/*
  Electrum API route
*/

'use strict'

const express = require('express')
const router = express.Router()
const axios = require('axios')
const util = require('util')
// const bitcore = require('bitcore-lib-cash')

// const ElectrumCash = require('electrum-cash').ElectrumClient
// const ElectrumCash = require('/home/trout/work/personal/electrum-cash/electrum.js').Client // eslint-disable-line

const wlogger = require('../../util/winston-logging')
const config = require('../../../config')

const RouteUtils = require('../../util/route-utils')
const routeUtils = new RouteUtils()

const BCHJS = require('@psf/bch-js')
const bchjs = new BCHJS()

let _this

class Electrum {
  constructor () {
    this.config = config
    this.axios = axios
    this.routeUtils = routeUtils
    this.bchjs = bchjs
    // _this.bitcore = bitcore

    this.fulcrumApi = process.env.FULCRUM_API
    if (!this.fulcrumApi) {
      throw new Error(
        'FULCRUM_API env var not set. Can not connect to Fulcrum indexer.'
      )
    }

    // _this.electrumx = new ElectrumCash(
    //   'bch-api',
    //   '1.4.1',
    //   process.env.FULCRUM_URL,
    //   process.env.FULCRUM_PORT
    //   // '192.168.0.6',
    //   // '50002'
    // )

    // _this.isReady = false
    // _this.connectToServers()

    this.router = router
    this.router.get('/', this.root)
    this.router.get('/balance/:address', this.getBalance)
    this.router.post('/balance', this.balanceBulk)
    this.router.get('/utxos/:address', this.getUtxos)
    this.router.post('/utxos', this.utxosBulk)
    this.router.get('/tx/data/:txid', this.getTransactionDetails)
    this.router.post('/tx/data', this.transactionDetailsBulk)
    this.router.post('/tx/broadcast', this.broadcastTransaction)
    this.router.get('/block/headers/:height', this.getBlockHeaders)
    this.router.post('/block/headers', this.blockHeadersBulk)
    this.router.get('/transactions/:address', this.getTransactions)
    this.router.post('/transactions', this.transactionsBulk)
    this.router.get('/unconfirmed/:address', this.getMempool)
    this.router.post('/unconfirmed', this.mempoolBulk)

    _this = this
  }

  /**
   * @api {get} /electrumx/balance/{addr} Get balance for a single address.
   * @apiName Balance for a single address
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an object with confirmed and unconfirmed balance associated with an address.
   *
   *
   * @apiExample Example usage:
   * curl -X GET "https://api.fullstack.cash/v5/electrumx/balance/bitcoincash:qr69kyzha07dcecrsvjwsj4s6slnlq4r8c30lxnur3" -H "accept: application/json"
   *
   */
  // GET handler for single balance
  async getBalance (req, res, next) {
    try {
      const address = req.params.address

      // Reject if address is an array.
      if (Array.isArray(address)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'address can not be an array. Use POST for bulk upload.'
        })
      }

      // Ensure the address is in cash address format.
      const cashAddr = _this.bchjs.Address.toCashAddress(address)

      // Prevent a common user error. Ensure they are using the correct network address.
      const networkIsValid = _this.routeUtils.validateNetwork(cashAddr)
      if (!networkIsValid) {
        res.status(400)
        return res.json({
          success: false,
          error:
            'Invalid network. Trying to use a testnet address on mainnet, or vice versa.'
        })
      }

      wlogger.debug(
        'Executing electrumx/getBalance with this address: ',
        cashAddr
      )

      const response = await _this.axios.get(
        `${_this.fulcrumApi}electrumx/balance/${address}`
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in elecrumx.js/getBalance().', err)

      return _this.errorHandler(err, res)
    }
  }

  /**
   * @api {post} /electrumx/balance Get balances for an array of addresses.
   * @apiName  Balances for an array of addresses
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of balanes associated with an array of address.
   * Limited to 20 items per request.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/balance" -H "accept: application/json" -H "Content-Type: application/json" -d '{"addresses":["bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf","bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf"]}'
   *
   *
   */
  // POST handler for bulk queries on address balance
  async balanceBulk (req, res, next) {
    try {
      const addresses = req.body.addresses

      // Reject if addresses is not an array.
      if (!Array.isArray(addresses)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'addresses needs to be an array. Use GET for single address.'
        })
      }

      // Enforce array size rate limits
      if (!_this.routeUtils.validateArraySize(req, addresses)) {
        res.status(400) // https://github.com/Bitcoin-com/rest.bitcoin.com/issues/330
        return res.json({
          success: false,
          error: 'Array too large.'
        })
      }

      wlogger.debug(
        'Executing electrumx.js/balanceBulk with these addresses: ',
        addresses
      )

      // Validate each element in the address array.
      for (let i = 0; i < addresses.length; i++) {
        const thisAddress = addresses[i]

        // Ensure the input is a valid BCH address.
        try {
          _this.bchjs.Address.toLegacyAddress(thisAddress)
        } catch (err) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid BCH address. Double check your address is valid: ${thisAddress}`
          })
        }

        // Prevent a common user error. Ensure they are using the correct network address.
        const networkIsValid = _this.routeUtils.validateNetwork(thisAddress)
        if (!networkIsValid) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid network for address ${thisAddress}. Trying to use a testnet address on mainnet, or vice versa.`
          })
        }
      }

      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/balance/`,
        { addresses }
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in electrumx.js/balanceBulk().', err)

      return _this.errorHandler(err, res)
    }
  }

  // Returns a promise that resolves to UTXO data for an address. Expects input
  // to be a cash address, and input validation to have already been done by
  // parent, calling function.
  // async _utxosFromElectrumx (address) {
  //   try {
  //     // Convert the address to a scripthash.
  //     const scripthash = _this.addressToScripthash(address)
  //
  //     if (!_this.isReady) {
  //       throw new Error(
  //         'ElectrumX server connection is not ready. Call await connectToServer() first.'
  //       )
  //     }
  //
  //     // Query the utxos from the ElectrumX server.
  //     const electrumResponse = await _this.electrumx.request(
  //       'blockchain.scripthash.listunspent',
  //       scripthash
  //     )
  //     // console.log(
  //     //   `electrumResponse: ${JSON.stringify(electrumResponse, null, 2)}`
  //     // )
  //
  //     return electrumResponse
  //   } catch (err) {
  //     // console.log('err: ', err)
  //
  //     // Write out error to error log.
  //     wlogger.error('Error in elecrumx.js/_utxosFromElectrumx(): ', err)
  //     throw err
  //   }
  // }

  /**
   * @api {get} /electrumx/utxos/{addr} Get utxos for a single address.
   * @apiName UTXOs for a single address
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an object with UTXOs associated with an address.
   *
   *
   * @apiExample Example usage:
   * curl -X GET "https://api.fullstack.cash/v5/electrumx/utxos/bitcoincash:qr69kyzha07dcecrsvjwsj4s6slnlq4r8c30lxnur3" -H "accept: application/json"
   *
   */
  // GET handler for single balance
  async getUtxos (req, res, next) {
    try {
      const address = req.params.address

      // Reject if address is an array.
      if (Array.isArray(address)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'address can not be an array. Use POST for bulk upload.'
        })
      }

      const cashAddr = _this.bchjs.Address.toCashAddress(address)

      // Prevent a common user error. Ensure they are using the correct network address.
      const networkIsValid = _this.routeUtils.validateNetwork(cashAddr)
      if (!networkIsValid) {
        res.status(400)
        return res.json({
          success: false,
          error:
            'Invalid network. Trying to use a testnet address on mainnet, or vice versa.'
        })
      }

      wlogger.debug(
        'Executing electrumx/getUtxos with this address: ',
        cashAddr
      )

      // Get data from ElectrumX server.
      const response = await _this.axios.get(
        `${_this.fulcrumApi}electrumx/utxos/${address}`
      )
      // console.log('response', response, _this.fulcrumApi)

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in elecrumx.js/getUtxos().', err)

      return _this.errorHandler(err, res)
    }
  }

  /**
   * @api {post} /electrumx/utxo Get utxos for an array of addresses.
   * @apiName  UTXOs for an array of addresses
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of objects with UTXOs associated with an address.
   * Limited to 20 items per request.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/utxos" -H "accept: application/json" -H "Content-Type: application/json" -d '{"addresses":["bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf","bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf"]}'
   *
   *
   */
  // POST handler for bulk queries on address details
  async utxosBulk (req, res, next) {
    try {
      const addresses = req.body.addresses
      // const currentPage = req.body.page ? parseInt(req.body.page, 10) : 0

      // Reject if addresses is not an array.
      if (!Array.isArray(addresses)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'addresses needs to be an array. Use GET for single address.'
        })
      }

      // Enforce array size rate limits
      if (!_this.routeUtils.validateArraySize(req, addresses)) {
        res.status(400) // https://github.com/Bitcoin-com/rest.bitcoin.com/issues/330
        return res.json({
          success: false,
          error: 'Array too large.'
        })
      }

      wlogger.debug(
        'Executing electrumx.js/utxoBulk with these addresses: ',
        addresses
      )

      // Validate each element in the address array.
      for (let i = 0; i < addresses.length; i++) {
        const thisAddress = addresses[i]

        // Ensure the input is a valid BCH address.
        try {
          _this.bchjs.Address.toLegacyAddress(thisAddress)
        } catch (err) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid BCH address. Double check your address is valid: ${thisAddress}`
          })
        }

        // Prevent a common user error. Ensure they are using the correct network address.
        const networkIsValid = _this.routeUtils.validateNetwork(thisAddress)
        if (!networkIsValid) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid network for address ${thisAddress}. Trying to use a testnet address on mainnet, or vice versa.`
          })
        }
      }

      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/utxos/`,
        { addresses }
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      wlogger.error('Error in electrumx.js/utxoBulk().', err)

      return _this.errorHandler(err, res)
    }
  }

  // Returns a promise that resolves to transaction details data for a txid.
  // Expects input to be a txid string, and input validation to have already
  // been done by parent, calling function.
  // async _transactionDetailsFromElectrum (txid, verbose = true) {
  //   try {
  //     if (!_this.isReady) {
  //       throw new Error(
  //         'ElectrumX server connection is not ready. Call await connectToServer() first.'
  //       )
  //     }
  //
  //     // Query the utxos from the ElectrumX server.
  //     const electrumResponse = await _this.electrumx.request(
  //       'blockchain.transaction.get',
  //       txid,
  //       verbose
  //     )
  //     // console.log(
  //     //   `electrumResponse: ${JSON.stringify(electrumResponse, null, 2)}`
  //     // )
  //
  //     return electrumResponse
  //   } catch (err) {
  //     // console.log('err: ', err)
  //
  //     // Write out error to error log.
  //     wlogger.error(
  //       'Error in elecrumx.js/_transactionDetailsFromElectrum(): ',
  //       err
  //     )
  //     throw err
  //   }
  // }

  /**
   * @api {get} /electrumx/tx/data/{txid} Get transaction details for a TXID
   * @apiName transaction details for a TXID
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an object with transaction details of the TXID
   *
   *
   * @apiExample Example usage:
   * curl -X GET "https://api.fullstack.cash/v5/electrumx/tx/data/a1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d" -H "accept: application/json"
   *
   */
  // GET handler for single transaction
  async getTransactionDetails (req, res, next) {
    try {
      const txid = req.params.txid
      // const verbose = req.query.verbose

      // Reject if txid is anything other than a string
      if (typeof txid !== 'string') {
        res.status(400)
        return res.json({
          success: false,
          error: 'txid must be a string'
        })
      }

      wlogger.debug(
        'Executing electrumx/getTransactionDetails with this txid: ',
        txid
      )

      // Get data from ElectrumX server.
      const response = await _this.axios.get(
        `${_this.fulcrumApi}electrumx/tx/data/${txid}`
      )
      // console.log(`_transactionDetailsFromElectrum(): ${JSON.stringify(electrumResponse, null, 2)}`)

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in elecrumx.js/getTransactionDetails().', err)

      return _this.errorHandler(err, res)
    }
  }

  /**
   * @api {post} /electrumx/tx/data Get transaction details for an array of TXIDs
   * @apiName  Transaction details for an array of TXIDs
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of objects with transaction details of an array of TXIDs.
   * Limited to 20 items per request.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/tx/data" -H "accept: application/json" -H "Content-Type: application/json" -d '{"txids":["a1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d","a1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d"], "verbose":false}'
   *
   *
   */
  // POST handler for bulk queries on transaction details
  async transactionDetailsBulk (req, res, next) {
    try {
      const txids = req.body.txids
      const verbose = req.body.verbose || true
      // Reject if txids is not an array.
      if (!Array.isArray(txids)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'txids needs to be an array. Use GET for single txid.'
        })
      }

      // Enforce array size rate limits
      if (!_this.routeUtils.validateArraySize(req, txids)) {
        res.status(400) // https://github.com/Bitcoin-com/rest.bitcoin.com/issues/330
        return res.json({
          success: false,
          error: 'Array too large.'
        })
      }

      wlogger.debug(
        'Executing electrumx.js/transactionDetailsBulk with these txids: ',
        txids
      )

      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/tx/data`,
        { txids, verbose }
      )

      // Return the array of retrieved transaction details.
      res.status(200)
      return res.json(response.data)
    } catch (err) {
      wlogger.error('Error in electrumx.js/transactionDetailsBulk().', err)

      return _this.errorHandler(err, res)
    }
  }

  // Returns a promise that resolves to transaction ID of the broadcasted transaction or an error.
  // Expects input to be a txHex string, and input validation to have already
  // been done by parent, calling function.
  // async _broadcastTransactionWithElectrum (txHex) {
  //   try {
  //     if (!_this.isReady) {
  //       throw new Error(
  //         'ElectrumX server connection is not ready. Call await connectToServer() first.'
  //       )
  //     }
  //
  //     // Broadcast the transaction hex to the ElectrumX server.
  //     const electrumResponse = await _this.electrumx.request(
  //       'blockchain.transaction.broadcast',
  //       txHex
  //     )
  //     // console.log(
  //     //   `electrumResponse: ${JSON.stringify(electrumResponse, null, 2)}`
  //     // )
  //
  //     return electrumResponse
  //   } catch (err) {
  //     // console.log('err: ', err)
  //
  //     // Write out error to error log.
  //     wlogger.error(
  //       'Error in elecrumx.js/_transactionDetailsFromElectrum(): ',
  //       err
  //     )
  //     throw err
  //   }
  // }

  /**
   * @api {post} /electrumx/tx/broadcast Broadcast a raw transaction
   * @apiName Broadcast a raw transaction
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Broadcast a raw transaction and return the transaction ID on success or error on failure.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/tx/broadcast" -H "accept: application/json" -H "Content-Type: application/json" -d '{"txHex":"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"}'
   *
   */
  // POST handler for broadcasting a single transaction
  async broadcastTransaction (req, res, next) {
    try {
      const txHex = req.body.txHex
      if (typeof txHex !== 'string') {
        res.status(400)
        return res.json({
          success: false,
          error: 'request body must be a string.'
        })
      }

      wlogger.debug(
        'Executing electrumx/broadcastTransaction with this tx hex: ',
        txHex
      )

      // Get data from ElectrumX server.
      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/tx/broadcast`,
        { txHex }
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      wlogger.error('Error in electrumx.js/broadcastTransaction().', err)

      return _this.errorHandler(err, res)
    }
  }

  // Returns a promise that resolves to block header data for a block height.
  // Expects input to be a height number, and input validation to have already
  // been done by parent, calling function.
  // async _blockHeadersFromElectrum (height, count = 1) {
  //   try {
  //     if (!_this.isReady) {
  //       throw new Error(
  //         'ElectrumX server connection is not ready. Call await connectToServer() first.'
  //       )
  //     }
  //
  //     // Query the block header from the ElectrumX server.
  //     const electrumResponse = await _this.electrumx.request('blockchain.block.headers', height, count)
  //     // console.log(
  //     //   `electrumResponse: ${JSON.stringify(electrumResponse, null, 2)}`
  //     // )
  //
  //     const HEADER_SIZE = 80 * 2
  //
  //     if (!(electrumResponse instanceof Error)) {
  //       const headers = electrumResponse.hex.match(new RegExp(`.{1,${HEADER_SIZE}}`, 'g'))
  //       return headers
  //     }
  //
  //     return electrumResponse
  //   } catch (err) {
  //     // console.log('err: ', err)
  //
  //     // Write out error to error log.
  //     wlogger.error(
  //       'Error in elecrumx.js/_blockHeaderFromElectrum(): ',
  //       err
  //     )
  //     throw err
  //   }
  // }

  /**
   * @api {get} /electrumx/block/headers/{height} Get `count` block headers starting at a height
   * @apiName Block header data for a `count` blocks starting at a block height
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array with block headers starting at the block height
   *
   *
   * @apiExample Example usage:
   * curl -X GET "https://api.fullstack.cash/v5/electrumx/block/headers/42?count=2" -H "accept: application/json"
   *
   */
  // GET handler for single block headers
  async getBlockHeaders (req, res, next) {
    try {
      const height = Number(req.params.height)
      const count = req.query.count === undefined ? 1 : Number(req.query.count)

      // Reject if height is not a number
      if (Number.isNaN(height) || height < 0) {
        res.status(400)
        return res.json({
          success: false,
          error: 'height must be a positive number'
        })
      }

      // Reject if height is not a number
      if (Number.isNaN(count) || count < 0) {
        res.status(400)
        return res.json({
          success: false,
          error: 'count must be a positive number'
        })
      }

      wlogger.debug(
        'Executing electrumx/getBlockHeaders with this height: ',
        height
      )

      const response = await _this.axios.get(
        `${_this.fulcrumApi}electrumx/block/headers/${height}?count=${count}`
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in elecrumx.js/getBlockHeader().', err)

      return _this.errorHandler(err, res)
    }
  }

  /**
   * @api {post} /electrumx/block/headers Get block headers for an array of height + count pairs
   * @apiName  Block headers for an array of height + count pairs
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of objects with blockheaders of an array of TXIDs.
   * Limited to 20 items per request.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/block/headers" -H "accept: application/json" -H "Content-Type: application/json" -d '{"heights":[{ "height": 42, "count": 2 }, { "height": 100, "count": 5 }]}'
   *
   */
  // POST handler for bulk queries on block headers
  async blockHeadersBulk (req, res, next) {
    try {
      const heights = req.body.heights

      // Reject if heights is not an array.
      if (!Array.isArray(heights)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'heights needs to be an array. Use GET for single height.'
        })
      }

      // Enforce array size rate limits
      if (!_this.routeUtils.validateArraySize(req, heights)) {
        res.status(400) // https://github.com/Bitcoin-com/rest.bitcoin.com/issues/330
        return res.json({
          success: false,
          error: 'Array too large.'
        })
      }

      wlogger.debug(
        'Executing electrumx.js/blockHeadersBulk with these txids: ',
        heights
      )

      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/block/headers`,
        { heights }
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      wlogger.error('Error in electrumx.js/blockHeadersBulk().', err)

      return _this.errorHandler(err, res)
    }
  }

  // Returns a promise that resolves an array of transaction history for an
  // address. Expects input to be a cash address, and input validation to have
  // already been done by parent, calling function.
  // async _transactionsFromElectrumx (address) {
  //   try {
  //     // Convert the address to a scripthash.
  //     const scripthash = _this.addressToScripthash(address)
  //
  //     if (!_this.isReady) {
  //       throw new Error(
  //         'ElectrumX server connection is not ready. Call await connectToServer() first.'
  //       )
  //     }
  //
  //     // Query the address transaction history from the ElectrumX server.
  //     const electrumResponse = await _this.electrumx.request(
  //       'blockchain.scripthash.get_history',
  //       scripthash
  //     )
  //     // console.log(
  //     //   `electrumResponse: ${JSON.stringify(electrumResponse, null, 2)}`
  //     // )
  //
  //     return electrumResponse
  //   } catch (err) {
  //     // console.log('err1: ', err)
  //
  //     // Write out error to error log.
  //     wlogger.error('Error in elecrumx.js/_transactionsFromElectrumx(): ', err)
  //     throw err
  //   }
  // }

  /**
   * @api {get} /electrumx/transactions/{addr} Get transaction history for a single address.
   * @apiName Transaction history for a single address
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of historical transactions associated with an address.
   *
   *
   * @apiExample Example usage:
   * curl -X GET "https://api.fullstack.cash/v5/electrumx/transactions/bitcoincash:qr69kyzha07dcecrsvjwsj4s6slnlq4r8c30lxnur3" -H "accept: application/json"
   *
   */
  // GET handler for single balance
  async getTransactions (req, res, next) {
    try {
      const address = req.params.address

      // Reject if address is an array.
      if (Array.isArray(address)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'address can not be an array. Use POST for bulk upload.'
        })
      }

      // Ensure the address is in cash address format.
      const cashAddr = _this.bchjs.Address.toCashAddress(address)

      // Prevent a common user error. Ensure they are using the correct network address.
      const networkIsValid = _this.routeUtils.validateNetwork(cashAddr)
      if (!networkIsValid) {
        res.status(400)
        return res.json({
          success: false,
          error:
            'Invalid network. Trying to use a testnet address on mainnet, or vice versa.'
        })
      }

      wlogger.debug(
        'Executing electrumx/getTransactions with this address: ',
        cashAddr
      )

      // Get data from ElectrumX server.
      const response = await _this.axios.get(
        `${_this.fulcrumApi}electrumx/transactions/${address}`
      )
      // console.log('response', response, _this.fulcrumApi)

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in elecrumx.js/getTransactions().', err)

      return _this.errorHandler(err, res)
    }
  }

  /**
   * @api {post} /electrumx/transactions Get the transaction history for an array of addresses.
   * @apiName  Transactions for an array of addresses
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of transactions associated with an array of address.
   * Limited to 20 items per request.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/transactions" -H "accept: application/json" -H "Content-Type: application/json" -d '{"addresses":["bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf","bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf"]}'
   *
   *
   */
  // POST handler for bulk queries on transaction histories for addresses.
  async transactionsBulk (req, res, next) {
    try {
      const addresses = req.body.addresses

      // Reject if addresses is not an array.
      if (!Array.isArray(addresses)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'addresses needs to be an array. Use GET for single address.'
        })
      }

      // Enforce array size rate limits
      if (!_this.routeUtils.validateArraySize(req, addresses)) {
        res.status(400) // https://github.com/Bitcoin-com/rest.bitcoin.com/issues/330
        return res.json({
          success: false,
          error: 'Array too large.'
        })
      }

      wlogger.debug(
        'Executing electrumx.js/transactionsBulk with these addresses: ',
        addresses
      )

      // Validate each element in the address array.
      for (let i = 0; i < addresses.length; i++) {
        const thisAddress = addresses[i]

        // Ensure the input is a valid BCH address.
        try {
          _this.bchjs.Address.toLegacyAddress(thisAddress)
        } catch (err) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid BCH address. Double check your address is valid: ${thisAddress}`
          })
        }

        // Prevent a common user error. Ensure they are using the correct network address.
        const networkIsValid = _this.routeUtils.validateNetwork(thisAddress)
        if (!networkIsValid) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid network for address ${thisAddress}. Trying to use a testnet address on mainnet, or vice versa.`
          })
        }
      }

      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/transactions/`,
        { addresses }
      )

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      wlogger.error('Error in electrumx.js/transactionsBulk().', err)

      return _this.errorHandler(err, res)
    }
  }

  // Returns a promise that resolves to unconfirmed UTXO data (mempool) for an address.
  // Expects input to be a cash address, and input validation to have
  // already been done by parent, calling function.
  // async _mempoolFromElectrumx (address) {
  //   try {
  //     // Convert the address to a scripthash.
  //     const scripthash = _this.addressToScripthash(address)
  //
  //     if (!_this.isReady) {
  //       throw new Error(
  //         'ElectrumX server connection is not ready. Call await connectToServer() first.'
  //       )
  //     }
  //
  //     // Query the unconfirmed utxos from the ElectrumX server.
  //     const electrumResponse = await _this.electrumx.request(
  //       'blockchain.scripthash.get_mempool',
  //       scripthash
  //     )
  //     // console.log(
  //     //   `electrumResponse: ${JSON.stringify(electrumResponse, null, 2)}`
  //     // )
  //
  //     return electrumResponse
  //   } catch (err) {
  //     // console.log('err: ', err)
  //
  //     // Write out error to error log.
  //     wlogger.error('Error in elecrumx.js/_mempoolFromElectrumx(): ', err)
  //     throw err
  //   }
  // }

  /**
   * @api {get} /electrumx/unconfirmed/{addr} Get unconfirmed utxos for a single address.
   * @apiName Unconfirmed UTXOs for a single address
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an object with unconfirmed UTXOs associated with an address.
   *
   *
   * @apiExample Example usage:
   * curl -X GET "https://api.fullstack.cash/v5/electrumx/unconfirmed/bitcoincash:qr69kyzha07dcecrsvjwsj4s6slnlq4r8c30lxnur3" -H "accept: application/json"
   *
   */
  // GET handler for single balance
  async getMempool (req, res, next) {
    try {
      const address = req.params.address

      // Reject if address is an array.
      if (Array.isArray(address)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'address can not be an array. Use POST for bulk upload.'
        })
      }

      // Ensure the address is in cash address format.
      const cashAddr = _this.bchjs.Address.toCashAddress(address)

      // Prevent a common user error. Ensure they are using the correct network address.
      const networkIsValid = _this.routeUtils.validateNetwork(cashAddr)
      if (!networkIsValid) {
        res.status(400)
        return res.json({
          success: false,
          error:
            'Invalid network. Trying to use a testnet address on mainnet, or vice versa.'
        })
      }

      wlogger.debug(
        'Executing electrumx/getMempool with this address: ',
        cashAddr
      )

      // Get data from ElectrumX server.
      const response = await _this.axios.get(
        `${_this.fulcrumApi}electrumx/unconfirmed/${address}`
      )
      // console.log('response', response, _this.fulcrumApi)

      res.status(200)
      return res.json(response.data)
    } catch (err) {
      // Write out error to error log.
      wlogger.error('Error in elecrumx.js/getMempool().', err)

      return _this.errorHandler(err, res)
    }
  }

  /**
   * @api {post} /electrumx/unconfirmed Get unconfirmed utxos for an array of addresses.
   * @apiName  Unconfirmed UTXOs for an array of addresses
   * @apiGroup ElectrumX / Fulcrum
   * @apiDescription Returns an array of objects with unconfirmed UTXOs associated with an address.
   * Limited to 20 items per request.
   *
   * @apiExample Example usage:
   * curl -X POST "https://api.fullstack.cash/v5/electrumx/unconfirmed" -H "accept: application/json" -H "Content-Type: application/json" -d '{"addresses":["bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf","bitcoincash:qrdka2205f4hyukutc2g0s6lykperc8nsu5u2ddpqf"]}'
   *
   *
   */
  // POST handler for bulk queries on address details
  async mempoolBulk (req, res, next) {
    try {
      const addresses = req.body.addresses

      // Reject if addresses is not an array.
      if (!Array.isArray(addresses)) {
        res.status(400)
        return res.json({
          success: false,
          error: 'addresses needs to be an array. Use GET for single address.'
        })
      }

      // Enforce array size rate limits
      if (!_this.routeUtils.validateArraySize(req, addresses)) {
        res.status(400) // https://github.com/Bitcoin-com/rest.bitcoin.com/issues/330
        return res.json({
          success: false,
          error: 'Array too large.'
        })
      }

      wlogger.debug(
        'Executing electrumx.js/mempoolBulk with these addresses: ',
        addresses
      )

      // Validate each element in the address array.
      for (let i = 0; i < addresses.length; i++) {
        const thisAddress = addresses[i]

        // Ensure the input is a valid BCH address.
        try {
          _this.bchjs.Address.toLegacyAddress(thisAddress)
        } catch (err) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid BCH address. Double check your address is valid: ${thisAddress}`
          })
        }

        // Prevent a common user error. Ensure they are using the correct network address.
        const networkIsValid = _this.routeUtils.validateNetwork(thisAddress)
        if (!networkIsValid) {
          res.status(400)
          return res.json({
            success: false,
            error: `Invalid network for address ${thisAddress}. Trying to use a testnet address on mainnet, or vice versa.`
          })
        }
      }
      const response = await _this.axios.post(
        `${_this.fulcrumApi}electrumx/unconfirmed/`,
        { addresses }
      )
      res.status(200)
      return res.json(response.data)
    } catch (err) {
      wlogger.error('Error in electrumx.js/mempoolBulk().', err)

      return _this.errorHandler(err, res)
    }
  }

  // DRY error handler.
  errorHandler (err, res) {
    // Attempt to decode the error message.
    const { msg, status } = _this.routeUtils.decodeError(err)
    if (msg) {
      res.status(status)
      return res.json({ success: false, error: msg })
    }

    // Handle error patterns specific to this route.
    if (err.message) {
      res.status(400)
      return res.json({ success: false, error: err.message })
    }

    // If error can be handled, return the stack trace
    res.status(500)
    return res.json({ error: util.inspect(err) })
  }

  // Root API endpoint. Simply acknowledges that it exists.
  root (req, res, next) {
    return res.json({ status: 'electrumx' })
  }
}

module.exports = Electrum