rid(instance_rid);
        if (mesh_rid.is_valid()) rs->free_rid(mesh_rid);
        if (camera_rid.is_valid()) rs->free_rid(camera_rid);
        if (scenario_rid.is_valid()) rs->free_rid(scenario_rid);
        if (viewport_rid.is_valid()) rs->free_rid(viewport_rid);
    }
};

#include <godot_cpp/classes/display_server.hpp>

class DisplayInteraction : public Node {
    GDCLASS(DisplayInteraction, Node)

public:
    void demonstrate_display_server() {
        DisplayServer *ds = DisplayServer::get_singleton();

        // Screen information
        int screen_count = ds->get_screen_count();
        int primary_screen = ds->get_primary_screen();

        for (int i = 0; i < screen_count; i++) {
            Vector2i screen_pos = ds->screen_get_position(i);
            Vector2i screen_size = ds->screen_get_size(i);
            int dpi = ds->screen_get_dpi(i);
            float scale = ds->screen_get_scale(i);
            float refresh_rate = ds->screen_get_refresh_rate(i);

            print_line(vformat("Screen %d: %dx%d at %d,%d, %d DPI, %.1f Hz",
                i, screen_size.x, screen_size.y,
                screen_pos.x, screen_pos.y, dpi, refresh_rate));
        }

        // Window management
        int main_window = DisplayServer::MAIN_WINDOW_ID;

        // Window properties
        ds->window_set_title("GDExtension Window", main_window);
        ds->window_set_size(Vector2i(1280, 720), main_window);
        ds->window_set_position(Vector2i(100, 100), main_window);

        // Window modes
        ds->window_set_mode(DisplayServer::WINDOW_MODE_WINDOWED, main_window);
        // ds->window_set_mode(DisplayServer::WINDOW_MODE_FULLSCREEN, main_window);
        // ds->window_set_mode(DisplayServer::WINDOW_MODE_EXCLUSIVE_FULLSCREEN, main_window);

        // Window flags
        ds->window_set_flag(DisplayServer::WINDOW_FLAG_ALWAYS_ON_TOP, true, main_window);
        ds->window_set_flag(DisplayServer::WINDOW_FLAG_BORDERLESS, false, main_window);
        ds->window_set_flag(DisplayServer::WINDOW_FLAG_RESIZE_DISABLED, false, main_window);

        // Cursor
        ds->cursor_set_shape(DisplayServer::CURSOR_ARROW);
        ds->cursor_set_custom_image(Ref<Resource>(), Vector2());

        // Clipboard with MIME types
        ds->clipboard_set("text/plain", "Hello from GDExtension");
        String clipboard_text = ds->clipboard_get();

        // IME (Input Method Editor)
        ds->window_set_ime_active(true, main_window);
        ds->window_set_ime_position(Vector2i(100, 100), main_window);

        // Native dialogs
        // ds->dialog_show("Title", "Description", {"OK", "Cancel"}, callback);

        // Screen orientation (mobile)
        ds->screen_set_orientation(DisplayServer::SCREEN_LANDSCAPE);

        // Virtual keyboard (mobile)
        // ds->virtual_keyboard_show("", Rect2(), 0, -1, -1);
        // ds->virtual_keyboard_hide();
    }

    void handle_window_events() {
        DisplayServer *ds = DisplayServer::get_singleton();

        // Check window focus
        bool has_focus = ds->window_is_focused();

        // Get mouse position
        Vector2i mouse_pos = ds->mouse_get_position();

        // Warp mouse
        ds->warp_mouse(Vector2i(640, 360));

        // Get window under mouse
        int window_id = ds->get_window_at_screen_position(mouse_pos);

        print_line(vformat("Mouse at: %d,%d, Window focused: %s",
            mouse_pos.x, mouse_pos.y, has_focus ? "true" : "false"));
    }
};

#include <godot_cpp/classes/physics_server3d.hpp>
#include <godot_cpp/classes/physics_server2d.hpp>

class PhysicsInteraction : public Node {
    GDCLASS(PhysicsInteraction, Node)

private:
    RID space_rid;
    RID body_rid;
    RID shape_rid;

public:
    void demonstrate_physics_3d() {
        PhysicsServer3D *ps = PhysicsServer3D::get_singleton();

        // Create physics space
        space_rid = ps->space_create();
        ps->space_set_active(space_rid, true);

        // Set space parameters
        ps->space_set_param(space_rid,
            PhysicsServer3D::SPACE_PARAM_GRAVITY, 9.8);
        ps->space_set_param(space_rid,
            PhysicsServer3D::SPACE_PARAM_GRAVITY_VECTOR, Vector3(0, -1, 0));

        // Create collision shape
        shape_rid = ps->sphere_shape_create();
        ps->shape_set_data(shape_rid, 0.5);  // Radius

        // Create rigid body
        body_rid = ps->body_create();
        ps->body_set_mode(body_rid, PhysicsServer3D::BODY_MODE_RIGID);
        ps->body_set_space(body_rid, space_rid);

        // Add shape to body
        ps->body_add_shape(body_rid, shape_rid, Transform3D());

        // Set body properties
        ps->body_set_param(body_rid, PhysicsServer3D::BODY_PARAM_MASS, 1.0);
        ps->body_set_param(body_rid, PhysicsServer3D::BODY_PARAM_FRICTION, 0.5);
        ps->body_set_param(body_rid, PhysicsServer3D::BODY_PARAM_BOUNCE, 0.2);

        // Set initial state
        ps->body_set_state(body_rid,
            PhysicsServer3D::BODY_STATE_TRANSFORM,
            Transform3D(Basis(), Vector3(0, 10, 0)));

        // Apply forces
        ps->body_apply_central_impulse(body_rid, Vector3(5, 10, 0));
        ps->body_apply_torque_impulse(body_rid, Vector3(0, 1, 0));

        // Direct state access
        PhysicsDirectBodyState3D *state = ps->body_get_direct_state(body_rid);
        if (state) {
            Vector3 velocity = state->get_linear_velocity();
            Vector3 angular_velocity = state->get_angular_velocity();
            Transform3D transform = state->get_transform();
        }

        // Perform raycast
        perform_raycast();

        // Area detection
        create_area_detector();
    }

    void perform_raycast() {
        PhysicsServer3D *ps = PhysicsServer3D::get_singleton();

        // Setup raycast parameters
        PhysicsRayQueryParameters3D *ray_params =
            PhysicsRayQueryParameters3D::create(
                Vector3(0, 10, 0),  // From
                Vector3(0, -10, 0)  // To
            );

        ray_params->set_collision_mask(0xFFFFFFFF);
        ray_params->set_collide_with_areas(true);
        ray_params->set_collide_with_bodies(true);

        // Perform raycast
        Dictionary result = ps->space_get_direct_state(space_rid)->
            intersect_ray(ray_params->get_from(), ray_params->get_to(),
                         ray_params->get_exclude(),
                         ray_params->get_collision_mask());

        if (!result.is_empty()) {
            Vector3 position = result["position"];
            Vector3 normal = result["normal"];
            Object *collider = result["collider"];
            RID collider_rid = result["rid"];

            print_line(vformat("Ray hit at: %.2f, %.2f, %.2f",
                position.x, position.y, position.z));
        }
    }

    void create_area_detector() {
        PhysicsServer3D *ps = PhysicsServer3D::get_singleton();

        // Create area
        RID area_rid = ps->area_create();
        ps->area_set_space(area_rid, space_rid);

        // Create shape for area
        RID area_shape = ps->box_shape_create();
        ps->shape_set_data(area_shape, Vector3(5, 5, 5));

        ps->area_add_shape(area_shape, area_shape, Transform3D());

        // Set area monitoring
        ps->area_set_monitor_callback(area_rid,
            Callable(this, "on_body_entered_area"));

        // Set area parameters
        ps->area_set_param(area_rid,
            PhysicsServer3D::AREA_PARAM_GRAVITY, 5.0);
        ps->area_set_param(area_rid,
            PhysicsServer3D::AREA_PARAM_GRAVITY_IS_POINT, true);
        ps->area_set_param(area_rid,
            PhysicsServer3D::AREA_PARAM_GRAVITY_POINT,
            Vector3(0, 0, 0));
    }

    void on_body_entered_area(RID body, ObjectID instance,
                              int body_shape, int area_shape) {
        print_line("Body entered area!");
    }

    void cleanup_physics() {
        PhysicsServer3D *ps = PhysicsServer3D::get_singleton();

        if (body_rid.is_valid()) ps->free_rid(body_rid);
        if (shape_rid.is_valid()) ps->free_rid(shape_rid);
        if (space_rid.is_valid()) ps->free_rid(space_rid);
    }
};

#include <godot_cpp/classes/audio_server.hpp>

class AudioInteraction : public Node {
    GDCLASS(AudioInteraction, Node)

public:
    void demonstrate_audio_server() {
        AudioServer *audio = AudioServer::get_singleton();

        // Bus management
        int bus_count = audio->get_bus_count();

        for (int i = 0; i < bus_count; i++) {
            String bus_name = audio->get_bus_name(i);
            float volume_db = audio->get_bus_volume_db(i);
            bool solo = audio->is_bus_solo(i);
            bool mute = audio->is_bus_mute(i);
            bool bypass = audio->is_bus_bypassing_effects(i);

            print_line(vformat("Bus %s: %.1f dB, Mute: %s",
                bus_name, volume_db, mute ? "true" : "false"));
        }

        // Master bus control
        int master_bus = audio->get_bus_index("Master");
        audio->set_bus_volume_db(master_bus, -6.0);  // -6 dB
        audio->set_bus_mute(master_bus, false);

        // Create custom bus
        audio->add_bus();
        int custom_bus = audio->get_bus_count() - 1;
        audio->set_bus_name(custom_bus, "CustomBus");
        audio->set_bus_send(custom_bus, "Master");

        // Add effects
        Ref<AudioEffect> reverb = memnew(AudioEffectReverb);
        audio->add_bus_effect(custom_bus, reverb);

        // Audio settings
        float mix_rate = audio->get_mix_rate();
        AudioServer::SpeakerMode speaker_mode = audio->get_speaker_mode();

        // Device management
        PackedStringArray output_devices = audio->get_output_device_list();
        String current_device = audio->get_output_device();

        for (const String &device : output_devices) {
            print_line("Audio device: " + device);
        }

        // audio->set_output_device("Device Name");

        // Capture devices (microphone)
        PackedStringArray input_devices = audio->get_input_device_list();

        // Performance metrics
        double output_latency = audio->get_output_latency();
        double time_to_next_mix = audio->get_time_to_next_mix();
        double time_since_last_mix = audio->get_time_since_last_mix();

        print_line(vformat("Audio latency: %.3f ms", output_latency * 1000));

        // Bus peak detection
        float peak_left = audio->get_bus_peak_volume_left_db(master_bus, 0);
        float peak_right = audio->get_bus_peak_volume_right_db(master_bus, 0);

        // Global audio control
        audio->set_bus_layout(Ref<AudioBusLayout>());
        audio->lock();  // Lock for thread-safe operations
        // Perform thread-safe audio operations
        audio->unlock();
    }

    void setup_audio_effects() {
        AudioServer *audio = AudioServer::get_singleton();

        int fx_bus = audio->get_bus_index("Master");

        // Add compressor
        Ref<AudioEffectCompressor> compressor;
        compressor.instantiate();
        compressor->set_threshold(-20.0);
        compressor->set_ratio(4.0);
        compressor->set_attack_us(10.0);
        compressor->set_release_ms(100.0);
        audio->add_bus_effect(fx_bus, compressor);

        // Add EQ
        Ref<AudioEffectEQ> eq;
        eq.instantiate();
        audio->add_bus_effect(fx_bus, eq);

        // Enable/disable effect
        audio->set_bus_effect_enabled(fx_bus, 0, true);

        // Remove effect
        // audio->remove_bus_effect(fx_bus, 0);
    }
};

#include <godot_cpp/classes/input.hpp>
#include <godot_cpp/classes/input_event.hpp>

class InputInteraction : public Node {
    GDCLASS(InputInteraction, Node)

public:
    virtual void _ready() override {
        // Map actions programmatically
        setup_input_actions();
    }

    virtual void _process(double delta) override {
        demonstrate_input();
    }

    void setup_input_actions() {
        // Note: InputMap is a separate singleton for action configuration
        // Input singleton is for querying input state

        Input *input = Input::get_singleton();

        // Set mouse mode
        input->set_mouse_mode(Input::MOUSE_MODE_CAPTURED);  // FPS-style
        // input->set_mouse_mode(Input::MOUSE_MODE_CONFINED);  // Keep in window
        // input->set_mouse_mode(Input::MOUSE_MODE_HIDDEN);    // Hide cursor
        // input->set_mouse_mode(Input::MOUSE_MODE_VISIBLE);   // Normal

        // Configure input settings
        input->set_use_accumulated_input(true);
    }

    void demonstrate_input() {
        Input *input = Input::get_singleton();

        // Check action states
        bool jump_pressed = input->is_action_pressed("jump");
        bool jump_just_pressed = input->is_action_just_pressed("jump");
        bool jump_just_released = input->is_action_just_released("jump");
        float move_strength = input->get_action_strength("move_forward");

        // Get action raw strength (ignoring deadzones)
        float raw_strength = input->get_action_raw_strength("move_forward");

        // Check multiple actions
        if (input->is_action_pressed("move_left")) {
            move_left();
        }
        if (input->is_action_pressed("move_right")) {
            move_right();
        }

        // Direct key checks (use sparingly, actions are preferred)
        bool space_pressed = input->is_key_pressed(KEY_SPACE);
        bool shift_held = input->is_key_pressed(KEY_SHIFT);

        // Mouse button states
        bool left_click = input->is_mouse_button_pressed(MOUSE_BUTTON_LEFT);
        bool right_click = input->is_mouse_button_pressed(MOUSE_BUTTON_RIGHT);

        // Mouse position and movement
        Vector2 mouse_pos = input->get_mouse_position();
        Vector2 last_mouse_speed = input->get_last_mouse_velocity();

        // Joystick/gamepad input
        int device = 0;  // First controller
        if (input->is_joy_button_pressed(device, JOY_BUTTON_A)) {
            print_line("A button pressed");
        }

        float left_stick_x = input->get_joy_axis(device, JOY_AXIS_LEFT_X);
        float left_stick_y = input->get_joy_axis(device, JOY_AXIS_LEFT_Y);
        Vector2 left_stick = Vector2(left_stick_x, left_stick_y);

        // Apply deadzone
        if (left_stick.length() < 0.2) {
            left_stick = Vector2();
        }

        // Vibration (gamepad)
        input->start_joy_vibration(device, 0.5, 0.5, 0.5);  // weak, strong, duration

        // Get connected joysticks
        Array connected_joysticks = input->get_connected_joypads();
        for (int i = 0; i < connected_joysticks.size(); i++) {
            int joy_id = connected_joysticks[i];
            String joy_name = input->get_joy_name(joy_id);
            print_line("Controller " + itos(joy_id) + ": " + joy_name);
        }

        // Touch input (mobile)
        // Vector2 touch_pos = input->get_touch_position(0);  // First finger

        // Accelerometer (mobile)
        Vector3 accelerometer = input->get_accelerometer();
        Vector3 gravity = input->get_gravity();
        Vector3 gyroscope = input->get_gyroscope();
        Vector3 magnetometer = input->get_magnetometer();

        // Action simulation (useful for automation/testing)
        // input->action_press("jump");
        // input->action_release("jump");

        // Parse input event
        // Ref<InputEvent> event = input->parse_input_event(raw_event);
    }

    void handle_mouse_capture() {
        Input *input = Input::get_singleton();

        // Toggle mouse capture on ESC
        if (input->is_action_just_pressed("ui_cancel")) {
            if (input->get_mouse_mode() == Input::MOUSE_MODE_CAPTURED) {
                input->set_mouse_mode(Input::MOUSE_MODE_VISIBLE);
            } else {
                input->set_mouse_mode(Input::MOUSE_MODE_CAPTURED);
            }
        }

        // Warp mouse to center (useful for FPS controls)
        if (input->get_mouse_mode() == Input::MOUSE_MODE_CAPTURED) {
            // Mouse is automatically centered when captured
            // But you can manually warp if needed:
            // input->warp_mouse(get_viewport()->get_size() / 2);
        }
    }

private:
    void move_left() { /* Movement logic */ }
    void move_right() { /* Movement logic */ }
};

#include <godot_cpp/classes/resource_loader.hpp>
#include <godot_cpp/classes/resource_saver.hpp>

class ResourceInteraction : public Node {
    GDCLASS(ResourceInteraction, Node)

public:
    void demonstrate_resource_management() {
        // Loading resources
        load_resources();

        // Saving resources
        save_resources();

        // Preloading and caching
        manage_resource_cache();
    }

    void load_resources() {
        // Load resource (blocks until loaded)
        Ref<Resource> resource = ResourceLoader::load("res://data/config.tres");

        // Type-safe loading
        Ref<Texture2D> texture = ResourceLoader::load("res://icon.png");
        Ref<PackedScene> scene = ResourceLoader::load("res://scenes/level.tscn");

        // Check if resource exists
        bool exists = ResourceLoader::exists("res://data/config.tres");

        // Get resource type
        String type = ResourceLoader::get_resource_type("res://icon.png");
        print_line("Resource type: " + type);  // "Texture2D"

        // Load with type hint (faster)
        Ref<Resource> typed_resource = ResourceLoader::load(
            "res://data/config.tres", "Resource");

        // Get dependencies
        PackedStringArray dependencies = ResourceLoader::get_dependencies(
            "res://scenes/level.tscn");
        for (const String &dep : dependencies) {
            print_line("Dependency: " + dep);
        }

        // Threaded loading
        Error err = ResourceLoader::load_threaded_request(
            "res://large_asset.res");

        // Check loading status
        ResourceLoader::ThreadLoadStatus status;
        Array progress;
        status = ResourceLoader::load_threaded_get_status(
            "res://large_asset.res", progress);

        if (status == ResourceLoader::THREAD_LOAD_LOADED) {
            Ref<Resource> loaded = ResourceLoader::load_threaded_get(
                "res://large_asset.res");
        }
    }

    void save_resources() {
        // Create custom resource
        Ref<Resource> custom_resource;
        custom_resource.instantiate();
        custom_resource->set_meta("version", 1);
        custom_resource->set_meta("data", "custom_data");

        // Save resource
        Error err = ResourceSaver::save(custom_resource,
            "user://saved_resource.tres");

        if (err == OK) {
            print_line("Resource saved successfully");
        }

        // Save with flags
        uint32_t flags = ResourceSaver::FLAG_COMPRESS |
                        ResourceSaver::FLAG_BUNDLE_RESOURCES;
        ResourceSaver::save(custom_resource,
            "user://compressed_resource.res", flags);

        // Get recognized extensions
        PackedStringArray extensions = ResourceSaver::get_recognized_extensions(
            custom_resource);
        for (const String &ext : extensions) {
            print_line("Can save as: ." + ext);
        }
    }

    void manage_resource_cache() {
        // Set cache mode
        ResourceLoader::set_cache_mode(ResourceLoader::CACHE_MODE_REPLACE);

        // Check if cached
        bool has_cached = ResourceLoader::has_cached("res://icon.png");

        // Get cached resource
        if (has_cached) {
            Ref<Resource> cached = ResourceLoader::load("res://icon.png");
            // This returns the cached version without disk access
        }

        // Custom resource format loader (advanced)
        // Ref<ResourceFormatLoader> custom_loader;
        // ResourceLoader::add_resource_format_loader(custom_loader);
    }
};

#include <godot_cpp/classes/editor_interface.hpp>
#include <godot_cpp/classes/editor_selection.hpp>

class EditorInteraction : public Node {
    GDCLASS(EditorInteraction, Node)

public:
    void demonstrate_editor_interface() {
        if (!Engine::get_singleton()->is_editor_hint()) {
            return;  // Not in editor
        }

        EditorInterface *editor = EditorInterface::get_singleton();

        // Get editor viewport
        SubViewport *viewport = editor->get_editor_viewport_3d();

        // Get edited scene
        Node *edited_scene = editor->get_edited_scene_root();

        // Open scenes
        editor->open_scene_from_path("res://scenes/level.tscn");
        editor->reload_scene_from_path("res://scenes/level.tscn");

        // Save scenes
        editor->save_scene();
        // editor->save_scene_as("res://scenes/level_backup.tscn");

        // Get selection
        EditorSelection *selection = editor->get_selection();
        TypedArray<Node> selected = selection->get_selected_nodes();

        for (int i = 0; i < selected.size(); i++) {
            Node *node = Object::cast_to<Node>(selected[i]);
            print_line("Selected: " + node->get_name());
        }

        // Play scenes
        editor->play_main_scene();
        editor->play_current_scene();
        editor->play_custom_scene("res://scenes/test.tscn");
        editor->stop_playing_scene();

        // Editor settings
        editor->set_main_screen_editor("3D");  // or "2D", "Script", etc.

        // Inspector
        editor->inspect_object(edited_scene);

        // File system
        editor->select_file("res://icon.png");

        // Resource preview
        // Ref<Texture2D> preview = editor->get_resource_preview(resource);

        // Make visible in editor
        // editor->make_bottom_panel_item_visible(panel);
    }

    void handle_selection_changes() {
        if (!Engine::get_singleton()->is_editor_hint()) {
            return;
        }

        EditorSelection *selection = EditorInterface::get_singleton()->
            get_selection();

        // Connect to selection changed
        selection->connect("selection_changed",
            Callable(this, "on_selection_changed"));

        // Add to selection
        // selection->add_node(node);

        // Clear selection
        // selection->clear();

        // Remove from selection
        // selection->remove_node(node);
    }

    void on_selection_changed() {
        print_line("Editor selection changed");
    }
};

// Custom singleton implementation
class GameManager : public Object {
    GDCLASS(GameManager, Object)

private:
    static GameManager *singleton;

    int score = 0;
    int level = 1;
    Dictionary game_state;

protected:
    static void _bind_methods() {
        ClassDB::bind_method(D_METHOD("get_score"), &GameManager::get_score);
        ClassDB::bind_method(D_METHOD("set_score", "score"),
                           &GameManager::set_score);
        ClassDB::bind_method(D_METHOD("add_score", "points"),
                           &GameManager::add_score);

        ClassDB::bind_method(D_METHOD("get_level"), &GameManager::get_level);
        ClassDB::bind_method(D_METHOD("next_level"), &GameManager::next_level);

        ClassDB::bind_method(D_METHOD("save_game"), &GameManager::save_game);
        ClassDB::bind_method(D_METHOD("load_game"), &GameManager::load_game);

        ADD_PROPERTY(PropertyInfo(Variant::INT, "score"),
                    "set_score", "get_score");
        ADD_PROPERTY(PropertyInfo(Variant::INT, "level", PROPERTY_HINT_RANGE,
                    "1,100"), "", "get_level");

        ADD_SIGNAL(MethodInfo("score_changed",
                             PropertyInfo(Variant::INT, "new_score")));
        ADD_SIGNAL(MethodInfo("level_changed",
                             PropertyInfo(Variant::INT, "new_level")));
    }

public:
    static GameManager *get_singleton() {
        return singleton;
    }

    GameManager() {
        ERR_FAIL_COND(singleton != nullptr);
        singleton = this;
    }

    ~GameManager() {
        ERR_FAIL_COND(singleton != this);
        singleton = nullptr;
    }

    void initialize() {
        // Load saved game state
        load_game();

        // Register with engine
        Engine::get_singleton()->register_singleton(
            Engine::Singleton("GameManager", this));
    }

    void cleanup() {
        // Save game state
        save_game();

        // Unregister from engine
        Engine::get_singleton()->unregister_singleton("GameManager");
    }

    int get_score() const { return score; }

    void set_score(int p_score) {
        score = p_score;
        emit_signal("score_changed", score);
    }

    void add_score(int points) {
        set_score(score + points);
    }

    int get_level() const { return level; }

    void next_level() {
        level++;
        emit_signal("level_changed", level);
    }

    void save_game() {
        Ref<ConfigFile> config;
        config.instantiate();

        config->set_value("game", "score", score);
        config->set_value("game", "level", level);
        config->set_value("game", "state", game_state);

        config->save("user://savegame.cfg");
    }

    void load_game() {
        Ref<ConfigFile> config;
        config.instantiate();

        Error err = config->load("user://savegame.cfg");
        if (err != OK) {
            return;  // No save file
        }

        score = config->get_value("game", "score", 0);
        level = config->get_value("game", "level", 1);
        game_state = config->get_value("game", "state", Dictionary());
    }
};

GameManager *GameManager::singleton = nullptr;

// Register during module initialization
void initialize_game_module(ModuleInitializationLevel p_level) {
    if (p_level == MODULE_INITIALIZATION_LEVEL_SCENE) {
        ClassDB::register_class<GameManager>();

        // Create and register singleton
        GameManager *game_manager = memnew(GameManager);
        game_manager->initialize();
    }
}

void uninitialize_game_module(ModuleInitializationLevel p_level) {
    if (p_level == MODULE_INITIALIZATION_LEVEL_SCENE) {
        if (GameManager::get_singleton()) {
            GameManager::get_singleton()->cleanup();
            memdelete(GameManager::get_singleton());
        }
    }
}

class OptimizedSingletonAccess : public Node {
    GDCLASS(OptimizedSingletonAccess, Node)

private:
    // Cache singleton pointers for hot paths
    Engine *cached_engine = nullptr;
    Input *cached_input = nullptr;
    RenderingServer *cached_rs = nullptr;
    PhysicsServer3D *cached_ps = nullptr;

public:
    virtual void _ready() override {
        // Cache singletons once
        cached_engine = Engine::get_singleton();
        cached_input = Input::get_singleton();
        cached_rs = RenderingServer::get_singleton();
        cached_ps = PhysicsServer3D::get_singleton();
    }

    virtual void _process(double delta) override {
        // Use cached pointers in hot paths
        // Avoids repeated singleton lookups

        if (cached_input->is_action_pressed("move")) {
            // Process movement
        }

        uint64_t frame = cached_engine->get_process_frames();
        // Use frame counter
    }

    void batch_singleton_operations() {
        // Batch operations to reduce API calls
        RenderingServer *rs = cached_rs;

        // Bad: Multiple individual calls
        // rs->set_scenario_setting(scenario, SETTING_1, value1);
        // rs->set_scenario_setting(scenario, SETTING_2, value2);
        // rs->set_scenario_setting(scenario, SETTING_3, value3);

        // Good: Batched update
        Dictionary settings;
        settings[SETTING_1] = value1;
        settings[SETTING_2] = value2;
        settings[SETTING_3] = value3;
        // rs->set_scenario_settings(scenario, settings);  // If available
    }
};