import http from 'node:http';
import { HarborError } from '../shared/errors.js';

function request(socketPath, pathname, method = 'GET') {
  return new Promise((resolve, reject) => {
    const req = http.request({ socketPath, path: pathname, method }, (res) => {
      const chunks = [];
      res.on('data', (chunk) => chunks.push(chunk));
      res.on('end', () => {
        let body = {};
        try {
          body = JSON.parse(Buffer.concat(chunks).toString('utf8') || '{}');
        } catch {
          return reject(new Error('Dataplane вернул невалидный JSON'));
        }
        if ((res.statusCode || 500) >= 400) {
          return reject(new Error(body.error || `Dataplane HTTP ${res.statusCode}`));
        }
        resolve(body);
      });
    });
    req.on('error', reject);
    req.setTimeout(6000, () => req.destroy(new Error('Dataplane не ответил за 6 секунд')));
    req.end();
  });
}

export function createDataplaneClient(socketPath, send = request) {
  let current = { running: false, startedAt: null };
  const update = async (pathname, method) => {
    try {
      current = await send(socketPath, pathname, method);
      return current;
    } catch (cause) {
      if (pathname === '/apply' || pathname === '/restart') {
        throw new HarborError('PROCESS_START_FAILED', { cause });
      }
      throw cause;
    }
  };

  return {
    get running() { return Boolean(current.running); },
    get startedAt() { return current.startedAt || null; },
    refresh: () => update('/status', 'GET'),
    apply: () => update('/apply', 'POST'),
    restart: () => update('/restart', 'POST'),
    stop: () => update('/stop', 'POST'),
    shutdown: async () => current,
  };
}