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/Model/InvoiceModel.php

@@ -17,7 +17,8 @@ use App\Invoice\NumberGeneratorInterface;
 use App\Repository\Query\InvoiceQuery;
 
 /**
- * Class InvoiceModel is the ONLY value that a renderer template receives for generating the invoice.
+ * InvoiceModel is the ONLY value that a RendererInterface receives for generating the invoice,
+ * besides the InvoiceDocument which is used as a "template".
  */
 class InvoiceModel
 {
@@ -51,10 +52,20 @@ class InvoiceModel
      */
     protected $generator;
 
+    /**
+     * @var \DateTime
+     */
+    protected $invoiceDate;
+
+    public function __construct()
+    {
+        $this->invoiceDate = new \DateTime();
+    }
+
     /**
      * @return InvoiceQuery
      */
-    public function getQuery(): InvoiceQuery
+    public function getQuery(): ?InvoiceQuery
     {
         return $this->query;
     }
@@ -103,7 +114,7 @@ class InvoiceModel
      * @param InvoiceTemplate $template
      * @return InvoiceModel
      */
-    public function setTemplate($template)
+    public function setTemplate(InvoiceTemplate $template)
     {
         $this->template = $template;
 
@@ -132,8 +143,12 @@ class InvoiceModel
     /**
      * @return \DateTime
      */
-    public function getDueDate(): \DateTime
+    public function getDueDate(): ?\DateTime
     {
+        if (null === $this->getTemplate()) {
+            return null;
+        }
+
         return new \DateTime('+' . $this->getTemplate()->getDueDays() . ' days');
     }
 
@@ -142,7 +157,7 @@ class InvoiceModel
      */
     public function getInvoiceDate(): \DateTime
     {
-        return new \DateTime();
+        return $this->invoiceDate;
     }
 
     /**
@@ -160,7 +175,7 @@ class InvoiceModel
     /**
      * @return NumberGeneratorInterface
      */
-    public function getNumberGenerator(): NumberGeneratorInterface
+    public function getNumberGenerator(): ?NumberGeneratorInterface
     {
         return $this->generator;
     }
@@ -180,7 +195,7 @@ class InvoiceModel
     /**
      * @return CalculatorInterface
      */
-    public function getCalculator(): CalculatorInterface
+    public function getCalculator(): ?CalculatorInterface
     {
         return $this->calculator;
     }

src/Model/Statistic/Month.php

@@ -10,7 +10,7 @@
 namespace App\Model\Statistic;
 
 /**
- * Yearly statistics
+ * Monthly statistics
  */
 class Month
 {
@@ -28,11 +28,14 @@ class Month
     protected $totalRate = 0;
 
     /**
-     * Month constructor.
      * @param string $month
      */
-    public function __construct($month)
+    public function __construct(string $month)
     {
+        $monthNumber = (int) $month;
+        if ($monthNumber < 1 || $monthNumber > 12) {
+            throw new \InvalidArgumentException('Invalid month given, expected 01-12 but given: ' . $monthNumber);
+        }
         $this->month = $month;
     }
 

src/Model/Statistic/Year.php

@@ -21,7 +21,7 @@ class Year
     /**
      * @var Month[]
      */
-    protected $months;
+    protected $months = [];
 
     /**
      * Year constructor.
@@ -52,10 +52,10 @@ class Year
     }
 
     /**
-     * @param $month
+     * @param int $month
      * @return null|Month
      */
-    public function getMonth($month)
+    public function getMonth(int $month)
     {
         if (isset($this->months[$month])) {
             return $this->months[$month];