Coverage Summary for Class: GetSafeToSpendUseCase (com.georgeci.moneysurfer.domain.usecase)

 package com.georgeci.moneysurfer.domain.usecase
 
 import com.georgeci.moneysurfer.domain.model.BudgetPeriod
 import com.georgeci.moneysurfer.domain.model.SafeToSpend
 import com.georgeci.moneysurfer.domain.model.safeToSpend
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
 import kotlinx.datetime.TimeZone
 import org.koin.core.annotation.Single
 
 /**
  * Live safe-to-spend for the active workspace, or null while nothing backs it — no workspace, no
  * active budget, or a workspace whose budgets were all archived.
  *
  * The figure is a projection of the same active-budget progress the budgets widget lists: see
  * [GetActiveBudgetProgressUseCase], which owns the archived-budget filter and the rule that the
  * workspace comes from the budgets themselves. Sharing that source is what keeps the headline and
  * the budget rows from ever disagreeing about a budget.
  *
  * [preferredPeriod] arrives as a flow rather than a value so that changing it re-picks the budget
  * without tearing down the subscription underneath. The progress query reads the workspace's whole
  * transaction list per emission, and re-running that every time the dashboard's Week/Month switch
  * is tapped would be the most expensive query in the app answering a question it already has the
  * data for. It is required rather than defaulted: this figure is about a period, so a caller has
  * to say which one it is answering for — `flowOf(null)` spells "no period on screen, pick the
  * largest cap", which is a claim worth making out loud.
  */
 @Single
 class GetSafeToSpendUseCase(
     private val getActiveBudgetProgress: GetActiveBudgetProgressUseCase,
 ) {
 
     operator fun invoke(
         preferredPeriod: Flow<BudgetPeriod?>,
         timeZone: TimeZone = TimeZone.currentSystemDefault(),
     ): Flow<SafeToSpend?> =
         combine(
             getActiveBudgetProgress(timeZone),
             preferredPeriod,
         ) { progresses, period -> progresses.safeToSpend(period) }
 }