<?php

declare(strict_types=1);

namespace app\common\service\prescriptionai;

use DomainException;
use think\facade\Db;

/** Save-response recovery for new clients; contains hashes, never prescription content. */
final class PrescriptionAiRequest
{
    private static function key(array $params, int $actorId): ?string
    {
        $key = $params['request_key'] ?? '';
        if (!PrescriptionAiStore::enabled() || $key === '') {
            return null;
        }
        if (!is_string($key) || !preg_match('/^[a-zA-Z0-9_-]{16,64}$/D', $key)) {
            throw new DomainException('保存请求标识无效');
        }
        return hash('sha256', $actorId . ':' . $key);
    }

    private static function fingerprint(array $params): string
    {
        unset($params['request_key']);
        return hash('sha256', PrescriptionAiPolicy::canonical($params));
    }

    public static function replay(array $params, int $actorId, bool $reserve = false): ?int
    {
        $key = self::key($params, $actorId);
        if ($key === null) {
            return null;
        }
        $hash = self::fingerprint($params);
        if ($reserve) {
            Db::name('prescription_ai_request')->extra('IGNORE')->insert([
                'request_key' => $key, 'actor_id' => $actorId, 'request_hash' => $hash,
                'prescription_id' => 0, 'created_at' => time(),
            ]);
        }
        $row = Db::name('prescription_ai_request')->where('request_key', $key)->lock($reserve)->find();
        if (!$row) {
            return null;
        }
        if ((int) $row['actor_id'] !== $actorId || !hash_equals($row['request_hash'], $hash)) {
            throw new DomainException('请求标识已用于其他处方内容，请重新保存');
        }
        if ((int) $row['prescription_id'] > 0) {
            $exists = Db::name('tcm_prescription')->where('id', $row['prescription_id'])
                ->where('creator_id', $actorId)->whereNull('delete_time')->count();
            if (!$exists) {
                throw new DomainException('此保存请求对应处方已删除，请重新开方');
            }
            return (int) $row['prescription_id'];
        }
        return null;
    }

    public static function complete(array $params, int $actorId, int $prescriptionId): void
    {
        $key = self::key($params, $actorId);
        if ($key !== null) {
            Db::name('prescription_ai_request')->where('request_key', $key)->update(['prescription_id' => $prescriptionId]);
        }
    }
}