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.Payment as Payment exposing (Payment, Frequency(..))
import Model.Income as Income exposing (Income)
import Model.Category exposing (Category)
import Model.PaymentCategory as PaymentCategory

import Server
import LoggedData

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

import LoggedIn.Home.Msg as Home
import LoggedIn.Home.Update as Home
import LoggedIn.Home.Model as Home

import LoggedIn.Income.Update as Income
import LoggedIn.Income.Model as Income

import LoggedIn.Category.Update as Categories
import LoggedIn.Category.Model as Categories

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

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

        LoggedInMsg.CategoriesMsg categoriesMsg ->
          case Categories.update loggedData categoriesMsg loggedIn.category of
            (category, cmd) ->
              ( { loggedIn | category = category }
              , Cmd.map LoggedInMsg.CategoriesMsg cmd
              )

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

        LoggedInMsg.ValidateEditPayment paymentId name cost date category frequency ->
          let updatedPayment = Payment paymentId name cost date loggedIn.me frequency
              mbOldPayment = Payment.find paymentId loggedIn.payments
          in  ( { loggedIn
                | payments = Payment.edit updatedPayment loggedIn.payments
                , paymentCategories =
                    case mbOldPayment of
                      Just oldPayment ->
                        PaymentCategory.save name category loggedIn.paymentCategories
                      Nothing ->
                        loggedData.paymentCategories
                }
              , Cmd.none
              )

        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 <| Home.SearchMsg (Form.Reset (Home.searchInitial Punctual))) loggedIn
                    :> (\loggedIn ->
                         ( { loggedIn | payments = payments }
                         , Cmd.none
                         )
                       )
                else
                  ( { loggedIn | payments = payments }
                  , Cmd.none
                  )

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

        LoggedInMsg.ValidateEditIncome incomeId amount date ->
          let updateIncome _ = Just <| Income loggedIn.me (Date.toTime date) amount
          in  ( { loggedIn | incomes = Dict.update incomeId updateIncome loggedIn.incomes }
              , Cmd.none
              )

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

        LoggedInMsg.ValidateCreateCategory categoryId name color ->
          let newCategory = { name = name, color = color }
          in  ( { loggedIn | categories = Dict.insert categoryId newCategory loggedIn.categories }
              , Cmd.none
              )

        LoggedInMsg.ValidateEditCategory categoryId name color ->
          let updateCategory _ = Just <| Category name color
          in  ( { loggedIn | categories = Dict.update categoryId updateCategory loggedIn.categories } , Cmd.none)

        LoggedInMsg.ValidateDeleteCategory categoryId ->
          ( { loggedIn | categories = Dict.remove categoryId loggedIn.categories }
          , Cmd.none
          )