improved invoices with new renderer (#306)

* added docx renderer and demo template
* added csv renderer and demo template
* added xlsx renderer and demo template
* added ods renderer and demo template
* added user calculator
* added invoice documentation

src/Invoice/Calculator/AbstractMergedCalculator.php

@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Invoice\Calculator;
+
+use App\Entity\Timesheet;
+
+abstract class AbstractMergedCalculator extends AbstractCalculator
+{
+    /**
+     * @param Timesheet $timesheet
+     * @param Timesheet $entry
+     */
+    protected function mergeTimesheets(Timesheet $timesheet, Timesheet $entry)
+    {
+        $timesheet->setUser($entry->getUser());
+        $timesheet->setFixedRate($entry->getFixedRate()); // FIXME invoice
+        $timesheet->setHourlyRate($entry->getHourlyRate()); // FIXME invoice
+        $timesheet->setRate($timesheet->getRate() + $entry->getRate());
+        $timesheet->setDuration($timesheet->getDuration() + $entry->getDuration());
+
+        if (null === $timesheet->getBegin() || $timesheet->getBegin()->getTimestamp() > $entry->getBegin()->getTimestamp()) {
+            $timesheet->setBegin($entry->getBegin());
+        }
+
+        if (null === $timesheet->getEnd() || $timesheet->getEnd()->getTimestamp() < $entry->getEnd()->getTimestamp()) {
+            $timesheet->setEnd($entry->getEnd());
+        }
+
+        if (null !== $this->model->getQuery()->getActivity()) {
+            $timesheet->setActivity($this->model->getQuery()->getActivity());
+            $timesheet->setDescription($this->model->getQuery()->getActivity()->getName());
+        } elseif (null !== $this->model->getQuery()->getProject()) {
+            $timesheet->setDescription($this->model->getQuery()->getProject()->getName());
+        }
+
+        if (null === $timesheet->getActivity()) {
+            $timesheet->setActivity($entry->getActivity());
+        }
+
+        if (empty($timesheet->getDescription())) {
+            $timesheet->setDescription($entry->getActivity()->getName());
+        }
+    }
+}