<?php

/**
 * Chill is a software for social workers
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

declare(strict_types=1);

namespace Chill\MainBundle\Entity\Workflow;

use Chill\MainBundle\Doctrine\Model\TrackCreationInterface;
use Chill\MainBundle\Doctrine\Model\TrackCreationTrait;
use Chill\MainBundle\Doctrine\Model\TrackUpdateInterface;
use Chill\MainBundle\Doctrine\Model\TrackUpdateTrait;
use Chill\MainBundle\Entity\User;
use Chill\MainBundle\Workflow\Validator\EntityWorkflowCreation;
use DateTimeInterface;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;
use Iterator;
use RuntimeException;
use Symfony\Component\Serializer\Annotation as Serializer;
use function count;

/**
 * @ORM\Entity
 * @ORM\Table("chill_main_workflow_entity")
 * @EntityWorkflowCreation(groups={"creation"})
 * @Serializer\DiscriminatorMap(typeProperty="type", mapping={
 *     "entity_workflow": EntityWorkflow::class
 * })
 */
class EntityWorkflow implements TrackCreationInterface, TrackUpdateInterface
{
    use TrackCreationTrait;

    use TrackUpdateTrait;

    /**
     * @ORM\OneToMany(targetEntity=EntityWorkflowComment::class, mappedBy="entityWorkflow", orphanRemoval=true)
     *
     * @var Collection|EntityWorkflowComment[]
     */
    private Collection $comments;

    /**
     * @ORM\Id
     * @ORM\GeneratedValue
     * @ORM\Column(type="integer")
     * @Serializer\Groups({"read"})
     */
    private ?int $id = null;

    /**
     * @ORM\Column(type="string", length=255)
     */
    private string $relatedEntityClass = '';

    /**
     * @ORM\Column(type="integer")
     */
    private int $relatedEntityId;

    /**
     * @ORM\OneToMany(targetEntity=EntityWorkflowStep::class, mappedBy="entityWorkflow", orphanRemoval=true, cascade={"persist"})
     * @ORM\OrderBy({"transitionAt": "ASC", "id": "ASC"})
     *
     * @var Collection|EntityWorkflowStep[]
     */
    private Collection $steps;

    /**
     * @ORM\ManyToMany(targetEntity=User::class)
     * @ORM\JoinTable(name="chill_main_workflow_entity_subscriber_to_final")
     *
     * @var Collection|User[]
     */
    private Collection $subscriberToFinal;

    /**
     * @ORM\ManyToMany(targetEntity=User::class)
     * @ORM\JoinTable(name="chill_main_workflow_entity_subscriber_to_step")
     *
     * @var Collection|User[]
     */
    private Collection $subscriberToStep;

    /**
     * a step which will store all the transition data.
     */
    private ?EntityWorkflowStep $transitionningStep = null;

    /**
     * @ORM\Column(type="text")
     */
    private string $workflowName;

    public function __construct()
    {
        $this->subscriberToFinal = new ArrayCollection();
        $this->subscriberToStep = new ArrayCollection();
        $this->comments = new ArrayCollection();
        $this->steps = new ArrayCollection();

        $initialStep = new EntityWorkflowStep();
        $initialStep
            ->setCurrentStep('initial');
        $this->addStep($initialStep);
    }

    public function addComment(EntityWorkflowComment $comment): self
    {
        if (!$this->comments->contains($comment)) {
            $this->comments[] = $comment;
            $comment->setEntityWorkflow($this);
        }

        return $this;
    }

    /**
     * @internal You should prepare a step and run a workflow transition instead of manually adding a step
     */
    public function addStep(EntityWorkflowStep $step): self
    {
        if (!$this->steps->contains($step)) {
            $this->steps[] = $step;
            $step->setEntityWorkflow($this);

            if ($this->isFinalize()) {
                $step->setFinalizeAfter(true);
            }
        }

        return $this;
    }

    public function addSubscriberToFinal(User $user): self
    {
        if (!$this->subscriberToFinal->contains($user)) {
            $this->subscriberToFinal[] = $user;
        }

        return $this;
    }

    public function addSubscriberToStep(User $user): self
    {
        if (!$this->subscriberToStep->contains($user)) {
            $this->subscriberToStep[] = $user;
        }

        return $this;
    }

    public function getComments(): Collection
    {
        return $this->comments;
    }

    public function getCurrentStep(): ?EntityWorkflowStep
    {
        $step = $this->steps->last();

        if (false !== $step) {
            return $step;
        }

        return null;
    }

    public function getCurrentStepCreatedAt(): ?DateTimeInterface
    {
        if (null !== $previous = $this->getPreviousStepIfAny()) {
            return $previous->getTransitionAt();
        }

        return null;
    }

    public function getCurrentStepCreatedBy(): ?User
    {
        if (null !== $previous = $this->getPreviousStepIfAny()) {
            return $previous->getTransitionBy();
        }

        return null;
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getRelatedEntityClass(): string
    {
        return $this->relatedEntityClass;
    }

    public function getRelatedEntityId(): int
    {
        return $this->relatedEntityId;
    }

    /**
     * Method used by MarkingStore.
     *
     * get a string representation of the step
     */
    public function getStep(): string
    {
        return $this->getCurrentStep()->getCurrentStep();
    }

    public function getStepAfter(EntityWorkflowStep $step): ?EntityWorkflowStep
    {
        $iterator = $this->steps->getIterator();

        if ($iterator instanceof Iterator) {
            $iterator->rewind();

            while ($iterator->valid()) {
                $curStep = $iterator->current();

                if ($curStep === $step) {
                    $iterator->next();

                    if ($iterator->valid()) {
                        return $iterator->current();
                    }

                    return null;
                }
                $iterator->next();
            }

            return null;
        }

        throw new RuntimeException();
    }

    /**
     * @return ArrayCollection|Collection
     */
    public function getSteps()
    {
        return $this->steps;
    }

    public function getStepsChained(): array
    {
        $iterator = $this->steps->getIterator();
        $previous = $next = $current = null;
        $steps = [];

        $iterator->rewind();

        while ($iterator->valid()) {
            $previous = $current;
            $steps[] = $current = $iterator->current();
            $current->setPrevious($previous);

            $iterator->next();

            if ($iterator->valid()) {
                $next = $iterator->current();
            } else {
                $next = null;
            }

            $current->setNext($next);
        }

        return $steps;
    }

    /**
     * @return ArrayCollection|Collection
     */
    public function getSubscriberToFinal()
    {
        return $this->subscriberToFinal;
    }

    /**
     * @return ArrayCollection|Collection
     */
    public function getSubscriberToStep()
    {
        return $this->subscriberToStep;
    }

    /**
     * get the step which is transitionning. Should be called only by event which will
     * concern the transition.
     */
    public function getTransitionningStep(): ?EntityWorkflowStep
    {
        return $this->transitionningStep;
    }

    public function getWorkflowName(): string
    {
        return $this->workflowName;
    }

    public function isFinalize(): bool
    {
        $steps = $this->getStepsChained();

        if (1 === count($steps)) {
            // the initial step cannot be finalized
            return false;
        }

        /** @var EntityWorkflowStep $last */
        $last = end($steps);

        return $last->getPrevious()->isFinalizeAfter();
    }

    public function isFreeze(): bool
    {
        $steps = $this->getStepsChained();

        if (1 === count($steps)) {
            // the initial step cannot be finalized
            return false;
        }

        /** @var EntityWorkflowStep $last */
        $last = end($steps);

        return $last->getPrevious()->isFreezeAfter();
    }

    public function isUserSubscribedToFinal(User $user): bool
    {
        return $this->subscriberToFinal->contains($user);
    }

    public function isUserSubscribedToStep(User $user): bool
    {
        return $this->subscriberToStep->contains($user);
    }

    public function prepareStepBeforeTransition(EntityWorkflowStep $step): self
    {
        $this->transitionningStep = $step;

        return $this;
    }

    public function removeComment(EntityWorkflowComment $comment): self
    {
        if ($this->comments->removeElement($comment)) {
            $comment->setEntityWorkflow(null);
        }

        return $this;
    }

    public function removeStep(EntityWorkflowStep $step): self
    {
        if ($this->steps->removeElement($step)) {
            $step->setEntityWorkflow(null);
        }

        return $this;
    }

    public function removeSubscriberToFinal(User $user): self
    {
        $this->subscriberToFinal->removeElement($user);

        return $this;
    }

    public function removeSubscriberToStep(User $user): self
    {
        $this->subscriberToStep->removeElement($user);

        return $this;
    }

    public function setRelatedEntityClass(string $relatedEntityClass): EntityWorkflow
    {
        $this->relatedEntityClass = $relatedEntityClass;

        return $this;
    }

    public function setRelatedEntityId(int $relatedEntityId): EntityWorkflow
    {
        $this->relatedEntityId = $relatedEntityId;

        return $this;
    }

    /**
     * Method use by marking store.
     *
     * @return $this
     */
    public function setStep(string $step): self
    {
        $newStep = new EntityWorkflowStep();
        $newStep->setCurrentStep($step);

        // copy the freeze
        if ($this->getCurrentStep()->isFreezeAfter()) {
            $newStep->setFreezeAfter(true);
        }

        $this->addStep($newStep);

        return $this;
    }

    public function setWorkflowName(string $workflowName): EntityWorkflow
    {
        $this->workflowName = $workflowName;

        return $this;
    }

    private function getPreviousStepIfAny(): ?EntityWorkflowStep
    {
        if (1 === count($this->steps)) {
            return null;
        }

        return $this->steps->get($this->steps->count() - 2);
    }
}