mitogh · Mar 31, 2022 · Mar 18, 2022 · Mar 21, 2022 · Mar 21, 2022 · Mar 23, 2022
diff --git a/modules/images/webp-uploads/load.php b/modules/images/webp-uploads/load.php
@@ -704,3 +704,68 @@ function webp_uploads_update_rest_attachment( WP_REST_Response $response, WP_Pos
 	return rest_ensure_response( $data );
 }
 add_filter( 'rest_prepare_attachment', 'webp_uploads_update_rest_attachment', 10, 3 );
+
+/**
+ * Returns the attachment sources array ordered by filesize.
+ *
+ * @since n.e.x.t
+ *
+ * @param int    $attachment_id The attachment ID.
+ * @param string $size          The attachment size.
+ * @return array The attachment sources array.
+ */
+function webp_uploads_get_attachment_sources( $attachment_id, $size = 'thumbnail' ) {
+	// Check for the sources attribute in attachment metadata.
+	$metadata = wp_get_attachment_metadata( $attachment_id );
+
+	// Return full image size sources.
+	if ( 'full' === $size && ! empty( $metadata['sources'] ) ) {
+		return $metadata['sources'];
+	}
+
+	// Return the resized image sources.
+	if ( ! empty( $metadata['sizes'][ $size ]['sources'] ) ) {
+		return $metadata['sizes'][ $size ]['sources'];
+	}
+
+	// Return an empty array if no sources found.
+	return array();
+}
+
+/**
+ * Filters on `webp_uploads_content_image_mimes` to generate the available mime types for an attachment
+ * and orders them by the smallest filesize first.
+ *
+ * @since n.e.x.t
+ *
+ * @param array $mime_types    The list of mime types that can be used to update images in the content.
+ * @param int   $attachment_id The attachment ID.
+ * @return array Array of available mime types ordered by filesize.
+ */
+function webp_uploads_get_mime_types_by_filesize( $mime_types, $attachment_id ) {
+	$sources = webp_uploads_get_attachment_sources( $attachment_id, 'full' );
+
+	if ( empty( $sources ) ) {
+		return $mime_types;
+	}
+
+	// Remove mime types with filesize of 0.
+	$sources = array_filter(
+		$sources,
+		function( $source ) {
+			return isset( $source['filesize'] ) && $source['filesize'] > 0;
+		}
+	);
+
+	// Order sources by filesize in ascending order.
+	uasort(
+		$sources,
+		function( $a, $b ) {
+			return $a['filesize'] - $b['filesize'];
+		}
+	);
+
+	// Create an array of available mime types ordered by smallest filesize.
+	return array_keys( $sources );
+}
+add_filter( 'webp_uploads_content_image_mimes', 'webp_uploads_get_mime_types_by_filesize', 10, 2 );
diff --git a/tests/modules/images/webp-uploads/webp-uploads-test.php b/tests/modules/images/webp-uploads/webp-uploads-test.php
@@ -836,4 +836,96 @@ function () {
 		$this->assertImageHasSizeSource( $attachment_id, 'thumbnail', 'image/jpeg' );
 		$this->assertImageHasSizeSource( $attachment_id, 'thumbnail', 'image/webp' );
 	}
+
+	/**
+	 * Test webp_uploads_get_mime_types_by_filesize returns smallest filesize, in this case webp.
+	 *
+	 * @test
+	 */
+	public function it_should_return_smaller_webp_mime_type() {
+		// File should generate smallest webp image size.
+		$attachment_id = $this->factory->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/car.jpeg' );
+
+		$mime_types = webp_uploads_get_mime_types_by_filesize( array( 'image/jpeg', 'image/webp' ), $attachment_id, 'the_content' );
+
+		$this->assertIsArray( $mime_types );
+		$this->assertSame( array( 'image/webp', 'image/jpeg' ), $mime_types );
+	}
+
+	/**
+	 * Test webp_uploads_get_mime_types_by_filesize returns smallest filesize, in this case jpeg.
+	 *
+	 * @test
+	 */
+	public function it_should_return_smaller_jpeg_mime_type() {
+		// File should generate smallest jpeg image size.
+		$attachment_id = $this->factory->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/paint.jpeg' );
+
+		// Mock attachment meta data to test when jpeg image is smaller.
+		add_filter(
+			'wp_get_attachment_metadata',
+			function( $data, $attachment_id ) {
+				$data['sources'] = array(
+					'image/jpeg' => array(
+						'file'     => 'paint.jpeg',
+						'filesize' => 1000,
+					),
+					'image/webp' => array(
+						'file'     => 'paint.webp',
+						'filesize' => 2000,
+					),
+				);
+
+				return $data;
+			},
+			10,
+			2
+		);
+
+		$mime_types = webp_uploads_get_mime_types_by_filesize( array( 'image/jpeg', 'image/webp' ), $attachment_id, 'the_content' );
+
+		$this->assertIsArray( $mime_types );
+		$this->assertSame( array( 'image/jpeg', 'image/webp' ), $mime_types );
+	}
+
+	/**
+	 * Test webp_uploads_get_mime_types_by_filesize removes invalid mime types with zero filesize.
+	 *
+	 * @test
+	 */
+	public function it_should_remove_mime_types_with_zero_filesize() {
+		// File should generate smallest jpeg image size.
+		$attachment_id = $this->factory->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/paint.jpeg' );
+
+		// Mock attachment meta data to test mime type with zero filesize.
+		add_filter(
+			'wp_get_attachment_metadata',
+			function( $data, $attachment_id ) {
+				$data['sources'] = array(
+					'image/jpeg'    => array(
+						'file'     => 'paint.jpeg',
+						'filesize' => 1000,
+					),
+					'image/webp'    => array(
+						'file'     => 'paint.webp',
+						'filesize' => 2000,
+					),
+					'image/invalid' => array(
+						'file'     => 'paint.avif',
+						'filesize' => 0,
+					),
+				);
+
+				return $data;
+			},
+			10,
+			2
+		);
+
+		$mime_types = webp_uploads_get_mime_types_by_filesize( array( 'image/jpeg', 'image/webp' ), $attachment_id, 'the_content' );
+
+		$this->assertIsArray( $mime_types );
+		$this->assertNotContains( 'image/invalid', $mime_types );
+		$this->assertSame( array( 'image/jpeg', 'image/webp' ), $mime_types );
+	}
 }