class Media

class Media extends EditorialContentEntityBase implements MediaInterface {
    use EntityOwnerTrait;
    use StringTranslationTrait;
    
    /**
     * {@inheritdoc}
     */
    public function getName() {
        $name = $this->getEntityKey('label');
        if (empty($name)) {
            $media_source = $this->getSource();
            return $media_source->getMetadata($this, $media_source->getPluginDefinition()['default_name_metadata_attribute']);
        }
        return $name;
    }
    
    /**
     * {@inheritdoc}
     */
    public function label() {
        return $this->getName();
    }
    
    /**
     * {@inheritdoc}
     */
    public function setName($name) {
        return $this->set('name', $name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCreatedTime() {
        return $this->get('created')->value;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setCreatedTime($timestamp) {
        return $this->set('created', $timestamp);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSource() {
        return $this->bundle->entity
            ->getSource();
    }
    
    /**
     * Update the thumbnail for the media item.
     *
     * @param bool $from_queue
     *   Specifies whether the thumbnail update is triggered from the queue.
     *
     * @return \Drupal\media\MediaInterface
     *   The updated media item.
     *
     * @internal
     *
     * @todo There has been some disagreement about how to handle updates to
     *   thumbnails. We need to decide on what the API will be for this.
     *   https://www.drupal.org/node/2878119
     */
    protected function updateThumbnail($from_queue = FALSE) {
        $this->thumbnail->target_id = $this->loadThumbnail($this->getThumbnailUri($from_queue))
            ->id();
        $this->thumbnail->width = $this->getThumbnailWidth($from_queue);
        $this->thumbnail->height = $this->getThumbnailHeight($from_queue);
        // Set the thumbnail alt.
        $media_source = $this->getSource();
        $plugin_definition = $media_source->getPluginDefinition();
        $this->thumbnail->alt = '';
        if (!empty($plugin_definition['thumbnail_alt_metadata_attribute'])) {
            $this->thumbnail->alt = $media_source->getMetadata($this, $plugin_definition['thumbnail_alt_metadata_attribute']);
        }
        return $this;
    }
    
    /**
     * Loads the file entity for the thumbnail.
     *
     * If the file entity does not exist, it will be created.
     *
     * @param string $thumbnail_uri
     *   (optional) The URI of the thumbnail, used to load or create the file
     *   entity. If omitted, the default thumbnail URI will be used.
     *
     * @return \Drupal\file\FileInterface
     *   The thumbnail file entity.
     */
    protected function loadThumbnail($thumbnail_uri = NULL) {
        $values = [
            'uri' => $thumbnail_uri ?: $this->getDefaultThumbnailUri(),
        ];
        $file_storage = $this->entityTypeManager()
            ->getStorage('file');
        $existing = $file_storage->loadByProperties($values);
        if ($existing) {
            $file = reset($existing);
        }
        else {
            
            /** @var \Drupal\file\FileInterface $file */
            $file = $file_storage->create($values);
            if ($owner = $this->getOwner()) {
                $file->setOwner($owner);
            }
            $file->setPermanent();
            $file->save();
        }
        return $file;
    }
    
    /**
     * Returns the URI of the default thumbnail.
     *
     * @return string
     *   The default thumbnail URI.
     */
    protected function getDefaultThumbnailUri() {
        $default_thumbnail_filename = $this->getSource()
            ->getPluginDefinition()['default_thumbnail_filename'];
        return \Drupal::config('media.settings')->get('icon_base_uri') . '/' . $default_thumbnail_filename;
    }
    
    /**
     * Updates the queued thumbnail for the media item.
     *
     * @return \Drupal\media\MediaInterface
     *   The updated media item.
     *
     * @internal
     *
     * @todo If the need arises in contrib, consider making this a public API,
     *   by adding an interface that extends MediaInterface.
     */
    public function updateQueuedThumbnail() {
        $this->updateThumbnail(TRUE);
        return $this;
    }
    
    /**
     * Gets the URI for the thumbnail of a media item.
     *
     * If thumbnail fetching is queued, new media items will use the default
     * thumbnail, and existing media items will use the current thumbnail, until
     * the queue is processed and the updated thumbnail has been fetched.
     * Otherwise, the new thumbnail will be fetched immediately.
     *
     * @param bool $from_queue
     *   Specifies whether the thumbnail is being fetched from the queue.
     *
     * @return string
     *   The file URI for the thumbnail of the media item.
     *
     * @internal
     */
    protected function getThumbnailUri($from_queue) {
        $thumbnails_queued = $this->bundle->entity
            ->thumbnailDownloadsAreQueued();
        if ($thumbnails_queued && $this->isNew()) {
            return $this->getDefaultThumbnailUri();
        }
        elseif ($thumbnails_queued && !$from_queue) {
            return $this->get('thumbnail')->entity
                ->getFileUri();
        }
        $source = $this->getSource();
        return $source->getMetadata($this, $source->getPluginDefinition()['thumbnail_uri_metadata_attribute']);
    }
    
    /**
     * Gets the width of the thumbnail of a media item.
     *
     * @param bool $from_queue
     *   Specifies whether the thumbnail is being fetched from the queue.
     *
     * @return int|null
     *   The width of the thumbnail of the media item or NULL if the media is new
     *   and the thumbnails are set to be downloaded in a queue.
     *
     * @internal
     */
    protected function getThumbnailWidth(bool $from_queue) : ?int {
        $thumbnails_queued = $this->bundle->entity
            ->thumbnailDownloadsAreQueued();
        if ($thumbnails_queued && $this->isNew()) {
            return NULL;
        }
        elseif ($thumbnails_queued && !$from_queue) {
            return $this->get('thumbnail')->width;
        }
        $source = $this->getSource();
        return $source->getMetadata($this, $source->getPluginDefinition()['thumbnail_width_metadata_attribute']);
    }
    
    /**
     * Gets the height of the thumbnail of a media item.
     *
     * @param bool $from_queue
     *   Specifies whether the thumbnail is being fetched from the queue.
     *
     * @return int|null
     *   The height of the thumbnail of the media item or NULL if the media is new
     *   and the thumbnails are set to be downloaded in a queue.
     *
     * @internal
     */
    protected function getThumbnailHeight(bool $from_queue) : ?int {
        $thumbnails_queued = $this->bundle->entity
            ->thumbnailDownloadsAreQueued();
        if ($thumbnails_queued && $this->isNew()) {
            return NULL;
        }
        elseif ($thumbnails_queued && !$from_queue) {
            return $this->get('thumbnail')->height;
        }
        $source = $this->getSource();
        return $source->getMetadata($this, $source->getPluginDefinition()['thumbnail_height_metadata_attribute']);
    }
    
    /**
     * Determines if the source field value has changed.
     *
     * The comparison uses MediaSourceInterface::getSourceFieldValue() to ensure
     * that the correct property from the source field is used.
     *
     * @return bool
     *   TRUE if the source field value changed, FALSE otherwise.
     *
     * @see \Drupal\media\MediaSourceInterface::getSourceFieldValue()
     *
     * @internal
     */
    protected function hasSourceFieldChanged() {
        $source = $this->getSource();
        return isset($this->original) && $source->getSourceFieldValue($this) !== $source->getSourceFieldValue($this->original);
    }
    
    /**
     * Determines if the thumbnail should be updated for a media item.
     *
     * @param bool $is_new
     *   Specifies whether the media item is new.
     *
     * @return bool
     *   TRUE if the thumbnail should be updated, FALSE otherwise.
     */
    protected function shouldUpdateThumbnail($is_new = FALSE) {
        // Update thumbnail if we don't have a thumbnail yet or when the source
        // field value changes.
        return !$this->get('thumbnail')->entity || $is_new || $this->hasSourceFieldChanged();
    }
    
    /**
     * {@inheritdoc}
     */
    public function preSave(EntityStorageInterface $storage) {
        parent::preSave($storage);
        if (!$this->getOwner()) {
            $this->setOwnerId(0);
        }
        // If no thumbnail has been explicitly set, use the default thumbnail.
        if ($this->get('thumbnail')
            ->isEmpty()) {
            $this->thumbnail->target_id = $this->loadThumbnail()
                ->id();
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function postSave(EntityStorageInterface $storage, $update = TRUE) {
        parent::postSave($storage, $update);
        $is_new = !$update;
        foreach ($this->translations as $langcode => $data) {
            if ($this->hasTranslation($langcode)) {
                $translation = $this->getTranslation($langcode);
                if ($translation->bundle->entity
                    ->thumbnailDownloadsAreQueued() && $translation->shouldUpdateThumbnail($is_new)) {
                    \Drupal::queue('media_entity_thumbnail')->createItem([
                        'id' => $translation->id(),
                    ]);
                }
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function preSaveRevision(EntityStorageInterface $storage, \stdClass $record) {
        parent::preSaveRevision($storage, $record);
        if (!$this->isNewRevision() && isset($this->original) && empty($record->revision_log_message)) {
            // If we are updating an existing media item without adding a
            // new revision, we need to make sure $entity->revision_log_message is
            // reset whenever it is empty.
            // Therefore, this code allows us to avoid clobbering an existing log
            // entry with an empty one.
            $this->setRevisionLogMessage($this->original
                ->getRevisionLogMessage());
        }
    }
    
    /**
     * Sets the media entity's field values from the source's metadata.
     *
     * Fetching the metadata could be slow (e.g., if requesting it from a remote
     * API), so this is called by \Drupal\media\MediaStorage::save() prior to it
     * beginning the database transaction, whereas static::preSave() executes
     * after the transaction has already started.
     *
     * @internal
     *   Expose this as an API in
     *   https://www.drupal.org/project/drupal/issues/2992426.
     */
    public function prepareSave() {
        // @todo If the source plugin talks to a remote API (e.g. oEmbed), this code
        // might be performing a fair number of HTTP requests. This is dangerously
        // brittle and should probably be handled by a queue, to avoid doing HTTP
        // operations during entity save. See
        // https://www.drupal.org/project/drupal/issues/2976875 for more.
        // In order for metadata to be mapped correctly, $this->original must be
        // set. However, that is only set once parent::save() is called, so work
        // around that by setting it here.
        if (!isset($this->original) && ($id = $this->id())) {
            $this->original = $this->entityTypeManager()
                ->getStorage('media')
                ->loadUnchanged($id);
        }
        $media_source = $this->getSource();
        foreach ($this->translations as $langcode => $data) {
            if ($this->hasTranslation($langcode)) {
                $translation = $this->getTranslation($langcode);
                // Try to set fields provided by the media source and mapped in
                // media type config.
                foreach ($translation->bundle->entity
                    ->getFieldMap() as $metadata_attribute_name => $entity_field_name) {
                    // Only save value in the entity if the field is empty or if the
                    // source field changed.
                    if ($translation->hasField($entity_field_name) && ($translation->get($entity_field_name)
                        ->isEmpty() || $translation->hasSourceFieldChanged())) {
                        $translation->set($entity_field_name, $media_source->getMetadata($translation, $metadata_attribute_name));
                    }
                }
                // Try to set a default name for this media item if no name is provided.
                if ($translation->get('name')
                    ->isEmpty()) {
                    $translation->setName($translation->getName());
                }
                // Set thumbnail.
                if ($translation->shouldUpdateThumbnail($this->isNew())) {
                    $translation->updateThumbnail();
                }
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function validate() {
        $media_source = $this->getSource();
        if ($media_source instanceof MediaSourceEntityConstraintsInterface) {
            $entity_constraints = $media_source->getEntityConstraints();
            $this->getTypedData()
                ->getDataDefinition()
                ->setConstraints($entity_constraints);
        }
        if ($media_source instanceof MediaSourceFieldConstraintsInterface) {
            $source_field_name = $media_source->getConfiguration()['source_field'];
            $source_field_constraints = $media_source->getSourceFieldConstraints();
            $this->get($source_field_name)
                ->getDataDefinition()
                ->setConstraints($source_field_constraints);
        }
        return parent::validate();
    }
    
    /**
     * {@inheritdoc}
     */
    public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
        $fields = parent::baseFieldDefinitions($entity_type);
        $fields += static::ownerBaseFieldDefinitions($entity_type);
        $fields['name'] = BaseFieldDefinition::create('string')->setLabel(t('Name'))
            ->setRequired(TRUE)
            ->setTranslatable(TRUE)
            ->setRevisionable(TRUE)
            ->setDefaultValue('')
            ->setSetting('max_length', 255)
            ->setDisplayOptions('form', [
            'type' => 'string_textfield',
            'weight' => -5,
        ])
            ->setDisplayConfigurable('form', TRUE)
            ->setDisplayConfigurable('view', TRUE);
        $fields['thumbnail'] = BaseFieldDefinition::create('image')->setLabel(t('Thumbnail'))
            ->setDescription(t('The thumbnail of the media item.'))
            ->setRevisionable(TRUE)
            ->setTranslatable(TRUE)
            ->setDisplayOptions('view', [
            'type' => 'image',
            'weight' => 5,
            'label' => 'hidden',
            'settings' => [
                'image_style' => 'thumbnail',
            ],
        ])
            ->setDisplayConfigurable('view', TRUE)
            ->setReadOnly(TRUE);
        $fields['uid']->setLabel(t('Authored by'))
            ->setDescription(t('The user ID of the author.'))
            ->setRevisionable(TRUE)
            ->setDisplayOptions('form', [
            'type' => 'entity_reference_autocomplete',
            'weight' => 5,
            'settings' => [
                'match_operator' => 'CONTAINS',
                'size' => '60',
                'autocomplete_type' => 'tags',
                'placeholder' => '',
            ],
        ])
            ->setDisplayConfigurable('form', TRUE)
            ->setDisplayOptions('view', [
            'label' => 'hidden',
            'type' => 'author',
            'weight' => 0,
        ])
            ->setDisplayConfigurable('view', TRUE);
        $fields['status']->setDisplayOptions('form', [
            'type' => 'boolean_checkbox',
            'settings' => [
                'display_label' => TRUE,
            ],
            'weight' => 100,
        ])
            ->setDisplayConfigurable('form', TRUE);
        $fields['created'] = BaseFieldDefinition::create('created')->setLabel(t('Authored on'))
            ->setDescription(t('The time the media item was created.'))
            ->setTranslatable(TRUE)
            ->setRevisionable(TRUE)
            ->setDefaultValueCallback(static::class . '::getRequestTime')
            ->setDisplayOptions('form', [
            'type' => 'datetime_timestamp',
            'weight' => 10,
        ])
            ->setDisplayConfigurable('form', TRUE)
            ->setDisplayOptions('view', [
            'label' => 'hidden',
            'type' => 'timestamp',
            'weight' => 0,
        ])
            ->setDisplayConfigurable('view', TRUE);
        $fields['changed'] = BaseFieldDefinition::create('changed')->setLabel(t('Changed'))
            ->setDescription(t('The time the media item was last edited.'))
            ->setTranslatable(TRUE)
            ->setRevisionable(TRUE);
        return $fields;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getRequestTime() {
        return \Drupal::time()->getRequestTime();
    }

}