feat: extract checker class

Author: adhocore

src/SegmentChecker.php

@@ -0,0 +1,176 @@
+<?php
+
+namespace Ahc\Cron;
+
+/**
+ * Cron Expression Parser.
+ *
+ * This class checks if a cron segment satisfies given time.
+ *
+ * @author Jitendra Adhikari <[email protected]>
+ */
+class SegmentChecker
+{
+    public static function isDue($segment, $pos, $time)
+    {
+        $isDue   = true;
+        $offsets = explode(',', trim($segment));
+
+        foreach ($offsets as $offset) {
+            if (null === $isDue = static::isOffsetDue($offset, $pos, $time)) {
+                throw new \UnexpectedValueException(
+                    sprintf('Invalid offset value %s for segment #%d', $offset, $pos)
+                );
+            }
+
+            if ($isDue) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Check if a given offset at a position is due with respect to given time.
+     *
+     * @param string $offset
+     * @param int    $pos
+     * @param array  $time
+     *
+     * @return bool|null
+     */
+    protected static function isOffsetDue($offset, $pos, $time)
+    {
+        if (strpos($offset, '/') !== false) {
+            return static::inStep($time[$pos], $offset);
+        }
+
+        if (strpos($offset, '-') !== false) {
+            return static::inRange($time[$pos], $offset);
+        }
+
+        if (is_numeric($offset)) {
+            return $time[$pos] == $offset;
+        }
+
+        $isModifier = strpbrk($offset, 'LCW#');
+
+        if ($pos === 2 && $isModifier) {
+            return static::checkMonthDay($offset, $time);
+        }
+
+        if ($pos === 4 && $isModifier) {
+            return static::checkWeekDay($offset, $time);
+        }
+    }
+
+    protected static function inRange($value, $offset)
+    {
+        $parts = explode('-', $offset);
+
+        return $parts[0] <= $value && $value <= $parts[1];
+    }
+
+    protected static function inStep($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 modifiers [L C W #] are satisfied.
+     *
+     * @internal
+     *
+     * @param string $value
+     * @param int    $time
+     *
+     * @return bool|null
+     */
+    protected static function checkMonthDay($value, $time)
+    {
+        $month = $time[8] < 10 ? '0' . $time[8] : $time[8];
+
+        if ($value == 'L') {
+            return $time[2] == $time[6];
+        }
+
+        if ($pos = strpos($value, 'W')) {
+            $value = substr($value, 0, $pos);
+
+            return static::isClosestWeekDay($value, $month, $time);
+        }
+    }
+
+    protected static function isClosestWeekDay($value, $month, $time)
+    {
+        foreach ([0, -1, 1, -2, 2] as $i) {
+            $incr = $value + $i;
+            if ($incr > 0 && $incr <= $time[6]) {
+                if ($incr < 10) {
+                    $incr = '0' . $incr;
+                }
+
+                $parts = explode(' ', date('N m j', strtotime("$time[5]-$month-$incr")));
+                if ($parts[0] < 6 && $parts[1] == $month) {
+                    return $time[2] == $parts[2];
+                }
+            }
+        }
+    }
+
+    /**
+     * Check if modifiers [L C W #] are satisfied.
+     *
+     * @internal
+     *
+     * @param string $value
+     * @param int    $time
+     *
+     * @return bool|null
+     */
+    protected static function checkWeekDay($value, $time)
+    {
+        $month = $time[8] < 10 ? '0' . $time[8] : $time[8];
+
+        if (strpos($value, 'L')) {
+            return static::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) == $value[1] - 1;
+        }
+    }
+
+    protected static function lastWeekDay($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;
+    }
+}