<?php
/**
 * Small database helpers.
 *
 * @package SiteAuditHub
 */

namespace SiteAuditHub;

defined( 'ABSPATH' ) || exit;

/**
 * Table names and shared helpers.
 */
class Db {

	/**
	 * Full table name for a plugin table.
	 *
	 * @param string $name Short name.
	 * @return string
	 */
	public static function table( $name ) {
		global $wpdb;
		return $wpdb->prefix . 'siteaudithub_' . preg_replace( '/[^a-z_]/', '', $name );
	}

	/**
	 * Whether a plugin table exists.
	 *
	 * @param string $name Short name.
	 * @return bool
	 */
	public static function table_exists( $name ) {
		global $wpdb;
		$table = self::table( $name );
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		return $table === $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) );
	}

	/**
	 * Current UTC datetime string for DB columns.
	 *
	 * @return string
	 */
	public static function now() {
		return gmdate( 'Y-m-d H:i:s' );
	}

	/**
	 * Safe JSON encode for storage.
	 *
	 * @param mixed $value Value.
	 * @return string
	 */
	public static function encode( $value ) {
		$json = wp_json_encode( $value, JSON_UNESCAPED_SLASHES | JSON_PARTIAL_OUTPUT_ON_ERROR );
		return false === $json ? '{}' : $json;
	}

	/**
	 * Safe JSON decode (never unserialize).
	 *
	 * @param string|null $json JSON.
	 * @return array
	 */
	public static function decode( $json ) {
		if ( ! is_string( $json ) || '' === $json ) {
			return array();
		}
		$data = json_decode( $json, true );
		return is_array( $data ) ? $data : array();
	}
}