From 5037e23f2c655d493186b0d092704f36a3f28e94 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Barto=C5=A1?= <bartos.developer152@gmail.com>
Date: Mon, 4 Mar 2024 11:05:18 +0100
Subject: [PATCH] ExplainCommand

---
 CHANGELOG.md                   |  2 +
 src/Command/ExplainCommand.php | 69 ++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 src/Command/ExplainCommand.php

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 027dea7..15293e5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 
+- `ExplainCommand`
+	- explains cron expression syntax
 - `ListCommand`
 	- adds `--explain` option to explain whole expression
 
diff --git a/src/Command/ExplainCommand.php b/src/Command/ExplainCommand.php
new file mode 100644
index 0000000..746787f
--- /dev/null
+++ b/src/Command/ExplainCommand.php
@@ -0,0 +1,69 @@
+<?php declare(strict_types = 1);
+
+namespace Orisai\Scheduler\Command;
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class ExplainCommand extends Command
+{
+
+	public static function getDefaultName(): string
+	{
+		return 'scheduler:explain';
+	}
+
+	public static function getDefaultDescription(): string
+	{
+		return 'Explain cron expression';
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int
+	{
+		$this->explainSyntax($output);
+
+		return 0;
+	}
+
+	private function explainSyntax(OutputInterface $output): void
+	{
+		$output->writeln(
+			<<<'CMD'
+<fg=yellow>*   *   *   *   *</>
+-   -   -   -   -
+|   |   |   |   |
+|   |   |   |   |
+|   |   |   |   +----- day of week (0-7) (Sunday = 0 or 7) (or SUN-SAT)
+|   |   |   +--------- month (1-12) (or JAN-DEC)
+|   |   +------------- day of month (1-31)
+|   +----------------- hour (0-23)
++--------------------- minute (0-59)
+
+Each part of expression can also use wildcard, lists, ranges and steps:
+
+- wildcard - <fg=yellow>* * * * *</> - At every minute.
+- lists - e.g. <fg=yellow>15,30 * * * *</> - At minute 15 and 30.
+- ranges - e.g. <fg=yellow>1-9 * * * *</> - At every minute from 1 through 9.
+- steps
+	- e.g. <fg=yellow>*/5 * * * *</> - At every 5th minute.
+	- e.g. <fg=yellow>0-30/5 * * * *</> - At every 5th minute from 0 through 30.
+- combinations - e.g. <fg=yellow>0-14,30-44 * * * *</> - At every minute from 0 through 14 and every minute from 30 through 44.
+
+You can also use macro instead of an expression:
+
+- <fg=yellow>@yearly</>, <fg=yellow>@annually</> - Run once a year, midnight, Jan. 1 - <fg=yellow>0 0 1 1 *</>
+- <fg=yellow>@monthly</> - Run once a month, midnight, first of month - <fg=yellow>0 0 1 * *</>
+- <fg=yellow>@weekly</> - Run once a week, midnight on Sun - <fg=yellow>0 0 * * 0</>
+- <fg=yellow>@daily</>, <fg=yellow>@midnight</> - Run once a day, midnight - <fg=yellow>0 0 * * *</>
+- <fg=yellow>@hourly</> - Run once an hour, first minute - <fg=yellow>0 * * * *</>
+
+Although they are not part of cron expression syntax, you can also add to job:
+
+- seconds - repeat job every n seconds
+- timezone - run only when cron expression matches within given timezone
+CMD,
+		);
+	}
+
+}