import Web3 from 'web3'

const DEFAULT_INTERVAL = 500

const DEFAULT_BLOCKS_TO_WAIT = 6

interface Options {
  interval: number
  blocksToWait: number
}

/**
 * Wait for one or multiple transactions to confirm.
 *
 * @param web3
 * @param txnHash A transaction hash or list of those
 * @param options Wait timers
 * @return Transaction receipt
 */
export function waitTransaction(web3: Web3, txnHash: string | string[], options: Options = null): Promise<any> {
  const interval = options && options.interval ? options.interval : DEFAULT_INTERVAL
  const blocksToWait = options && options.blocksToWait ? options.blocksToWait : DEFAULT_BLOCKS_TO_WAIT
  var transactionReceiptAsync = async function (txnHash, resolve, reject) {
    try {
      var receipt = web3.eth.getTransactionReceipt(txnHash)
      if (!receipt) {
        setTimeout(function () {
          transactionReceiptAsync(txnHash, resolve, reject)
        }, interval)
      } else {
        if (blocksToWait > 0) {
          var resolvedReceipt = await receipt
          if (!resolvedReceipt || !resolvedReceipt.blockNumber)
            setTimeout(function () {
              transactionReceiptAsync(txnHash, resolve, reject)
            }, interval)
          else {
            try {
              var block = await web3.eth.getBlock(resolvedReceipt.blockNumber)
              var current = await web3.eth.getBlock('latest')
              if (current.number - block.number >= blocksToWait) {
                var txn = await web3.eth.getTransaction(txnHash)
                if (txn.blockNumber != null) resolve(resolvedReceipt)
                else reject(new Error('Transaction with hash: ' + txnHash + ' ended up in an uncle block.'))
              } else
                setTimeout(function () {
                  transactionReceiptAsync(txnHash, resolve, reject)
                }, interval)
            } catch (e) {
              setTimeout(function () {
                transactionReceiptAsync(txnHash, resolve, reject)
              }, interval)
            }
          }
        } else resolve(receipt)
      }
    } catch (e) {
      reject(e)
    }
  }

  // Resolve multiple transactions once
  if (Array.isArray(txnHash)) {
    var promises = []
    txnHash.forEach(function (oneTxHash) {
      promises.push(waitTransaction(web3, oneTxHash, options))
    })
    return Promise.all(promises)
  } else {
    return new Promise(function (resolve, reject) {
      transactionReceiptAsync(txnHash, resolve, reject)
    })
  }
}

/**
 * Check if the transaction was success based on the receipt.
 *
 * https://ethereum.stackexchange.com/a/45967/620
 *
 * @param receipt Transaction receipt
 */
export function isSuccessfulTransaction(receipt: any): boolean {
  if (receipt.status == '0x1' || receipt.status == 1) {
    return true
  } else {
    return false
  }
}