Renamed haveAllTransactionsBeenRetrieved to haveAllRetainedTransactionsBeenRetrieved and made it evaluating countDaysForWhichTransactionsAreKeptOnBankServer and retrievedTransactionsFrom instead of being set to a fixed value

BankingClientModel/src/commonMain/kotlin/net/codinux/banking/client/model/BankAccount.kt

@@ -1,7 +1,6 @@
 package net.codinux.banking.client.model
 
-import kotlinx.datetime.Instant
-import kotlinx.datetime.LocalDate
+import kotlinx.datetime.*
 import net.codinux.banking.client.model.config.JsonIgnore
 import net.codinux.banking.client.model.config.NoArgConstructor
 
@@ -22,12 +21,10 @@ open class BankAccount(
     val isAccountTypeSupportedByApplication: Boolean = false,
     val features: Set<BankAccountFeatures> = emptySet(),
 
+    val countDaysForWhichTransactionsAreKeptOnBankServer: Int? = null,
     open var lastTransactionsRetrievalTime: Instant? = null,
     var retrievedTransactionsFrom: LocalDate? = null,
 
-    var haveAllTransactionsBeenRetrieved: Boolean = false,
-    val countDaysForWhichTransactionsAreKept: Int? = null,
-
     open val bookedTransactions: MutableList<AccountTransaction> = mutableListOf(),
     open val unbookedTransactions: MutableList<UnbookedAccountTransaction> = mutableListOf(),
 
@@ -44,5 +41,21 @@ open class BankAccount(
     fun supportsAnyFeature(vararg features: BankAccountFeatures): Boolean =
         features.any { this.features.contains(it) }
 
+    /**
+     * Determines if all transactions that are retained on bank server have been fetched.
+     *
+     * Does this by comparing [countDaysForWhichTransactionsAreKeptOnBankServer] to [retrievedTransactionsFrom].
+     */
+    open val haveAllRetainedTransactionsBeenRetrieved: Boolean by lazy {
+        val fromDay = retrievedTransactionsFrom
+        if (fromDay == null) {
+            false
+        } else {
+            // if countDaysForWhichTransactionsAreKeptOnBankServer is not set, we cannot know for how long bank server keeps transactions. We then assume for 90 days
+            val storageDays = countDaysForWhichTransactionsAreKeptOnBankServer ?: 90
+            fromDay < Clock.System.now().toLocalDateTime(TimeZone.of("Europe/Berlin")).date.minus(storageDays, DateTimeUnit.DAY)
+        }
+    }
+
     override fun toString() = "$type $identifier $productName (IBAN: $iban)"
 }