Account:: namespace simplifications and cleanup (#2110)

* Flatten Holding model

* Flatten balance model

* Entries domain renames

* Fix valuations reference

* Fix trades stream

* Fix brakeman warnings

* Fix tests

* Replace existing entryable type references in DB

app/models/trade_builder.rb

@@ -0,0 +1,121 @@
+class TradeBuilder
+  include ActiveModel::Model
+
+  attr_accessor :account, :date, :amount, :currency, :qty,
+                :price, :ticker, :manual_ticker, :type, :transfer_account_id
+
+  attr_reader :buildable
+
+  def initialize(attributes = {})
+    super
+    @buildable = set_buildable
+  end
+
+  def save
+    buildable.save
+  end
+
+  def errors
+    buildable.errors
+  end
+
+  def sync_account_later
+    buildable.sync_account_later
+  end
+
+  private
+    def set_buildable
+      case type
+      when "buy", "sell"
+        build_trade
+      when "deposit", "withdrawal"
+        build_transfer
+      when "interest"
+        build_interest
+      else
+        raise "Unknown trade type: #{type}"
+      end
+    end
+
+    def build_trade
+      prefix = type == "sell" ? "Sell " : "Buy "
+      trade_name = prefix + "#{qty.to_i.abs} shares of #{security.ticker}"
+
+      account.entries.new(
+        name: trade_name,
+        date: date,
+        amount: signed_amount,
+        currency: currency,
+        entryable: Trade.new(
+          qty: signed_qty,
+          price: price,
+          currency: currency,
+          security: security
+        )
+      )
+    end
+
+    def build_transfer
+      transfer_account = family.accounts.find(transfer_account_id) if transfer_account_id.present?
+
+      if transfer_account
+        from_account = type == "withdrawal" ? account : transfer_account
+        to_account = type == "withdrawal" ? transfer_account : account
+
+        Transfer.from_accounts(
+          from_account: from_account,
+          to_account: to_account,
+          date: date,
+          amount: signed_amount
+        )
+      else
+        account.entries.build(
+          name: signed_amount < 0 ? "Deposit to #{account.name}" : "Withdrawal from #{account.name}",
+          date: date,
+          amount: signed_amount,
+          currency: currency,
+          entryable: Transaction.new
+        )
+      end
+    end
+
+    def build_interest
+      account.entries.build(
+        name: "Interest payment",
+        date: date,
+        amount: signed_amount,
+        currency: currency,
+        entryable: Transaction.new
+      )
+    end
+
+    def signed_qty
+      return nil unless type.in?([ "buy", "sell" ])
+
+      type == "sell" ? -qty.to_d : qty.to_d
+    end
+
+    def signed_amount
+      case type
+      when "buy", "sell"
+        signed_qty * price.to_d
+      when "deposit", "withdrawal"
+        type == "deposit" ? -amount.to_d : amount.to_d
+      when "interest"
+        amount.to_d * -1
+      end
+    end
+
+    def family
+      account.family
+    end
+
+    # Users can either look up a ticker from our provider (Synth) or enter a manual, "offline" ticker (that we won't fetch prices for)
+    def security
+      ticker_symbol, exchange_operating_mic = ticker.present? ? ticker.split("|") : [ manual_ticker, nil ]
+
+      Security.find_or_create_by(ticker: ticker_symbol, exchange_operating_mic: exchange_operating_mic) do |s|
+        FetchSecurityInfoJob.perform_later(s.id)
+      end
+    end
+end