import Decimal from 'decimal.js-light'
import { User, Transaction } from '../../entity'
import { TransactionTypeId } from '../../enum'
import { fullName } from 'shared'
import { getLastTransaction } from '../../queries'
import { calculateDecay, Decay } from 'shared'

export async function createTransaction(
  amount: Decimal,
  memo: string,
  user: User,
  linkedUser: User,
  type: TransactionTypeId,
  balanceDate: Date,
  creationDate?: Date,  
  store: boolean = true,
): Promise<Transaction> {
  
  const lastTransaction = await getLastTransaction(user.id)
  // balance and decay calculation
  let newBalance = new Decimal(0)
  let decay: Decay | null = null
  if (lastTransaction) {
    decay = calculateDecay(
      lastTransaction.balance,
      lastTransaction.balanceDate,
      balanceDate,
    )
    newBalance = decay.balance
  }
  newBalance = newBalance.add(amount.toString())

  const transaction = new Transaction()
  transaction.typeId = type
  transaction.memo = memo
  transaction.userId = user.id
  transaction.userGradidoID = user.gradidoID
  transaction.userName = fullName(user.firstName, user.lastName)
  transaction.userCommunityUuid = user.communityUuid
  transaction.linkedUserId = linkedUser.id
  transaction.linkedUserGradidoID = linkedUser.gradidoID
  transaction.linkedUserName = fullName(linkedUser.firstName, linkedUser.lastName)
  transaction.linkedUserCommunityUuid = linkedUser.communityUuid
  transaction.previous = lastTransaction ? lastTransaction.id : null
  transaction.amount = amount
  if (creationDate) {
    transaction.creationDate = creationDate
  }
  transaction.balance = newBalance
  transaction.balanceDate = balanceDate
  transaction.decay = decay ? decay.decay : new Decimal(0)
  transaction.decayStart = decay ? decay.start : null
  
  return store ? transaction.save() : transaction
}