Generate missing exchange rate error during entry normalization

app/models/account/balance/calculator.rb

@@ -42,7 +42,7 @@ def calculate
 
     private
       def convert_balances_to_family_currency
-        rates = ExchangeRate.get_rate_series(
+        rates = ExchangeRate.get_rates(
           @account.currency,
           @account.family.currency,
           @calc_start_date..Date.current
@@ -54,28 +54,38 @@ def convert_balances_to_family_currency
           return []
         end
 
-        @daily_balances.map do |balance|
-          rate = rates.find { |rate| rate.date == balance[:date] }
-          raise "Rate for #{@account.currency} to #{@account.family.currency} on #{balance[:date]} not found" if rate.nil?
-          converted_balance = balance[:balance] * rate.rate
+        @daily_balances.map.with_index do |balance, index|
+          converted_balance = balance[:balance] * rates[index].rate
           { date: balance[:date], balance: converted_balance, currency: @account.family.currency, updated_at: Time.current }
         end
       end
 
       # For calculation, all transactions and valuations need to be normalized to the same currency (the account's primary currency)
       def normalize_entries_to_account_currency(entries, value_key)
-        entries.map do |entry|
-          currency = entry.currency
-          date = entry.date
-          value = entry.send(value_key)
+        grouped_entries = entries.group_by(&:currency)
+        normalized_entries = []
 
+        grouped_entries.each do |currency, entries|
           if currency != @account.currency
-            value = ExchangeRate.convert(value:, from: currency, to: @account.currency, date:)
-            currency = @account.currency
+            dates = entries.map(&:date).uniq
+            rates = ExchangeRate.get_rates(currency, @account.currency, dates).to_a
+            if rates.length != dates.length
+              @errors << :sync_message_missing_rates
+            else
+              entries.each do |entry|
+                ## There can be several entries on the same date so we cannot rely on indeces
+                rate = rates.find { |rate| rate.date == entry.date }
+                value = entry.send(value_key)
+                value *= rate.rate
+                normalized_entries << entry.attributes.merge(value_key.to_s => value, "currency" => currency)
+              end
+            end
+          else
+            normalized_entries.concat(entries)
           end
-
-          entry.attributes.merge(value_key.to_s => value, "currency" => currency)
         end
+
+        normalized_entries
       end
 
       def normalized_valuations
@@ -97,8 +107,8 @@ def implied_start_balance
           return @account.balance_on(@calc_start_date)
         end
 
-        oldest_valuation_date = normalized_valuations.first&.dig("date")
-        oldest_transaction_date = normalized_transactions.first&.dig("date")
+        oldest_valuation_date = normalized_valuations.first&.date
+        oldest_transaction_date = normalized_transactions.first&.date
         oldest_entry_date = [ oldest_valuation_date, oldest_transaction_date ].compact.min
 
         if oldest_entry_date.present? && oldest_entry_date == oldest_valuation_date

app/models/account/syncable.rb

@@ -20,7 +20,7 @@ def sync(start_date = nil)
 
     update!(status: "ok", last_sync_date: Date.today, balance: new_balance, sync_errors: calculator.errors, sync_warnings: calculator.warnings)
   rescue => e
-    update!(status: "error")
+    update!(status: "error", sync_errors: [ :sync_message_unknown_error ])
     logger.error("Failed to sync account #{id}: #{e.message}")
   end
 

app/models/exchange_rate.rb

@@ -15,8 +15,8 @@ def find_rate_or_fetch(from:, to:, date:)
       find_rate(from:, to:, date:) || fetch_rate_from_provider(from:, to:, date:)&.tap(&:save!)
     end
 
-    def get_rate_series(from, to, date_range)
-      where(base_currency: from, converted_currency: to, date: date_range).order(:date)
+    def get_rates(from, to, dates)
+      where(base_currency: from, converted_currency: to, date: dates).order(:date)
     end
 
     def convert(value:, from:, to:, date:)

config/locales/views/account/en.yml

@@ -37,6 +37,7 @@ en:
       confirm_title: Delete account?
       sync_message_missing_rates: Since exchange rates haven't been synced, balance
         graphs may not reflect accurate values.
+      sync_message_unknown_error: An error has occurred during the sync.
     summary:
       new: New account
     sync: