const _ = require('lodash/fp')

const db = require('./db')
const dbm = require('./postgresql_interface')
const T = require('./time')
const BN = require('./bn')

const TRANSACTION_EXPIRATION = T.day

function httpError (msg, code) {
  const err = new Error(msg)
  err.name = 'HTTPError'
  err.code = code || 500

  return err
}

function stateChange (deviceId, deviceTime, rec) {
  const event = {
    id: rec.uuid,
    deviceId: deviceId,
    eventType: 'stateChange',
    note: JSON.stringify({ state: rec.state, isIdle: rec.isIdle, txId: rec.txId }),
    deviceTime: deviceTime
  }
  return dbm.machineEvent(event)
}

function toCashOutTx (row) {
  if (!row) return null

  const keys = _.keys(row)
  let newObj = {}

  keys.forEach(key => {
    const objKey = _.camelCase(key)
    if (key === 'crypto_atoms' || key === 'fiat') {
      newObj[objKey] = new BN(row[key])
      return
    }

    newObj[objKey] = row[key]
  })

  return _.set('direction', 'cashOut', newObj)
}

function fetchEmailOrPhoneTx (data, type) {
  const sql = `select * from cash_out_txs
    where ${type === 'email' ? 'email' : 'phone'}=$1 and dispense=$2
    and (extract(epoch from (now() - created))) * 1000 < $3`

  const values = [data, false, TRANSACTION_EXPIRATION]

  return db.any(sql, values)
    .then(_.map(toCashOutTx))
    .then(txs => {
      const seenTxs = _.some(it => it.status !== 'notSeen', txs)
      const confirmedTxs = txs.filter(tx => _.includes(tx.status, ['instant', 'confirmed']))
      if (confirmedTxs.length > 0) {
        const reducer = (acc, val) => {
          return !acc || val.cryptoAtoms.gt(acc.cryptoAtoms) ? val : acc
        }

        const maxTx = _.reduce(reducer, null, confirmedTxs)

        return maxTx
      }

      if (txs.length > 0 && !seenTxs) throw httpError('Transaction not seen', 411)
      if (txs.length > 0 && seenTxs) throw httpError('Pending transactions', 412)
      throw httpError('No transactions', 404)
    })
}
function fetchEmailTx (email) {
  return fetchEmailOrPhoneTx(email, 'email')
}

function fetchPhoneTx (phone) {
  return fetchEmailOrPhoneTx(phone, 'phone')
}

function fetchStatusTx (txId, status) {
  const sql = 'select * from cash_out_txs where id=$1'

  return db.oneOrNone(sql, [txId])
    .then(toCashOutTx)
    .then(tx => {
      if (!tx) throw httpError('No transaction', 404)
      if (tx.status === status) throw httpError('Not Modified', 304)
      return tx
    })
}

module.exports = {
  stateChange,
  fetchPhoneTx,
  fetchEmailTx,
  fetchStatusTx,
  httpError
}
