module Update.LoggedIn
  ( updateLoggedIn
  ) where

import Date
import Dict
import Debug
import Task

import Effects exposing (Effects)
import Http exposing (Error(..))

import Server

import Model exposing (Model)
import Model.User exposing (UserId)
import Model.Payment exposing (..)
import Model.Action.LoggedInAction exposing (..)
import Model.Action.AccountAction as Account
import Model.Action.MonthlyAction as Monthly
import Model.Action.AddPaymentAction as AddPayment
import Model.View.LoggedInView exposing (..)
import Model.View.LoggedIn.AddPayment exposing (..)

import Update.LoggedIn.AddPayment exposing (updateAddPayment, addPaymentError)
import Update.LoggedIn.Monthly exposing (updateMonthly)
import Update.LoggedIn.Account exposing (updateAccount)

updateLoggedIn : Model -> LoggedInAction -> LoggedInView -> (LoggedInView, Effects LoggedInAction)
updateLoggedIn model action loggedInView =
  case action of

    NoOp -> (loggedInView, Effects.none)

    UpdateAdd addPaymentAction ->
      ( { loggedInView | add = updateAddPayment addPaymentAction loggedInView.add }
      , Effects.none
      )

    UpdatePayments payments ->
      ( { loggedInView | payments = payments }
      , Effects.none
      )

    AddPayment name cost frequency ->
      ( { loggedInView | add = updateAddPayment AddPayment.WaitingServer loggedInView.add }
      , Server.addPayment model.translations name cost frequency
          |> flip Task.onError (\err ->
              case err of
                BadResponse 400 jsonErr ->
                  case addPaymentError model.translations jsonErr of
                    Just addPaymentAction -> Task.succeed (UpdateAdd addPaymentAction)
                    Nothing -> Task.succeed NoOp
                _ ->
                  Task.succeed NoOp
             )
          |> Effects.task
      )

    ValidateAddPayment paymentId name cost frequency ->
      let newPayment = Payment paymentId (Date.fromTime model.currentTime) name cost loggedInView.account.me
          newAdd = initAddPayment frequency
      in  case frequency of
            Punctual ->
              let (newAccount, accountEffects) =
                    updateAccount (Account.UpdatePayer loggedInView.account.me model.currentTime cost) loggedInView.account
              in  ( { loggedInView
                  | currentPage = 1
                  , add = newAdd
                  , account = newAccount
                  , payments = newPayment :: loggedInView.payments
                  , paymentsCount = loggedInView.paymentsCount + 1
                  }
                , Effects.map UpdateAccount accountEffects
                )
            Monthly ->
              ( { loggedInView
                | add = newAdd
                , monthly = updateMonthly (Monthly.AddPayment newPayment) loggedInView.monthly
                }
              , Effects.none
              )

    ToggleEdit id ->
      ( { loggedInView | paymentEdition = if loggedInView.paymentEdition == Just id then Nothing else Just id }
      , Effects.none
      )

    DeletePayment payment frequency ->
      ( loggedInView
      , Server.deletePayment payment frequency
          |> flip Task.onError (always <| Task.succeed NoOp)
          |> Effects.task
      )

    ValidateDeletePayment payment frequency ->
      case frequency of
        Monthly ->
          ( { loggedInView
            | monthly = updateMonthly (Monthly.DeletePayment payment) loggedInView.monthly
            }
          , Effects.none
          )
        Punctual ->
          let (newAccount, accountEffects) =
                updateAccount (Account.UpdatePayer payment.userId (Date.toTime payment.creation) -payment.cost) loggedInView.account
          in  ( { loggedInView
                | account = newAccount
                , payments = deletePayment payment.id loggedInView.payments
                , paymentsCount = loggedInView.paymentsCount - 1
                }
              , Effects.map UpdateAccount accountEffects
              )

    UpdatePage page ->
      ( { loggedInView | currentPage = page }
      , Effects.none
      )

    UpdateMonthly monthlyAction ->
      ( { loggedInView | monthly = updateMonthly monthlyAction loggedInView.monthly }
      , Effects.none
      )

    UpdateAccount accountAction ->
      let (newAccount, accountEffects) = updateAccount accountAction loggedInView.account
      in  ( { loggedInView | account = newAccount }
          , Effects.map UpdateAccount accountEffects
          )