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

 package com.georgeci.moneysurfer.domain.usecase
 
 import com.georgeci.moneysurfer.domain.model.Account
 import com.georgeci.moneysurfer.domain.model.ConvertedTotal
 import com.georgeci.moneysurfer.domain.model.CurrencyTotal
 import com.georgeci.moneysurfer.domain.model.ExchangeRateTable
 import com.georgeci.moneysurfer.domain.model.totalsByCurrency
 import com.georgeci.moneysurfer.domain.primitives.CurrencyCode
 import com.georgeci.moneysurfer.domain.primitives.Money
 import org.koin.core.annotation.Single
 
 /**
  * Folds every account balance into one figure in the workspace base currency, using [rates].
  *
  * Conversion happens per *currency total*, not per account: one rounding per currency instead of
  * one per row, so the headline does not drift by a cent for every extra account.
  *
  * Accounts in a currency [rates] cannot price are not dropped — they come back in
  * [ConvertedTotal.unconverted] for the caller to show beside the headline. With no rates cached
  * at all (offline first run, or the offline build, which has no provider) that degrades to
  * "base-currency accounts sum, the rest listed" rather than to a wrong number.
  */
 @Single
 class ConvertAccountsTotalUseCase {
 
     operator fun invoke(
         accounts: List<Account>,
         baseCurrency: CurrencyCode,
         rates: ExchangeRateTable?,
     ): ConvertedTotal {
         // A table quoted against some other base cannot price this workspace: only the window
         // between a base-currency change and the next refresh can produce one, and re-basing
         // second-hand quotes is a worse answer than saying "not converted".
         val usable = rates?.takeIf { it.baseCurrency == baseCurrency }
         val byCurrency = accounts.totalsByCurrency()
 
         var converted: Money? = null
         var usedRates = false
         val unconverted = mutableListOf<CurrencyTotal>()
 
         byCurrency.forEach { bucket ->
             val inBase: Money? = bucket.inBaseCurrency(baseCurrency, usable)
             if (inBase == null) {
                 unconverted += bucket
             } else {
                 // A bucket already in the base needed no quote; anything else got here through
                 // one, and that is what earns the "as of" label below.
                 if (bucket.currencyCode != baseCurrency) usedRates = true
                 converted = (converted ?: Money.zero()) + inBase
             }
         }
 
         return ConvertedTotal(
             baseCurrency = baseCurrency,
             total = converted,
             unconverted = unconverted,
             // Only claim an "as of" when a quote actually moved money — a single-currency
             // workspace needs no rates and must not be labelled with yesterday's date.
             asOf = usable?.asOf?.takeIf { usedRates },
         )
     }
 
     /** This bucket expressed in [base], or `null` when [rates] cannot price its currency. */
     private fun CurrencyTotal.inBaseCurrency(base: CurrencyCode, rates: ExchangeRateTable?): Money? =
         if (currencyCode == base) amount else rates?.convertToBase(amount, currencyCode)
 }