Remove plaid initialiser (#317)

* Remove plaid initialiser

The initializer can be safely removed because:
  - Config is lazily loaded via Provider::Registry
  - reload_configuration is called after settings updates
  - All calling code handles nil configs gracefully
  - Initial nil state is fine - config loads on first use

* Fix for missing config

* Actually don't pollute application.rb

* Add currency loading for balances

* Fix race condition on lazy load

* Allow loans to be imported in lunch flow also

* Fix currency processor

app/models/concerns/currency_normalizable.rb

@@ -0,0 +1,50 @@
+# Provides currency normalization and validation for provider data imports
+#
+# This concern provides a shared method to parse and normalize currency codes
+# from external providers (Plaid, SimpleFIN, LunchFlow), ensuring:
+# - Consistent uppercase formatting (e.g., "eur" -> "EUR")
+# - Validation of 3-letter ISO currency codes
+# - Proper handling of nil, empty, and invalid values
+#
+# Usage:
+#   include CurrencyNormalizable
+#   currency = parse_currency(api_data[:currency])
+module CurrencyNormalizable
+  extend ActiveSupport::Concern
+
+  private
+
+    # Parse and normalize a currency code from provider data
+    #
+    # @param currency_value [String, nil] Raw currency value from provider API
+    # @return [String, nil] Normalized uppercase 3-letter currency code, or nil if invalid
+    #
+    # @example
+    #   parse_currency("usd")     # => "USD"
+    #   parse_currency("EUR")     # => "EUR"
+    #   parse_currency("  gbp  ") # => "GBP"
+    #   parse_currency("invalid") # => nil (logs warning)
+    #   parse_currency(nil)       # => nil
+    #   parse_currency("")        # => nil
+    def parse_currency(currency_value)
+      # Handle nil, empty string, or whitespace-only strings
+      return nil if currency_value.blank?
+
+      # Normalize to uppercase 3-letter code
+      normalized = currency_value.to_s.strip.upcase
+
+      # Validate it's a reasonable currency code (3 letters)
+      if normalized.match?(/\A[A-Z]{3}\z/)
+        normalized
+      else
+        log_invalid_currency(currency_value)
+        nil
+      end
+    end
+
+    # Log warning for invalid currency codes
+    # Override this method in including classes to provide context-specific logging
+    def log_invalid_currency(currency_value)
+      Rails.logger.warn("Invalid currency code '#{currency_value}', defaulting to fallback")
+    end
+end

app/models/lunchflow_account.rb

@@ -1,4 +1,6 @@
 class LunchflowAccount < ApplicationRecord
+  include CurrencyNormalizable
+
   belongs_to :lunchflow_item
 
   # New association through account_providers
@@ -21,7 +23,7 @@ class LunchflowAccount < ApplicationRecord
     # Lunchflow API returns: { id, name, institution_name, institution_logo, provider, currency, status }
     update!(
       current_balance: nil, # Balance not provided by accounts endpoint
-      currency: snapshot[:currency] || "USD",
+      currency: parse_currency(snapshot[:currency]) || "USD",
       name: snapshot[:name],
       account_id: snapshot[:id].to_s,
       account_status: snapshot[:status],
@@ -41,4 +43,10 @@ class LunchflowAccount < ApplicationRecord
 
     save!
   end
+
+  private
+
+    def log_invalid_currency(currency_value)
+      Rails.logger.warn("Invalid currency code '#{currency_value}' for LunchFlow account #{id}, defaulting to USD")
+    end
 end

app/models/lunchflow_account/processor.rb

@@ -1,4 +1,6 @@
 class LunchflowAccount::Processor
+  include CurrencyNormalizable
+
   attr_reader :lunchflow_account
 
   def initialize(lunchflow_account)
@@ -37,14 +39,20 @@ class LunchflowAccount::Processor
       account = lunchflow_account.current_account
       balance = lunchflow_account.current_balance || 0
 
-      # For credit cards and loans, ensure positive balances
+      # For liability accounts (credit cards and loans), ensure positive balances
+      # LunchFlow may return negative values for liabilities, but Sure expects positive
       if account.accountable_type == "CreditCard" || account.accountable_type == "Loan"
         balance = balance.abs
       end
 
+      # Normalize currency with fallback chain: parsed lunchflow currency -> existing account currency -> USD
+      currency = parse_currency(lunchflow_account.currency) || account.currency || "USD"
+
+      # Update account balance
       account.update!(
         balance: balance,
-        cash_balance: balance
+        cash_balance: balance,
+        currency: currency
       )
     end
 

app/models/lunchflow_entry/processor.rb

@@ -1,6 +1,7 @@
 require "digest/md5"
 
 class LunchflowEntry::Processor
+  include CurrencyNormalizable
   # lunchflow_transaction is the raw hash fetched from Lunchflow API and converted to JSONB
   # Transaction structure: { id, accountId, amount, currency, date, merchant, description }
   def initialize(lunchflow_transaction, lunchflow_account:)
@@ -122,7 +123,11 @@ class LunchflowEntry::Processor
     end
 
     def currency
-      data[:currency].presence || account&.currency || "USD"
+      parse_currency(data[:currency]) || account&.currency || "USD"
+    end
+
+    def log_invalid_currency(currency_value)
+      Rails.logger.warn("Invalid currency code '#{currency_value}' in LunchFlow transaction #{external_id}, falling back to account currency")
     end
 
     def date

app/models/provider/plaid_adapter.rb

@@ -17,6 +17,10 @@ class Provider::PlaidAdapter < Provider::Base
   # Register this adapter with the factory for ALL PlaidAccount instances
   Provider::Factory.register("PlaidAccount", self)
 
+  # Mutex for thread-safe configuration loading
+  # Initialized at class load time to avoid race conditions on mutex creation
+  @config_mutex = Mutex.new
+
   # Configuration for Plaid US
   configure do
     description <<~DESC
@@ -51,6 +55,21 @@ class Provider::PlaidAdapter < Provider::Base
     "plaid"
   end
 
+  # Thread-safe lazy loading of Plaid US configuration
+  # Ensures configuration is loaded exactly once even under concurrent access
+  def self.ensure_configuration_loaded
+    # Fast path: return immediately if already loaded (no lock needed)
+    return if Rails.application.config.plaid.present?
+
+    # Slow path: acquire lock and reload if still needed
+    @config_mutex.synchronize do
+      # Double-check after acquiring lock (another thread may have loaded it)
+      return if Rails.application.config.plaid.present?
+
+      reload_configuration
+    end
+  end
+
   # Reload Plaid US configuration when settings are updated
   def self.reload_configuration
     client_id = config_value(:client_id).presence || ENV["PLAID_CLIENT_ID"]

app/models/provider/plaid_eu_adapter.rb

@@ -13,6 +13,10 @@
 class Provider::PlaidEuAdapter
   include Provider::Configurable
 
+  # Mutex for thread-safe configuration loading
+  # Initialized at class load time to avoid race conditions on mutex creation
+  @config_mutex = Mutex.new
+
   # Configuration for Plaid EU
   configure do
     description <<~DESC
@@ -43,6 +47,21 @@ class Provider::PlaidEuAdapter
           description: "Plaid environment: sandbox, development, or production"
   end
 
+  # Thread-safe lazy loading of Plaid EU configuration
+  # Ensures configuration is loaded exactly once even under concurrent access
+  def self.ensure_configuration_loaded
+    # Fast path: return immediately if already loaded (no lock needed)
+    return if Rails.application.config.plaid_eu.present?
+
+    # Slow path: acquire lock and reload if still needed
+    @config_mutex.synchronize do
+      # Double-check after acquiring lock (another thread may have loaded it)
+      return if Rails.application.config.plaid_eu.present?
+
+      reload_configuration
+    end
+  end
+
   # Reload Plaid EU configuration when settings are updated
   def self.reload_configuration
     client_id = config_value(:client_id).presence || ENV["PLAID_EU_CLIENT_ID"]

app/models/provider/plaid_sandbox.rb

@@ -40,6 +40,8 @@ class Provider::PlaidSandbox < Provider::Plaid
     def create_client
       raise "Plaid sandbox is not supported in production" if Rails.env.production?
 
+      Provider::PlaidAdapter.ensure_configuration_loaded
+
       api_client = Plaid::ApiClient.new(
         Rails.application.config.plaid
       )

app/models/provider/registry.rb

@@ -41,6 +41,7 @@ class Provider::Registry
       end
 
       def plaid_us
+        Provider::PlaidAdapter.ensure_configuration_loaded
         config = Rails.application.config.plaid
 
         return nil unless config.present?
@@ -49,6 +50,7 @@ class Provider::Registry
       end
 
       def plaid_eu
+        Provider::PlaidEuAdapter.ensure_configuration_loaded
         config = Rails.application.config.plaid_eu
 
         return nil unless config.present?

app/models/simplefin_account/processor.rb

@@ -49,7 +49,8 @@ class SimplefinAccount::Processor
 
       account.update!(
         balance: balance,
-        cash_balance: cash_balance
+        cash_balance: cash_balance,
+        currency: simplefin_account.currency
       )
     end
 

app/models/simplefin_entry/processor.rb

@@ -1,6 +1,7 @@
 require "digest/md5"
 
 class SimplefinEntry::Processor
+  include CurrencyNormalizable
   # simplefin_transaction is the raw hash fetched from SimpleFin API and converted to JSONB
   def initialize(simplefin_transaction, simplefin_account:)
     @simplefin_transaction = simplefin_transaction
@@ -77,7 +78,11 @@ class SimplefinEntry::Processor
     end
 
     def currency
-      data[:currency] || account.currency
+      parse_currency(data[:currency]) || account.currency
+    end
+
+    def log_invalid_currency(currency_value)
+      Rails.logger.warn("Invalid currency code '#{currency_value}' in SimpleFIN transaction #{external_id}, falling back to account currency")
     end
 
     def date

app/views/loans/new.html.erb

@@ -3,6 +3,7 @@
              path: new_loan_path(return_to: params[:return_to]),
              show_us_link: @show_us_link,
              show_eu_link: @show_eu_link,
+             show_lunchflow_link: @show_lunchflow_link,
              accountable_type: "Loan" %>
 <% else %>
   <%= render DS::Dialog.new do |dialog| %>

config/initializers/plaid.rb

@@ -1,21 +0,0 @@
-Rails.application.configure do
-  # Initialize Plaid configuration to nil
-  config.plaid = nil
-  config.plaid_eu = nil
-end
-
-# Load Plaid configuration from adapters after initialization
-Rails.application.config.after_initialize do
-  # Skip if database is not ready (e.g., during db:create)
-  next unless ActiveRecord::Base.connection.table_exists?("settings")
-
-  # Ensure provider adapters are loaded
-  Provider::Factory.ensure_adapters_loaded
-
-  # Reload configurations from settings/ENV
-  Provider::PlaidAdapter.reload_configuration      # US region
-  Provider::PlaidEuAdapter.reload_configuration    # EU region
-rescue ActiveRecord::NoDatabaseError, PG::ConnectionBad
-  # Database doesn't exist yet, skip initialization
-  nil
-end

config/initializers/plaid_config.rb

@@ -0,0 +1,7 @@
+# Plaid configuration attributes
+# These are initialized to nil and loaded lazily on first access by Provider::Registry
+# Configuration is loaded from database settings or ENV variables via the adapter's reload_configuration method
+Rails.application.configure do
+  config.plaid = nil
+  config.plaid_eu = nil
+end

lib/tasks/data_migration.rake

@@ -3,6 +3,7 @@ namespace :data_migration do
   # 2025-02-07: EU Plaid items need to be moved over to a new webhook URL so that we can
   # instantiate the correct Plaid client for verification based on which Plaid instance it comes from
   task eu_plaid_webhooks: :environment do
+    Provider::PlaidEuAdapter.ensure_configuration_loaded
     provider = Provider::Plaid.new(Rails.application.config.plaid_eu, region: :eu)
 
     eu_items = PlaidItem.where(plaid_region: "eu")