Fix Account Holding validation and synchronization (#1818)

* Fix Account Holding validation and synchronization

Fixes #1781

- Add comprehensive validations for Account::Holding
- Implement validation to ensure amount matches qty * price
- Update Account::Syncer to include qty and price during synchronization
- Add database constraints for holding attributes and calculations

* Remove database check constraints for Account Holdings

Align with project convention of keeping complex validations in ActiveRecord
- Remove database-level check constraints for quantity, price, and amount
- Maintain database-level null and unique constraints
- Prepare for more flexible validation in the model layer

app/models/account/holding.rb

@@ -6,7 +6,9 @@ class Account::Holding < ApplicationRecord
   belongs_to :account
   belongs_to :security
 
-  validates :qty, :currency, presence: true
+  validates :qty, :currency, :date, :price, :amount, presence: true
+  validates :qty, :price, :amount, numericality: { greater_than_or_equal_to: 0 }
+  validate :amount_matches_qty_and_price
 
   scope :chronological, -> { order(:date) }
   scope :for, ->(security) { where(security_id: security).order(:date) }
@@ -62,4 +64,13 @@ class Account::Holding < ApplicationRecord
         current: amount_money,
         previous: start_amount
     end
+
+    def amount_matches_qty_and_price
+      return if qty.blank? || price.blank? || amount.blank?
+
+      expected_amount = qty * price
+      return if amount == expected_amount
+
+      errors.add(:amount, "must equal qty * price (expected: #{expected_amount})")
+    end
 end

app/models/account/syncer.rb

@@ -99,6 +99,8 @@ class Account::Syncer
         account.holdings.build(
           security: holding.security,
           date: holding.date,
+          qty: holding.qty,
+          price: exchange_rate.rate * holding.price,
           amount: exchange_rate.rate * holding.amount,
           currency: to_currency
         )