feat: add cron segment validator

Author: adhocore

src/Validator.php

@@ -0,0 +1,128 @@
+<?php
+
+namespace Ahc\Cron;
+
+/**
+ * Cron segment validator.
+ *
+ * This class checks if a cron segment is valid.
+ *
+ * @author Jitendra Adhikari <[email protected]>
+ */
+class Validator
+{
+    public function inRange($value, $offset)
+    {
+        $parts = \explode('-', $offset);
+
+        return $parts[0] <= $value && $value <= $parts[1];
+    }
+
+    public function inStep($value, $offset)
+    {
+        if (\strpos($offset, '*/') !== false || \strpos($offset, '0/') !== false) {
+            $parts = \explode('/', $offset, 2);
+
+            return $value % $parts[1] === 0;
+        }
+
+        $parts    = \explode('/', $offset, 2);
+        $subparts = \explode('-', $parts[0], 2) + [1 => $value];
+
+        return ($subparts[0] <= $value && $value <= $subparts[1] && $parts[1])
+            ? \in_array($value, \range($subparts[0], $subparts[1], $parts[1]))
+            : false;
+    }
+
+    /**
+     * Check if month modifiers [L C W #] are satisfied.
+     *
+     * @internal
+     *
+     * @param string $value
+     * @param array  $time
+     *
+     * @return bool|null
+     */
+    public function isValidMonthDay($value, $time)
+    {
+        if ($value == 'L') {
+            return $time[2] == $time[6];
+        }
+
+        if ($pos = \strpos($value, 'W')) {
+            $value = \substr($value, 0, $pos);
+            $month = \str_pad($time[8], 2, '0', \STR_PAD_LEFT);
+
+            return $this->isClosestWeekDay($value, $month, $time);
+        }
+    }
+
+    protected function isClosestWeekDay($value, $month, $time)
+    {
+        foreach ([0, -1, 1, -2, 2] as $i) {
+            $incr = $value + $i;
+            if ($incr < 1 || $incr > $time[6]) {
+                continue;
+            }
+
+            $incr  = \str_pad($incr, 2, '0', \STR_PAD_LEFT);
+            $parts = \explode(' ', \date('N m j', \strtotime("{$time[5]}-$month-$incr")));
+            if ($parts[0] < 6 && $parts[1] == $month) {
+                return $time[2] == $parts[2];
+            }
+        }
+
+        // @codeCoverageIgnoreStart
+        return false;
+        // @codeCoverageIgnoreEnd
+    }
+
+    /**
+     * Check if week modifiers [L C W #] are satisfied.
+     *
+     * @internal
+     *
+     * @param string $value
+     * @param array  $time
+     *
+     * @return bool|null
+     */
+    public function isValidWeekDay($value, $time)
+    {
+        $month = \str_pad($time[8], 2, '0', \STR_PAD_LEFT);
+
+        if (\strpos($value, 'L')) {
+            return $this->lastWeekDay($value, $month, $time);
+        }
+
+        if (\strpos($value, '#')) {
+            $value = \explode('#', \str_replace('0#', '7#', $value));
+
+            if ($value[0] < 0 || $value[0] > 7 || $value[1] < 1 || $value[1] > 5 || $time[9] != $value[0]) {
+                return false;
+            }
+
+            return \intval($time[7] / 7) == $value[1] - 1;
+        }
+
+        // @codeCoverageIgnoreStart
+        return false;
+        // @codeCoverageIgnoreEnd
+    }
+
+    protected function lastWeekDay($value, $month, $time)
+    {
+        $value = \explode('L', \str_replace('7L', '0L', $value));
+        $decr  = $time[6];
+
+        for ($i = 0; $i < 7; $i++) {
+            $decr -= $i;
+            if (\date('w', \strtotime("{$time[5]}-$month-$decr")) == $value[0]) {
+                return $time[2] == $decr;
+            }
+        }
+
+        return false;
+    }
+}