class TipPluginBase

abstract class TipPluginBase extends PluginBase implements TipPluginInterface {
    
    /**
     * The label which is used for render of this tip.
     *
     * @var string
     */
    protected $label;
    
    /**
     * Allows tips to take more priority that others.
     *
     * @var string
     */
    protected $weight;
    
    /**
     * {@inheritdoc}
     */
    public function id() {
        return $this->get('id');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getLabel() {
        return $this->get('label');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getWeight() {
        return $this->get('weight');
    }
    
    /**
     * {@inheritdoc}
     */
    public function get($key) {
        if (!empty($this->configuration[$key])) {
            return $this->configuration[$key];
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function set($key, $value) {
        $this->configuration[$key] = $value;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getLocation() : ?string {
        $location = $this->get('position');
        // The location values accepted by PopperJS, the library used for
        // positioning the tip.
        assert(in_array(trim($location ?? ''), [
            'auto',
            'auto-start',
            'auto-end',
            'top',
            'top-start',
            'top-end',
            'bottom',
            'bottom-start',
            'bottom-end',
            'right',
            'right-start',
            'right-end',
            'left',
            'left-start',
            'left-end',
            '',
        ], TRUE), "{$location} is not a valid Tour Tip position value");
        return $location;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSelector() : ?string {
        return $this->get('selector');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getBody() : array {
        return [];
    }

}