'use strict'

const _ = require('lodash/fp')
const Web3 = require('web3')
const web3 = new Web3()
const hdkey = require('ethereumjs-wallet/hdkey')
const { FeeMarketEIP1559Transaction } = require('@ethereumjs/tx')
const { default: Common, Chain, Hardfork } = require('@ethereumjs/common')
const { default: PQueue } = require('p-queue')
const util = require('ethereumjs-util')
const coins = require('@lamassu/coins')

const _pify = require('pify')
const BN = require('../../../bn')
const ABI = require('../../tokens')
const logger = require('../../../logger')

const paymentPrefixPath = "m/44'/60'/0'/0'"
const defaultPrefixPath = "m/44'/60'/1'/0'"
let lastUsedNonces = {}

module.exports = {
  balance,
  sendCoins,
  newAddress,
  getStatus,
  sweep,
  defaultAddress,
  supportsHd: true,
  newFunding,
  privateKey,
  isStrictAddress,
  connect,
  checkBlockchainStatus,
  getTxHashesByAddress,
  _balance,
}

const SWEEP_QUEUE = new PQueue({
  concurrency: 3,
  interval: 250,
})

const SEND_QUEUE = new PQueue({
  concurrency: 1,
})

const infuraCalls = {}

const pify = _function => {
  if (_.isString(_function.call)) logInfuraCall(_function.call)
  return _pify(_function)
}

const logInfuraCall = call => {
  if (!_.includes('infura', web3.currentProvider.host)) return
  _.isNil(infuraCalls[call]) ? (infuraCalls[call] = 1) : infuraCalls[call]++
  logger.info(
    `Calling web3 method ${call} via Infura. Current count for this session: ${JSON.stringify(infuraCalls)}`,
  )
}

function connect(url) {
  web3.setProvider(new web3.providers.HttpProvider(url))
}

const hex = bigNum => '0x' + bigNum.integerValue(BN.ROUND_DOWN).toString(16)

function privateKey(account) {
  return defaultWallet(account).getPrivateKey()
}

function isStrictAddress(cryptoCode, toAddress) {
  return checkCryptoCode(cryptoCode).then(() =>
    util.isValidChecksumAddress(toAddress),
  )
}

function getTxHashesByAddress() {
  throw new Error(
    `Transactions hash retrieval is not implemented for this coin!`,
  )
}

function sendCoins(account, tx) {
  const { toAddress, cryptoAtoms, cryptoCode } = tx
  const isErc20Token = coins.utils.isErc20Token(cryptoCode)

  return SEND_QUEUE.add(() =>
    (isErc20Token ? generateErc20Tx : generateTx)(
      toAddress,
      defaultWallet(account),
      cryptoAtoms,
      false,
      cryptoCode,
    )
      .then(pify(web3.eth.sendSignedTransaction))
      .then(txid => {
        return pify(web3.eth.getTransaction)(txid).then(tx => {
          if (!tx) return { txid }

          const fee = new BN(tx.gas).times(new BN(tx.gasPrice)).decimalPlaces(0)

          return { txid, fee }
        })
      }),
  )
}

function checkCryptoCode(cryptoCode) {
  if (cryptoCode === 'ETH' || coins.utils.isErc20Token(cryptoCode)) {
    return Promise.resolve(cryptoCode)
  }
  return Promise.reject(new Error('cryptoCode must be ETH'))
}

function balance(account, cryptoCode) {
  return checkCryptoCode(cryptoCode).then(code =>
    confirmedBalance(defaultAddress(account), code),
  )
}

const pendingBalance = (address, cryptoCode) => {
  const promises = [
    _balance(true, address, cryptoCode),
    _balance(false, address, cryptoCode),
  ]
  return Promise.all(promises).then(([pending, confirmed]) =>
    BN(pending).minus(confirmed),
  )
}
const confirmedBalance = (address, cryptoCode) =>
  _balance(false, address, cryptoCode)

function _balance(includePending, address, cryptoCode) {
  if (coins.utils.isErc20Token(cryptoCode)) {
    const contract = new web3.eth.Contract(
      ABI.ERC20,
      coins.utils.getErc20Token(cryptoCode).contractAddress,
    )
    return contract.methods
      .balanceOf(address.toLowerCase())
      .call((_, balance) => {
        return contract.methods
          .decimals()
          .call((_, decimals) => BN(balance).div(10 ** decimals))
      })
  }
  const block = includePending ? 'pending' : undefined
  return (
    pify(web3.eth.getBalance)(address.toLowerCase(), block)
      /* NOTE: Convert bn.js bignum to bignumber.js bignum */
      .then(balance => (balance ? BN(balance) : BN(0)))
  )
}

function generateErc20Tx(_toAddress, wallet, amount, includesFee, cryptoCode) {
  const fromAddress = '0x' + wallet.getAddress().toString('hex')

  const toAddress = coins.utils.getErc20Token(cryptoCode).contractAddress

  const contract = new web3.eth.Contract(ABI.ERC20, toAddress)
  const contractData = contract.methods.transfer(
    _toAddress.toLowerCase(),
    hex(amount),
  )

  const txTemplate = {
    from: fromAddress,
    to: toAddress,
    value: hex(BN(0)),
    data: contractData.encodeABI(),
  }

  const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.London })

  const promises = [
    pify(contractData.estimateGas)(txTemplate),
    pify(web3.eth.getTransactionCount)(fromAddress),
    pify(web3.eth.getBlock)('pending'),
  ]

  return Promise.all(promises)
    .then(([gas, txCount, { baseFeePerGas }]) => [
      BN(gas),
      _.max([0, txCount, lastUsedNonces[fromAddress] + 1]),
      BN(baseFeePerGas),
    ])
    .then(([gas, txCount, baseFeePerGas]) => {
      lastUsedNonces[fromAddress] = txCount

      const maxPriorityFeePerGas = new BN(web3.utils.toWei('1.0', 'gwei')) // web3 default value
      const maxFeePerGas = new BN(2)
        .times(baseFeePerGas)
        .plus(maxPriorityFeePerGas)

      const rawTx = {
        chainId: 1,
        nonce: txCount,
        maxPriorityFeePerGas: web3.utils.toHex(maxPriorityFeePerGas),
        maxFeePerGas: web3.utils.toHex(maxFeePerGas),
        gasLimit: hex(gas),
        to: toAddress,
        from: fromAddress,
        value: hex(BN(0)),
        data: contractData.encodeABI(),
      }

      const tx = FeeMarketEIP1559Transaction.fromTxData(rawTx, { common })
      const privateKey = wallet.getPrivateKey()

      const signedTx = tx.sign(privateKey)

      return '0x' + signedTx.serialize().toString('hex')
    })
}

function generateTx(_toAddress, wallet, amount, includesFee) {
  const fromAddress = '0x' + wallet.getAddress().toString('hex')

  const toAddress = _toAddress.toLowerCase()

  const txTemplate = {
    from: fromAddress,
    to: toAddress,
    value: amount.toString(),
  }

  const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.London })

  const promises = [
    pify(web3.eth.estimateGas)(txTemplate),
    pify(web3.eth.getGasPrice)(),
    pify(web3.eth.getTransactionCount)(fromAddress),
    pify(web3.eth.getBlock)('pending'),
  ]

  return Promise.all(promises)
    .then(([gas, gasPrice, txCount, { baseFeePerGas }]) => [
      BN(gas),
      BN(gasPrice),
      _.max([0, txCount, lastUsedNonces[fromAddress] + 1]),
      BN(baseFeePerGas),
    ])
    .then(([gas, , txCount, baseFeePerGas]) => {
      lastUsedNonces[fromAddress] = txCount

      const maxPriorityFeePerGas = new BN(web3.utils.toWei('1.0', 'gwei')) // web3 default value
      const maxFeePerGas = baseFeePerGas.times(2).plus(maxPriorityFeePerGas)

      const toSend = includesFee
        ? new BN(amount).minus(maxFeePerGas.times(gas))
        : amount

      const rawTx = {
        chainId: 1,
        nonce: txCount,
        maxPriorityFeePerGas: web3.utils.toHex(maxPriorityFeePerGas),
        maxFeePerGas: web3.utils.toHex(maxFeePerGas),
        gasLimit: hex(gas),
        to: toAddress,
        from: fromAddress,
        value: hex(toSend),
      }

      const tx = FeeMarketEIP1559Transaction.fromTxData(rawTx, { common })
      const privateKey = wallet.getPrivateKey()

      const signedTx = tx.sign(privateKey)

      return '0x' + signedTx.serialize().toString('hex')
    })
}

function defaultWallet(account) {
  return defaultHdNode(account).deriveChild(0).getWallet()
}

function defaultAddress(account) {
  return defaultWallet(account).getChecksumAddressString()
}

function sweep(account, txId, cryptoCode, hdIndex) {
  const wallet = paymentHdNode(account).deriveChild(hdIndex).getWallet()
  const fromAddress = wallet.getChecksumAddressString()

  return SWEEP_QUEUE.add(() =>
    confirmedBalance(fromAddress, cryptoCode).then(r => {
      if (r.eq(0)) return

      return generateTx(
        defaultAddress(account),
        wallet,
        r,
        true,
        cryptoCode,
        txId,
      ).then(signedTx => pify(web3.eth.sendSignedTransaction)(signedTx))
    }),
  )
}

function newAddress(account, info) {
  const childNode = paymentHdNode(account).deriveChild(info.hdIndex)
  return Promise.resolve(childNode.getWallet().getChecksumAddressString())
}

function getStatus(account, tx, requested) {
  const { toAddress, cryptoCode } = tx
  return checkCryptoCode(cryptoCode)
    .then(code => Promise.all([confirmedBalance(toAddress, code), code]))
    .then(([confirmed, code]) => {
      if (confirmed.gte(requested))
        return { receivedCryptoAtoms: confirmed, status: 'confirmed' }

      return pendingBalance(toAddress, code).then(pending => {
        if (pending.gte(requested))
          return { receivedCryptoAtoms: pending, status: 'published' }
        if (pending.gt(0))
          return { receivedCryptoAtoms: pending, status: 'insufficientFunds' }
        return { receivedCryptoAtoms: pending, status: 'notSeen' }
      })
    })
}

function paymentHdNode(account) {
  const masterSeed = account.seed
  if (!masterSeed) throw new Error('No master seed!')
  const key = hdkey.fromMasterSeed(masterSeed)
  return key.derivePath(paymentPrefixPath)
}

function defaultHdNode(account) {
  const masterSeed = account.seed
  if (!masterSeed) throw new Error('No master seed!')
  const key = hdkey.fromMasterSeed(masterSeed)
  return key.derivePath(defaultPrefixPath)
}

function newFunding(account, cryptoCode) {
  return checkCryptoCode(cryptoCode).then(code => {
    const fundingAddress = defaultAddress(account)

    const promises = [
      pendingBalance(fundingAddress, code),
      confirmedBalance(fundingAddress, code),
    ]

    return Promise.all(promises).then(
      ([fundingPendingBalance, fundingConfirmedBalance]) => ({
        fundingPendingBalance,
        fundingConfirmedBalance,
        fundingAddress,
      }),
    )
  })
}

function checkBlockchainStatus(cryptoCode) {
  return checkCryptoCode(cryptoCode)
    .then(() =>
      connect(
        `http://localhost:${coins.utils.getCryptoCurrency(cryptoCode).defaultPort}`,
      ),
    )
    .then(() => web3.eth.syncing)
    .then(res => (res === false ? 'ready' : 'syncing'))
}