Tenside\Core\Task\TaskList

Complexity

Total Complexity

20

Size/Duplication

Total Lines	202
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	3

Importance

Changes	1
Bugs	0	Features	0

11 Methods

Rating	Name	Duplication	Size	Complexity
A	dequeue()	0	16	4
A	getNext()	0	9	2
A	remove()	0	11	2
A	getIds()	0	4	1
A	getTask()	0	9	2
A	taskIdToFileName()	0	4	1
A	generateId()	0	4	1
A	getConfig()	0	4	1
A	__construct()	0	5	1
B	queue()	0	27	3
A	createTaskFromMetaData()	0	9	2

<?php

/**
 * This file is part of tenside/core.
 *
 * (c) Christian Schiffler <c.schiffler@cyberspectrum.de>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * This project is provided in good faith and hope to be usable by anyone.
 *
 * @package    tenside/core
 * @author     Christian Schiffler <c.schiffler@cyberspectrum.de>
 * @copyright  2015 Christian Schiffler <c.schiffler@cyberspectrum.de>
 * @license    https://github.com/tenside/core/blob/master/LICENSE MIT
 * @link       https://github.com/tenside/core
 * @filesource
 */

namespace Tenside\Core\Task;

use Tenside\Core\Util\JsonArray;
use Tenside\Core\Util\JsonFile;

/**
 * This class is an implementation of the task list.
 */
class TaskList
{
    /**
     * The config to read from.
     *
     * @var string
     */
    private $dataDir;

    /**
     * The task factory to use.
     *
     * @var TaskFactoryInterface
     */
    private $factory;

    /**
     * Create a new instance.
     *
     * @param string               $dataDir The directory to keep the database in.
     *
     * @param TaskFactoryInterface $factory The task factory to use.
     */
    public function __construct($dataDir, TaskFactoryInterface $factory)
    {
        $this->dataDir = $dataDir;
        $this->factory = $factory;
    }

    /**
     * Add the task to the list.
     *
     * @param string         $type     The type name.
     *
     * @param JsonArray|null $metaData The (optional) meta data.
     *
     * @return string
     *
     * @throws \InvalidArgumentException When no task instance can be created from the meta data.
     */
    public function queue($type, JsonArray $metaData = null)
    {
        $taskId = $this->generateId();

        if (null === $metaData) {
            $metaData = new JsonArray();
        }

        $metaData
            ->set(Task::SETTING_ID, $taskId)
            ->set(Task::SETTING_TYPE, $type)
            ->set('status', Task::STATE_PENDING)
            ->set(Task::SETTING_CREATED_AT, date('c'));

        $taskFile = new JsonFile($this->taskIdToFileName($taskId), null);
        $taskFile->setData($metaData->getData());
        $taskFile->save();

        if (!$this->createTaskFromMetaData($taskFile)) {
            unlink($taskFile->getFilename());
            throw new \InvalidArgumentException('Could not create task of type "' . $metaData->get('type') . '"');
        }

        $this->getConfig()->set($taskId, $metaData->getData());

        return $taskId;
    }

    /**
     * Remove a task from the queue (or the first one if no id given).
     *
     * @param null|string $taskId The id of the task to dequeue, if null the first queued task will be returned.
     *
     * @return Task|null
     */
    public function dequeue($taskId = null)
    {
        $idList = $this->getIds();
        if ((null === $taskId) && (false === ($taskId = current($idList)))) {
            return null;
        }

        if (!in_array($taskId, $idList)) {
            // Not in list, get out.
            return null;
        }

        $this->getConfig()->remove($taskId);

        return $this->getTask($taskId);
    }

    /**
     * Retrieve the first task from the queue without removing it.
     *
     * @return Task|null
     */
    public function getNext()
    {
        $idList = $this->getIds();
        if (false === ($taskId = current($idList))) {
            return null;
        }

        return $this->getTask($taskId);
    }

    /**
     * Remove a task from the list, including it's task file.
     *
     * @param string $taskId The task to remove.
     *
     * @return TaskList
     */
    public function remove($taskId)
    {
        $idList = $this->getIds();

        if (in_array($taskId, $idList)) {
            $this->getConfig()->remove($taskId);
            unlink($this->taskIdToFileName($taskId));
        }

        return $this;
    }

    /**
     * Retrieve the ids of all registered tasks.
     *
     * @return string[]
     */
    public function getIds()
    {
        return  $this->getConfig()->getEntries('/');
    }

    /**
     * Retrieve a task.
     *
     * @param string $taskId The id of the task to retrieve.
     *
     * @return Task|null
     */
    public function getTask($taskId)
    {
        $filename = $this->taskIdToFileName($taskId);
        if (!file_exists($filename)) {
            return null;
        }

        return $this->createTaskFromMetaData(new JsonFile($filename, null));
    }

    /**
     * Retrieve the correct filename for the given task id.
     *
     * @param string $taskId The task id to generate the file name for.
     *
     * @return string
     */
    private function taskIdToFileName($taskId)
    {
        return $this->dataDir . DIRECTORY_SEPARATOR . 'tenside-task-' . $taskId . '.json';
    }

    /**
     * Create a task instance from the given MetaData.
     *
     * @param JsonArray $config The configuration of the task.
     *
     * @return Task|null
     */
    private function createTaskFromMetaData(JsonArray $config)
    {
        $typeName = $config->get(Task::SETTING_TYPE);
        if ($this->factory->isTypeSupported($typeName)) {
            return $this->factory->createInstance($typeName, $config);
        }

        return null;
    }

    /**
     * Generate a task id.
     *
     * @return string
     */
    private function generateId()
    {
        return md5(uniqid('', true));
    }

    /**
     * Get the config file instance.
     *
     * @return JsonFile
     */
    private function getConfig()
    {
        return new JsonFile($this->dataDir . DIRECTORY_SEPARATOR . 'tenside-tasks.json', null);
    }
}