<?php

/**
 * Gearman Bundle for Symfony2
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * Feel free to edit as you please, and have fun.
 *
 * @author Marc Morera <yuhu@mmoreram.com>
 */

namespace Mmoreram\GearmanBundle\Service;

use Mmoreram\GearmanBundle\Dispatcher\GearmanCallbacksDispatcher;
use Mmoreram\GearmanBundle\GearmanMethods;
use Mmoreram\GearmanBundle\Generator\UniqueJobIdentifierGenerator;
use Mmoreram\GearmanBundle\Module\JobStatus;
use Mmoreram\GearmanBundle\Service\Abstracts\AbstractGearmanService;

/**
 * GearmanClient. Implementation of AbstractGearmanService
 *
 * @since 2.3.1
 */
class GearmanClient extends AbstractGearmanService
{
    /**
     * @var \GearmanClient
     *
     * Gearman native client instance
     */
    protected $gearmanClient;

    /**
     * @var GearmanCallbacksDispatcher
     *
     * Gearman callbacks dispatcher
     */
    protected $gearmanCallbacksDispatcher;

    /**
     * @var array
     *
     * Server set to define in what server must connect to
     */
    protected $servers = array();

    /**
     * @var array
     *
     * task structure to store all about called tasks
     */
    protected $taskStructure = array();

    /**
     * @var array
     *
     * Set default servers
     */
    protected $defaultServers;

    /**
     * @var array
     *
     * Set default settings
     */
    protected $settings;

    /**
     * @var UniqueJobIdentifierGenerator
     *
     * Unique Job Intefier Generator
     */
    protected $uniqueJobIdentifierGenerator;

    /**
     * @var int
     *
     * Return code from internal client.
     */
    protected $returnCode;

    /**
     * @return \GearmanClient
     */
    public function getNativeClient(){
        if ($this->gearmanClient === null){
            $this->gearmanClient = new \GearmanClient();
        }
        return $this->gearmanClient;
    }

    /**
     * Init tasks structure
     *
     * @return GearmanClient self Object
     */
    public function initTaskStructure()
    {
        $this->taskStructure = array();

        return $this;
    }

    /**
     * Set  default servers
     *
     * @param array $defaultServers Default servers
     *
     * @return GearmanClient self Object
     */
    public function setDefaultServers(array $defaultServers)
    {
        $this->defaultServers = $defaultServers;

        return $this;
    }

    /**
     * Set UniqueJobIdentifierGenerator object
     *
     * @param UniqueJobIdentifierGenerator $uniqueJobIdentifierGenerator Unique Job Intefier Generator
     *
     * @return GearmanClient self Object
     */
    public function setUniqueJobIdentifierGenerator(UniqueJobIdentifierGenerator $uniqueJobIdentifierGenerator)
    {
        $this->uniqueJobIdentifierGenerator = $uniqueJobIdentifierGenerator;

        return $this;
    }

    /**
     * Set gearman callbacks
     *
     * @param GearmanCallbacksDispatcher $gearmanCallbacksDispatcher Gearman callbacks dispatcher
     *
     * @return GearmanClient self Object
     */
    public function setGearmanCallbacksDispatcher(GearmanCallbacksDispatcher $gearmanCallbacksDispatcher)
    {
        $this->gearmanCallbacksDispatcher = $gearmanCallbacksDispatcher;

        return $this;
    }

    /**
     * Set default settings
     *
     * @param array $settings
     *
     * @return GearmanClient self Object
     */
    public function setDefaultSettings($settings)
    {
        $this->settings = $settings;

        return $this;
    }

    /**
     * Set server to client. Empty all servers and set this one
     *
     * @param string $servername Server name (must be ip)
     * @param int    $port       Port of server. By default 4730
     *
     * @return GearmanClient Returns self object
     */
    public function setServer($servername, $port = 4730)
    {
        $this
            ->clearServers()
            ->addServer($servername, $port);

        return $this;
    }

    /**
     * Add server to client
     *
     * @param string $servername Server name (must be ip)
     * @param int    $port       Port of server. By default 4730
     *
     * @return GearmanClient Returns self object
     */
    public function addServer($servername, $port = 4730)
    {
        $this->servers[] = array(
            'host' => $servername,
            'port' => $port,
        );

        return $this;
    }

    /**
     * Clear server list
     *
     * @return GearmanClient Returns self object
     */
    public function clearServers()
    {
        $this->servers = array();

        return $this;
    }

    /**
     * Get real worker from job name and enqueues the action given one
     *     method.
     *
     * @param string $jobName A GearmanBundle registered function the worker is to execute
     * @param string $params  Parameters to send to job as string
     * @param string $method  Method to execute
     * @param string $unique  A unique ID used to identify a particular task
     *
     * @return mixed Return result of the call. If worker is not valid, return false
     */
    protected function enqueue($jobName, $params, $method, $unique)
    {
        $worker = $this->getJob($jobName);

        $unique = $this
            ->uniqueJobIdentifierGenerator
            ->generateUniqueKey($jobName, $params, $unique, $method);

        return $worker
            ? $this->doEnqueue($worker, $params, $method, $unique)
            : false;
    }

    /**
     * Execute a GearmanClient call given a worker, params and a method.
     *
     * If he GarmanClient call is asyncronous, result value will be a handler.
     * Otherwise, will return job result.
     *
     * @param array  $worker Worker definition
     * @param string $params Parameters to send to job as string
     * @param string $method Method to execute
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return mixed Return result of the GearmanClient call
     */
    protected function doEnqueue(array $worker, $params, $method, $unique)
    {
        $gearmanClient = $this->getNativeClient();
        $this->assignServers($gearmanClient);

        $result = $gearmanClient->$method($worker['job']['realCallableName'], $params, $unique);
        $this->returnCode = $gearmanClient->returnCode();

        $this->gearmanClient = null;

        return $result;
    }

    /**
     * Given a GearmanClient, set all included servers
     *
     * @param \GearmanClient $gearmanClient Object to include servers
     *
     * @return GearmanClient Returns self object
     */
    protected function assignServers(\GearmanClient $gearmanClient)
    {
        $servers = $this->defaultServers;

        if (!empty($this->servers)) {

            $servers = $this->servers;
        }

        /**
         * We include each server into gearman client
         */
        foreach ($servers as $server) {

            $gearmanClient->addServer($server['host'], $server['port']);
        }

        return $this;
    }

    /**
     * Job methods
     */

    /**
     * Runs a single task and returns some result, depending of method called.
     * Method called depends of default callable method setted on gearman
     * settings or overwritted on work or job annotations
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return mixed result depending of method called.
     */
    public function callJob($name, $params = '', $unique = null)
    {
        $worker = $this->getJob($name);
        $methodCallable = $worker['job']['defaultMethod'];

        return $this->enqueue($name, $params, $methodCallable, $unique);
    }

    /**
     * Runs a single task and returns a string representation of the result.
     * It is up to the GearmanClient and GearmanWorker to agree on the format of
     * the result.
     *
     * The GearmanClient::do() method is deprecated as of pecl/gearman 1.0.0.
     * Use GearmanClient::doNormal().
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string A string representing the results of running a task.
     * @deprecated
     */
    public function doJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DONORMAL, $unique);
    }

    /**
     * Runs a single task and returns a string representation of the result.
     * It is up to the GearmanClient and GearmanWorker to agree on the format of
     * the result.
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string A string representing the results of running a task.
     */
    public function doNormalJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DONORMAL, $unique);
    }

    /**
     * Runs a task in the background, returning a job handle which can be used
     * to get the status of the running task.
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string Job handle for the submitted task.
     */
    public function doBackgroundJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DOBACKGROUND, $unique);
    }

    /**
     * Runs a single high priority task and returns a string representation of
     * the result.
     *
     * It is up to the GearmanClient and GearmanWorker to agree on the format of
     * the result.
     *
     * High priority tasks will get precedence over normal and low priority
     * tasks in the job queue.
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string A string representing the results of running a task.
     */
    public function doHighJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DOHIGH, $unique);
    }

    /**
     * Runs a high priority task in the background, returning a job handle which
     * can be used to get the status of the running task.
     *
     * High priority tasks take precedence over normal and low priority tasks in
     * the job queue.
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string The job handle for the submitted task.
     */
    public function doHighBackgroundJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DOHIGHBACKGROUND, $unique);
    }

    /**
     * Runs a single low priority task and returns a string representation of
     * the result.
     *
     * It is up to the GearmanClient and GearmanWorker to agree on the format of
     * the result.
     *
     * Normal and high priority tasks will get precedence over low priority
     * tasks in the job queue.
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string A string representing the results of running a task.
     */
    public function doLowJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DOLOW, $unique);
    }

    /**
     * Runs a low priority task in the background, returning a job handle which
     * can be used to get the status of the running task.
     *
     * Normal and high priority tasks will get precedence over low priority
     * tasks in the job queue.
     *
     * @param string $name   A GearmanBundle registered function the worker is to execute
     * @param string $params Parameters to send to job as string
     * @param string $unique A unique ID used to identify a particular task
     *
     * @return string The job handle for the submitted task.
     */
    public function doLowBackgroundJob($name, $params = '', $unique = null)
    {
        return $this->enqueue($name, $params, GearmanMethods::GEARMAN_METHOD_DOLOWBACKGROUND, $unique);
    }

    /**
     * Fetches the Status of a special Background Job.
     *
     * @param string $idJob The job handle string
     *
     * @return JobStatus Job status
     */
    public function getJobStatus($idJob)
    {
        $gearmanClient = $this->getNativeClient();
        $this->assignServers($gearmanClient);
        $statusData = $gearmanClient->jobStatus($idJob);

        $jobStatus = new JobStatus($statusData);

        $this->gearmanClient = null;

        return $jobStatus;
    }

    /**
     * Gets the return code from the last run job.
     *
     * @return int
     */
    public function getReturnCode()
    {
        return $this->returnCode;
    }

    /**
     * Task methods
     */

    /**
     * Adds a task to be run in parallel with other tasks.
     * Call this method for all the tasks to be run in parallel, then call
     * GearmanClient::runTasks() to perform the work.
     *
     * Note that enough workers need to be available for the tasks to all run in
     * parallel.
     *
     * @param string $name     A GermanBundle registered function to be executed
     * @param string $params   Parameters to send to task as string
     * @param Mixed  &$context Application context to associate with a task
     * @param string $unique   A unique ID used to identify a particular task
     *
     * @return GearmanClient Return this object
     */
    public function addTask($name, $params = '', &$context = null, $unique = null)
    {
        $this->enqueueTask($name, $params, $context, $unique, GearmanMethods::GEARMAN_METHOD_ADDTASK);

        return $this;
    }

    /**
     * Adds a high priority task to be run in parallel with other tasks.
     * Call this method for all the high priority tasks to be run in parallel,
     * then call GearmanClient::runTasks() to perform the work.
     *
     * Tasks with a high priority will be selected from the queue before those
     * of normal or low priority.
     *
     * @param string $name     A GermanBundle registered function to be executed
     * @param string $params   Parameters to send to task as string
     * @param Mixed  &$context Application context to associate with a task
     * @param string $unique   A unique ID used to identify a particular task
     *
     * @return GearmanClient Return this object
     */
    public function addTaskHigh($name, $params = '', &$context = null, $unique = null)
    {
        $this->enqueueTask($name, $params, $context, $unique, GearmanMethods::GEARMAN_METHOD_ADDTASKHIGH);

        return $this;
    }

    /**
     * Adds a low priority background task to be run in parallel with other
     * tasks.
     *
     * Call this method for all the tasks to be run in parallel, then call
     * GearmanClient::runTasks() to perform the work.
     *
     * Tasks with a low priority will be selected from the queue after those of
     * normal or low priority.
     *
     * @param string $name     A GermanBundle registered function to be executed
     * @param string $params   Parameters to send to task as string
     * @param Mixed  &$context Application context to associate with a task
     * @param string $unique   A unique ID used to identify a particular task
     *
     * @return GearmanClient Return this object
     */
    public function addTaskLow($name, $params = '', &$context = null, $unique = null)
    {
        $this->enqueueTask($name, $params, $context, $unique, GearmanMethods::GEARMAN_METHOD_ADDTASKLOW);

        return $this;
    }

    /**
     * Adds a background task to be run in parallel with other tasks
     * Call this method for all the tasks to be run in parallel, then call
     * GearmanClient::runTasks() to perform the work.
     *
     * @param string $name     A GermanBundle registered function to be executed
     * @param string $params   Parameters to send to task as string
     * @param Mixed  &$context Application context to associate with a task
     * @param string $unique   A unique ID used to identify a particular task
     *
     * @return GearmanClient Return this object
     */
    public function addTaskBackground($name, $params = '', &$context = null, $unique = null)
    {
        $this->enqueueTask($name, $params, $context, $unique, GearmanMethods::GEARMAN_METHOD_ADDTASKBACKGROUND);

        return $this;
    }

    /**
     * Adds a high priority background task to be run in parallel with other
     * tasks.
     *
     * Call this method for all the tasks to be run in parallel, then call
     * GearmanClient::runTasks() to perform the work.
     *
     * Tasks with a high priority will be selected from the queue before those
     * of normal or low priority.
     *
     * @param string $name     A GermanBundle registered function to be executed
     * @param string $params   Parameters to send to task as string
     * @param Mixed  &$context Application context to associate with a task
     * @param string $unique   A unique ID used to identify a particular task
     *
     * @return GearmanClient Return this object
     */
    public function addTaskHighBackground($name, $params = '', &$context = null, $unique = null)
    {
        $this->enqueueTask($name, $params, $context, $unique, GearmanMethods::GEARMAN_METHOD_ADDTASKHIGHBACKGROUND);

        return $this;
    }

    /**
     * Adds a low priority background task to be run in parallel with other
     * tasks.
     *
     * Call this method for all the tasks to be run in parallel, then call
     * GearmanClient::runTasks() to perform the work.
     *
     * Tasks with a low priority will be selected from the queue after those of
     * normal or high priority.
     *
     * @param string $name     A GermanBundle registered function to be executed
     * @param string $params   Parameters to send to task as string
     * @param Mixed  &$context Application context to associate with a task
     * @param string $unique   A unique ID used to identify a particular task
     *
     * @return GearmanClient Return this object
     */
    public function addTaskLowBackground($name, $params = '', &$context = null, $unique = null)
    {
        $this->enqueueTask($name, $params, $context, $unique, GearmanMethods::GEARMAN_METHOD_ADDTASKLOWBACKGROUND);

        return $this;
    }

    /**
     * Adds a task into the structure of tasks with included type of call
     *
     * @param string $name    A GermanBundle registered function to be executed
     * @param string $params  Parameters to send to task as string
     * @param Mixed  $context Application context to associate with a task
     * @param string $unique  A unique ID used to identify a particular task
     * @param string $method  Method to perform
     *
     * @return GearmanClient Return this object
     */
    protected function enqueueTask($name, $params, &$context, $unique, $method)
    {
        $contextReference = array('context' => &$context);
        $task = array(
            'name'    => $name,
            'params'  => $params,
            'context' => $contextReference,
            'unique'  => $this->uniqueJobIdentifierGenerator->generateUniqueKey($name, $params, $unique, $method),
            'method'  => $method,
        );

        $this->addTaskToStructure($task);

        return $this;
    }

    /**
     * Appends a task structure into taskStructure array
     *
     * @param array $task Task structure
     *
     * @return GearmanClient Return this object
     */
    protected function addTaskToStructure(array $task)
    {
        $this->taskStructure[] = $task;

        return $this;
    }

    /**
     * For a set of tasks previously added with
     *
     * GearmanClient::addTask(),
     * GearmanClient::addTaskHigh(),
     * GearmanClient::addTaskLow(),
     * GearmanClient::addTaskBackground(),
     * GearmanClient::addTaskHighBackground(),
     * GearmanClient::addTaskLowBackground(),
     *
     * this call starts running the tasks in parallel.
     * Note that enough workers need to be available for the tasks to all run in parallel
     *
     * @return boolean run tasks result
     */
    public function runTasks()
    {
        $gearmanClient = $this->getNativeClient();
        $this->assignServers($gearmanClient);

        if ($this->settings['callbacks']) {

            $this->gearmanCallbacksDispatcher->assignTaskCallbacks($gearmanClient);
        }

        foreach ($this->taskStructure as $task) {

            $type = $task['method'];
            $jobName = $task['name'];
            $worker = $this->getJob($jobName);

            if (false !== $worker) {

                $gearmanClient->$type(
                    $worker['job']['realCallableName'],
                    $task['params'],
                    $task['context'],
                    $task['unique']
                );
            }
        }

        $this->initTaskStructure();

        $this->gearmanClient = null;

        return $gearmanClient->runTasks();
    }
}