module Import.Ing.Convert where

import Control.Monad (when)
import Data.Decimal
import Data.Dependent.Map
import Data.Dependent.Sum ((==>))
import Data.Functor.Identity
import Data.Iban qualified as Iban
import Data.Ledger as L
import Data.Map qualified as M
import Data.Text qualified as T
import Import.Ing.CurrentAccountCsv as C
import Import.Ing.SavingsAccountCsv as S

virtCheckingAccount :: Iban.Iban -> L.AccountId
virtCheckingAccount iban = AccountId ["Unfiled", "Asset", "Current", "Checking", "Iban", Iban.toText iban]

virtCounterparty :: T.Text -> L.AccountId
virtCounterparty name = AccountId ["Unfiled", "Expenses", "Counterparty", "Name", name]

toCents :: Decimal -> Either String L.Money
toCents m
  | f == 0 =
      return (L.Money m')
  | otherwise =
      Left "Cannot convert to whole cents: amount of money is more specific"
  where
    (m', f) = properFraction (m * 100)

condUnitLabel :: UnitTag -> Bool -> L.Labels
condUnitLabel _ False = empty
condUnitLabel t True = singleton (UnitLabel t) (Identity ())

fromCurrentAccountTx :: CommodityId -> C.Tx -> Either String L.Tx
fromCurrentAccountTx eucId (C.Tx base spec) = do
  let acc = virtCheckingAccount base.account
  when (base.amount < 0) $
    Left "Transaction amount may not be lower than zero"
  amount <- L.Amount <$> toCents base.amount
  case spec of
    PaymentTerminalPayment
      { counterpartyName,
        cardSequenceNo,
        timestamp,
        transaction,
        terminal,
        googlePay
      } ->
        return $
          L.Tx
            { cleared = Just base.date,
              commodityId = eucId,
              credit = M.singleton acc amount,
              debit = M.singleton (virtCounterparty counterpartyName) amount,
              labels =
                fromList
                  [ IbanLabel AccountTag ==> base.account,
                    TextLabel CardSeqNoTag ==> cardSequenceNo,
                    TextLabel TerminalTag ==> terminal,
                    TextLabel TransactionTag ==> transaction,
                    TimestampLabel ==> timestamp
                  ]
                  `union` condUnitLabel GooglePayTag googlePay
            }
    PaymentTerminalCashback
      { counterpartyName,
        cardSequenceNo,
        timestamp,
        transaction,
        terminal
      } ->
        return $
          L.Tx
            { cleared = Just base.date,
              commodityId = eucId,
              debit = M.singleton acc amount,
              credit = M.singleton (virtCounterparty counterpartyName) amount,
              labels =
                fromList
                  [ IbanLabel AccountTag ==> base.account,
                    TextLabel CardSeqNoTag ==> cardSequenceNo,
                    TextLabel TerminalTag ==> terminal,
                    TextLabel TransactionTag ==> transaction,
                    TimestampLabel ==> timestamp
                  ]
            }
    OnlineBankingCredit
      { counterpartyName,
        counterpartyIban,
        description,
        timestamp
      } ->
        return $
          L.Tx
            { cleared = Just base.date,
              commodityId = eucId,
              debit = M.singleton acc amount,
              credit = M.singleton (virtCounterparty counterpartyName) amount,
              labels =
                fromList
                  [ IbanLabel AccountTag ==> base.account,
                    IbanLabel CounterpartyIbanTag ==> counterpartyIban,
                    TextLabel DescTag ==> description,
                    TimestampLabel ==> timestamp
                  ]
            }
    OnlineBankingDebit
      { counterpartyName,
        counterpartyIban,
        description,
        mtimestamp
      } ->
        return $
          L.Tx
            { cleared = Just base.date,
              commodityId = eucId,
              debit = M.singleton (virtCounterparty counterpartyName) amount,
              credit = M.singleton acc amount,
              labels =
                fromList
                  [ IbanLabel AccountTag ==> base.account,
                    IbanLabel CounterpartyIbanTag ==> counterpartyIban,
                    TextLabel DescTag ==> description
                  ]
                  `union` (maybe empty (singleton TimestampLabel . Identity) mtimestamp)
            }