<?php

class stTaskScheluderProgressBar extends stProgressBarTask
{
    /**
     * 
     * @var \stTaskInterface
     */
    protected $currentTask = null;

    protected $taskChanged = false;

    public function initialize($offset = 0)
    {
        $this->currentTask = $this->getCurrentTask($offset);
    }

    public function count() 
    {
        return $this->getParameter('count');
    }

    public function execute($offset = 0)
    {         
        if ($this->taskChanged && null === $this->currentTask)
        {
            return $this->count();
        }
        
        if ($this->taskChanged && !$this->currentTask->isReadyToExecute(false))
        {
            return $offset + $this->currentTask->doCount();
        }

        $this->currentTask->getTask()->doStart();

        $taskOffset = $offset - $this->getParameter('current_task_start_offset');

        if ($this->currentTask->getTask()->getTaskConfigurationParameter('frontend'))
        {
            sfLoader::loadHelpers(['Helper', 'stUrl']);
            $url = st_url_for('@stTaskScheluderFrontend?task_id='.$this->currentTask->getId().'&offset='.$taskOffset.'&token='.$this->getToken(), true, 'frontend');
            $postData = http_build_query(['parameters' => $this->getParameter('current_task_parameters', [])], '', '&');
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
            curl_setopt($ch, CURLINFO_HEADER_OUT, true); 
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);            
            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);

            $result = curl_exec($ch);
            $error = curl_error($ch);

            curl_close($ch);

            if (empty($result) || !empty($error))
            {
                $this->currentTask->getTask()->doFinish();
                return $offset + $this->currentTask->doCount() - $taskOffset;
            }
            
            $response = json_decode($result, true);

            if (null === $response)
            {
                $this->currentTask->getTask()->doFinish();
                return $offset + $this->currentTask->doCount() - $taskOffset;
            }

            $currentTaskOffset = $response['offset'];

            $this->currentTask->setParameters($response['parameters']);
        }
        else
        {
            if (false === $this->currentTask->doInitialize())
            {
                $this->currentTask->getTask()->doFinish();
                return $offset + $this->currentTask->doCount();
            }

            $currentTaskOffset = $this->currentTask->doExecute($taskOffset);
        }

        $this->setMessage($this->currentTask->getName());
        $this->setParameter('current_task_parameters', $this->currentTask->getParameters());

        usleep(250000);

        return $offset + $currentTaskOffset - $taskOffset;
    }

    protected function getCurrentTask($offset): ?stTaskInterface
    {
        $task = $this->getParameter('current_task_id') ? stTaskFactory::createTaskById($this->getParameter('current_task_id')) : null;

        if (null !== $task)
        {
            $task->setParameters($this->getParameter('current_task_parameters', []));
        
            if (false === $task->doInitialize())
            {
                return $task;
            }
        }

        $this->taskChanged = false;

        if (null === $this->getParameter('current_task_id') || 0 === $task->doCount() || $offset - $this->getParameter('current_task_start_offset') >= $task->doCount())
        {
            $currentTask = $this->getNextTask();
            $this->taskChanged = true;
            $this->setParameter('current_task_id', $currentTask ? $currentTask['id'] : null);
            $this->setParameter('current_task_start_offset', $currentTask ? $currentTask['offset'] : null);
            $this->setParameter('current_task_parameters', isset($currentTask['parameters']) ? $currentTask['parameters'] : []);

            if ($this->getParameter('current_task_id'))
            {
                $task = stTaskFactory::createTaskById($this->getParameter('current_task_id'));
                $task->setParameters($this->getParameter('current_task_parameters', []));
            }
            else
            {
                $task = null;
            }

            sleep(1);
        }

        return $task;
    }

    public function finished()
    {
        stSecureToken::invalidateDBToken($this->getToken());
        
        sfLoader::loadHelpers(array('Helper', 'stPartial', 'stAdminGenerator', 'stTaskScheluder'));

        $this->setMessage(st_task_scheluder_progress_finished_message());
    }

    protected function getNextTask(): ?array
    {
        $taskPool = $this->getParameter('task_pool');

        $task = array_pop($taskPool);

        $this->setParameter('task_pool', $taskPool);

        return $task;
    }

    protected function getToken(): string
    {
        $token = $this->getParameter('token');

        if (null === $token)
        {
            $token = stSecureToken::createDBToken(3600 * 48);
            $this->setParameter('token', $token);
        }

        return $token;
    }
}