import Fastify, { FastifyInstance } from 'fastify';
import { AppError } from '../../src/utils/errors.js';
import { adminQuestionsRoutes } from '../../src/routes/admin/questions.js';
import type { MockDb } from '../test-utils.js';
import { createMockDb } from '../test-utils.js';

const mockAdminUser = { id: 'admin-1', email: 'admin@test.com' };

/**
 * Build a minimal Fastify app for admin route integration tests.
 * Bypasses real auth - preHandlers set req.user to mock admin.
 */
export async function buildAdminTestApp(mockDb?: MockDb): Promise<FastifyInstance> {
  const db = mockDb ?? createMockDb();

  const app = Fastify({
    logger: false,
    requestIdHeader: 'x-request-id',
    requestIdLogLabel: 'requestId',
  });

  app.setErrorHandler((err: unknown, _request, reply) => {
    const error = err as Error & { statusCode?: number; validation?: unknown };
    if (err instanceof AppError) {
      return reply.status(err.statusCode).send(err.toJSON());
    }
    if (error.validation) {
      return reply.status(422).send({
        error: { code: 'VALIDATION_ERROR', message: 'Validation failed', details: error.validation },
      });
    }
    return reply.status(500).send({ error: { code: 'INTERNAL_ERROR', message: error.message } });
  });

  app.decorate('db', db);
  app.decorate('rateLimitOptions', {
    apiAuthed: { max: 100, timeWindow: '1 minute' },
  });
  app.decorateRequest('user', undefined);
  app.decorate('authenticate', async (req: { user?: { id: string; email: string } }) => {
    req.user = mockAdminUser;
  });
  app.decorate('authenticateAdmin', async (req: { user?: { id: string; email: string } }) => {
    if (!req.user) req.user = mockAdminUser;
    (req.user as { role?: string }).role = 'admin';
  });

  await app.register(adminQuestionsRoutes, { prefix: '/admin' });

  return app;
}