Next run

.gitignore

@@ -3,5 +3,6 @@
 /.env
 /.idea/
 /vendor/
+*.result.cache
 composer.lock
 coverage.xml

composer.json

@@ -26,7 +26,7 @@
         "php": ">=7.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.5 || ^7.5"
+        "phpunit/phpunit": "^6.5 || ^7.5 || ^8.5"
     },
     "scripts": {
         "test": "phpunit",

src/Expression.php

@@ -13,6 +13,8 @@
 
 namespace Ahc\Cron;
 
+use DateTime;
+
 /**
  * Cron Expression Parser.
  *
@@ -32,10 +34,14 @@ class Expression
     /** @var Normalizer */
     protected $normalizer;
 
+    /** @var Ticks */
+    protected $ticks;
+
     public function __construct(SegmentChecker $checker = null, Normalizer $normalizer = null)
     {
         $this->checker    = $checker ?: new SegmentChecker;
         $this->normalizer = $normalizer ?: new Normalizer;
+        $this->ticks      = new Ticks($this);
 
         if (null === static::$instance) {
             static::$instance = $this;
@@ -64,6 +70,55 @@ public static function isDue(string $expr, $time = null): bool
         return static::instance()->isCronDue($expr, $time);
     }
 
+    /**
+     * Next DateTime when the expr would be due again.
+     *
+     * @param string $expr The cron expression.
+     * @param mixed  $time The timestamp to validate the cron expr against. Defaults to now.
+     *
+     * @throws \RuntimeException
+     * @throws \UnexpectedValueException
+     *
+     * @return \DateTime
+     */
+    public function nextTick(string $expr, $time = null): DateTime
+    {
+        return $this->ticks->next($expr, $time);
+    }
+
+    /**
+     * Next DateTime when the expr would be due again.
+     *
+     * @param string $expr The cron expression.
+     * @param mixed  $time The timestamp to validate the cron expr against. Defaults to now.
+     *
+     * @throws \RuntimeException
+     * @throws \UnexpectedValueException
+     *
+     * @return \DateTime
+     */
+    public static function next(string $expr, $time = null): DateTime
+    {
+        return static::instance()->nextTick($expr, $time);
+    }
+
+    /**
+     * Next date time as formatted string when the expr would be due again.
+     *
+     * @param string $expr The cron expression.
+     * @param mixed  $time The timestamp to validate the cron expr against. Defaults to now.
+     * @param string $fmt  The format
+     *
+     * @throws \RuntimeException
+     * @throws \UnexpectedValueException
+     *
+     * @return \DateTime
+     */
+    public static function nextf(string $expr, $time = null, string $fmt = 'Y-m-d H:i:s'): string
+    {
+        return static::next($expr, $time)->format($fmt);
+    }
+
     /**
      * Filter only the jobs that are due.
      *
@@ -88,10 +143,15 @@ public static function getDues(array $jobs, $time = null): array
      * @return bool
      */
     public function isCronDue(string $expr, $time = null): bool
+    {
+        return $this->segmentsDue($this->segments($expr), $time);
+    }
+
+    public function segmentsDue(array $segments, $time = null): bool
     {
         $this->checker->setReference(new ReferenceTime($time));
 
-        foreach (\explode(' ', $this->normalizer->normalizeExpr($expr)) as $pos => $segment) {
+        foreach ($segments as $pos => $segment) {
             if ($segment === '*' || $segment === '?') {
                 continue;
             }
@@ -104,6 +164,16 @@ public function isCronDue(string $expr, $time = null): bool
         return true;
     }
 
+    public function segments(string $expr): array
+    {
+        return \explode(' ', $this->normalizer->normalizeExpr($expr));
+    }
+
+    public function segmentChecker(): SegmentChecker
+    {
+        return $this->checker;
+    }
+
     /**
      * Filter only the jobs that are due.
      *

src/ReferenceTime.php

@@ -13,6 +13,8 @@
 
 namespace Ahc\Cron;
 
+use DateTime;
+
 /**
  * @method int minute()
  * @method int hour()
@@ -45,14 +47,50 @@ class ReferenceTime
     /** @var array The Magic methods */
     protected $methods = [];
 
+    public $timestamp;
+
     public function __construct($time)
     {
-        $timestamp = $this->normalizeTime($time);
-
-        $this->values  = $this->parse($timestamp);
+        $this->reset($this->normalizeTime($time));
         $this->methods = (new \ReflectionClass($this))->getConstants();
     }
 
+    public function reset(int $timestamp)
+    {
+        $this->timestamp = $timestamp;
+        $this->values    = $this->parse($timestamp);
+    }
+
+    public function add(int $sec)
+    {
+        $this->reset($this->timestamp + $sec);
+    }
+
+    public function addMonth()
+    {
+        $year  = $this->values[self::YEAR];
+        $month = $this->values[self::MONTH] + 1;
+
+        if ($month > 12) {
+            [$year, $month] = [$year + 1, 1];
+        }
+
+        $new = "$year-$month-" . date('d H:i:s', $this->timestamp);
+        $this->reset(\strtotime($new));
+    }
+
+    public function addYear()
+    {
+        $year = $this->values[self::YEAR] + 1;
+        $new  = "$year-" . date('m-d H:i:s', $this->timestamp);
+        $this->reset(\strtotime($new));
+    }
+
+    public function dateTime(): DateTime
+    {
+        return new DateTime(date('Y-m-d H:i:s', $this->timestamp));
+    }
+
     public function __call(string $method, array $args): int
     {
         $method = \preg_replace('/^GET/', '', \strtoupper($method));
@@ -81,7 +119,7 @@ protected function normalizeTime($time): int
             $time = \time();
         } elseif (\is_string($time)) {
             $time = \strtotime($time);
-        } elseif ($time instanceof \DateTime) {
+        } elseif ($time instanceof DateTime) {
             $time = $time->getTimestamp();
         }
 

src/SegmentChecker.php

@@ -33,9 +33,11 @@ public function __construct(Validator $validator = null)
         $this->validator = $validator ?: new Validator;
     }
 
-    public function setReference(ReferenceTime $reference)
+    public function setReference(ReferenceTime $reference): self
     {
         $this->reference = $reference;
+
+        return $this;
     }
 
     /**
@@ -96,7 +98,7 @@ protected function checkModifier(string $offset, int $pos): bool
             return $this->validator->isValidWeekDay($offset, $this->reference);
         }
 
-        $this->validator->unexpectedValue($pos, $offset);
+        throw $this->validator->unexpectedValue($pos, $offset);
         // @codeCoverageIgnoreStart
     }
     // @codeCoverageIgnoreEnd

src/Ticks.php

@@ -0,0 +1,97 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the PHP-CRON-EXPR package.
+ *
+ * (c) Jitendra Adhikari <jiten.adhikary@gmail.com>
+ *     <https://github.com/adhocore>
+ *
+ * Licensed under MIT license.
+ */
+
+namespace Ahc\Cron;
+
+use DateTime;
+
+/**
+ * Ticks for next/prev ticks of an expr based on given time.
+ * Next tick support is experimental.
+ * Prev tick is not yet implemented.
+ */
+class Ticks
+{
+    /** @var Expression */
+    protected $expr;
+
+    protected $limits = [
+        ReferenceTime::MINUTE   => 60,
+        ReferenceTime::HOUR     => 24,
+        ReferenceTime::MONTHDAY => 31,
+        ReferenceTime::MONTH    => 12,
+        ReferenceTime::WEEKDAY  => 366,
+        ReferenceTime::YEAR     => 100,
+    ];
+
+    public function __construct(Expression $expr)
+    {
+        $this->expr = $expr;
+    }
+
+    public function next(string $expr, $time = null): DateTime
+    {
+        $checker  = $this->expr->segmentChecker();
+        $segments = $this->expr->segments($expr);
+
+        $iter = 500;
+        $ref  = new ReferenceTime($time);
+        $ref->add(60 - $ref->timestamp % 60); // truncate seconds
+
+        over:
+        while ($iter > 0) {
+            $iter--;
+            foreach ($segments as $pos => $seg) {
+                if ($seg === '*' || $seg === '?') {
+                    continue;
+                }
+                [$new, $isOk] = $this->bumpUntilDue($checker, $seg, $pos, $ref);
+                if ($isOk) {
+                    $ref = $new;
+                    goto over;
+                }
+            }
+        }
+
+        $date = $ref->dateTime();
+        if ($this->expr->segmentsDue($segments, $date)) {
+            return $date;
+        }
+
+        throw new \RuntimeException('Tried so hard');
+    }
+
+    private function bumpUntilDue(SegmentChecker $checker, string $seg, int $pos, ReferenceTime $ref): array
+    {
+        $iter = $this->limits[$pos];
+        while ($iter > 0) {
+            $iter--;
+            if ($checker->setReference($ref)->checkDue($seg, $pos)) {
+                return [$ref, true];
+            }
+            if ($pos === ReferenceTime::MINUTE) {
+                $ref->add(60);
+            } elseif ($pos === ReferenceTime::HOUR) {
+                $ref->add(3600);
+            } elseif ($pos === ReferenceTime::MONTHDAY || $pos === ReferenceTime::WEEKDAY) {
+                $ref->add(86400);
+            } elseif ($pos === ReferenceTime::MONTH) {
+                $ref->addMonth();
+            } elseif ($pos === ReferenceTime::YEAR) {
+                $ref->addYear();
+            }
+        }
+
+        return [$ref, false];
+    }
+}

src/Validator.php

@@ -13,6 +13,8 @@
 
 namespace Ahc\Cron;
 
+use UnexpectedValueException;
+
 /**
  * Cron segment validator.
  *
@@ -108,7 +110,7 @@ public function isValidMonthDay(string $value, ReferenceTime $reference): bool
             return $this->isClosestWeekDay((int) $value, $month, $reference);
         }
 
-        $this->unexpectedValue(2, $value);
+        throw $this->unexpectedValue(2, $value);
         // @codeCoverageIgnoreStart
     }
 
@@ -153,7 +155,7 @@ public function isValidWeekDay(string $value, ReferenceTime $reference): bool
         }
 
         if (!\strpos($value, '#')) {
-            $this->unexpectedValue(4, $value);
+            throw $this->unexpectedValue(4, $value);
         }
 
         list($day, $nth) = \explode('#', \str_replace('7#', '0#', $value));
@@ -171,11 +173,11 @@ public function isValidWeekDay(string $value, ReferenceTime $reference): bool
      * @param int    $pos
      * @param string $value
      *
-     * @throws \UnexpectedValueException
+     * @return \UnexpectedValueException
      */
-    public function unexpectedValue(int $pos, string $value)
+    public function unexpectedValue(int $pos, string $value): UnexpectedValueException
     {
-        throw new \UnexpectedValueException(
+        return new UnexpectedValueException(
             \sprintf('Invalid offset value at segment #%d: %s', $pos, $value)
         );
     }