loans: Remove inital_balance field from Loan model

Fixes part of #2115.

app/models/account.rb

@@ -33,8 +33,8 @@ class Account < ApplicationRecord
   class << self
     def create_and_sync(attributes)
       attributes[:accountable_attributes] ||= {} # Ensure accountable is created, even if empty
+      initial_balance = handle_initial_balance(attributes)
       account = new(attributes.merge(cash_balance: attributes[:balance]))
-      initial_balance = attributes.dig(:accountable_attributes, :initial_balance)&.to_d || 0
 
       transaction do
         # Create 2 valuations for new accounts to establish a value history for users to see
@@ -95,13 +95,14 @@ class Account < ApplicationRecord
   def update_with_sync!(attributes)
     should_update_balance = attributes[:balance] && attributes[:balance].to_d != balance
 
-    initial_balance = attributes.dig(:accountable_attributes, :initial_balance)
-    should_update_initial_balance = initial_balance && initial_balance.to_d != accountable.initial_balance
+    initial_balance = self.class.handle_initial_balance(attributes)
+    currency=attributes[:currency]
+    should_update_initial_balance = initial_balance && Money.new(initial_balance, currency) != first_valuation_amount
 
     transaction do
       update!(attributes)
       update_balance!(attributes[:balance]) if should_update_balance
-      update_inital_balance!(attributes[:accountable_attributes][:initial_balance]) if should_update_initial_balance
+      update_inital_balance!(initial_balance) if should_update_initial_balance
     end
 
     sync_later
@@ -160,4 +161,16 @@ class Account < ApplicationRecord
       strategy = linked? ? :reverse : :forward
       Balance::Syncer.new(self, strategy: strategy).sync_balances
     end
+
+    def self.handle_initial_balance(attributes)
+      account_type = attributes.dig(:accountable_type)
+      initial_balance = 0
+
+      if account_type == "Loan"
+        initial_balance = attributes.dig(:accountable_attributes, :initial_balance)&.to_d
+        attributes[:accountable_attributes].delete("initial_balance")
+      end
+
+      initial_balance
+    end
 end

app/views/loans/_form.html.erb

@@ -9,6 +9,7 @@
         <%= loan_form.money_field :initial_balance,
                                  label: t("loans.form.initial_balance"),
                                  default_currency: Current.family.currency,
+                                 value: account.first_valuation_amount,
                                  required: true %>
       </div>
 

db/migrate/20250420011909_remove_initial_balance_field.rb

@@ -0,0 +1,5 @@
+class RemoveInitialBalanceField < ActiveRecord::Migration[7.2]
+  def change
+    remove_column :loans, :initial_balance, :decimal
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2025_04_16_235758) do
+ActiveRecord::Schema[7.2].define(version: 2025_04_20_011909) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -373,7 +373,6 @@ ActiveRecord::Schema[7.2].define(version: 2025_04_16_235758) do
     t.string "rate_type"
     t.decimal "interest_rate", precision: 10, scale: 3
     t.integer "term_months"
-    t.decimal "initial_balance", precision: 19, scale: 4
     t.jsonb "locked_attributes", default: {}
   end