Base fixes and test harness

PortfolioJournal/ViewModels/SnapshotFormViewModel.swift

@@ -12,6 +12,7 @@ class SnapshotFormViewModel: ObservableObject {
     @Published var includeContribution = false
     @Published var inputMode: InputMode = .simple
     @Published var currencySymbol = "€"
+    private let currencyCode: String
 
     @Published var isValid = false
     @Published var errorMessage: String?
@@ -37,8 +38,10 @@ class SnapshotFormViewModel: ObservableObject {
         self.mode = mode
         let settings = AppSettings.getOrCreate(in: CoreDataStack.shared.viewContext)
         if let accountCurrency = source.account?.currency, !accountCurrency.isEmpty {
+            currencyCode = accountCurrency
             currencySymbol = CurrencyFormatter.symbol(for: accountCurrency)
         } else {
+            currencyCode = settings.currency
             currencySymbol = settings.currencySymbol
         }
         if let accountMode = InputMode(rawValue: source.account?.inputMode ?? "") {
@@ -99,23 +102,49 @@ class SnapshotFormViewModel: ObservableObject {
     // MARK: - Parsing
 
     private func parseDecimal(_ string: String) -> Decimal? {
+        let locale = CurrencyFormatter.locale(for: currencyCode)
         let cleaned = string
             .replacingOccurrences(of: currencySymbol, with: "")
-            .replacingOccurrences(of: ",", with: ".")
+            .replacingOccurrences(of: locale.groupingSeparator ?? "", with: "")
             .trimmingCharacters(in: .whitespaces)
 
         guard !cleaned.isEmpty else { return nil }
 
+        let decimalSeparator = locale.decimalSeparator ?? "."
+        let usesAlternateDecimal =
+            (decimalSeparator == "," && cleaned.contains(".") && !cleaned.contains(",")) ||
+            (decimalSeparator == "." && cleaned.contains(",") && !cleaned.contains("."))
+
+        if usesAlternateDecimal {
+            let normalized = cleaned
+                .replacingOccurrences(of: ",", with: ".")
+            let formatter = NumberFormatter()
+            formatter.numberStyle = .decimal
+            formatter.locale = Locale(identifier: "en_US_POSIX")
+            return formatter.number(from: normalized)?.decimalValue
+        }
+
         let formatter = NumberFormatter()
         formatter.numberStyle = .decimal
-        formatter.locale = Locale(identifier: "en_US")
+        formatter.locale = locale
 
-        return formatter.number(from: cleaned)?.decimalValue
+        if let result = formatter.number(from: cleaned)?.decimalValue {
+            return result
+        }
+
+        // Fallback for mixed locale input
+        let normalized = cleaned
+            .replacingOccurrences(of: locale.decimalSeparator ?? ",", with: ".")
+            .replacingOccurrences(of: ",", with: ".")
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        return formatter.number(from: normalized)?.decimalValue
     }
 
     private func formatDecimalForInput(_ decimal: Decimal) -> String {
+        let locale = CurrencyFormatter.locale(for: currencyCode)
         let formatter = NumberFormatter()
         formatter.numberStyle = .decimal
+        formatter.locale = locale
         formatter.minimumFractionDigits = 2
         formatter.maximumFractionDigits = 2
         formatter.groupingSeparator = ""