class ManyToOne

class ManyToOne extends ArgumentPluginBase {
  
  /**
   * {@inheritdoc}
   */
  public function init(ViewExecutable $view, DisplayPluginBase $display, array &$options = NULL) {
    parent::init($view, $display, $options);
    $this->helper = new ManyToOneHelper($this);
    // Ensure defaults for these, during summaries and stuff:
    $this->operator = 'or';
    $this->value = [];
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['break_phrase'] = [
      'default' => FALSE,
    ];
    $options['add_table'] = [
      'default' => FALSE,
    ];
    $options['require_value'] = [
      'default' => FALSE,
    ];
    if (isset($this->helper)) {
      $this->helper
        ->defineOptions($options);
    }
    else {
      $helper = new ManyToOneHelper($this);
      $helper->defineOptions($options);
    }
    return $options;
  }
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    parent::buildOptionsForm($form, $form_state);
    // allow + for or, , for and
    $form['break_phrase'] = [
      '#type' => 'checkbox',
      '#title' => $this->t('Allow multiple values'),
      '#description' => $this->t('If selected, users can enter multiple values in the form of 1+2+3 (for OR) or 1,2,3 (for AND).'),
      '#default_value' => !empty($this->options['break_phrase']),
      '#group' => 'options][more',
    ];
    $form['add_table'] = [
      '#type' => 'checkbox',
      '#title' => $this->t('Allow multiple filter values to work together'),
      '#description' => $this->t('If selected, multiple instances of this filter can work together, as though multiple values were supplied to the same filter. This setting is not compatible with the "Reduce duplicates" setting.'),
      '#default_value' => !empty($this->options['add_table']),
      '#group' => 'options][more',
    ];
    $form['require_value'] = [
      '#type' => 'checkbox',
      '#title' => $this->t('Do not display items with no value in summary'),
      '#default_value' => !empty($this->options['require_value']),
      '#group' => 'options][more',
    ];
    $this->helper
      ->buildOptionsForm($form, $form_state);
  }
  
  /**
   * {@inheritdoc}
   */
  public function ensureMyTable() {
    $this->helper
      ->ensureMyTable();
  }
  public function query($group_by = FALSE) {
    $empty = FALSE;
    if (isset($this->definition['zero is null']) && $this->definition['zero is null']) {
      if (empty($this->argument)) {
        $empty = TRUE;
      }
    }
    else {
      if (!isset($this->argument)) {
        $empty = TRUE;
      }
    }
    if ($empty) {
      parent::ensureMyTable();
      $this->query
        ->addWhere(0, "{$this->tableAlias}.{$this->realField}", NULL, 'IS NULL');
      return;
    }
    if (!empty($this->options['break_phrase'])) {
      $force_int = !empty($this->definition['numeric']);
      $this->unpackArgumentValue($force_int);
    }
    else {
      $this->value = [
        $this->argument,
      ];
      $this->operator = 'or';
    }
    $this->helper
      ->addFilter();
  }
  public function title() {
    if (!$this->argument) {
      return !empty($this->definition['empty field name']) ? $this->definition['empty field name'] : $this->t('Uncategorized');
    }
    if (!empty($this->options['break_phrase'])) {
      $force_int = !empty($this->definition['numeric']);
      $this->unpackArgumentValue($force_int);
    }
    else {
      $this->value = [
        $this->argument,
      ];
      $this->operator = 'or';
    }
    // @todo -- both of these should check definition for alternate keywords.
    if (empty($this->value)) {
      return !empty($this->definition['empty field name']) ? $this->definition['empty field name'] : $this->t('Uncategorized');
    }
    if ($this->value === [
      -1,
    ]) {
      return !empty($this->definition['invalid input']) ? $this->definition['invalid input'] : $this->t('Invalid input');
    }
    return implode($this->operator == 'or' ? ' + ' : ', ', $this->titleQuery());
  }
  protected function summaryQuery() {
    $field = $this->table . '.' . $this->field;
    $join = $this->getJoin();
    if (!empty($this->options['require_value'])) {
      $join->type = 'INNER';
    }
    if (empty($this->options['add_table']) || empty($this->view->many_to_one_tables[$field])) {
      $this->tableAlias = $this->query
        ->ensureTable($this->table, $this->relationship, $join);
    }
    else {
      $this->tableAlias = $this->helper
        ->summaryJoin();
    }
    // Add the field.
    $this->base_alias = $this->query
      ->addField($this->tableAlias, $this->realField);
    $this->summaryNameField();
    return $this->summaryBasics();
  }
  public function summaryArgument($data) {
    $value = $data->{$this->base_alias};
    if (empty($value)) {
      $value = 0;
    }
    return $value;
  }
  
  /**
   * Override for specific title lookups.
   */
  public function titleQuery() {
    return $this->value;
  }

}