Some code cleanup.

app/Repositories/Tag/TagRepository.php

@@ -143,6 +143,79 @@ class TagRepository implements TagRepositoryInterface
 
     }
 
+    /**
+     * Can a tag become an advance payment?
+     *
+     * @param Tag $tag
+     *
+     * @return bool
+     */
+    public function tagAllowAdvance(Tag $tag)
+    {
+        /*
+         * If this tag is a balancing act, and it contains transfers, it cannot be
+         * changes to an advancePayment.
+         */
+
+        if ($tag->tagMode == 'balancingAct' || $tag->tagMode == 'nothing') {
+            foreach ($tag->transactionjournals as $journal) {
+                if ($journal->transactionType->type == 'Transfer') {
+                    return false;
+                }
+            }
+        }
+
+        /*
+         * If this tag contains more than one expenses, it cannot become an advance payment.
+         */
+        $count = 0;
+        foreach ($tag->transactionjournals as $journal) {
+            if ($journal->transactionType->type == 'Withdrawal') {
+                $count++;
+            }
+        }
+        if ($count > 1) {
+            return false;
+        }
+
+        return true;
+
+    }
+
+    /**
+     * Can a tag become a balancing act?
+     *
+     * @param Tag $tag
+     *
+     * @return bool
+     */
+    public function tagAllowBalancing(Tag $tag)
+    {
+        /*
+         * If has more than two transactions already, cannot become a balancing act:
+         */
+        if ($tag->transactionjournals->count() > 2) {
+            return false;
+        }
+
+        /*
+         * If any transaction is a deposit, cannot become a balancing act.
+         */
+        $count = 0;
+        foreach ($tag->transactionjournals as $journal) {
+            if ($journal->transactionType->type == 'Deposit') {
+                $count++;
+            }
+        }
+        if ($count > 0) {
+            return false;
+        }
+
+
+        return true;
+    }
+
+
     /**
      * @param Tag   $tag
      * @param array $data

app/Repositories/Tag/TagRepositoryInterface.php

@@ -18,6 +18,14 @@ interface TagRepositoryInterface
 {
 
 
+    /**
+     * @param TransactionJournal $journal
+     * @param Tag                $tag
+     *
+     * @return boolean
+     */
+    public function connect(TransactionJournal $journal, Tag $tag);
+
     /**
      * This method scans the transaction journals from or to the given asset account
      * and checks if these are part of a balancing act. If so, it will sum up the amounts
@@ -34,6 +42,18 @@ interface TagRepositoryInterface
      */
     public function coveredByBalancingActs(Account $account, Carbon $start, Carbon $end);
 
+    /**
+     * @param Tag $tag
+     *
+     * @return boolean
+     */
+    public function destroy(Tag $tag);
+
+    /**
+     * @return Collection
+     */
+    public function get();
+
     /**
      * @param array $data
      *
@@ -42,9 +62,22 @@ interface TagRepositoryInterface
     public function store(array $data);
 
     /**
-     * @return Collection
+     * Can a tag become an advance payment?
+     *
+     * @param Tag $tag
+     *
+     * @return bool
      */
-    public function get();
+    public function tagAllowAdvance(Tag $tag);
+
+    /**
+     * Can a tag become a balancing act?
+     *
+     * @param Tag $tag
+     *
+     * @return bool
+     */
+    public function tagAllowBalancing(Tag $tag);
 
     /**
      * @param Tag   $tag
@@ -53,19 +86,4 @@ interface TagRepositoryInterface
      * @return Tag
      */
     public function update(Tag $tag, array $data);
-
-    /**
-     * @param Tag $tag
-     *
-     * @return boolean
-     */
-    public function destroy(Tag $tag);
-
-    /**
-     * @param TransactionJournal $journal
-     * @param Tag                $tag
-     *
-     * @return boolean
-     */
-    public function connect(TransactionJournal $journal, Tag $tag);
 }