Plaid sync domain improvements (#2267)

Breaks our Plaid sync process out into more manageable classes. Notably, this moves the sync process to a distinct, 2-step flow:

1. Import stage - we first make API calls and import Plaid data to "mirror" tables
2. Processing stage - read the raw data, apply business rules, build internal domain models and sync balances

This provides several benefits:

- Plaid syncs can now be "replayed" without fetching API data again
- Mirror tables provide better audit and debugging capabilities
- Eliminates the "all or nothing" sync behavior that is currently in place, which is brittle

app/models/plaid_account.rb

@@ -1,167 +1,54 @@
 class PlaidAccount < ApplicationRecord
-  TYPE_MAPPING = {
-    "depository" => Depository,
-    "credit" => CreditCard,
-    "loan" => Loan,
-    "investment" => Investment,
-    "other" => OtherAsset
-  }
-
   belongs_to :plaid_item
 
   has_one :account, dependent: :destroy
 
-  accepts_nested_attributes_for :account
+  validates :name, :plaid_type, :currency, presence: true
+  validate :has_balance
 
-  class << self
-    def find_or_create_from_plaid_data!(plaid_data, family)
-      PlaidAccount.transaction do
-        plaid_account = find_or_create_by!(plaid_id: plaid_data.account_id)
-
-        internal_account = family.accounts.find_or_initialize_by(plaid_account_id: plaid_account.id)
-
-        # Only set the name for new records or if the name is not locked
-        if internal_account.new_record? || internal_account.enrichable?(:name)
-          internal_account.name = plaid_data.name
-        end
-        internal_account.balance = plaid_data.balances.current || plaid_data.balances.available
-        internal_account.currency = plaid_data.balances.iso_currency_code
-        internal_account.accountable = TYPE_MAPPING[plaid_data.type].new
-
-        internal_account.save!
-        plaid_account.save!
-
-        plaid_account
-      end
-    end
-  end
-
-  def sync_account_data!(plaid_account_data)
-    update!(
-      current_balance: plaid_account_data.balances.current,
-      available_balance: plaid_account_data.balances.available,
-      currency: plaid_account_data.balances.iso_currency_code,
-      plaid_type: plaid_account_data.type,
-      plaid_subtype: plaid_account_data.subtype,
-      account_attributes: {
-        id: account.id,
-        # Plaid guarantees at least 1 of these
-        balance: plaid_account_data.balances.current || plaid_account_data.balances.available,
-        cash_balance: derive_plaid_cash_balance(plaid_account_data.balances)
-      }
+  def upsert_plaid_snapshot!(account_snapshot)
+    assign_attributes(
+      current_balance: account_snapshot.balances.current,
+      available_balance: account_snapshot.balances.available,
+      currency: account_snapshot.balances.iso_currency_code,
+      plaid_type: account_snapshot.type,
+      plaid_subtype: account_snapshot.subtype,
+      name: account_snapshot.name,
+      mask: account_snapshot.mask,
+      raw_payload: account_snapshot
     )
+
+    save!
   end
 
-  def sync_investments!(transactions:, holdings:, securities:)
-    PlaidInvestmentSync.new(self).sync!(transactions:, holdings:, securities:)
-  end
-
-  def sync_credit_data!(plaid_credit_data)
-    account.update!(
-      accountable_attributes: {
-        id: account.accountable_id,
-        minimum_payment: plaid_credit_data.minimum_payment_amount,
-        apr: plaid_credit_data.aprs.first&.apr_percentage
-      }
+  def upsert_plaid_transactions_snapshot!(transactions_snapshot)
+    assign_attributes(
+      raw_transactions_payload: transactions_snapshot
     )
+
+    save!
   end
 
-  def sync_mortgage_data!(plaid_mortgage_data)
-    create_initial_loan_balance(plaid_mortgage_data)
-
-    account.update!(
-      accountable_attributes: {
-        id: account.accountable_id,
-        rate_type: plaid_mortgage_data.interest_rate&.type,
-        interest_rate: plaid_mortgage_data.interest_rate&.percentage
-      }
+  def upsert_plaid_investments_snapshot!(investments_snapshot)
+    assign_attributes(
+      raw_investments_payload: investments_snapshot
     )
+
+    save!
   end
 
-  def sync_student_loan_data!(plaid_student_loan_data)
-    create_initial_loan_balance(plaid_student_loan_data)
-
-    account.update!(
-      accountable_attributes: {
-        id: account.accountable_id,
-        rate_type: "fixed",
-        interest_rate: plaid_student_loan_data.interest_rate_percentage
-      }
+  def upsert_plaid_liabilities_snapshot!(liabilities_snapshot)
+    assign_attributes(
+      raw_liabilities_payload: liabilities_snapshot
     )
-  end
 
-  def sync_transactions!(added:, modified:, removed:)
-    added.each do |plaid_txn|
-      account.entries.find_or_create_by!(plaid_id: plaid_txn.transaction_id) do |t|
-        t.name = plaid_txn.merchant_name || plaid_txn.original_description
-        t.amount = plaid_txn.amount
-        t.currency = plaid_txn.iso_currency_code
-        t.date = plaid_txn.date
-        t.entryable = Transaction.new(
-          plaid_category: plaid_txn.personal_finance_category.primary,
-          plaid_category_detailed: plaid_txn.personal_finance_category.detailed,
-          merchant: find_or_create_merchant(plaid_txn)
-        )
-      end
-    end
-
-    modified.each do |plaid_txn|
-      existing_txn = account.entries.find_by(plaid_id: plaid_txn.transaction_id)
-
-      existing_txn.update!(
-        amount: plaid_txn.amount,
-        date: plaid_txn.date,
-        entryable_attributes: {
-          plaid_category: plaid_txn.personal_finance_category.primary,
-          plaid_category_detailed: plaid_txn.personal_finance_category.detailed,
-          merchant: find_or_create_merchant(plaid_txn)
-        }
-      )
-    end
-
-    removed.each do |plaid_txn|
-      account.entries.find_by(plaid_id: plaid_txn.transaction_id)&.destroy
-    end
+    save!
   end
 
   private
-    def family
-      plaid_item.family
-    end
-
-    def create_initial_loan_balance(loan_data)
-      if loan_data.origination_principal_amount.present? && loan_data.origination_date.present?
-        account.entries.find_or_create_by!(plaid_id: loan_data.account_id) do |e|
-          e.name = "Initial Principal"
-          e.amount = loan_data.origination_principal_amount
-          e.currency = account.currency
-          e.date = loan_data.origination_date
-          e.entryable = Valuation.new
-        end
-      end
-    end
-
-    def find_or_create_merchant(plaid_txn)
-      unless plaid_txn.merchant_entity_id.present? && plaid_txn.merchant_name.present?
-        return nil
-      end
-
-      ProviderMerchant.find_or_create_by!(
-        source: "plaid",
-        name: plaid_txn.merchant_name,
-      ) do |m|
-        m.provider_merchant_id = plaid_txn.merchant_entity_id
-        m.website_url = plaid_txn.website
-        m.logo_url = plaid_txn.logo_url
-      end
-    end
-
-    def derive_plaid_cash_balance(plaid_balances)
-      if account.investment?
-        plaid_balances.available || 0
-      else
-        # For now, we will not distinguish between "cash" and "overall" balance for non-investment accounts
-        plaid_balances.current || plaid_balances.available
-      end
+    # Plaid guarantees at least one of these.  This validation is a sanity check for that guarantee.
+    def has_balance
+      return if current_balance.present? || available_balance.present?
+      errors.add(:base, "Plaid account must have either current or available balance")
     end
 end