QMK Layer Cycling key

/*  https://www.reddit.com/r/olkb/comments/z6lm89/help_with_layer_switching_stack_overflow_the_key/
 *  Code to create a button that will cycle through the layers, looping around to the beginning.
 *  This can go into keymap.c
 */

enum layer_names {
    _LAYER0,
    _LAYER1,
    _LAYER2,
    NUM_LAYERS,  // Leave this at the end of the list
};

enum custom_keycodes {
    CYCLE_LAYERS = SAFE_RANGE,  // Rename CYCLE_LAYERS to whatever you want, but leave SAFE_RANGE
    // Other macros...
};

/* This function is called automatically any time there is a layer change. */
layer_state_t layer_state_set_user(layer_state_t state) {
    switch(get_highest_layer(state) {
        case _LAYER0:                   // If _LAYER0 is the highest active layer
            rgblight_setrgb(RGB_RED);   // Set RGB to RED
            break;
        case _LAYER1:                   // If _LAYER1 is the highest active layer
            rgblight_setrgb(RGB_BLUE);  // Set RGB to BLUE
            break;
        case _LAYER2:                   // If _LAYER2 is the highest active layer
            rgblight_setrgb(RGB_GREEN); // Set RGB to GREEN
            break;
        default:
            // instructions for any other layer
            break;
    }
    return true;
}


bool process_record_user(uint16_t keycode, keyrecord_t *record) {
    switch (keycode) {
        case CYCLE_LAYERS:
            if (record->event.pressed) {
                // Go to the next layer up, looping around to the beginning when the end is reached
                uint8_t next_layer = (get_highest_layer(layer_state) + 1) % NUM_LAYERS;
                layer_move(next_layer);  // layer_move(layer) is the same as the TO(layer) keycode
                break;
            }
    }
    return true;
}