<?php
/**
 * Filesystem helpers.
 *
 * Wraps WP_Filesystem, and answers what the uploads directory can take.
 *
 * @package PageCore
 */

namespace PageCore;

defined( 'ABSPATH' ) || exit;

/**
 * WP_Filesystem access, writability and free space checks.
 */
class Filesystem {

	/**
	 * Cached WP_Filesystem instance.
	 *
	 * @var \WP_Filesystem_Base|null
	 */
	private $fs = null;

	/**
	 * Initialise and return WP_Filesystem.
	 *
	 * @return \WP_Filesystem_Base|\WP_Error
	 */
	public function fs() {
		if ( $this->fs ) {
			return $this->fs;
		}

		global $wp_filesystem;

		if ( ! function_exists( 'WP_Filesystem' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
		}

		if ( ! WP_Filesystem() ) {
			return new \WP_Error(
				'pagecore_filesystem',
				__( 'WordPress could not get direct access to the filesystem on this host.', 'pagecore' )
			);
		}

		$this->fs = $wp_filesystem;

		return $this->fs;
	}

	/**
	 * Whether the uploads directory can be written to.
	 *
	 * @return bool
	 */
	public function uploads_writable() {
		$uploads = wp_upload_dir();

		if ( ! empty( $uploads['error'] ) ) {
			return false;
		}

		return wp_is_writable( $uploads['basedir'] );
	}

	/**
	 * Free space on the uploads volume, in bytes.
	 *
	 * @return int|null Null when the host does not report it.
	 */
	public function free_space() {
		$uploads = wp_upload_dir();

		if ( ! empty( $uploads['error'] ) || ! function_exists( 'disk_free_space' ) ) {
			return null;
		}

		// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
		$free = @disk_free_space( $uploads['basedir'] );

		return false === $free ? null : (int) $free;
	}
}