import cors from '@fastify/cors';
import Fastify from 'fastify';
import { ZodError } from 'zod';
import { authPlugin } from './auth/plugin.js';
import { config } from './config.js';
import { pool } from './db/pool.js';
import { authRoutes } from './routes/auth.js';
import { courseRoutes } from './routes/courses.js';
import { manageCourseRoutes } from './routes/manage-courses.js';

export function buildApp() {
  const app = Fastify({ logger: true });

  app.register(cors, {
    origin: config.FRONTEND_ORIGIN,
    methods: ['GET', 'POST', 'PATCH', 'DELETE'],
  });

  app.setErrorHandler((error, _request, reply) => {
    if (error instanceof ZodError) {
      return reply.code(400).send({ error: 'Invalid request', details: error.flatten() });
    }

    app.log.error(error);
    return reply.code(500).send({ error: 'Internal server error' });
  });

  app.get('/api/v1/health', async () => ({ status: 'ok' }));
  app.get('/api/v1/ready', async (_request, reply) => {
    try {
      await pool.query('select 1');
      return { status: 'ready' };
    } catch {
      return reply.code(503).send({ status: 'unavailable' });
    }
  });

  app.register(authPlugin);
  app.register(authRoutes, { prefix: '/api/v1/auth' });
  app.register(courseRoutes, { prefix: '/api/v1/courses' });
  app.register(manageCourseRoutes, { prefix: '/api/v1/manage/courses' });
  return app;
}