module LoggedIn.Update exposing
  ( update
  )

import Dict
import String
import Task

import Http exposing (Error(..))
import Date exposing (Date)
import Platform.Cmd exposing (Cmd)

import Model exposing (Model)
import Model.Translations exposing (getMessage)
import Model.Payment exposing (Payment, Frequency(..), deletePayment)

import Server
import LoggedData

import LoggedIn.Msg as LoggedInMsg
import LoggedIn.Model as LoggedInModel

import LoggedIn.Home.Msg as HomeMsg
import LoggedIn.Home.Update as HomeUpdate

import LoggedIn.Income.Msg as IncomeMsg
import LoggedIn.Income.Update as IncomeUpdate

import LoggedIn.Home.AddPayment.Msg as AddPaymentMsg
import LoggedIn.Home.AddPayment.Update as AddPaymentUpdate

import Utils.Tuple as Tuple
import Utils.Cmd exposing ((:>))

update : Model -> LoggedInMsg.Msg -> LoggedInModel.Model -> (LoggedInModel.Model, Cmd LoggedInMsg.Msg)
update model action loggedIn =
  let loggedData = LoggedData.build model loggedIn
  in  case action of

        LoggedInMsg.NoOp ->
          (loggedIn, Cmd.none)

        LoggedInMsg.HomeMsg homeMsg ->
          case HomeUpdate.update loggedData homeMsg loggedIn.home of
            (home, effects) ->
              ( { loggedIn | home = home }
              , Cmd.map LoggedInMsg.HomeMsg effects
              )

        LoggedInMsg.IncomeMsg incomeMsg ->
          case IncomeUpdate.update loggedData incomeMsg loggedIn.income of
            (income, cmd) ->
              ( { loggedIn | income = income }
              , Cmd.map LoggedInMsg.IncomeMsg cmd
              )

        LoggedInMsg.AddPayment name cost frequency ->
          update model (LoggedInMsg.HomeMsg <| HomeMsg.UpdateAdd <| AddPaymentMsg.WaitingServer) loggedIn
            :> \loggedIn ->
                 Server.addPayment name cost frequency
                   |> Task.perform
                        (\err ->
                          case err of
                            BadResponse 400 jsonErr ->
                              case AddPaymentUpdate.addPaymentError model.translations jsonErr of
                                Just addPaymentMsg -> (LoggedInMsg.HomeMsg <| HomeMsg.UpdateAdd addPaymentMsg)
                                Nothing -> LoggedInMsg.NoOp
                            _ ->
                              LoggedInMsg.NoOp
                        )
                        (\paymentId ->
                          case String.toInt cost of
                            Err _ ->
                              LoggedInMsg.HomeMsg <| HomeMsg.UpdateAdd (AddPaymentMsg.AddError Nothing (Just (getMessage "CostRequired" loggedData.translations)))
                            Ok costNumber ->
                              LoggedInMsg.ValidateAddPayment paymentId name costNumber frequency
                        )
                   |> \cmd -> (loggedIn, cmd)

        LoggedInMsg.ValidateAddPayment paymentId name cost frequency ->
          update model (LoggedInMsg.HomeMsg <| HomeMsg.UpdateAdd <| AddPaymentMsg.Init frequency) loggedIn
            :> (\loggedIn ->
                 case frequency of
                   Punctual ->
                     update model (LoggedInMsg.HomeMsg <| HomeMsg.UpdatePage 1) loggedIn
                   Monthly ->
                     update model (LoggedInMsg.HomeMsg <| HomeMsg.ShowMonthlyDetail) loggedIn
               )
            :> (\loggedIn ->
                 let newPayment = Payment paymentId (Date.fromTime model.currentTime) name cost loggedIn.me frequency
                 in  ( { loggedIn | payments = newPayment :: loggedIn.payments }
                     , Cmd.none
                     )
               )

        LoggedInMsg.DeletePayment paymentId ->
          ( loggedIn
          , Server.deletePayment paymentId
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (always (LoggedInMsg.ValidateDeletePayment paymentId))
          )

        LoggedInMsg.ValidateDeletePayment paymentId ->
          ( { loggedIn | payments = deletePayment paymentId loggedIn.payments }
          , Cmd.none
          )

        LoggedInMsg.AddIncome creation amount ->
          ( loggedIn
          , Server.addIncome creation amount
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (\incomeId -> (LoggedInMsg.ValidateAddIncome incomeId creation amount))
          )

        LoggedInMsg.ValidateAddIncome incomeId creation amount ->
          let newIncome = { userId = loggedIn.me, creation = (Date.toTime creation), amount = amount }
          in  ( { loggedIn | incomes = Dict.insert incomeId newIncome loggedIn.incomes }
              , Cmd.none
              )

        LoggedInMsg.DeleteIncome incomeId ->
          ( loggedIn
          , Server.deleteIncome incomeId
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (always <| LoggedInMsg.ValidateDeleteIncome incomeId)
          )

        LoggedInMsg.ValidateDeleteIncome incomeId ->
          ( { loggedIn | incomes = Dict.remove incomeId loggedIn.incomes }
          , Cmd.none
          )