Coverage Summary for Class: ExchangeRateApiConfig (com.georgeci.moneysurfer.data.remote)

 package com.georgeci.moneysurfer.data.remote
 
 import com.georgeci.moneysurfer.domain.model.ExchangeRateTable
 import com.georgeci.moneysurfer.domain.primitives.CurrencyCode
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 import kotlin.time.Instant
 
 /**
  * Where the FX quotes come from.
  *
  * Default is ExchangeRate-API's *open* endpoint (`open.er-api.com`): free, no API key, no
  * registration, ~160 currencies, refreshed daily. Its free tier asks for attribution wherever the
  * rates are shown, which the dashboard's "as of" footnote carries.
  *
  * Bound in `RemoteDataModule` so the URL is one override away — swapping providers means replacing
  * this binding and [ExchangeRateLatestDto], nothing above the data layer.
  */
 data class ExchangeRateApiConfig(
     val baseUrl: String = DEFAULT_BASE_URL,
 ) {
     /** `…/v6/latest/USD` — the base currency is a path segment, so nothing needs URL-encoding. */
     fun latestUrl(base: CurrencyCode): String = "$baseUrl/${base.value}"
 
     companion object {
         const val DEFAULT_BASE_URL: String = "https://open.er-api.com/v6/latest"
     }
 }
 
 /**
  * The subset of the provider's payload that matters. Unknown fields (`provider`, `terms_of_use`,
  * `time_next_update_*`, …) are ignored by the decoder rather than modelled.
  */
 @Serializable
 internal data class ExchangeRateLatestDto(
     val result: String = "",
     @SerialName("base_code") val baseCode: String = "",
     @SerialName("time_last_update_unix") val timeLastUpdateUnix: Long = 0L,
     val rates: Map<String, Double> = emptyMap(),
 )
 
 /**
  * Maps the payload to the domain table, or `null` when it is not usable: a non-success `result`,
  * an empty quote set, a base that is not the one asked for (a redirect or a provider fallback), or
  * a missing publication timestamp — all of which would otherwise cache a table the UI would
  * mislabel.
  */
 internal fun ExchangeRateLatestDto.toDomain(requested: CurrencyCode): ExchangeRateTable? {
     if (result != RESULT_SUCCESS || rates.isEmpty() || timeLastUpdateUnix <= 0L) return null
     if (!baseCode.equals(requested.value, ignoreCase = true)) return null
     return ExchangeRateTable(
         baseCurrency = requested,
         rates = rates
             .filterValues { it.isFinite() && it > 0.0 }
             .mapKeys { (code, _) -> CurrencyCode(code.uppercase()) },
         asOf = Instant.fromEpochSeconds(timeLastUpdateUnix),
     )
 }
 
 private const val RESULT_SUCCESS = "success"