app.get('/api/getHistory/:contractAddress/:method', function (req, res) {
  const contractAddress = req.params.contractAddress
  const method = req.params.method
  let contract = null
  // First we obtain the contract.
  return Parity.getContract(contractAddress)
  // Then, we get the history of transactions
    .then(function (parsedContract) {
      contract = parsedContract
      return Parity.getHistory(contractAddress)
    })
    .then(function (events) {
      // console.log(events)
      Parity.generateDataPoints(events, contract, method, res)
      // return res.status(200).json(history)
    })
    .then(results => res.status(200).json(results))
    .catch(function (err) {
      console.log(err)
      return res.status(400).json(err.message)
    })
})


/////////////////////////////////////////////

generateDataPoints: function (events, contract, method, res) {
  Promise.all(
    events.map(function(event) {
      console.log('mapping')
      return Promise.all([
        Parity.getBlockTime(event.blockNumber.valueOf()),
        Parity.queryAtBlock(contract[method], event.blockNumber.valueOf())
      ])
    })
  )
    .then(function (pairs) {
      console.log('filtering')
      let prevTime = 0
      return pairs.filter(([time, val]) => {
        if (time !== prevTime) {
          prevTime = time;
          return true;
        } else {
          return false;
        }
      })
    })
}