// Mock backend server (port 3001) - matches /config API from api.rest
import { createServer } from 'node:http';
import { fileURLToPath } from 'node:url';
import path from 'node:path';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

// In-memory mock data store
const store = {
  lan: { dhcp: false, ip: '192.168.6.51', mask: '255.255.255.0', gateway: '192.168.6.1', dns: '8.8.8.8' },
  main_relay: { lockDelayMs: 5000, unlockDelayMs: 2000 },
  elevator: { enabled: true, timeoutMs: 8000, portHintList: [], portCount: 0 },
  device: { type: 0, sn: 1, name: 'test', unit: 1, room: 101 },
};

const server = createServer((req, res) => {
  const url = new URL(req.url, `http://${req.headers.host}`);
  const pathname = url.pathname; // e.g. /config/lan
  const apiKey = req.headers['x-api-key'] || '';

  // CORS
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET,PUT,OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization, X-API-Key');
  if (req.method === 'OPTIONS') { res.writeHead(204); return res.end(); }

  // Auth check
  const auth = req.headers['authorization'] || '';
  if (auth && !auth.startsWith('Basic ') && !auth.startsWith('Bearer ')) {
    res.writeHead(401, { 'Content-Type': 'application/json' });
    return res.end(JSON.stringify({ err: 'Authorization header must start with Basic or Bearer' }));
  }

  if (!pathname.startsWith('/config/')) {
    res.writeHead(404, { 'Content-Type': 'application/json' });
    return res.end(JSON.stringify({ err: 'Not found' }));
  }

  const resource = pathname.replace(/^\/config\//, '');
  const routeKey = ['lan', 'main_relay', 'elevator', 'device'];

  if (!routeKey.includes(resource)) {
    res.writeHead(404, { 'Content-Type': 'application/json' });
    return res.end(JSON.stringify({ err: `Unknown resource: ${resource}` }));
  }

  const timeout = setTimeout(() => {
    if (!res.headersSent) {
      res.writeHead(504, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ err: 'Gateway timeout' }));
    }
  }, 3000);

  if (req.method === 'GET') {
    // Simulate latency: 100-400ms
    const delay = Math.random() * 300 + 100;
    setTimeout(() => {
      clearTimeout(timeout);
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify(store[resource]));
    }, delay);
  } else if (req.method === 'PUT') {
    let body = '';
    req.on('data', chunk => { body += chunk; });
    req.on('end', () => {
      const delay = Math.random() * 300 + 100;
      setTimeout(() => {
        try {
          const data = JSON.parse(body);
          // Validate based on resource type
          if (resource === 'lan') {
            if (!data.ip || !data.mask || !data.gateway) {
              throw new Error('request error: missing required fields');
            }
            store[resource] = { ...store[resource], ...data };
          } else if (resource === 'main_relay') {
            if (typeof data.lockDelayMs !== 'number' || typeof data.unlockDelayMs !== 'number') {
              throw new Error('request error: invalid delay values');
            }
            store[resource] = { ...store[resource], ...data };
          } else if (resource === 'elevator') {
            if (!data.enabled) {
              throw new Error('request error: disabled not allowed');
            }
            store[resource] = { ...store[resource], ...data, portHintList: [], portCount: Object.keys(data).filter(k => k.startsWith('port')).length };
          } else if (resource === 'device') {
            if (!data.name) {
              throw new Error('request error: name required');
            }
            store[resource] = { ...store[resource], ...data, sn: Date.now() % 10000 };
          }
          res.writeHead(200, { 'Content-Type': 'application/json' });
          res.end(JSON.stringify(store[resource]));
        } catch (e) {
          res.writeHead(400, { 'Content-Type': 'application/json' });
          res.end(JSON.stringify({ err: e.message }));
        }
      }, delay);
    });
  } else {
    clearTimeout(timeout);
    res.writeHead(405, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ err: `Method ${req.method} not allowed` }));
  }
});

const PORT = 3001;
server.listen(PORT, () => {
  console.log(`Mock server running at http://localhost:${PORT}/config/{lan,main_relay,elevator,device}`);
});