<?php

class remote__data_formatter extends WebServicesFieldFormatter {

  // The default label for this field.
  public static $default_label = 'Remote Data';

  // The list of field types for which this formatter is appropriate.
  public static $field_types = ['remote__data'];

  // The list of default settings for this formatter.
  public static $default_settings = [
    'setting1' => 'default_value',
  ];

  /**
   * @see TripalFieldFormatter::view()
   */
  public function view(&$element, $entity_type, $entity, $langcode, $items, $display) {
    $content = '';

    // Get the settings
    $settings = $display['settings'];
    $field_name = $this->field['field_name'];

    // Get any subfields and the header label.  Shift the array because the
    // results should already be the value of the first entry.
    $rd_field_name = $this->instance['settings']['data_info']['rd_field_name'];
    $subfields = explode(',', $rd_field_name);
    $header_label = $this->getHeaderLabel($subfields);
    $flabel = array_shift($subfields);

    // Get the site logo if one is provided
    $site_logo = $this->instance['settings']['data_info']['site_logo'];
    if ($site_logo) {
      $site_logo = file_load($site_logo);
    }

    // Get the site name where the data came from.
    $site_id_ws = $this->instance['settings']['data_info']['remote_site'];
    $site = db_select('tripal_sites', 'ts')
      ->fields('ts', ['name', 'url'])
      ->condition('ts.id', $site_id_ws)
      ->execute()
      ->fetchObject();

    // Iterate through the results and create a generic table.
    $rows = [];
    $headers = [''];
    foreach ($items as $index => $item) {
      if (!$item['value'] or empty($item['value'])) {
        continue;
      }
      $value = $item['value'];
      $error = $item['error'];
      $warning = $item['warning'];

      // If there is an error or warning then clear the cache for this field
      // so that next time the page is loaded it will try to reload again.
      if ($error or $warning) {
        $cid = "field:TripalEntity:" . $entity->id . ':' . $field_name;
        cache_clear_all($cid, 'cache_field');
        if ($item['admin_message']) {
          $severity = TRIPAL_ERROR;
          if ($warning) {
            $severity = TRIPAL_WARNING;
          }
          $value .= tripal_set_message($item['admin_message'] . 'The query URL was: ' . l($item['query_str'], $item['query_str'], ['attributes' => ['target' => '_blank']]),
            $severity, ['return_html' => TRUE]);
        }
        $rows[] = [$value];
        continue;
      }

      $remote_entity_label = array_key_exists('label', $item) ? $item['remote_entity']['label'] : '';
      $remote_entity_page = $item['remote_entity']['ItemPage'];
      $remote_entity_link = t('View !data on %site',
        [
          '!data' => l('this data', $remote_entity_page, ['attributes' => ['target' => '_blank']]),
          '%site' => $site->name,
        ]);

      // If this is a collection then handle it as a list of members.
      if (array_key_exists('members', $value)) {
        foreach ($value['members'] as $subvalue) {
          $subvalue = $this->refineSubValue($subvalue, $subfields, $header_label);
          $rows[] = [$subvalue];
        }
      }
      else {
        if (count($subfields) > 0) {
          $subvalue = $this->refineSubValue($value, $subfields, $header_label);
          $rows[] = [$subvalue];
        }
        else {
          if (array_key_exists($flabel, $value)) {
            $rows[] = [$value[$flabel]];
          }
          else {
            $value['Link'] = l('View content on ' . $site->name, $remote_entity_page, ['attributes' => ['target' => '_blank']]);
            $rows[] = [$value];
          }
        }
      }
    }

    // TODO: we need to handle paged elements.

    $has_sub_tables = FALSE;
    for ($i = 0; $i < count($rows); $i++) {
      if (is_array($rows[$i][0])) {
        $rows[$i][0] = $this->createTable($rows[$i]);
        $has_sub_tables = TRUE;
      }
      else {
        $rows[$i] = [
          'colspan' => 2,
          'data' => $rows[$i],
        ];
      }
    }

    // If we don't have  tables for each row then we'll put everything into
    // a table.
    if (!$has_sub_tables) {
      $headers = [$header_label . '(s)'];
      $content .= theme_table([
        'header' => $headers,
        'rows' => $rows,
        'attributes' => [
          'class' => 'tripal-remote--data-field-table',
        ],
        'sticky' => FALSE,
        'caption' => "",
        'colgroups' => [],
        'empty' => 'There are no results.',
      ]);
    }
    else {
      for ($i = 0; $i < count($rows); $i++) {
        if (count($rows) > 1) {
          $content .= '<span class="tripal-remote--data-field-table-label">' . $header_label . ' ' . ($i + 1) . '</span>';
        }
        $content .= $rows[$i][0];
      }
    }

    $content .= '<p>';

    if ($site) {
      $content .= t('This content provided by !site.', [
        '!site' => l($site->name, $site->url,
          ['attributes' => ["target" => '_blank']]),
      ]);
    }
    else {
      tripal_report_error('tripal_ws', TRIPAL_ERROR, 'Unable to find remote site while attempting to format results.');
    }

    if (is_object($site_logo)) {
      $content .= '<img class="tripal-remote--data-field-logo" src="' . file_create_url($site_logo->uri) . '"><br/>';
    }
    if (count($items) == 1) {
      $content .= isset($remote_entity_link) ? $remote_entity_link : '';
    }
    $content .= '</p>';

    // Return the content for this field.
    $element[0] = [
      '#type' => 'markup',
      '#markup' => '<div class="tripal-remote--data-field">' . $content . '</div>',
    ];
  }


  /**
   * Retrieves the header label given the subfields criteria.
   *
   * @param $subfields
   *   An array of the sequence of subfields.
   */
  private function getHeaderLabel($subfields) {
    $subfield = array_shift($subfields);
    $header_label = ucwords(preg_replace('/_/', ' ', $subfield));
    if (count($subfields) > 0) {
      $header_label .= ' ' . $this->getHeaderLabel($subfields);
    }
    return $header_label;
  }

  /**
   * Adjusts the items array to contain only the section/subsection desired.
   *
   * The field settings can indicate a field with sub fields that should
   * be displayed (e.g. organism,genus or relationship,clause).  We want
   * to adjust the item to only include what the user requested.
   *
   * @param $values
   * @param $subfields
   */
  private function refineSubValue($values, $subfields) {

    // Remove unwanted elements.
    unset($values['@id']);
    unset($values['@context']);
    unset($values['@type']);
    unset($values['remote_entity']);

    $subfield = array_shift($subfields);
    if (array_key_exists($subfield, $values)) {
      if (is_array($values[$subfield]) and count($subfields) > 0) {
        return $this->refineSubvalue($values[$subfield], $subfields);
      }
      else {
        return $values[$subfield];
      }
    }
    else {
      return $values;
    }
  }

  /**
   * A recursive function for displaying an item in a table.
   *
   * @param $item
   *   An item from the $items array passed to the view() function.
   *
   * @return
   *   An HTML formatted Table.
   */
  private function createTable($item, &$pkey = '', &$rows = [], $depth = 0) {
    foreach ($item as $key => $value) {
      // Skip JSON-LD keys.
      if (preg_match('/^\@/', $key)) {
        continue;
      }
      $key = preg_replace('/_/', ' ', $key);
      $key = ucwords($key);
      if ($pkey) {
        $key = $pkey . ' ' . $key;
      }
      if (is_array($value)) {
        $this->createTable($value, $key, $rows, $depth + 1);
      }
      else {
        $rows[] = [
          'data' => [
            $key,
            $value,
          ],
          'no_striping' => TRUE,
        ];
      }
    }
    if ($depth == 0) {
      $headers = ['Data Type', 'Value'];
      return theme_table([
        'header' => $headers,
        'rows' => $rows,
        'attributes' => [
          'class' => 'tripal-remote--data-field-table',
        ],
        'sticky' => FALSE,
        'caption' => "",
        'colgroups' => [],
        'empty' => 'There are no results.',
      ]);
    }
  }

  /**
   * A recursive function for creating an HTML dictionary list from
   * the results for the item provided.
   *
   * @param $item
   *   An item from the $items array passed to the view() function.
   *
   * @return
   *   An HTML formatted DL.
   */
  private function createDL($item, &$pkey = '', &$content = '', $depth = 0) {
    if ($depth == 0) {
      $content = '<dl class="tripal-remote--data-field-dl">';
    }
    foreach ($item as $key => $value) {
      // Skip JSON-LD keys.
      if (preg_match('/^\@/', $key)) {
        continue;
      }

      $key = preg_replace('/_/', ' ', $key);
      $key = ucwords($key);
      if ($pkey) {
        $key = $pkey . ' ' . $key;
      }
      if (is_array($value)) {
        $this->createDL($value, $key, $content, $depth + 1);
      }
      else {
        $content .= '<dt>' . $key . '&nbsp;:&nbsp;</dt><dd>' . $value . '</dd>';
      }
    }
    if ($depth == 0) {
      $content .= '</dl>';
      return $content;
    }
  }

  /**
   * A recursive function for creating an HTML dictionary list from
   * the results for the item provided.
   *
   * @param $item
   *   An item from the $items array passed to the view() function.
   *
   * @return
   *   An HTML formatted DL.
   */
  private function createNestedDL($item) {
    $content = '<dl>';
    foreach ($item as $key => $value) {
      // Skip JSON-LD keys.
      if (preg_match('/^\@/', $key)) {
        continue;
      }

      $key = preg_replace('/_/', ' ', $key);
      $key = ucwords($key);
      if (is_array($value)) {
        $value = $this->createDL($value);
      }
      $content .= '<dt>' . $key . '</dt><dd>' . $value . '</dd>';
    }
    $content .= '</dl>';
    return $content;
  }

  /**
   * Provides a summary of the formatter settings.
   *
   * This function corresponds to the hook_field_formatter_settings_summary()
   * function of the Drupal Field API.
   *
   * On the 'Manage Display' page of the content type administration page,
   * fields are allowed to provide a settings form.  This settings form can
   * be used to allow the site admin to define how the field should be
   * formatted.  The settings are then available for the formatter()
   * function of this class.  This function provides a text-based description
   * of the settings for the site developer to see.  It appears on the manage
   * display page inline with the field.  A field must always return a
   * value in this function if the settings form gear button is to appear.
   *
   * See the hook_field_formatter_settings_summary() function for more
   * information.
   *
   * @param $field
   * @param $instance
   * @param $view_mode
   *
   * @return string
   *   A string that provides a very brief summary of the field settings
   *   to the user.
   *
   */
  public function settingsSummary($view_mode) {
  }
}