<?php
/**
 * What every import did, kept so it can be read back and taken back.
 *
 * @package AiRankSuite
 */

declare(strict_types=1);

namespace AiRankSuite\Modules\ImportExport\Services;

use AiRankSuite\Support\Database;

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

/**
 * An import is not finished when the progress bar fills: somebody has to be
 * able to look, a day later, at what it changed and decide to keep it. So
 * every run gets an id, a record of what it touched, the first errors it hit,
 * and a flag saying whether its journal is still complete enough to undo.
 *
 * The list is capped: twenty runs is more history than anyone reads, and an
 * option that grows without a bound is how a plugin ends up on a support
 * ticket about a slow admin.
 */
final class ImportLog {

	private const OPTION = 'airanksuite_import_runs';
	private const KEEP   = 20;
	private const ERRORS = 25;

	/**
	 * @return array<int, array<string, mixed>>
	 */
	public static function runs(): array {
		$stored = get_option( self::OPTION, array() );
		return is_array( $stored ) ? array_values( $stored ) : array();
	}

	/**
	 * @return array<string, mixed>|null
	 */
	public static function run( string $import_id ): ?array {
		foreach ( self::runs() as $run ) {
			if ( (string) ( $run['import_id'] ?? '' ) === $import_id ) {
				return $run;
			}
		}
		return null;
	}

	/**
	 * Create or update a run record. Newest first.
	 *
	 * @param array<string, mixed> $patch
	 * @return array<string, mixed>
	 */
	public static function save( string $import_id, array $patch ): array {
		$runs  = self::runs();
		$index = null;
		foreach ( $runs as $i => $run ) {
			if ( (string) ( $run['import_id'] ?? '' ) === $import_id ) {
				$index = $i;
				break;
			}
		}
		$record = null === $index ? array( 'import_id' => $import_id ) : $runs[ $index ];
		$record = array_merge( $record, $patch );
		if ( null === $index ) {
			array_unshift( $runs, $record );
		} else {
			$runs[ $index ] = $record;
		}
		usort( $runs, static fn( array $a, array $b ) => (int) ( $b['started'] ?? 0 ) <=> (int) ( $a['started'] ?? 0 ) );
		$runs = array_slice( $runs, 0, self::KEEP );
		update_option( self::OPTION, $runs, false );
		return $record;
	}

	/**
	 * Record one failed record. Bounded — the count is what matters, the first
	 * few messages are what a support conversation needs.
	 */
	public static function error( string $import_id, string $what, string $message ): void {
		$run    = self::run( $import_id ) ?? array( 'import_id' => $import_id );
		$errors = (array) ( $run['errors'] ?? array() );
		if ( count( $errors ) < self::ERRORS ) {
			$errors[] = array( 'what' => $what, 'message' => mb_substr( $message, 0, 300 ) );
		}
		$counts           = (array) ( $run['counts'] ?? array() );
		$counts['errors'] = (int) ( $counts['errors'] ?? 0 ) + 1;
		self::save( $import_id, array( 'errors' => $errors, 'counts' => $counts ) );
	}

	/**
	 * Drop the journals of runs that have fallen off the list, so the table
	 * cannot outlive the history that explains it.
	 */
	public static function prune(): void {
		global $wpdb;
		$ids = array();
		foreach ( self::runs() as $run ) {
			$ids[] = (string) ( $run['import_id'] ?? '' );
		}
		$ids = array_values( array_filter( $ids ) );
		if ( empty( $ids ) ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
			$wpdb->query( $wpdb->prepare( 'DELETE FROM %i', Database::import_undo() ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- table name from this plugin's own Database class/adapter, never from input; values go through $wpdb->prepare().
			return;
		}
		$in = implode( ',', array_fill( 0, count( $ids ), '%s' ) );
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$wpdb->query( $wpdb->prepare( 'DELETE FROM ' . Database::import_undo() . " WHERE import_id NOT IN ({$in})", ...$ids ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- table name from this plugin's own Database class/adapter, never from input; values go through $wpdb->prepare().
	}
}