const { redisClient } = require('./redis')
const config = require('../config')
const { toBN, toHex, toWei, BN, fromWei } = require('web3-utils')

class Sender {
  constructor(web3) {
    this.web3 = web3
    this.watherInterval = config.watherInterval
    this.pendingTxTimeout = config.pendingTxTimeout
    this.gasBumpPercentage = config.gasBumpPercentage
    this.watcher()
  }

  async watcher() {
    try {
      const networkNonce = await this.web3.eth.getTransactionCount(this.web3.eth.defaultAccount)
      let tx = await redisClient.get('tx:' + networkNonce)
      if (tx) {
        tx = JSON.parse(tx)
        if (Date.now() - tx.date > this.pendingTxTimeout) {
          const newGasPrice = toBN(tx.gasPrice).mul(toBN(this.gasBumpPercentage)).div(toBN(100))
          const maxGasPrice = toBN(toWei(config.maxGasPrice))
          tx.gasPrice = toHex(BN.min(newGasPrice, maxGasPrice))
          tx.date = Date.now()
          await redisClient.set('tx:' + tx.nonce, JSON.stringify(tx) )
          console.log('resubmitting with gas price', fromWei(tx.gasPrice.toString()))
          this.sendTx(tx, null, 9999)
        }
      }
    } catch(e) {
      console.error('watcher error:', e)
    } finally {
      setTimeout(() => this.watcher(), this.watherInterval)
    }
  }

  async sendTx(tx, done, retryAttempt = 1) {
    let signedTx = await this.web3.eth.accounts.signTransaction(tx, config.privateKey)
    let result = this.web3.eth.sendSignedTransaction(signedTx.rawTransaction)

    result.once('transactionHash', function(txHash){
      console.log(`A new successfully sent tx ${txHash}`)
      if (done) {
        done(null, {
          status: 200,
          msg: { txHash }
        })
      }
    }).on('error', async function(e){
      console.log(`Error for tx with nonce ${tx.nonce}\n${e.message}`)
      if(e.message === 'Returned error: Transaction gas price supplied is too low. There is another transaction with same nonce in the queue. Try increasing the gas price or incrementing the nonce.'
      || e.message === 'Returned error: Transaction nonce is too low. Try incrementing the nonce.'
      || e.message === 'Returned error: nonce too low'
      || e.message === 'Returned error: replacement transaction underpriced') {
        console.log('nonce too low, retrying')
        if(retryAttempt <= 10) {
          retryAttempt++
          const newNonce = tx.nonce + 1
          tx.nonce = newNonce
          await redisClient.set('nonce', newNonce)
          await redisClient.set('tx:' + newNonce, JSON.stringify(tx))
          this.sendTx(tx, done, retryAttempt)
          return
        }
      }
      if (done) {
        done(null, {
          status: 400,
          msg: { error: 'Internal Relayer Error. Please use a different relayer service' }
        })
      }
    })
  }
}

module.exports = Sender