<?php

namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\Workflow\Registry;

class DocumentationController extends AbstractController {

  /**
   * Visualise a workflow using vis.js.
   *
   * Documentation about vis.js can be found at:
   * https://visjs.github.io/vis-network/docs/network/
   *
   * Check the corresponding template for the options that are in use.
   *
   * @Route("/docs/workflows/{workflow}/visualise", name="documentation_workflow_visualise", methods={"GET"})
   *
   * @param string $workflow
   *   The name of the workflow to visualise in hyphenated-form.
   */
  public function visualiseWorkflowAction(string $workflow, Registry $registry): Response
  {
    // We use hyphens for our URL and templates but underscores for the workflow
    // machine names.
    $workflow = str_replace('-', '_', $workflow);

    if (!$registry->has($workflow))
    {
      throw new NotFoundHttpException(sprintf('Workflow "%1$s" does not exist.".', $workflow));
    }

    $workflow = $registry->getByName($workflow);

    $options = [
      'nodes' => [
        // Our places are boxes by default.
        'shape' => 'box',
      ],
      'edges' => [
        // Our workflows are directional so we show arrows to indicate where
        // they're going.
        'arrows' => 'to',
        'color' => [
          // The color of the transition matches where we're going to. This
          // ensures transitions to errors have the error color.
          'inherit' => 'to',
        ],
      ],
    ];

    $definition = $workflow->getDefinition();
    $nodes = [];
    foreach ($definition->getPlaces() as $place)
    {
      $node = ['id' => $place, 'label' => $place];
      // Make the initial place stand out.
      if (in_array($place, $definition->getInitialPlaces(), TRUE))
      {
        $node['shape'] = 'circle';
      }

      // Differentiate error states.
      if (substr($place, 0, 6) === 'error_')
      {
        $node['color'] = '#ffb5a7';
      }

      $nodes[] = $node;
    }

    $edges = [];
    foreach ($definition->getTransitions() as $transition)
    {
      // A transition may specify multiple origins and destinations which means
      // We need to plot all of them.
      foreach ($transition->getFroms() as $from)
      {
        foreach ($transition->getTos() as $to)
        {
          $edges[] = ['label' => $transition->getName(), 'from' => $from, 'to' => $to];
        }
      }
    }

    return $this->render(
      'documentation/workflows/visualise.html.twig',
      [
        'workflow_slug' => str_replace('_', '-', $workflow->getName()),
        'workflow_label' => ucwords(str_replace('_', ' ', $workflow->getName())),
        'nodes' => $nodes,
        'edges' => $edges,
        'options' => $options,
      ]
    );
  }
}