<?php
declare(strict_types=1);

namespace WebCalendar\WP\Integrations\QueryMonitor;

defined( 'ABSPATH' ) || exit;

/**
 * Query Monitor integration: exposes webcalendar-core PDO queries in QM's panel.
 *
 * Hooks into QM's output via the `qm/outputter/html` filter and adds
 * webcalendar-core query data to the "Queries" panel as an additional
 * database connection.
 */
final class QueryMonitorCollector {

	/**
	 * Register hooks if Query Monitor is active.
	 */
	public static function register(): void {
		if ( ! class_exists( 'QM_Collectors' ) ) {
			return;
		}

		/** @psalm-suppress HookNotFound -- External Query Monitor hook. */
		add_filter( 'qm/collect/db_queries', [ self::class, 'collect_queries' ] );
	}

	/**
	 * Append WebCalendar PDO queries to the QM database queries collection.
	 *
	 * @psalm-suppress PossiblyUnusedMethod -- Registered via add_filter().
	 *
	 * @param mixed $data Existing QM data.
	 * @return mixed
	 */
	public static function collect_queries( mixed $data ): mixed {
		$container = \WebCalendar\WP\Container::get_instance();

		try {
			$pdo = $container->get_pdo();
		} catch ( \Throwable $e ) {
			return $data;
		}

		if ( ! $pdo instanceof TracingPdo ) {
			return $data;
		}

		$queries = $pdo->get_queries();

		if ( empty( $queries ) ) {
			return $data;
		}

		if ( ! is_array( $data ) ) {
			return $data;
		}

		if ( ! isset( $data['dbs'] ) || ! is_array( $data['dbs'] ) ) {
			$data['dbs'] = [];
		}

		$total_time = 0.0;
		$rows       = [];

		foreach ( $queries as $query ) {
			$total_time += $query['time'];
			$rows[]      = [
				'sql'    => $query['sql'],
				'ltime'  => $query['time'],
				'caller' => $query['caller'],
				'result' => null,
			];
		}

		$data['dbs']['webcalendar-core (PDO)'] = [
			'rows'       => $rows,
			'total_time' => $total_time,
			'total_qs'   => count( $rows ),
		];

		return $data;
	}
}