generate thumbnails for oembed able URL documents

src/classes/class-tainacan-embed.php

@@ -78,4 +78,27 @@ class Embed {
 		return $pdf;
 	}
 	
+	/**
+	 * Retrieves the thumbnail URL, if provided, for a given URL
+	 * 
+	 * @param  $string $url the URL for the content
+	 * @return string|null  The thumbnail URL or null on failure
+	 */
+	public function oembed_get_thumbnail($url) {
+		
+		add_filter( 'oembed_dataparse', ['\Tainacan\Embed', 'oembed_get_thumbnail_filter'], 10, 3);
+		return wp_oembed_get($url);
+		remove_filter( 'oembed_dataparse', ['\Tainacan\Embed', 'oembed_get_thumbnail_filter']);
+		
+	}
+	public static function oembed_get_thumbnail_filter($return, $data, $url) {
+		
+		if ( isset($data->thumbnail_url) ) {
+			return $data->thumbnail_url;
+		}
+		
+		return null;
+		
+	}
+	
 }

src/classes/class-tainacan-media.php

@@ -0,0 +1,91 @@
+<?php
+namespace Tainacan;
+
+/**
+ * Class withe helpful methods to handle media in Tainacan
+ */
+class Media {
+	
+	private static $instance = null;
+
+    public static function get_instance() {
+        if(!isset(self::$instance)) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+	
+	protected function __construct() {
+		
+		
+	}
+
+	/**
+	 * Insert an attachment from an URL address.
+	 *
+	 * @param  String $url 
+	 * @param  Int    $post_id (optional) the post this attachement should be attached to. empty for none
+	 * @return Int|false    Attachment ID. False on failure
+	 */
+	public function insert_attachment_from_url($url, $post_id = null) {
+		if( !class_exists( '\WP_Http' ) )
+			include_once( ABSPATH . WPINC . '/class-http.php' );
+
+		$http = new \WP_Http();
+		
+		$response = $http->request( $url );
+		
+		if( !is_array($response) || !isset($response['response']) || $response['response']['code'] != 200 ) {
+			return false;
+		}
+		
+		return $this->insert_attachment_from_blob($response['body'], basename($url), $post_id);
+		
+	}
+	
+	/**
+	 * Insert an attachment from an URL address.
+	 *
+	 * @param  blob $blob bitstream of the attachment
+	 * @param  String $filename The filename that will be created
+	 * @param  Int    $post_id (optional) the post this attachement should be attached to. empty for none
+	 * @return Int|false    Attachment ID. False on failure
+	 */
+	public function insert_attachment_from_blob($blob, $filename, $post_id = null) {
+
+		$upload = wp_upload_bits( $filename, null, $blob );
+		if( !empty( $upload['error'] ) ) {
+			return false;
+		}
+
+		$file_path = $upload['file'];
+		$file_name = basename( $file_path );
+		$file_type = wp_check_filetype( $file_name, null );
+		$attachment_title = sanitize_file_name( pathinfo( $file_name, PATHINFO_FILENAME ) );
+		$wp_upload_dir = wp_upload_dir();
+
+		$post_info = array(
+			'guid'				=> $wp_upload_dir['url'] . '/' . $file_name, 
+			'post_mime_type'	=> $file_type['type'],
+			'post_title'		=> $attachment_title,
+			'post_content'		=> '',
+			'post_status'		=> 'inherit',
+		);
+
+		// Create the attachment
+		$attach_id = wp_insert_attachment( $post_info, $file_path, $post_id );
+
+		// Include image.php
+		require_once( ABSPATH . 'wp-admin/includes/image.php' );
+
+		// Define attachment metadata
+		$attach_data = wp_generate_attachment_metadata( $attach_id, $file_path );
+
+		// Assign metadata to attachment
+		wp_update_attachment_metadata( $attach_id,  $attach_data );
+
+		return $attach_id;
+	}
+	
+}

src/classes/repositories/class-tainacan-items.php

@@ -391,6 +391,24 @@ class Items extends Repository {
 			if ( wp_attachment_is_image( $item->get_document() ) ) {
 				return $item->get_document();
 			}
+		} elseif ( $item->get_document_type() == 'url' ) {
+			
+			$TainacanEmbed = \Tainacan\Embed::get_instance();
+			if ( $thumb_url = $TainacanEmbed->oembed_get_thumbnail( $item->get_document() ) ) {
+				$meta_key = '_' . $thumb_url . '__thumb';
+				
+				$existing_thumb = get_post_meta($item->get_id(), $meta_key, true);
+				
+				if ( is_numeric( $existing_thumb ) ) {
+					return $existing_thumb;
+				} else {
+					$TainacanMedia = \Tainacan\Media::get_instance();
+					$thumb_id = $TainacanMedia->insert_attachment_from_url($thumb_url, $item->get_id());
+					update_post_meta($item->get_id(), $meta_key, $thumb_id);
+					return $thumb_id;
+				}
+			}
+			
 		}
 		
 		return $thumb_id;