Implemented balances report.

app/Http/Controllers/ReportsController.php

@@ -51,7 +51,62 @@ class ReportsController extends Controller
      */
     public function balances($year)
     {
-        //
+        # Load monthly incomes, expeditures and the start account balance from
+        # the database.
+        $incomes = SubBooking::incomesInInterval(firstDayOfYear($year),
+            lastDayOfYear($year), true)->sortBy('month');
+        $expeditures = SubBooking::expedituresInInterval(firstDayOfYear($year),
+            lastDayOfYear($year), true)->sortBy('month');
+        $startBalance = SubBooking::balanceAt(lastDayOfYear($year - 1));
+
+        # If the data contains future months remove the data of all incomplete
+        # months.
+        if (date('Y') <= $year) {
+            foreach ([$incomes, $expeditures] as $cashflows) {
+                foreach ($cashflows as $key => $cashflow) {
+                    if ($cashflow->month >= date('n')) {
+                        $cashflows->forget($key);
+                    }
+                }
+            }
+        }
+
+        # Create a collection of balances, every entry holds information about
+        # one month.
+        $balances = collect();
+
+        for ($i = 0; $i < count($incomes); $i++) {
+            $balance = collect();
+
+            $balance->incomes = $incomes[$i]->incomes;
+            $balance->expeditures = $expeditures[$i]->expeditures;
+            $balance->monthBalance = $incomes[$i]->incomes
+                + $expeditures[$i]->expeditures;
+
+            # Set date separately if the next month is in the new year.
+            if ($incomes[$i]->month == 12) {
+                $balance->date = firstDayOfYear($incomes[$i]->year + 1);
+            } else {
+                $balance->date = startOfMonth($incomes[$i]->year,
+                    $incomes[$i]->month + 1);
+            }
+
+            # Set the balance of the first month separately since the value
+            # depends on the startBalance value and not on a value already
+            # existing in the balances collection.
+            if ($incomes[$i]->month == 1) {
+                $balance->accountBalance = $startBalance
+                    + $balance->monthBalance;
+            } else {
+                $balance->accountBalance = $balances[$i - 1]->accountBalance
+                    + $balance->monthBalance;
+            }
+
+            # Add complete balance to the balances collection
+            $balances->push($balance);
+        }
+
+        return view('reports.balances', compact('year', 'balances', 'startBalance'));
     }
     
     /**

app/SubBooking.php

@@ -213,7 +213,7 @@ class SubBooking extends Model
                 }
             }
 
-            return $result;
+            return $result->sortBy('month')->sortBy('year')->values();
         }
 
         return $result->get();