bch-api/src/routes/v3/route-utils2.js

/*
  A private library of utility functions used by several different routes.
*/

"use strict"

const axios = require("axios")
const wlogger = require("../../util/winston-logging")

const util = require("util")
util.inspect.defaultOptions = { depth: 1 }

const BCHJS = require("@chris.troutner/bch-js")
const bchjs = new BCHJS()

let _this

class RouteUtils {
  constructor() {
    _this = this

    this.bchjs = bchjs
    this.axios = axios
  }

  // This function expects the Request Express.js object and an array as input.
  // The array is then validated against freemium and pro-tier rate limiting
  // requirements. A boolean is returned to indicate if the array size if valid
  // or not.
  validateArraySize(req, array) {
    const FREEMIUM_INPUT_SIZE = 20
    const PRO_INPUT_SIZE = 20

    if (req.locals && req.locals.proLimit) {
      if (array.length <= PRO_INPUT_SIZE) return true
    } else if (array.length <= FREEMIUM_INPUT_SIZE) {
      return true
    }

    return false
  }

  // Axios options used when calling axios.post() to talk with a full node.
  getAxiosOptions() {
    return {
      method: "post",
      baseURL: process.env.RPC_BASEURL,
      timeout: 15000,
      auth: {
        username: process.env.RPC_USERNAME,
        password: process.env.RPC_PASSWORD
      },
      data: {
        jsonrpc: "1.0"
      }
    }
  }

  // Returns true if user-provided cash address matches the correct network,
  // mainnet or testnet. If NETWORK env var is not defined, it returns false.
  // This prevent a common user-error issue that is easy to make: passing a
  // testnet address into rest.bitcoin.com or passing a mainnet address into
  // trest.bitcoin.com.
  validateNetwork(addr) {
    try {
      const network = process.env.NETWORK

      // Return false if NETWORK is not defined.
      if (!network || network === "") {
        console.log(`Warning: NETWORK environment variable is not defined!`)
        return false
      }

      // Convert the user-provided address to a cashaddress, for easy detection
      // of the intended network.
      const cashAddr = this.bchjs.Address.toCashAddress(addr)

      // Return true if the network and address both match testnet
      const addrIsTest = this.bchjs.Address.isTestnetAddress(cashAddr)
      if (network === "testnet" && addrIsTest) return true

      // Return true if the network and address both match mainnet
      const addrIsMain = this.bchjs.Address.isMainnetAddress(cashAddr)
      if (network === "mainnet" && addrIsMain) return true

      return false
    } catch (err) {
      logger.error(`Error in validateNetwork()`)
      return false
    }
  }

  // Error messages returned by a full node can be burried pretty deep inside the
  // error object returned by Axios. This function attempts to extract and interpret
  // error messages.
  // Returns an object. If successful, obj.msg is a string.
  // If there is a failure, obj.msg is false.
  decodeError(err) {
    try {
      // Attempt to extract the full node error message.
      if (
        err.response &&
        err.response.data &&
        err.response.data.error &&
        err.response.data.error.message
      )
        return { msg: err.response.data.error.message, status: 400 }

      // Attempt to extract the Insight error message
      if (err.response && err.response.data)
        return { msg: err.response.data, status: err.response.status }

      // console.log(`err.message: ${err.message}`)
      // console.log(`err: `, err)

      // Attempt to detect a network connection error.
      if (err.message && err.message.indexOf("ENOTFOUND") > -1) {
        return {
          msg:
            "Network error: Could not communicate with full node or other external service.",
          status: 503
        }
      }

      // Different kind of network error
      if (err.message && err.message.indexOf("ENETUNREACH") > -1) {
        return {
          msg:
            "Network error: Could not communicate with full node or other external service.",
          status: 503
        }
      }

      // Different kind of network error
      if (err.message && err.message.indexOf("EAI_AGAIN") > -1) {
        return {
          msg:
            "Network error: Could not communicate with full node or other external service.",
          status: 503
        }
      }

      // Axios timeout (aborted) error, or service is down (connection refused).
      if (
        err.code &&
        (err.code === "ECONNABORTED" || err.code === "ECONNREFUSED")
      ) {
        return {
          msg:
            "Network error: Could not communicate with full node or other external service.",
          status: 503
        }
      }

      return { msg: false, status: 500 }
    } catch (err) {
      wlogger.error(`unhandled error in route-utils.js/decodeError(): `, err)
      return { msg: false, status: 500 }
    }
  }
}

module.exports = RouteUtils