<?php

declare(strict_types=1);

/*
 * 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.
 */

namespace Chill\MainBundle\Workflow;

use Chill\MainBundle\Entity\User;
use Chill\MainBundle\Entity\Workflow\EntityWorkflowSignatureStateEnum;
use Chill\MainBundle\Entity\Workflow\EntityWorkflowStep;
use Chill\MainBundle\Entity\Workflow\EntityWorkflowStepSignature;
use Chill\MainBundle\Workflow\Messenger\PostSignatureStateChangeMessage;
use Doctrine\DBAL\LockMode;
use Doctrine\ORM\EntityManagerInterface;
use Psr\Log\LoggerInterface;
use Symfony\Component\Clock\ClockInterface;
use Symfony\Component\Messenger\MessageBusInterface;
use Symfony\Component\Workflow\Registry;
use Symfony\Component\Workflow\Transition;

/**
 * Handles state changes for signature steps within a workflow.
 */
class SignatureStepStateChanger
{
    private const LOG_PREFIX = '[SignatureStepStateChanger] ';

    public function __construct(
        private readonly Registry $registry,
        private readonly ClockInterface $clock,
        private readonly LoggerInterface $logger,
        private readonly MessageBusInterface $messageBus,
        private readonly EntityManagerInterface $entityManager,
    ) {}

    /**
     * Marks a signature as signed.
     *
     * This method will acquire a lock on the database side, so it must be wrapped into an explicit
     * transaction.
     *
     * This method updates the state of the provided signature entity, sets the signature index,
     * and logs the action. Additionally, it dispatches a message indicating that the signature
     * state has changed.
     *
     * @param EntityWorkflowStepSignature $signature the signature entity to be marked as signed
     * @param int|null                    $atIndex   optional index position for the signature within the zone
     *
     * @return string The expected new workflow's step, after transition is applyied
     */
    public function markSignatureAsSigned(EntityWorkflowStepSignature $signature, ?int $atIndex): string
    {
        $this->entityManager->refresh($signature, LockMode::PESSIMISTIC_WRITE);

        $signature
            ->setState(EntityWorkflowSignatureStateEnum::SIGNED)
            ->setZoneSignatureIndex($atIndex)
            ->setStateDate($this->clock->now());
        $this->logger->info(self::LOG_PREFIX.'Mark signature entity as signed', ['signatureId' => $signature->getId(), 'index' => (string) $atIndex]);
        ['transition' => $transition, 'futureUser' => $futureUser] = $this->decideTransition($signature);

        $this->messageBus->dispatch(new PostSignatureStateChangeMessage((int) $signature->getId()));
        if (null === $transition) {
            return $signature->getStep()->getEntityWorkflow()->getStep();
        }

        return $transition->getTos()[0];
    }

    /**
     * Marks a signature as canceled.
     *
     * This method will acquire a lock on the database side, so it must be wrapped into an explicit
     * transaction.
     *
     * This method updates the signature state to 'canceled' and logs the action.
     * It also dispatches a message to notify about the state change.
     *
     * @return string The expected new workflow's step, after transition is applyied
     */
    public function markSignatureAsCanceled(EntityWorkflowStepSignature $signature): string
    {
        $this->entityManager->refresh($signature, LockMode::PESSIMISTIC_WRITE);

        $signature
            ->setState(EntityWorkflowSignatureStateEnum::CANCELED)
            ->setStateDate($this->clock->now());
        $this->logger->info(self::LOG_PREFIX.'Mark signature entity as canceled', ['signatureId' => $signature->getId()]);

        ['transition' => $transition, 'futureUser' => $futureUser] = $this->decideTransition($signature);

        $this->messageBus->dispatch(new PostSignatureStateChangeMessage((int) $signature->getId()));
        if (null === $transition) {
            return $signature->getStep()->getEntityWorkflow()->getStep();
        }

        return $transition->getTos()[0];
    }

    /**
     * Marks the given signature as rejected and updates its state and state date accordingly.
     *
     * This method will acquire a lock on the database side, so it must be wrapped into an explicit
     * transaction.
     *
     * This method logs the rejection of the signature and dispatches a message indicating
     * a state change has occurred.
     *
     * @param EntityWorkflowStepSignature $signature the signature entity to be marked as rejected
     *
     * @return string The expected new workflow's step, after transition is applyied
     */
    public function markSignatureAsRejected(EntityWorkflowStepSignature $signature): string
    {
        $this->entityManager->refresh($signature, LockMode::PESSIMISTIC_WRITE);

        $signature
            ->setState(EntityWorkflowSignatureStateEnum::REJECTED)
            ->setStateDate($this->clock->now());
        $this->logger->info(self::LOG_PREFIX.'Mark signature entity as rejected', ['signatureId' => $signature->getId()]);

        ['transition' => $transition, 'futureUser' => $futureUser] = $this->decideTransition($signature);

        $this->messageBus->dispatch(new PostSignatureStateChangeMessage((int) $signature->getId()));

        if (null === $transition) {
            return $signature->getStep()->getEntityWorkflow()->getStep();
        }

        return $transition->getTos()[0];
    }

    /**
     * Executed after a signature has a new state.
     *
     * This method will acquire a lock on the database side, so it must be wrapped into an explicit
     * transaction.
     *
     * This should be executed only by a system user (without any user registered)
     */
    public function onPostMark(EntityWorkflowStepSignature $signature): void
    {
        $this->entityManager->refresh($signature, LockMode::PESSIMISTIC_READ);

        ['transition' => $transition, 'futureUser' => $futureUser] = $this->decideTransition($signature);

        if (null === $transition) {
            return;
        }

        $entityWorkflow = $signature->getStep()->getEntityWorkflow();
        $workflow = $this->registry->get($entityWorkflow, $entityWorkflow->getWorkflowName());
        $transitionDto = new WorkflowTransitionContextDTO($entityWorkflow);
        $transitionDto->futureDestUsers[] = $futureUser;

        $workflow->apply($entityWorkflow, $transition->getName(), [
            'context' => $transitionDto,
            'transitionAt' => $this->clock->now(),
            'transition' => $transition->getName(),
        ]);

        $this->logger->info(self::LOG_PREFIX.'Transition automatically applied', ['signatureId' => $signature->getId()]);
    }

    /**
     * @return array{transition: Transition|null, futureUser: User|null}
     */
    private function decideTransition(EntityWorkflowStepSignature $signature): array
    {
        if (!EntityWorkflowStepSignature::isAllSignatureNotPendingForStep($signature->getStep())) {
            $this->logger->info(self::LOG_PREFIX.'This is not the last signature, skipping transition to another place', ['signatureId' => $signature->getId()]);

            return ['transition' => null, 'futureUser' => null];
        }

        $this->logger->debug(self::LOG_PREFIX.'Continuing the process to find a transition', ['signatureId' => $signature->getId()]);

        $entityWorkflow = $signature->getStep()->getEntityWorkflow();
        $workflow = $this->registry->get($entityWorkflow, $entityWorkflow->getWorkflowName());
        $metadataStore = $workflow->getMetadataStore();

        // find a transition
        $marking = $workflow->getMarking($entityWorkflow);
        $places = $marking->getPlaces();

        $transition = null;
        foreach ($places as $place => $int) {
            $metadata = $metadataStore->getPlaceMetadata($place);
            if (array_key_exists('onSignatureCompleted', $metadata)) {
                $transition = $metadata['onSignatureCompleted']['transitionName'];
            }
        }

        if (null === $transition) {
            $this->logger->info(self::LOG_PREFIX.'The transition is not configured, will not apply a transition', ['signatureId' => $signature->getId()]);

            return ['transition' => null, 'futureUser' => null];
        }

        if ('person' === $signature->getSignerKind()) {
            $futureUser = $this->getPreviousSender($signature->getStep());
        } else {
            $futureUser = $signature->getSigner();
        }

        if (null === $futureUser) {
            $this->logger->info(self::LOG_PREFIX.'No previous user, will not apply a transition', ['signatureId' => $signature->getId()]);

            return ['transition' => null, 'futureUser' => null];
        }

        foreach ($workflow->getDefinition()->getTransitions() as $transitionObj) {
            if ($transitionObj->getName() === $transition) {
                return ['transition' => $transitionObj, 'futureUser' => $futureUser];
            }
        }

        throw new \RuntimeException('Transition not found');
    }

    private function getPreviousSender(EntityWorkflowStep $entityWorkflowStep): ?User
    {
        $stepsChained = $entityWorkflowStep->getEntityWorkflow()->getStepsChained();

        foreach ($stepsChained as $stepChained) {
            if ($stepChained === $entityWorkflowStep) {
                if (null === $previous = $stepChained->getPrevious()) {
                    return null;
                }

                if (null !== $previousUser = $previous->getTransitionBy()) {
                    return $previousUser;
                }

                return $this->getPreviousSender($previous);
            }
        }

        throw new \LogicException('no same step found');
    }
}