import http from 'node:http';
import { paths } from '../env.mjs';
import { createRouter } from './router.mjs';
import { serveStatic } from './static.mjs';
import { openSse } from './sse.mjs';
import { registerMetaRoutes } from './routes/meta.mjs';
import { registerCaptureRoutes } from './routes/capture.mjs';
import { registerExtractionRoutes } from './routes/extractions.mjs';
import { registerLeadRoutes } from './routes/leads.mjs';
import { registerExportRoutes } from './routes/exports.mjs';
import { registerAuthRoutes } from './routes/auth.mjs';
import { registerOutreachRoutes } from './routes/outreach.mjs';
import { getCookie, getSession, SESSION_COOKIE } from './session.mjs';

const PUBLIC_API_PATHS = new Set(['/api/auth/login', '/api/health']);

const BODY_LIMIT = 1024 * 1024; // 1MB

function readJsonBody(req) {
  return new Promise((resolve, reject) => {
    let size = 0;
    const chunks = [];
    req.on('data', (chunk) => {
      size += chunk.length;
      if (size > BODY_LIMIT) {
        reject(new Error('corpo da requisicao muito grande'));
        req.destroy();
        return;
      }
      chunks.push(chunk);
    });
    req.on('end', () => {
      if (!chunks.length) {
        resolve(null);
        return;
      }
      try {
        resolve(JSON.parse(Buffer.concat(chunks).toString('utf8')));
      } catch {
        reject(new Error('JSON invalido no corpo da requisicao'));
      }
    });
    req.on('error', reject);
  });
}

export function createAppServer({ db, jobs, log = () => {} }) {
  const router = createRouter();
  const deps = { db, jobs };

  registerAuthRoutes(router, deps);
  registerMetaRoutes(router, deps);
  registerCaptureRoutes(router, deps);
  registerExtractionRoutes(router, deps);
  registerLeadRoutes(router, deps);
  registerExportRoutes(router, deps);
  registerOutreachRoutes(router, deps);

  // SSE de progresso dos jobs (rota especial: gerencia a resposta manualmente)
  router.add('GET', '/api/jobs/:jobId/events', async (req, res, { params }) => {
    const sse = openSse(res);
    const unsubscribe = jobs.subscribe(params.jobId, (event) => {
      const name = event.t === 'done' ? 'done' : event.t === 'error' ? 'error' : event.t;
      sse.send(name, event);
    });

    if (unsubscribe === null) {
      sse.send('error', { t: 'error', message: 'job nao encontrado (o servidor pode ter sido reiniciado)' });
      sse.close();
      return;
    }

    req.on('close', () => {
      unsubscribe();
      sse.close();
    });
  });

  const server = http.createServer(async (req, res) => {
    const url = new URL(req.url, 'http://127.0.0.1');
    const pathname = url.pathname;

    const json = (status, data) => {
      res.writeHead(status, { 'content-type': 'application/json; charset=utf-8' });
      res.end(JSON.stringify(data));
    };

    const session = getSession(getCookie(req, SESSION_COOKIE));
    const user = session?.user || null;

    try {
      if (pathname.startsWith('/api/') && !PUBLIC_API_PATHS.has(pathname) && !user) {
        json(401, { erro: 'não autenticado' });
        return;
      }

      const matched = router.match(req.method, pathname);
      if (matched) {
        let body = null;
        if (req.method === 'POST' || req.method === 'PUT') {
          body = await readJsonBody(req);
        }
        await matched.handler(req, res, { params: matched.params, query: url.searchParams, body, json, user });
        return;
      }

      if (req.method === 'GET' && !pathname.startsWith('/api/')) {
        if ((pathname === '/' || pathname === '/index.html') && !user) {
          res.writeHead(302, { location: '/login.html' });
          res.end();
          return;
        }
        if (serveStatic(paths.public, pathname, res)) return;
      }

      json(404, { erro: `rota nao encontrada: ${req.method} ${pathname}` });
    } catch (error) {
      log(`erro em ${req.method} ${pathname}: ${error.stack || error.message}`);
      if (!res.headersSent) {
        json(500, { erro: String(error.message || error) });
      } else {
        res.end();
      }
    }
  });

  return server;
}