Plaid portfolio sync algorithm and calculation improvements (#1526)

* Start tests rework

* Cash balance on schema

* Add reverse syncer

* Reverse balance sync with holdings

* Reverse holdings sync

* Reverse holdings sync should work with only trade entries

* Consolidate brokerage cash

* Add forward sync option

* Update new balance info after syncs

* Intraday balance calculator and sync fixes

* Show only balance for trade entries

* Tests passing

* Update Gemfile.lock

* Cleanup, performance improvements

* Remove account reloads for reliable sync outputs

* Simplify valuation view logic

* Special handling for Plaid cash holding

app/models/account/syncer.rb

@@ -0,0 +1,104 @@
+class Account::Syncer
+  def initialize(account, start_date: nil)
+    @account = account
+    @start_date = start_date
+  end
+
+  def run
+    holdings = sync_holdings
+    balances = sync_balances(holdings)
+    update_account_info(balances, holdings) unless account.plaid_account_id.present?
+    convert_foreign_records(balances)
+  end
+
+  private
+    attr_reader :account, :start_date
+
+    def account_start_date
+      @account_start_date ||= (account.entries.chronological.first&.date || Date.current) - 1.day
+    end
+
+    def update_account_info(balances, holdings)
+      new_balance = balances.sort_by(&:date).last.balance
+      new_holdings_value = holdings.select { |h| h.date == Date.current }.sum(&:amount)
+      new_cash_balance = new_balance - new_holdings_value
+
+      account.update!(
+        balance: new_balance,
+        cash_balance: new_cash_balance
+      )
+    end
+
+    def sync_holdings
+      calculator = Account::HoldingCalculator.new(account)
+      calculated_holdings = calculator.calculate(reverse: account.plaid_account_id.present?)
+
+      current_time = Time.now
+
+      Account.transaction do
+        account.holdings.upsert_all(
+          calculated_holdings.map { |h| h.attributes
+                 .slice("date", "currency", "qty", "price", "amount", "security_id")
+                 .merge("updated_at" => current_time) },
+          unique_by: %i[account_id security_id date currency]
+        ) if calculated_holdings.any?
+
+        # Purge outdated holdings
+        account.holdings.delete_by("date < ? OR security_id NOT IN (?)", account_start_date, calculated_holdings.map(&:security_id))
+      end
+
+      calculated_holdings
+    end
+
+    def sync_balances(holdings)
+      calculator = Account::BalanceCalculator.new(account, holdings: holdings)
+      calculated_balances = calculator.calculate(reverse: account.plaid_account_id.present?, start_date: start_date)
+
+      Account.transaction do
+        load_balances(calculated_balances)
+
+        # Purge outdated balances
+        account.balances.delete_by("date < ?", account_start_date)
+      end
+
+      calculated_balances
+    end
+
+    def convert_foreign_records(balances)
+      converted_balances = convert_balances(balances)
+      load_balances(converted_balances)
+    end
+
+    def load_balances(balances)
+      current_time = Time.now
+      account.balances.upsert_all(
+        balances.map { |b| b.attributes
+               .slice("date", "balance", "cash_balance", "currency")
+               .merge("updated_at" => current_time) },
+        unique_by: %i[account_id date currency]
+      ) if balances.any?
+    end
+
+    def convert_balances(balances)
+      return [] if account.currency == account.family.currency
+
+      from_currency = account.currency
+      to_currency = account.family.currency
+
+      exchange_rates = ExchangeRate.find_rates(
+        from: from_currency,
+        to: to_currency,
+        start_date: balances.first.date
+      )
+
+      balances.map do |balance|
+        exchange_rate = exchange_rates.find { |er| er.date == balance.date }
+
+        account.balances.build(
+          date: balance.date,
+          balance: exchange_rate.rate * balance.balance,
+          currency: to_currency
+        ) if exchange_rate.present?
+      end
+    end
+end