wp_save_image( int $post_id )

function wp_save_image( $post_id ) {
	$_wp_additional_image_sizes = wp_get_additional_image_sizes();

	$return = new stdClass;
	$success = $delete = $scaled = $nocrop = false;
	$post = get_post( $post_id );

	$img = wp_get_image_editor( _load_image_to_edit_path( $post_id, 'full' ) );
	if ( is_wp_error( $img ) ) {
		$return->error = esc_js( __('Unable to create new image.') );
		return $return;
	}

	$fwidth = !empty($_REQUEST['fwidth']) ? intval($_REQUEST['fwidth']) : 0;
	$fheight = !empty($_REQUEST['fheight']) ? intval($_REQUEST['fheight']) : 0;
	$target = !empty($_REQUEST['target']) ? preg_replace('/[^a-z0-9_-]+/i', '', $_REQUEST['target']) : '';
	$scale = !empty($_REQUEST['do']) && 'scale' == $_REQUEST['do'];

	if ( $scale && $fwidth > 0 && $fheight > 0 ) {
		$size = $img->get_size();
		$sX = $size['width'];
		$sY = $size['height'];

		// Check if it has roughly the same w / h ratio.
		$diff = round($sX / $sY, 2) - round($fwidth / $fheight, 2);
		if ( -0.1 < $diff && $diff < 0.1 ) {
			// Scale the full size image.
			if ( $img->resize( $fwidth, $fheight ) )
				$scaled = true;
		}

		if ( !$scaled ) {
			$return->error = esc_js( __('Error while saving the scaled image. Please reload the page and try again.') );
			return $return;
		}
	} elseif ( !empty($_REQUEST['history']) ) {
		$changes = json_decode( wp_unslash($_REQUEST['history']) );
		if ( $changes )
			$img = image_edit_apply_changes($img, $changes);
	} else {
		$return->error = esc_js( __('Nothing to save, the image has not changed.') );
		return $return;
	}

	$meta = wp_get_attachment_metadata($post_id);
	$backup_sizes = get_post_meta( $post->ID, '_wp_attachment_backup_sizes', true );

	if ( !is_array($meta) ) {
		$return->error = esc_js( __('Image data does not exist. Please re-upload the image.') );
		return $return;
	}

	if ( !is_array($backup_sizes) )
		$backup_sizes = array();

	// Generate new filename.
	$path = get_attached_file( $post_id );

	$basename = pathinfo( $path, PATHINFO_BASENAME );
	$dirname = pathinfo( $path, PATHINFO_DIRNAME );
	$ext = pathinfo( $path, PATHINFO_EXTENSION );
	$filename = pathinfo( $path, PATHINFO_FILENAME );
	$suffix = time() . rand(100, 999);

	if ( defined('IMAGE_EDIT_OVERWRITE') && IMAGE_EDIT_OVERWRITE &&
		isset($backup_sizes['full-orig']) && $backup_sizes['full-orig']['file'] != $basename ) {

		if ( 'thumbnail' == $target ) {
			$new_path = "{$dirname}/{$filename}-temp.{$ext}";
		} else {
			$new_path = $path;
		}
	} else {
		while ( true ) {
			$filename = preg_replace( '/-e([0-9]+)$/', '', $filename );
			$filename .= "-e{$suffix}";
			$new_filename = "{$filename}.{$ext}";
			$new_path = "{$dirname}/$new_filename";
			if ( file_exists($new_path) ) {
				$suffix++;
			} else {
				break;
			}
		}
	}

	// Save the full-size file, also needed to create sub-sizes.
	if ( !wp_save_image_file($new_path, $img, $post->post_mime_type, $post_id) ) {
		$return->error = esc_js( __('Unable to save the image.') );
		return $return;
	}

	if ( 'nothumb' === $target || 'all' === $target || 'full' === $target || $scaled ) {
		$tag = false;
		if ( isset( $backup_sizes['full-orig'] ) ) {
			if ( ( ! defined( 'IMAGE_EDIT_OVERWRITE' ) || ! IMAGE_EDIT_OVERWRITE ) && $backup_sizes['full-orig']['file'] !== $basename ) {
				$tag = "full-$suffix";
			}
		} else {
			$tag = 'full-orig';
		}

		if ( $tag ) {
			$backup_sizes[$tag] = array('width' => $meta['width'], 'height' => $meta['height'], 'file' => $basename );
		}
		$success = ( $path === $new_path ) || update_attached_file( $post_id, $new_path );

		$meta['file'] = _wp_relative_upload_path( $new_path );

		$size = $img->get_size();
		$meta['width'] = $size['width'];
		$meta['height'] = $size['height'];

		if ( $success && ('nothumb' == $target || 'all' == $target) ) {
			$sizes = get_intermediate_image_sizes();
			if ( 'nothumb' == $target )
				$sizes = array_diff( $sizes, array('thumbnail') );
		}

		$return->fw = $meta['width'];
		$return->fh = $meta['height'];
	} elseif ( 'thumbnail' == $target ) {
		$sizes = array( 'thumbnail' );
		$success = $delete = $nocrop = true;
	}

	/*
	 * We need to remove any existing resized image files because
	 * a new crop or rotate could generate different sizes (and hence, filenames),
	 * keeping the new resized images from overwriting the existing image files.
	 * https://core.trac.wordpress.org/ticket/32171
	 */
	if ( defined( 'IMAGE_EDIT_OVERWRITE' ) && IMAGE_EDIT_OVERWRITE && ! empty( $meta['sizes'] ) ) {
		foreach ( $meta['sizes'] as $size ) {
			if ( ! empty( $size['file'] ) && preg_match( '/-e[0-9]{13}-/', $size['file'] ) ) {
				$delete_file = path_join( $dirname, $size['file'] );
				wp_delete_file( $delete_file );
			}
		}
	}

	if ( isset( $sizes ) ) {
		$_sizes = array();

		foreach ( $sizes as $size ) {
			$tag = false;
			if ( isset( $meta['sizes'][$size] ) ) {
				if ( isset($backup_sizes["$size-orig"]) ) {
					if ( ( !defined('IMAGE_EDIT_OVERWRITE') || !IMAGE_EDIT_OVERWRITE ) && $backup_sizes["$size-orig"]['file'] != $meta['sizes'][$size]['file'] )
						$tag = "$size-$suffix";
				} else {
					$tag = "$size-orig";
				}

				if ( $tag )
					$backup_sizes[$tag] = $meta['sizes'][$size];
			}

			if ( isset( $_wp_additional_image_sizes[ $size ] ) ) {
				$width  = intval( $_wp_additional_image_sizes[ $size ]['width'] );
				$height = intval( $_wp_additional_image_sizes[ $size ]['height'] );
				$crop   = ( $nocrop ) ? false : $_wp_additional_image_sizes[ $size ]['crop'];
			} else {
				$height = get_option( "{$size}_size_h" );
				$width  = get_option( "{$size}_size_w" );
				$crop   = ( $nocrop ) ? false : get_option( "{$size}_crop" );
			}

			$_sizes[ $size ] = array( 'width' => $width, 'height' => $height, 'crop' => $crop );
		}

		$meta['sizes'] = array_merge( $meta['sizes'], $img->multi_resize( $_sizes ) );
	}

	unset( $img );

	if ( $success ) {
		wp_update_attachment_metadata( $post_id, $meta );
		update_post_meta( $post_id, '_wp_attachment_backup_sizes', $backup_sizes);

		if ( $target == 'thumbnail' || $target == 'all' || $target == 'full' ) {
			// Check if it's an image edit from attachment edit screen
			if ( ! empty( $_REQUEST['context'] ) && 'edit-attachment' == $_REQUEST['context'] ) {
				$thumb_url = wp_get_attachment_image_src( $post_id, array( 900, 600 ), true );
				$return->thumbnail = $thumb_url[0];
			} else {
				$file_url = wp_get_attachment_url($post_id);
				if ( ! empty( $meta['sizes']['thumbnail'] ) && $thumb = $meta['sizes']['thumbnail'] ) {
					$return->thumbnail = path_join( dirname($file_url), $thumb['file'] );
				} else {
					$return->thumbnail = "$file_url?w=128&h=128";
				}
			}
		}
	} else {
		$delete = true;
	}

	if ( $delete ) {
		wp_delete_file( $new_path );
	}

	$return->msg = esc_js( __('Image saved') );
	return $return;
}