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 Form

import Model exposing (Model)
import Model.Translations exposing (getMessage)
import Model.Payment as Payment exposing (Payment, Frequency(..))
import Model.Income as Income exposing (Income)

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.Home.Model as HomeModel

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

import LoggedIn.Income.Model as IncomeModel

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

update : Model -> LoggedInMsg.Msg -> LoggedInModel.Model -> (LoggedInModel.Model, Cmd LoggedInMsg.Msg)
update model msg loggedIn =
  let loggedData = LoggedData.build model loggedIn
  in  case msg 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.CreatePayment name cost date frequency ->
          ( loggedIn
          , Server.createPayment name cost date frequency
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (\paymentId -> LoggedInMsg.ValidateCreatePayment paymentId name cost date frequency)
          )

        LoggedInMsg.ValidateCreatePayment paymentId name cost date frequency ->
          update model (LoggedInMsg.HomeMsg <| HomeMsg.SearchMsg (Form.Reset (HomeModel.searchInitial frequency))) loggedIn
            :> update model (LoggedInMsg.HomeMsg <| HomeMsg.UpdatePage 1)
            :> (\loggedIn ->
                 let newPayment = Payment paymentId name cost date loggedIn.me frequency
                 in  ( { loggedIn | payments = newPayment :: loggedIn.payments }
                     , Cmd.none
                     )
               )

        LoggedInMsg.EditPayment paymentId name cost date frequency ->
          ( loggedIn
          , Server.editPayment paymentId name cost date frequency
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (always <| LoggedInMsg.ValidateEditPayment paymentId name cost date frequency)
          )

        LoggedInMsg.ValidateEditPayment paymentId name cost date frequency ->
          let updatedPayment = Payment paymentId name cost date loggedIn.me frequency
          in  ( { loggedIn | payments = Payment.edit updatedPayment loggedIn.payments }
              , Cmd.none
              )

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

        LoggedInMsg.ValidateDeletePayment paymentId ->
          let payments = Payment.delete paymentId loggedIn.payments
              frequency =
                case Form.getOutput loggedIn.home.search of
                  Just data -> data.frequency
                  Nothing -> Punctual
              switchToPunctual =
                (  frequency == Monthly
                && List.isEmpty (Payment.monthly payments)
                )
          in  if switchToPunctual
                then
                  update model (LoggedInMsg.HomeMsg <| HomeMsg.SearchMsg (Form.Reset (HomeModel.searchInitial Punctual))) loggedIn
                    :> (\loggedIn ->
                         ( { loggedIn | payments = payments }
                         , Cmd.none
                         )
                       )
                else
                  ( { loggedIn | payments = payments }
                  , Cmd.none
                  )

        LoggedInMsg.CreateIncome amount date ->
          ( loggedIn
          , Server.createIncome amount date
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (\incomeId -> (LoggedInMsg.ValidateCreateIncome incomeId amount date))
          )

        LoggedInMsg.ValidateCreateIncome incomeId amount date ->
          let newIncome = { userId = loggedIn.me, amount = amount, time = Date.toTime date }
              loggedInIncome = loggedIn.income
          in  ( { loggedIn
                | incomes = Dict.insert incomeId newIncome loggedIn.incomes
                , income = { loggedInIncome | addIncome = IncomeModel.initForm }
                }
              , Cmd.none
              )

        LoggedInMsg.EditIncome incomeId amount date ->
          ( loggedIn
          , Server.editIncome incomeId amount date
              |> Task.perform
                   (always LoggedInMsg.NoOp)
                   (always <| LoggedInMsg.ValidateEditIncome incomeId amount date)
          )

        LoggedInMsg.ValidateEditIncome incomeId amount date ->
          let updatedIncome = Income loggedIn.me (Date.toTime date) amount
              updateIncome mbIncome =
                case mbIncome of
                  Just _ -> Just updatedIncome
                  Nothing -> Just updatedIncome
          in  ( { loggedIn | incomes = Dict.update incomeId updateIncome 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
          )