db.ts

import dotenv from 'dotenv'
import { InfluxDB, WritePrecisionType } from '@influxdata/influxdb-client'
import { DeleteAPI, HealthAPI } from '@influxdata/influxdb-client-apis'
import { Agent } from 'http'

const agent = new Agent({
  keepAlive: true,
  keepAliveMsecs: 20 * 1000, // 20 seconds keep alive
})

dotenv.config()

export const {
  INFLUXDB_URL: url = 'http://localhost:8086',
  INFLUXDB_TOKEN: token,
  INFLUXDB_ORG: org = 'myOrg',
  INFLUXDB_BUCKET: bucket = 'mqtt_logger',
  PRECISION: precision = 'ns',
} = process.env

const influxDb = new InfluxDB({
  url,
  token,
  transportOptions: { agent },
})

export const writeApi = influxDb.getWriteApi(
  org,
  bucket,
  precision as WritePrecisionType
)
export const queryApi = influxDb.getQueryApi(org)
export const deleteApi = new DeleteAPI(influxDb)
export const healthApi = new HealthAPI(influxDb)

export const influx_read = (query: string) =>
  new Promise((resolve, reject) => {
    // helper function for Influx queries

    // TODO: find type
    const results: any[] = []
    queryApi.queryRows(query, {
      next(row, tableMeta) {
        // TODO: Find way to convert directly to an array
        const result = tableMeta.toObject(row)
        results.push(result)
      },
      error(error) {
        reject(error)
      },
      complete() {
        resolve(results)
      },
    })
  })

export const healthCheck = async () => {
  await healthApi.getHealth()
}