import {
    BadRequestException,
    ForbiddenException,
    HttpException,
} from '@nestjs/common';
import type { ContentStatus } from '@doodle/contracts';
import { Prisma } from '../generated/prisma/client';
import { requireCurrentAccount } from '../auth/account-policy';
import type { AuthenticatedUser } from '../common/http-request';
import { ApiException } from '../common/api-exception';

/** 只从 active 根节点展开；草稿祖先、失联或成环的分支均不对外可见。 */
export const visibleCategoryIds = Prisma.sql`WITH RECURSIVE visible_categories AS (
    SELECT id FROM public.categories WHERE parent_id IS NULL AND status = 'active'
    UNION
    SELECT c.id FROM public.categories c JOIN visible_categories p ON c.parent_id = p.id
    WHERE c.status = 'active'
) SELECT id FROM visible_categories`;

/** 题型列表、详情和管理预览共用规则，不能只过滤左侧分类菜单。SQL 中题型别名固定为 w。 */
export const visibleWorksheet = Prisma.sql`w.status = 'active' AND w.category_id IN (${visibleCategoryIds})`;

/** 发布状态显式校验；不接受布尔值、NULL 或客户端自行添加的测试状态。 */
export function contentStatus(value: unknown): ContentStatus {
    if (value !== 'draft' && value !== 'active' && value !== 'hidden')
        throw new BadRequestException('发布状态不合法');
    return value;
}

/** 写事务重新核对当前账户并持锁，避免守卫之后被禁用或降权仍然提交。 */
export async function lockContentAdmin(
    tx: Prisma.TransactionClient,
    actor: AuthenticatedUser,
): Promise<void> {
    const rows = await tx.$queryRaw<
        Array<{
            id: string;
            status: 'active' | 'disabled';
            role: 'user' | 'admin';
            authVersion: number;
        }>
    >`SELECT id, status, role, auth_version AS "authVersion" FROM public.users WHERE id = ${actor.userId} FOR UPDATE`;
    const account = requireCurrentAccount(
        rows[0] ?? null,
        actor.userId,
        actor.authVersion,
    );
    if (account.role !== 'admin') throw new ForbiddenException();
}

/** 先撤销数据库展示快照与发布标记；外部已分发的静态文件须由后续发布链路撤销/重建。 */
export async function invalidateContentSnapshots(
    tx: Prisma.TransactionClient,
): Promise<void> {
    await tx.pageConfig.updateMany({
        data: {
            home: Prisma.DbNull,
            category: Prisma.DbNull,
            age: Prisma.DbNull,
            version: { increment: 1 },
            publishedVersion: null,
            publishedAt: null,
            updatedAt: new Date(),
        },
    });
}

/** 保留业务 HTTP 错误；连接/约束诊断不原样输出给调用者。 */
export async function runContentQuery<T>(
    operation: () => Promise<T>,
): Promise<T> {
    try {
        return await operation();
    } catch (error) {
        if (error instanceof HttpException) throw error;
        throw new ApiException(503, 'DATABASE_UNAVAILABLE');
    }
}