class QueueTest

class QueueTest extends KernelTestBase {
    
    /**
     * Tests the System queue.
     */
    public function testSystemQueue() : void {
        // Create two queues.
        $queue1 = new DatabaseQueue($this->randomMachineName(), Database::getConnection());
        $queue1->createQueue();
        $queue2 = new DatabaseQueue($this->randomMachineName(), Database::getConnection());
        $queue2->createQueue();
        $this->runQueueTest($queue1, $queue2);
    }
    
    /**
     * Tests the Memory queue.
     */
    public function testMemoryQueue() : void {
        // Create two queues.
        $queue1 = new Memory($this->randomMachineName());
        $queue1->createQueue();
        $queue2 = new Memory($this->randomMachineName());
        $queue2->createQueue();
        $this->runQueueTest($queue1, $queue2);
    }
    
    /**
     * Queues and unqueues a set of items to check the basic queue functionality.
     *
     * @param \Drupal\Core\Queue\QueueInterface $queue1
     *   An instantiated queue object.
     * @param \Drupal\Core\Queue\QueueInterface $queue2
     *   An instantiated queue object.
     */
    protected function runQueueTest($queue1, $queue2) {
        // Create four items.
        $data = [];
        for ($i = 0; $i < 4; $i++) {
            $data[] = [
                $this->randomMachineName() => $this->randomMachineName(),
            ];
        }
        // Queue items 1 and 2 in the queue1.
        $queue1->createItem($data[0]);
        $queue1->createItem($data[1]);
        // Retrieve two items from queue1.
        $items = [];
        $new_items = [];
        $items[] = $item = $queue1->claimItem();
        $new_items[] = $item->data;
        $items[] = $item = $queue1->claimItem();
        $new_items[] = $item->data;
        // First two dequeued items should match the first two items we queued.
        $this->assertEquals(2, $this->queueScore($data, $new_items), 'Two items matched');
        // Add two more items.
        $queue1->createItem($data[2]);
        $queue1->createItem($data[3]);
        $this->assertSame(4, $queue1->numberOfItems(), 'Queue 1 is not empty after adding items.');
        $this->assertSame(0, $queue2->numberOfItems(), 'Queue 2 is empty while Queue 1 has items');
        $items[] = $item = $queue1->claimItem();
        $new_items[] = $item->data;
        $items[] = $item = $queue1->claimItem();
        $new_items[] = $item->data;
        // All dequeued items should match the items we queued exactly once,
        // therefore the score must be exactly 4.
        $this->assertEquals(4, $this->queueScore($data, $new_items), 'Four items matched');
        // There should be no duplicate items.
        $this->assertEquals(4, $this->queueScore($new_items, $new_items), 'Four items matched');
        // Delete all items from queue1.
        foreach ($items as $item) {
            $queue1->deleteItem($item);
        }
        // Check that both queues are empty.
        $this->assertSame(0, $queue1->numberOfItems(), 'Queue 1 is empty');
        $this->assertSame(0, $queue2->numberOfItems(), 'Queue 2 is empty');
    }
    
    /**
     * Returns the number of equal items in two arrays.
     */
    protected function queueScore($items, $new_items) {
        $score = 0;
        foreach ($items as $item) {
            foreach ($new_items as $new_item) {
                if ($item === $new_item) {
                    $score++;
                }
            }
        }
        return $score;
    }

}