Cronjob: Add ability to execute periodic tasks via cron job

index.php

@@ -5,27 +5,35 @@
 // that includes proper error handling and security measures.
 
 session_start();
-require_once("vendor/autoload.php");
+require_once ("vendor/autoload.php");
 
 use A11yBuddy\Application;
 
-$config = require_once("config.php");
+$config = require_once ("config.php");
 
 // Check if there is an example config file
 if (file_exists("config.example.php")) {
-    $exampleConfig = require_once("config.example.php");
+    $exampleConfig = require_once ("config.example.php");
 
     // Tell the user which keys are missing in their config file
     $missingKeys = array_diff_key($exampleConfig, $config);
-    if (!empty($missingKeys)) {
+    if (!empty ($missingKeys)) {
         echo "Your config file is missing the following keys:\n";
         foreach ($missingKeys as $key => $value) {
             echo "  - $key\n";
         }
         echo "Please add them to your config file.\n";
-        exit(1);
+        exit (1);
     }
 }
 
 $app = new Application($config);
+
+// If we are a CLI script, only run the periodic tasks
+if (php_sapi_name() === 'cli') {
+    $taskManager = new A11yBuddy\Cronjob\CronjobTaskManager();
+    $taskManager->runTasks();
+    exit (0);
+}
+
 $app->getBasePageRenderer()->render();

src/Cronjob/CronjobTask.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace A11yBuddy\Cronjob;
+
+/**
+ * A task that can be run periodically.
+ * Tasks will be run via CLI through cron job.
+ */
+abstract class CronjobTask
+{
+
+    /**
+     * Checks if the task can be run.
+     * Because cron jobs run every minute, this method can be used to check if the task should be run at this time or not.
+     */
+    public function canRun(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Runs the task.
+     */
+    public abstract function run(): void;
+
+}

src/Cronjob/CronjobTaskManager.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace A11yBuddy\Cronjob;
+
+/**
+ * Manages periodic tasks that run via cron job.
+ */
+class CronjobTaskManager
+{
+
+    /**
+     * @var CronjobTask[] The tasks that are registered with the manager.
+     */
+    private array $tasks = [];
+
+    public function __construct()
+    {
+        $this->registerAllTasks();
+    }
+
+    /**
+     * Registers all tasks that are shipped and required by the application.
+     */
+    private function registerAllTasks(): void
+    {
+        // TODO
+        return;
+    }
+
+    /** 
+     * Adds a task to the manager.
+     */
+    public function addTask(CronjobTask $task): void
+    {
+        $this->tasks[] = $task;
+    }
+
+    /**
+     * Runs all tasks that can be run.
+     */
+    public function runTasks()
+    {
+        foreach ($this->tasks as $task) {
+            if ($task->canRun())
+                $task->run();
+        }
+    }
+
+}