'use strict'
import { Transaction as Tx } from '@ethereumjs/tx'
import { Block } from '@ethereumjs/block'
import { BN, bufferToHex, Address } from 'ethereumjs-util'
import { vm as remixlibVM } from '@remix-project/remix-lib'
import VM from '@ethereumjs/vm'
import Common from '@ethereumjs/common'

export function sendTx (vm, from, to, value, data, cb?) {
  cb = cb || (() => {})
  return new Promise ((resolve, reject) => {
    var tx = new Tx({
      nonce: new BN(from.nonce++),
      // gasPrice: new BN(1),
      gasLimit: new BN(3000000, 10),
      to: to,
      value: new BN(value, 10),
      data: Buffer.from(data, 'hex')
    })
    tx = tx.sign(from.privateKey)
  
    var block = Block.fromBlockData({
      header: {
        timestamp: new Date().getTime() / 1000 | 0,
        number: 0
      }
    }) // still using default common
  
    try {
      vm.runTx({block: block, tx: tx, skipBalance: true, skipNonce: true}).then(function (result) {
        setTimeout(() => {
          const hash = bufferToHex(tx.hash())
          cb(null, { hash, result })
          resolve({ hash, result })
        }, 500)
      }).catch((error) => {
        console.error(error)
        cb(error)
        reject(error)
      })
    } catch (e) {
      console.error(e)
    }
  })
}

async function createVm (hardfork) {
  const common = new Common({ chain: 'mainnet', hardfork })
  const vm = new VM({ common })   
  await vm.init()
  return { vm, stateManager: vm.stateManager }
}

/*
  Init VM / Send Transaction
*/
export async function initVM (st, privateKey) {
  var VM = await createVm('berlin')
  const vm = VM.vm

  var address = Address.fromPrivateKey(privateKey)

  try {
    let account = await vm.stateManager.getAccount(address)
    account.balance = new BN('f00000000000000001', 16)
    await vm.stateManager.putAccount(address, account)
  } catch (error) {
    console.log(error)
  }
  
  var web3Provider = new remixlibVM.Web3VMProvider()
  web3Provider.setVM(vm)
  vm.web3 = web3Provider
  return vm
}