<?php

namespace Drupal\text\Plugin\Field\FieldType;

use Drupal\Component\Utility\Random;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\FieldItemBase;
use Drupal\Core\Field\FieldStorageDefinitionInterface;
use Drupal\Core\TypedData\DataDefinition;

/**
 * Base class for 'text' configurable field types.
 */
abstract class TextItemBase extends FieldItemBase {

  /**
   * {@inheritdoc}
   */
  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
    $properties['value'] = DataDefinition::create('string')
      ->setLabel(t('Text'))
      ->setRequired(TRUE);

    $properties['format'] = DataDefinition::create('filter_format')
      ->setLabel(t('Text format'));

    $properties['processed'] = DataDefinition::create('string')
      ->setLabel(t('Processed text'))
      ->setDescription(t('The text with the text format applied.'))
      ->setComputed(TRUE)
      ->setClass('\Drupal\text\TextProcessed')
      ->setSetting('text source', 'value')
      ->setInternal(FALSE);

    return $properties;
  }

  /**
   * {@inheritdoc}
   */
  public function applyDefaultValue($notify = TRUE) {
    // @todo: Add in the filter default format here.
    $this->setValue(['format' => NULL], $notify);
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function isEmpty() {
    $value = $this->get('value')->getValue();
    return $value === NULL || $value === '';
  }

  /**
   * {@inheritdoc}
   */
  public function onChange($property_name, $notify = TRUE) {
    // Unset processed properties that are affected by the change.
    foreach ($this->definition->getPropertyDefinitions() as $property => $definition) {
      if ($definition->getClass() == '\Drupal\text\TextProcessed') {
        if ($property_name == 'format' || ($definition->getSetting('text source') == $property_name)) {
          $this->writePropertyValue($property, NULL);
        }
      }
    }
    parent::onChange($property_name, $notify);
  }

  /**
   * {@inheritdoc}
   */
  public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
    $random = new Random();
    $settings = $field_definition->getSettings();

    if (empty($settings['max_length'])) {
      // Textarea handling
      $value = $random->paragraphs();
    }
    else {
      // Textfield handling.
      $value = substr($random->sentences(mt_rand(1, $settings['max_length'] / 3), FALSE), 0, $settings['max_length']);
    }

    $values = [
      'value' => $value,
      'summary' => $value,
      'format' => filter_fallback_format(),
    ];
    return $values;
  }

}