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();

resources/views/bookings/index.blade.php

@@ -5,6 +5,7 @@
 @section('subnav')
     <li class="nav-item ml-auto">
       <a href='/bookings/create' class="btn btn-outline-success">Neue Buchung</a>
+      <a href='/reports/balances/{{ $year }}' class="btn btn-outline-warning">HS-Rechnung</a>
     </li>
 @endsection
 

resources/views/reports/balances.blade.php

@@ -0,0 +1,36 @@
+@extends('layout.master')
+
+@section('title', 'HS-Rechnung für ' . $year)
+
+@section('subnav')
+    <a class='btn btn-outline-secondary' href='/bookings/year-{{ $year }}'>Zurück</a>
+@endsection
+
+@section('content')
+    <h2>@yield('title')</h2>
+    <table class='table table-striped table-bordered'>
+        <tr>
+            <th>Datum</th>
+            <th>Kontostand</th>
+            <th>Monatssaldo</th>
+            <th>Abgänge</th>
+            <th>Zugänge</th>
+        </tr>
+        <tr>
+            <td>{{ formatDate(firstDayOfYear($year)) }}</td>
+            <td>{!! formatAmount($startBalance) !!}</td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        @foreach($balances as $balance)
+            <tr>
+                <td>{{ formatDate($balance->date) }}</td>
+                <td>{!! formatAmount($balance->accountBalance) !!}</td>
+                <td>{!! formatAmount($balance->monthBalance) !!}</td>
+                <td>{!! formatAmount($balance->expeditures) !!}</td>
+                <td>{!! formatAmount($balance->incomes) !!}</td>
+            </tr>
+        @endforeach
+    </table>
+@endsection