Finally updated the transaction controller to have some more sensible code.

app/lib/FireflyIII/Helper/TransactionJournal/HelperInterface.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace FireflyIII\Helper\TransactionJournal;
+
+use Illuminate\Support\Collection;
+
+/**
+ * Interface HelperInterface
+ *
+ * @package FireflyIII\Helper\TransactionJournal
+ */
+interface HelperInterface
+{
+    /**
+     *
+     * Get the account_id, which is the asset account that paid for the transaction.
+     *
+     * @param string     $what
+     * @param Collection $transactions
+     *
+     * @return int
+     */
+    public function getAssetAccount($what, Collection $transactions);
+
+    /**
+     * @return Collection
+     */
+    public function getAssetAccounts();
+
+    /**
+     * @return Collection
+     */
+    public function getBudgets();
+
+    /**
+     * @return Collection
+     */
+    public function getPiggyBanks();
+
+    /**
+     * @return Collection
+     */
+    public function getRepeatedExpenses();
+
+}