import { jsonResponse, errorResponse } from '../utils/cors'
import { PORT_TERMINAL, PORT_GIT } from '../config'

/**
 * Proxy GET /api/ws-monitor → terminal server + sync server health.
 * Returns combined WebSocket connection stats from both servers.
 */
export async function handleWsMonitor(): Promise<Response> {
  const controller = new AbortController()
  const timeout = setTimeout(() => controller.abort(), 4000)

  try {
    const [terminalResp, syncResp] = await Promise.allSettled([
      fetch(`http://localhost:${PORT_TERMINAL}/health`, { signal: controller.signal }),
      fetch(`http://localhost:${PORT_GIT}/health`, { signal: controller.signal })
    ])

    const terminalData = terminalResp.status === 'fulfilled' && terminalResp.value.ok
      ? await terminalResp.value.json()
      : null

    const syncData = syncResp.status === 'fulfilled' && syncResp.value.ok
      ? await syncResp.value.json()
      : null

    return jsonResponse({
      terminal: {
        status: terminalData?.status ?? 'unreachable',
        sessions: terminalData?.sessions ?? [],
        broadcastClients: terminalData?.broadcastClients ?? 0,
        cwd: terminalData?.cwd ?? null,
      },
      sync: {
        status: syncData?.status ?? 'unreachable',
        clients: syncData?.clients ?? 0,
        torch: syncData?.torch ?? null,
      },
      timestamp: Date.now(),
    })
  } catch (e: any) {
    const msg = e.name === 'AbortError'
      ? 'Server health timeout (4s)'
      : `Failed to reach servers: ${e.message}`
    return errorResponse(msg, 502)
  } finally {
    clearTimeout(timeout)
  }
}