<?php
namespace Relay\Restore;

/** Values that carry the table prefix and must follow it when a backup is restored under another prefix. */
final class PrefixRewriter
{
    /** A TableCopier column rewrite for $table (this site's name), or null when the table needs none. */
    public static function for_table(string $table, string $from, string $to): ?callable
    {
        if ($from === $to) {
            return null;
        }
        if ($table === $to . 'options') {
            return static fn (string $column, string $value): string => $column === 'option_name' && $value === $from . 'user_roles' ? $to . 'user_roles' : $value;
        }
        if ($table === $to . 'usermeta') {
            return static fn (string $column, string $value): string => $column === 'meta_key' && strpos($value, $from) === 0 ? $to . substr($value, strlen($from)) : $value;
        }
        return null;
    }
}