<?php
/**
 * MLP5 site relations writer.
 *
 * Writes site connection rows to the MLP5 site_relations table.
 *
 * MLP5 site_relations schema (identical to MLP2):
 *   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_Writer_Site_Relations
 */
class Robotstxt_Mlp2_Mlp5_Writer_Site_Relations {

	/**
	 * Check whether a site relation already exists in MLP5.
	 *
	 * @param int $site_1 First site ID (will be normalised to lower).
	 * @param int $site_2 Second site ID.
	 * @return bool
	 */
	public static function relation_exists( int $site_1, int $site_2 ): bool {
		global $wpdb;

		$mlp5  = new Robotstxt_Mlp2_Mlp5_Detector_Mlp5();
		$table = $mlp5->get_site_relations_table();

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

		// Normalise: site_1 must be the lower value.
		if ( $site_1 > $site_2 ) {
			list( $site_1, $site_2 ) = array( $site_2, $site_1 );
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
		$found = $wpdb->get_var(
			$wpdb->prepare(
				// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
				"SELECT COUNT(*) FROM `{$table}` WHERE site_1 = %d AND site_2 = %d",
				$site_1,
				$site_2
			)
		);

		return (int) $found > 0;
	}

	/**
	 * Write a site relation to MLP5.
	 *
	 * Normalises site IDs (smaller value in site_1) before inserting.
	 * Returns false if the target table does not exist.
	 *
	 * @param int $site_1 First site ID.
	 * @param int $site_2 Second site ID.
	 * @return bool True on success, false on failure.
	 */
	public static function write_relation( int $site_1, int $site_2 ): bool {
		global $wpdb;

		$mlp5  = new Robotstxt_Mlp2_Mlp5_Detector_Mlp5();
		$table = $mlp5->get_site_relations_table();

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

		// Normalise.
		if ( $site_1 > $site_2 ) {
			list( $site_1, $site_2 ) = array( $site_2, $site_1 );
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
		$result = $wpdb->insert(
			$table,
			array(
				'site_1' => $site_1,
				'site_2' => $site_2,
			),
			array( '%d', '%d' )
		);

		return false !== $result;
	}
}