Add BYSETPOS to RecurrenceRule

src/Property/Event/RecurrenceRule.php

@@ -45,6 +45,13 @@ class RecurrenceRule implements ValueInterface
      */
     protected $freq = self::FREQ_YEARLY;
 
+    /**
+     * BYSETPOS must require use of other BY*.
+     *
+     * @var bool
+     */
+    protected $canUseBySetPos = false;
+
     /**
      * @var null|int
      */
@@ -65,6 +72,11 @@ class RecurrenceRule implements ValueInterface
      */
     protected $wkst;
 
+    /**
+     * @var null|array
+     */
+    protected $bySetPos = null;
+
     /**
      * @var null|string
      */
@@ -135,6 +147,10 @@ protected function buildParameterBag()
             $parameterBag->setParam('WKST', $this->wkst);
         }
 
+        if (null !== $this->bySetPos && $this->canUseBySetPos) {
+            $parameterBag->setParam('BYSETPOS', $this->bySetPos);
+        }
+
         if (null !== $this->byMonth) {
             $parameterBag->setParam('BYMONTH', explode(',', $this->byMonth));
         }
@@ -286,6 +302,69 @@ public function setWkst($value)
         return $this;
     }
 
+    /**
+     * The BYSETPOS filters one interval of events by the specified position.
+     * A positive position will start from the beginning and go forward while
+     * a negative position will start at the end and move backward.
+     *
+     * Valid values are a comma separated string or an array of integers
+     * from 1 to 366 or negative integers from -1 to -366.
+     *
+     * @param null|int|string|array $value
+     *
+     * @throws InvalidArgumentException
+     *
+     * @return $this
+     */
+    public function setBySetPos($value)
+    {
+        if (null === $value) {
+            $this->bySetPos = $value;
+
+            return $this;
+        }
+
+        if (!(is_string($value) || is_array($value) || is_int($value))) {
+            throw new InvalidArgumentException('Invalid value for BYSETPOS');
+        }
+
+        $list = $value;
+
+        if (is_int($value)) {
+            if ($value === 0 || $value < -366 || $value > 366) {
+                throw new InvalidArgumentException('Invalid value for BYSETPOS');
+            }
+            $this->bySetPos = [$value];
+
+            return $this;
+        }
+
+        if (is_string($value)) {
+            $list = explode(',', $value);
+        }
+
+        $output = [];
+
+        foreach ($list as $item) {
+            if (is_string($item)) {
+                if (!preg_match('/^ *-?[0-9]* *$/', $item)) {
+                    throw new InvalidArgumentException('Invalid value for BYSETPOS');
+                }
+                $item = intval($item);
+            }
+
+            if (!is_int($item) || $item === 0 || $item < -366 || $item > 366) {
+                throw new InvalidArgumentException('Invalid value for BYSETPOS');
+            }
+
+            $output[] = $item;
+        }
+
+        $this->bySetPos = $output;
+
+        return $this;
+    }
+
     /**
      * The BYMONTH rule part specifies a COMMA-separated list of months of the year.
      * Valid values are 1 to 12.
@@ -304,6 +383,8 @@ public function setByMonth($month)
 
         $this->byMonth = $month;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -319,6 +400,8 @@ public function setByWeekNo($value)
     {
         $this->byWeekNo = $value;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -334,6 +417,8 @@ public function setByYearDay($day)
     {
         $this->byYearDay = $day;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -349,6 +434,8 @@ public function setByMonthDay($day)
     {
         $this->byMonthDay = $day;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -369,6 +456,8 @@ public function setByDay(string $day)
     {
         $this->byDay = $day;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -390,6 +479,8 @@ public function setByHour($value)
 
         $this->byHour = $value;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -411,6 +502,8 @@ public function setByMinute($value)
 
         $this->byMinute = $value;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 
@@ -432,6 +525,8 @@ public function setBySecond($value)
 
         $this->bySecond = $value;
 
+        $this->canUseBySetPos = true;
+
         return $this;
     }
 }