Update a BuddyPress/BuddyBoss avatar from an external URL

update_buddypress_avatar_from_external_url.php

<?php
/**
 * Updates the avatar of a user based on the user's ID.
 *
 * This function downloads an image from an external URL and saves it
 * as the user's avatar. If the image is not square, it crops it to a
 * square shape before saving.
 *
 * @since     1.0.0
 * @access    public
 * @static
 *
 * @global    WP_Filesystem $wp_filesystem WordPress filesystem API.
 *
 * @param     int $user_id The ID of the user whose avatar is to be updated.
 * @return    mixed WP_Error object on failure, or string on success.
 */
function update_buddypress_avatar_from_external_url( $user_id ) {
	$user = get_user_by( 'id', $user_id );

	if ( empty( $user ) ) {
		return new WP_Error( 'invalid_user', 'Invalid user ID' );
	}

	$external_avatar_url = 'https://example.com/avatar.jpg'; // Replace with your external avatar URL.

	// Fetch the last updated avatar URL.
	$last_avatar_url      = get_user_meta( $user_id, 'last_avatar_url', true );
	$existing_avatar_path = get_user_meta( $user_id, 'existing_avatar_path', true );

	// Check if the avatar URL has changed.
	if ( $external_avatar_url === $last_avatar_url ) {
		// Fetch the size of the existing avatar on your server.
		$existing_avatar_size = filesize( $existing_avatar_path );

		// Fetch the header from the external URL (doesn't download the body).
		$response = wp_remote_head(
			$external_avatar_url,
			array(
				'timeout' => 30,
			)
		);

		// Check for an error.
		if ( is_wp_error( $response ) ) {
			return new WP_Error( 'retrieving_error', 'Error when retrieving avatar file' );
		}

		// Fetch the size of the image from the external URL.
		$new_avatar_size = (int) $response['headers']['content-length'];

		// If the sizes match, there's no need to update the avatar.
		if ( $existing_avatar_size === $new_avatar_size ) {
			return;
		}
	}

	// Download the image to our server.
	$response = wp_remote_get(
		$external_avatar_url,
		array(
			'timeout' => 30,
		)
	);
	if ( is_wp_error( $response ) ) {
		return new WP_Error( 'retrieving_error', 'Error when retrieving avatar file' );
	}
	$image_data = wp_remote_retrieve_body( $response );

	// Get the upload directory for avatars.
	$upload_dir = bp_core_avatar_upload_path() . '/avatars/' . $user_id;

	// If the directory doesn't exist, create it.
	if ( ! file_exists( $upload_dir ) ) {
		if ( ! mkdir( $upload_dir, 0755, true ) ) {
			return new WP_Error( 'directory_creation_error', 'Failed to create directory.' );
		}
	}

	// Get the image type and corresponding extension.
	$image_type = exif_imagetype( $external_avatar_url );
	$extension  = image_type_to_extension( $image_type, false );

	// Check if extension is valid.
	if ( ! in_array( $extension, array( 'jpg', 'jpeg', 'png', 'gif', 'webp' ), true ) ) {
		return new WP_Error( 'invalid_file_extension', 'Invalid file extension' );
	}

	// Construct the avatar file names.
	$avatar_original = time() . '-bporiginal.' . $extension;
	$avatar_full     = time() . '-bpfull.' . $extension;
	$avatar_thumb    = time() . '-bpthumb.' . $extension;

	// Remove existing avatar files to avoid conflicts.
	$existing_files = glob( $upload_dir . '/*-bp{full,thumb,original}.*', GLOB_BRACE );
	foreach ( $existing_files as $existing_file ) {
		if ( ! @unlink( $existing_file ) ) {
			return new WP_Error( 'unlink_error', 'Failed to delete existing file.' );
		}
	}

	// Clear the avatar cache so BuddyPress recognizes the new avatars.
	bp_core_delete_existing_avatar( array( 'item_id' => $user_id ) );

	// Create the full path to the avatar files.
	$filename_original = $upload_dir . '/' . $avatar_original;
	$filename_full     = $upload_dir . '/' . $avatar_full;
	$filename_thumb    = $upload_dir . '/' . $avatar_thumb;

	// Initialize WP_Filesystem API.
	global $wp_filesystem;
	if ( ! $wp_filesystem ) {
		if ( ! defined( 'FS_METHOD' ) ) {
			define( 'FS_METHOD', 'direct' );
		}
		require_once ABSPATH . '/wp-admin/includes/file.php';
		WP_Filesystem();
	}

	// Use WP_Filesystem to write file.
	if ( ! $wp_filesystem->put_contents( $filename_original, $image_data ) ) {
		return new WP_Error( 'writing_error', 'Error when writing file' );
	}

	// Resize the avatars to match BuddyPress's sizing.
	// Include the image manipulation library.
	require_once ABSPATH . 'wp-admin/includes/image.php';
	// Load the image.
	$image = wp_get_image_editor( $filename_original );

	if ( is_wp_error( $image ) ) {
		return $image;  // Return the WP_Error object.
	}

	// Get the image size.
	$size = $image->get_size();

	// Calculate new crop dimensions.
	$crop_width  = min( $size['width'], $size['height'] );
	$crop_height = $crop_width;

	// Calculate the x and y coordinates for cropping from the center.
	$x = max( 0, ( $size['width'] - $crop_width ) / 2 );
	$y = max( 0, ( $size['height'] - $crop_height ) / 2 );

	// Crop the image.
	$image->crop( $x, $y, $crop_width, $crop_height, $crop_width, $crop_height );

	// Save the image file.
	$new_image_path = $image->save( $filename_full );

	// Create a new instance of the image for thumbnail.
	$thumbnail = wp_get_image_editor( $filename_full );

	if ( is_wp_error( $thumbnail ) ) {
		return $thumbnail;  // Return the WP_Error object.
	}

	// Resize the thumbnail to 300x300 pixels.
	$thumbnail->resize( 300, 300, true );

	// Save the thumbnail with the appropriate filename.
	$thumbnail->save( $filename_thumb );

	if ( ! empty( $new_image_path['path'] ) ) {
		// After updating, save the user meta for next time.
		update_user_meta( $user_id, 'last_avatar_url', $external_avatar_url );
		update_user_meta( $user_id, 'existing_avatar_path', $filename_original );

		return $new_image_path['path'];
	} else {
		return new WP_Error( 'unknown_error', 'Unknown error' );
	}
}