hotkeys.ts

import { type WebSocket } from "ws"
import { VALKEY } from "../../../../common/src/constants"
import { withDeps, Deps } from "./utils"

type HotKeysResponse = {
  nodeId: string
  hotkeys: [[]]
  checkAt: number
  monitorRunning: boolean
}

const sendHotKeysFulfilled = (
  ws: WebSocket,
  connectionId: string,
  parsedResponse: HotKeysResponse,
) => {
  ws.send(
    JSON.stringify({
      type: VALKEY.HOTKEYS.hotKeysFulfilled,
      payload: {
        connectionId,
        parsedResponse,
      },
    }),
  )
}

const sendHotKeysError = (
  ws: WebSocket,
  connectionId: string,
  error: unknown,
) => {
  console.log(error)
  ws.send(
    JSON.stringify({
      type: VALKEY.HOTKEYS.hotKeysError,
      payload: {
        connectionId,
        error: error instanceof Error ? error.message : String(error),
      },
    }),
  )
}

export const hotKeysRequested = withDeps<Deps, void>(
  async ({ ws, connectionId, metricsServerURIs }) => {
    const metricsServerURI = metricsServerURIs.get(connectionId)
    try {
      const initialResponse = await fetch(`${metricsServerURI}/hot-keys`)
      const initialParsedResponse: HotKeysResponse = await initialResponse.json() as HotKeysResponse
      // Initial request starts monitoring and returns when to fetch results (`checkAt`).
      if (initialParsedResponse.checkAt) {
        const delay = Math.max(initialParsedResponse.checkAt - Date.now(), 0)
        // Schedule the follow-up request for when the monitor cycle finishes
        setTimeout(async () => {
          try {
            const dataResponse = await fetch(`${metricsServerURI}/hot-keys`)
            const dataParsedResponse = await dataResponse.json() as HotKeysResponse
            sendHotKeysFulfilled(ws, connectionId, dataParsedResponse)
          } catch (error) {
            sendHotKeysError(ws, connectionId, error)
          }
        }, delay)
      }
      else {
        sendHotKeysFulfilled(ws, connectionId, initialParsedResponse)
      }
    } catch (error) {
      sendHotKeysError(ws, connectionId, error)
    }
  },
)