<?php
/**
 * MLP2 site relations reader.
 *
 * Reads all site connection rows from the MLP2 backup site_relations table.
 *
 * MLP2 site_relations schema:
 *   site_1 INT UNSIGNED  -- lower site ID
 *   site_2 INT UNSIGNED  -- higher site ID
 *   PRIMARY KEY (site_1, site_2)
 *
 * @package Robotstxt_Mlp2_Mlp5
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Class Robotstxt_Mlp2_Mlp5_Reader_Site_Relations
 */
class Robotstxt_Mlp2_Mlp5_Reader_Site_Relations {

	/**
	 * Return all MLP2 site relation rows as an array of associative arrays.
	 *
	 * Each element has keys: site_1 (int), site_2 (int).
	 *
	 * @return array[]
	 */
	public static function get_all(): array {
		global $wpdb;

		$mlp2  = new Robotstxt_Mlp2_Mlp5_Detector_Mlp2();
		$table = $mlp2->get_site_relations_table();

		if ( '' === $table ) {
			return array();
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$rows = $wpdb->get_results( "SELECT site_1, site_2 FROM `{$table}`", ARRAY_A );

		if ( ! is_array( $rows ) ) {
			return array();
		}

		$result = array();
		foreach ( $rows as $row ) {
			$result[] = array(
				'site_1' => (int) $row['site_1'],
				'site_2' => (int) $row['site_2'],
			);
		}

		return $result;
	}
}