fix: prefer booked over available balance types in Enable Banking sync (#825)

The balance selection logic prioritized ITAV (Interim Available) which
includes overdraft capacity, inflating displayed balances. Reorder to
prefer booked types (CLBD > XPCD > ITBD) before available types
(CLAV > ITAV).

https://claude.ai/code/session_01EhxhgQqun8RuzfgkMxbp8x

app/models/enable_banking_item/importer.rb

@@ -3,6 +3,10 @@ class EnableBankingItem::Importer
   # Enable Banking typically returns ~100 transactions per page, so 100 pages = ~10,000 transactions
   MAX_PAGINATION_PAGES = 100
 
+  # Balance type priority: prefer booked balances over available balances.
+  # Available types (CLAV, ITAV) include overdraft/credit capacity and inflate balances.
+  BALANCE_TYPE_PRIORITY = %w[CLBD XPCD ITBD CLAV ITAV].freeze
+
   attr_reader :enable_banking_item, :enable_banking_provider
 
   def initialize(enable_banking_item, enable_banking_provider:)
@@ -161,12 +165,8 @@ class EnableBankingItem::Importer
       balances = balance_data[:balances] || []
       return if balances.empty?
 
-      # Find the most relevant balance (prefer "ITAV" or "CLAV" types)
-      balance = balances.find { |b| b[:balance_type] == "ITAV" } ||
-                balances.find { |b| b[:balance_type] == "CLAV" } ||
-                balances.find { |b| b[:balance_type] == "ITBD" } ||
-                balances.find { |b| b[:balance_type] == "CLBD" } ||
-                balances.first
+      # Find the most relevant balance (prefer booked over available types)
+      balance = select_balance(balances)
 
       if balance.present?
         amount = balance.dig(:balance_amount, :amount) || balance[:amount]
@@ -183,6 +183,14 @@ class EnableBankingItem::Importer
       Rails.logger.error "EnableBankingItem::Importer - Error fetching balance for account #{enable_banking_account.uid}: #{e.message}"
     end
 
+    def select_balance(balances)
+      BALANCE_TYPE_PRIORITY.each do |type|
+        found = balances.find { |b| b[:balance_type] == type }
+        return found if found
+      end
+      balances.first
+    end
+
     def fetch_and_store_transactions(enable_banking_account)
       start_date = determine_sync_start_date(enable_banking_account)
 

test/models/enable_banking_item/importer_balance_selection_test.rb

@@ -0,0 +1,88 @@
+require "test_helper"
+
+class EnableBankingItem::ImporterBalanceSelectionTest < ActiveSupport::TestCase
+  setup do
+    @family = families(:dylan_family)
+    @enable_banking_item = EnableBankingItem.create!(
+      family: @family,
+      name: "Test Enable Banking",
+      country_code: "AT",
+      application_id: "test_app_id",
+      client_certificate: "test_cert",
+      session_id: "test_session",
+      session_expires_at: 1.day.from_now
+    )
+
+    mock_provider = mock()
+    @importer = EnableBankingItem::Importer.new(@enable_banking_item, enable_banking_provider: mock_provider)
+  end
+
+  test "prefers CLBD when multiple balance types are present" do
+    balances = [
+      { balance_type: "ITAV", balance_amount: { amount: "4332.81", currency: "EUR" } },
+      { balance_type: "CLAV", balance_amount: { amount: "4332.81", currency: "EUR" } },
+      { balance_type: "ITBD", balance_amount: { amount: "232.81", currency: "EUR" } },
+      { balance_type: "CLBD", balance_amount: { amount: "232.81", currency: "EUR" } }
+    ]
+
+    result = @importer.send(:select_balance, balances)
+
+    assert_equal "CLBD", result[:balance_type]
+    assert_equal "232.81", result[:balance_amount][:amount]
+  end
+
+  test "prefers XPCD over ITBD" do
+    balances = [
+      { balance_type: "ITBD", balance_amount: { amount: "100.00", currency: "EUR" } },
+      { balance_type: "XPCD", balance_amount: { amount: "150.00", currency: "EUR" } }
+    ]
+
+    result = @importer.send(:select_balance, balances)
+
+    assert_equal "XPCD", result[:balance_type]
+  end
+
+  test "falls back through priority chain" do
+    balances = [
+      { balance_type: "ITAV", balance_amount: { amount: "5000.00", currency: "EUR" } },
+      { balance_type: "ITBD", balance_amount: { amount: "900.00", currency: "EUR" } }
+    ]
+
+    result = @importer.send(:select_balance, balances)
+
+    assert_equal "ITBD", result[:balance_type]
+  end
+
+  test "CLAV is preferred over ITAV" do
+    balances = [
+      { balance_type: "ITAV", balance_amount: { amount: "5000.00", currency: "EUR" } },
+      { balance_type: "CLAV", balance_amount: { amount: "4800.00", currency: "EUR" } }
+    ]
+
+    result = @importer.send(:select_balance, balances)
+
+    assert_equal "CLAV", result[:balance_type]
+  end
+
+  test "falls back to first balance when no known types present" do
+    balances = [
+      { balance_type: "PRCD", balance_amount: { amount: "500.00", currency: "EUR" } },
+      { balance_type: "INFO", balance_amount: { amount: "600.00", currency: "EUR" } }
+    ]
+
+    result = @importer.send(:select_balance, balances)
+
+    assert_equal "PRCD", result[:balance_type]
+    assert_equal "500.00", result[:balance_amount][:amount]
+  end
+
+  test "returns single balance regardless of type" do
+    balances = [
+      { balance_type: "ITAV", balance_amount: { amount: "1000.00", currency: "EUR" } }
+    ]
+
+    result = @importer.send(:select_balance, balances)
+
+    assert_equal "ITAV", result[:balance_type]
+  end
+end