Coverage Summary for Class: PreferencesEffect (com.georgeci.moneysurfer.feature.settings.preferences)

 package com.georgeci.moneysurfer.feature.settings.preferences
 
 import com.georgeci.moneysurfer.domain.model.Currency
 import com.georgeci.moneysurfer.domain.preferences.AppLanguage
 import com.georgeci.moneysurfer.domain.preferences.AppRegion
 import com.georgeci.moneysurfer.domain.preferences.DefaultTransactionType
 import com.georgeci.moneysurfer.domain.preferences.HourFormat
 import com.georgeci.moneysurfer.domain.preferences.NumberFormatStyle
 import com.georgeci.moneysurfer.domain.preferences.Pref
 import com.georgeci.moneysurfer.domain.preferences.UiPreferences
 import com.georgeci.moneysurfer.domain.preferences.WeekStart
 import com.georgeci.moneysurfer.domain.primitives.CurrencyCode
 import com.georgeci.moneysurfer.domain.usecase.GetCurrenciesUseCase
 import com.georgeci.moneysurfer.utils.MviViewModel
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.onEach
 import org.koin.core.annotation.KoinViewModel
 
 /**
  * Every row on the Preferences screen is a [UiPreferences] handle: state is a projection of the
  * stored values and a tap writes straight through, exactly as `AppearanceViewModel` does. Nothing
  * is held in the ViewModel that a pref does not already hold — the one exception is
  * [PreferencesState.activePicker], which is which sheet is open and dies with the screen on
  * purpose.
  *
  * The choices are stored, not yet obeyed: no locale, calendar or behaviour code reads these keys
  * today (see the `UiPreferences` KDoc). The screen therefore promises persistence and nothing more.
  */
 @KoinViewModel
 class PreferencesViewModel(
     private val uiPreferences: UiPreferences,
     getCurrencies: GetCurrenciesUseCase,
 ) : MviViewModel<PreferencesState, PreferencesEvent, PreferencesEffect>(
     initialState = PreferencesState(),
 ) {
 
     init {
         observe(uiPreferences.appLanguage) { copy(language = it) }
         observe(uiPreferences.appRegion) { copy(region = it) }
         observe(uiPreferences.defaultCurrency) { copy(currency = it) }
         observe(uiPreferences.numberFormat) { copy(numberFormat = it) }
         observe(uiPreferences.weekStart) { copy(weekStart = it) }
         observe(uiPreferences.hourFormat) { copy(hourFormat = it) }
         observe(uiPreferences.defaultTransactionType) { copy(defaultTransactionType = it) }
         observe(uiPreferences.hideAmounts) { copy(hideAmounts = it) }
         observe(uiPreferences.autoCategorize) { copy(autoCategorize = it) }
         observe(uiPreferences.roundUpSavings) { copy(roundUp = it) }
 
         launch {
             getCurrencies()
                 .onEach { currencies -> updateState { copy(currencies = currencies) } }
                 .collect()
         }
     }
 
     override fun onEvent(event: PreferencesEvent) {
         when (event) {
             PreferencesEvent.OnBackClick -> postSideEffect(PreferencesEffect.NavigateBack)
             is PreferencesEvent.OnPickerOpen -> updateState { copy(activePicker = event.picker) }
             PreferencesEvent.OnPickerDismiss -> closePicker()
 
             is PreferencesEvent.OnLanguageSelect -> select(uiPreferences.appLanguage, event.value)
             is PreferencesEvent.OnRegionSelect -> select(uiPreferences.appRegion, event.value)
             is PreferencesEvent.OnCurrencySelect -> select(uiPreferences.defaultCurrency, event.value)
             is PreferencesEvent.OnNumberFormatSelect -> select(uiPreferences.numberFormat, event.value)
             is PreferencesEvent.OnWeekStartSelect -> select(uiPreferences.weekStart, event.value)
             is PreferencesEvent.OnHourFormatSelect -> select(uiPreferences.hourFormat, event.value)
             is PreferencesEvent.OnDefaultTransactionTypeSelect ->
                 select(uiPreferences.defaultTransactionType, event.value)
 
             is PreferencesEvent.OnHideAmountsToggle -> write(uiPreferences.hideAmounts, event.enabled)
             is PreferencesEvent.OnAutoCategorizeToggle -> write(uiPreferences.autoCategorize, event.enabled)
             is PreferencesEvent.OnRoundUpToggle -> write(uiPreferences.roundUpSavings, event.enabled)
         }
     }
 
     private fun <T> observe(pref: Pref<T>, reduce: PreferencesState.(T) -> PreferencesState) {
         launch {
             pref.flow
                 .onEach { value -> updateState { reduce(value) } }
                 .collect()
         }
     }
 
     /**
      * Closes the sheet and writes. The pill is *not* updated here — it re-renders when the pref
      * flow emits, so what the row shows is what the store accepted and nothing else.
      */
     private fun <T> select(pref: Pref<T>, value: T) {
         closePicker()
         write(pref, value)
     }
 
     private fun <T> write(pref: Pref<T>, value: T) {
         launch { pref.set(value) }
     }
 
     private fun closePicker() = updateState { copy(activePicker = null) }
 }
 
 /**
  * Defaults here mirror the `UiConfigKeys` defaults on purpose: they are what the screen shows for
  * the frame before the first flow emission, and a mismatch would be a value the store never held.
  *
  * [currency] is nullable because it has no such constant — its default is the platform locale's
  * currency, resolved by the config engine — so the row shows a placeholder rather than a guess
  * until the flow arrives.
  */
 data class PreferencesState(
     val language: AppLanguage = AppLanguage.DEFAULT,
     val region: AppRegion = AppRegion.DEFAULT,
     val currency: CurrencyCode? = null,
     val currencies: List<Currency> = emptyList(),
     val numberFormat: NumberFormatStyle = NumberFormatStyle.DEFAULT,
     val weekStart: WeekStart = WeekStart.DEFAULT,
     val hourFormat: HourFormat = HourFormat.DEFAULT,
     val defaultTransactionType: DefaultTransactionType = DefaultTransactionType.DEFAULT,
     val hideAmounts: Boolean = false,
     val autoCategorize: Boolean = true,
     val roundUp: Boolean = false,
     val activePicker: PreferencePicker? = null,
 ) {
     /** The catalogue entry for [currency], or `null` while it loads or for a code we do not stock. */
     val selectedCurrency: Currency? get() = currencies.firstOrNull { it.code == currency }
 }
 
 /** Which row's chooser is open. One at a time — every picker is a modal sheet. */
 enum class PreferencePicker {
     Language,
     Region,
     Currency,
     NumberFormat,
     WeekStart,
     HourFormat,
     DefaultTransactionType,
 }
 
 sealed interface PreferencesEvent {
     data object OnBackClick : PreferencesEvent
     data class OnPickerOpen(val picker: PreferencePicker) : PreferencesEvent
     data object OnPickerDismiss : PreferencesEvent
 
     data class OnLanguageSelect(val value: AppLanguage) : PreferencesEvent
     data class OnRegionSelect(val value: AppRegion) : PreferencesEvent
     data class OnCurrencySelect(val value: CurrencyCode) : PreferencesEvent
     data class OnNumberFormatSelect(val value: NumberFormatStyle) : PreferencesEvent
     data class OnWeekStartSelect(val value: WeekStart) : PreferencesEvent
     data class OnHourFormatSelect(val value: HourFormat) : PreferencesEvent
     data class OnDefaultTransactionTypeSelect(val value: DefaultTransactionType) : PreferencesEvent
 
     data class OnHideAmountsToggle(val enabled: Boolean) : PreferencesEvent
     data class OnAutoCategorizeToggle(val enabled: Boolean) : PreferencesEvent
     data class OnRoundUpToggle(val enabled: Boolean) : PreferencesEvent
 }
 
 /**
  * Only navigation is left: the pickers used to be side effects that the screen mapped to `Unit`,
  * and they are state now — which sheet is open is something the screen must be able to re-render
  * after a configuration change, not a one-shot signal.
  */
 sealed interface PreferencesEffect {
     data object NavigateBack : PreferencesEffect
 }