<?php
namespace WorkflowBundle\Twig;

use Symfony\Component\Workflow\Registry;
use Symfony\Component\Translation\TranslatorInterface;

use Symfony\Component\Workflow\Exception\InvalidArgumentException;

class WorkflowExtension extends \Twig_Extension
{
    private $workflowRegistry;
    private $translator;

    public function __construct(Registry $workflowRegistry, TranslatorInterface $translator)
    {
        $this->workflowRegistry = $workflowRegistry;
        $this->translator = $translator;
    }

    public function getFunctions()
    {
        return array(
            new \Twig_SimpleFunction('workflow_can', array($this, 'canTransition')),
            new \Twig_SimpleFunction('workflow_transitions', array($this, 'getEnabledTransitions')),
            new \Twig_SimpleFunction('workflow_correct_state', array($this, 'isCorrectState')),
            new \Twig_SimpleFunction('get_class', array($this, 'getClass')),
            new \Twig_SimpleFunction('workflow_translate_label', array($this, 'getLabelTranslate')),
            new \Twig_SimpleFunction('workflow_go_json', array($this, 'getGoJson')),
        );
    }

    public function isCorrectState($object, $name = null) 
    {
        try {
            $places = $this->workflowRegistry->get($object, $name)->getDefinition()->getPlaces();
        } catch (\Exception $e) {
            $places = array();
        }

        $state = $object->getCurrentState();
        
        if(is_null($state)) return false;

        if(isset($places[$state])) return true;

        return false;
    }

    public function canTransition($object, $transition, $name = null)
    {
        return $this->workflowRegistry->get($object, $name)->can($object, $transition);
    }

    public function getEnabledTransitions($object, $name = null)
    {
        try {
            $return = $this->workflowRegistry->get($object, $name)->getEnabledTransitions($object);
        } catch (\Exception $e) {
            $return = array();
        }
        
        return $return;
    }

    public function getName()
    {
        return 'workflow';
    }

    public function getClass($object)
    {
        return get_class($object);
    }

    public function getLabelTranslate($label, $alternative, $params = null, $resource = "WorkflowLabel") 
    {
        if(is_null($params)) $params = array();
        
        $trans = $this->translator->trans($label,$params,$resource);

        if($trans == $label) {
            return $alternative;
        }

        return $trans;
    }

    public function getGoJson($object, $name = null)
    {
        $data = array();
        $nodes = array();
        $links = array();

       try{
        $definition = $this->workflowRegistry->get($object, $name)->getDefinition();
       }catch (InvalidArgumentException $e){
          return json_encode(array());
        }
        $places = $definition->getPlaces();
        $initial = $definition->getInitialPlace();
        $transitions = $definition->getTransitions();

        foreach($places as $p => $place) {
            
            $label = $p;
            
            $color = "white";
            if($p == $initial) $color = "lightblue";
            $nodes[] = array('key' => $label, 'color' => $color);
        }
        
        foreach($transitions as $transition) {
            
            $label = $transition->getName();
            $from = $transition->getFroms()[0];
            $to = $transition->getTos()[0];
            
            $links[] = array('from' => $from, 'to' => $to, 'text' => $label);
        }

        $data[] = $nodes;
        $data[] = $links;

        //return $data;

        $return = json_encode($nodes).",".json_encode($links);
        

        return $return;


    }
}