<?php

namespace Chill\MainBundle\CRUD\Controller;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\Serializer\SerializerInterface;
use Chill\MainBundle\Serializer\Model\Collection;
use Chill\MainBundle\Pagination\PaginatorInterface;
use Symfony\Component\Serializer\Normalizer\AbstractNormalizer;
use Symfony\Component\Validator\ConstraintViolationListInterface;
use Symfony\Component\Serializer\Exception\NotEncodableValueException;
use Symfony\Component\HttpFoundation\Exception\BadRequestException;

class ApiController extends AbstractCRUDController
{
    /**
     * The view action.
     * 
     * Some steps may be overriden during this process of rendering:
     * 
     * This method:
     * 
     * 1.  fetch the entity, using `getEntity`
     * 2.  launch `onPostFetchEntity`. If postfetch is an instance of Response,
     *     this response is returned.
     * 2.  throw an HttpNotFoundException if entity is null
     * 3.  check ACL using `checkACL` ;
     * 4.  launch `onPostCheckACL`. If the result is an instance of Response, 
     *     this response is returned ;
     * 5.  Serialize the entity and return the result. The serialization context is given by `getSerializationContext`
     * 
     */
    protected function entityGet(string $action, Request $request, $id, $_format = 'html'): Response
    {
        $entity = $this->getEntity($action, $id, $request, $_format);
        
        $postFetch = $this->onPostFetchEntity($action, $request, $entity, $_format);
        
        if ($postFetch instanceof Response) {
            return $postFetch;
        }
        
        $response = $this->checkACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }
        
        $response = $this->onPostCheckACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $response = $this->onBeforeSerialize($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        if ($_format === 'json') {
            $context = $this->getContextForSerialization($action, $request, $_format, $entity);

            return $this->json($entity, Response::HTTP_OK, [], $context);
        } else {
            throw new \Symfony\Component\HttpFoundation\Exception\BadRequestException("This format is not implemented");
        }
    }

    public function onBeforeSerialize(string $action, Request $request, $_format, $entity): ?Response
    {
        return null;
    }

    /**
     * Base method for handling api action
     *
     * @return void
     */
    public function entityApi(Request $request, $id, $_format): Response
    {
        switch ($request->getMethod()) {
            case Request::METHOD_GET:
            case Request::METHOD_HEAD:
                return $this->entityGet('_entity', $request, $id, $_format);
            case Request::METHOD_PUT:
            case Request::METHOD_PATCH:
                return $this->entityPut('_entity', $request, $id, $_format);
            case Request::METHOD_POST:
                return $this->entityPostAction('_entity', $request, $id, $_format);
            case Request::METHOD_DELETE:
                return $this->entityDelete('_entity', $request, $id, $_format);
            default:
                throw new \Symfony\Component\HttpFoundation\Exception\BadRequestException("This method is not implemented");
        }
    }
    public function entityPost(Request $request, $_format): Response
    {
        switch($request->getMethod()) {
            case Request::METHOD_POST:
                return $this->entityPostAction('_entity', $request, $_format);
            default:
                throw new \Symfony\Component\HttpFoundation\Exception\BadRequestException("This method is not implemented");
        }
    }

    protected function entityPostAction($action, Request $request, string $_format): Response
    {
        $entity = $this->createEntity($action, $request);

        try {
            $entity = $this->deserialize($action, $request, $_format, $entity);
        } catch (NotEncodableValueException $e) {
            throw new BadRequestException("invalid json", 400, $e);
        }
        
        $errors = $this->validate($action, $request, $_format, $entity);
        
        $response = $this->onAfterValidation($action, $request, $_format, $entity, $errors);
        if ($response instanceof Response) {
            return $response;
        }

        if ($errors->count() > 0) {
            $response = $this->json($errors);
            $response->setStatusCode(Response::HTTP_UNPROCESSABLE_ENTITY);

            return $response;
        }
        
        $response = $this->checkACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }
        
        $response = $this->onPostCheckACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $this->getDoctrine()->getManager()->persist($entity);
        $this->getDoctrine()->getManager()->flush();

        $response = $this->onAfterFlush($action, $request, $_format, $entity, $errors);
        if ($response instanceof Response) {
            return $response;
        }
        $response = $this->onBeforeSerialize($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }
        
        return $this->json(
            $entity,
            Response::HTTP_OK,
            [], 
            $this->getContextForSerializationPostAlter($action, $request, $_format, $entity)
        );
    }
    public function entityPut($action, Request $request, $id, string $_format): Response
    {
        $entity = $this->getEntity($action, $id, $request, $_format);
        
        $postFetch = $this->onPostFetchEntity($action, $request, $entity, $_format);
        if ($postFetch instanceof Response) {
            return $postFetch;
        }
        
        if (NULL === $entity) {
            throw $this->createNotFoundException(sprintf("The %s with id %s "
                . "is not found", $this->getCrudName(), $id));
        }
        
        $response = $this->checkACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }
        
        $response = $this->onPostCheckACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $response = $this->onBeforeSerialize($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }
        
        try {
            $entity = $this->deserialize($action, $request, $_format, $entity);
        } catch (NotEncodableValueException $e) {
            throw new BadRequestException("invalid json", 400, $e);
        }

        $errors = $this->validate($action, $request, $_format, $entity);

        $response = $this->onAfterValidation($action, $request, $_format, $entity, $errors);
        if ($response instanceof Response) {
            return $response;
        }

        if ($errors->count() > 0) {
            $response = $this->json($errors);
            $response->setStatusCode(Response::HTTP_UNPROCESSABLE_ENTITY);

            return $response;
        }

        $this->getDoctrine()->getManager()->flush();

        $response = $this->onAfterFlush($action, $request, $_format, $entity, $errors);
        if ($response instanceof Response) {
            return $response;
        }

        return $this->json(
            $entity,
            Response::HTTP_OK,
            [], 
            $this->getContextForSerializationPostAlter($action, $request, $_format, $entity)
        );
    }
    public function entityDelete($action, Request $request, $id, string $_format): Response
    {
        $entity = $this->getEntity($action, $id, $request, $_format);

        if (NULL === $entity) {
            throw $this->createNotFoundException(sprintf("The %s with id %s "
                . "is not found", $this->getCrudName(), $id));
        }

        $response = $this->checkACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $response = $this->onPostCheckACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $response = $this->onBeforeSerialize($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $errors = $this->validate($action, $request, $_format, $entity);

        $response = $this->onAfterValidation($action, $request, $_format, $entity, $errors);
        if ($response instanceof Response) {
            return $response;
        }

        if ($errors->count() > 0) {
            $response = $this->json($errors);
            $response->setStatusCode(Response::HTTP_UNPROCESSABLE_ENTITY);

            return $response;
        }

        $this->getDoctrine()->getManager()->remove($entity);
        $this->getDoctrine()->getManager()->flush();

        $response = $this->onAfterFlush($action, $request, $_format, $entity, $errors);
        if ($response instanceof Response) {
            return $response;
        }

        return $this->json(Response::HTTP_OK);
    }

    protected function onAfterValidation(string $action, Request $request, string $_format, $entity, ConstraintViolationListInterface $errors, array $more = []): ?Response
    {
        return null;
    }


    protected function onAfterFlush(string $action, Request $request, string $_format, $entity, ConstraintViolationListInterface $errors, array $more = []): ?Response
    {
        return null;
    }

    protected function getValidationGroups(string $action, Request $request, string $_format, $entity): ?array
    {
        return null;
    }

    protected function validate(string $action, Request $request, string $_format, $entity, array $more = []): ConstraintViolationListInterface
    {
        $validationGroups = $this->getValidationGroups($action, $request, $_format, $entity);
        
        return $this->getValidator()->validate($entity, null, $validationGroups);
    }

    /**
     * Deserialize the content of the request into the class associated with the curd
     */
    protected function deserialize(string $action, Request $request, string $_format, $entity = null): object
    {
        $default = [];

        if (NULL !== $entity) {
            $default[AbstractNormalizer::OBJECT_TO_POPULATE] = $entity;
        }

        $context = \array_merge(
            $default,
            $this->getContextForSerialization($action, $request, $_format, $entity)
        );

        return $this->getSerializer()->deserialize($request->getContent(), $this->getEntityClass(), $_format, $context);
    }
    

    /**
     * Base action for indexing entities
     */
    public function indexApi(Request $request, string $_format)
    {
        switch ($request->getMethod()) {
            case Request::METHOD_GET:
            case REQUEST::METHOD_HEAD:
                return $this->indexApiAction('_index', $request, $_format);
            default:
                throw $this->createNotFoundException("This method is not supported");
        }
    }

    /**
     * Build an index page.
     * 
     * Some steps may be overriden during this process of rendering.
     * 
     * This method:
     * 
     * 1.  Launch `onPreIndex`
     * x.  check acl. If it does return a response instance, return it
     * x.  launch `onPostCheckACL`. If it does return a response instance, return it
     * 1.  count the items, using `countEntities`
     * 2.  build a paginator element from the the number of entities ;
     * 3.  Launch `onPreIndexQuery`. If it does return a response instance, return it
     * 3.  build a query, using `queryEntities`
     * x.  fetch the results, using `getQueryResult`
     * x.  Launch `onPostIndexFetchQuery`. If it does return a response instance, return it
     * 4.  Serialize the entities in a Collection, using `SerializeCollection`
     * 
     * @param string $action
     * @param Request $request
     * @return type
     */
    protected function indexApiAction($action, Request $request, $_format)
    {
        $this->onPreIndex($action, $request, $_format);
        
        $response = $this->checkACL($action, $request, $_format);
        if ($response instanceof Response) {
            return $response;
        }
        
        if (!isset($entity)) {
            $entity = '';
        }
        
        $response = $this->onPostCheckACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }
        
        $totalItems = $this->countEntities($action, $request, $_format);
        $paginator = $this->getPaginatorFactory()->create($totalItems);
        
        $response = $this->onPreIndexBuildQuery($action, $request, $_format, $totalItems, 
            $paginator);
        
        if ($response instanceof Response) {
            return $response;
        }
        
        $query = $this->queryEntities($action, $request, $_format, $paginator);
        
        $response = $this->onPostIndexBuildQuery($action, $request, $_format, $totalItems, 
            $paginator, $query);
        
        if ($response instanceof Response) {
            return $response;
        }
        
        $entities = $this->getQueryResult($action, $request, $_format, $totalItems, $paginator, $query);
        
        $response = $this->onPostIndexFetchQuery($action, $request, $_format, $totalItems, 
            $paginator, $entities);
        
        if ($response instanceof Response) {
            return $response;
        }
        
        return $this->serializeCollection($action, $request, $_format, $paginator, $entities);    
    }

    /**
     * Add or remove an associated entity, using `add` and `remove` methods.
     *
     * This method:
     *
     * 1. Fetch the base entity (throw 404 if not found)
     * 2. checkACL, 
     * 3. run onPostCheckACL, return response if any,
     * 4. deserialize posted data into the entity given by $postedDataType, with the context in $postedDataContext
     * 5. run 'add+$property' for POST method, or 'remove+$property' for DELETE method
     * 6. validate the base entity (not the deserialized one). Groups are fetched from getValidationGroups, validation is perform by `validate`
     * 7. run onAfterValidation
     * 8. if errors, return a 422 response with errors
     * 9. if $forcePersist === true, persist the entity
     * 10. flush the data 
     * 11. run onAfterFlush
     * 12. return a 202 response for DELETE with empty body, or HTTP 200 for post with serialized posted entity
     *
     * @param string action
     * @param mixed id
     * @param Request $request
     * @param string $_format
     * @param string $property the name of the property. This will be used to make a `add+$property` and `remove+$property` method
     * @param string $postedDataType the type of the posted data (the content)
     * @param string $postedDataContext a context to deserialize posted data (the content)
     * @param bool $forcePersist force to persist the created element (only for POST request)
     * @throw BadRequestException if unable to deserialize the posted data
     * @throw BadRequestException if the method is not POST or DELETE
     *
     */ 
    protected function addRemoveSomething(string $action, $id, Request $request, string $_format, string $property, string $postedDataType, array $postedDataContext = [], bool $forcePersist = false): Response
    {
        $entity = $this->getEntity($action, $id, $request);

        $postFetch = $this->onPostFetchEntity($action, $request, $entity, $_format);
        if ($postFetch instanceof Response) {
            return $postFetch;
        }

        $response = $this->checkACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $response = $this->onPostCheckACL($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        $response = $this->onBeforeSerialize($action, $request, $_format, $entity);
        if ($response instanceof Response) {
            return $response;
        }

        try {
            $postedData = $this->getSerializer()->deserialize($request->getContent(), $postedDataType, $_format, $postedDataContext);
        } catch (\Symfony\Component\Serializer\Exception\UnexpectedValueException $e) {
            throw new BadRequestException(sprintf("Unable to deserialize posted ".
                "data: %s", $e->getMessage()), 0, $e);
        }

        switch ($request->getMethod()) {
            case Request::METHOD_DELETE:
                // oups... how to use property accessor to remove element ?
                $entity->{'remove'.\ucfirst($property)}($postedData);
                break;
            case Request::METHOD_POST:
                $entity->{'add'.\ucfirst($property)}($postedData);
                break;
            default:
                throw new BadRequestException("this method is not supported");
        }

        $errors = $this->validate($action, $request, $_format, $entity, [$postedData]);

        $response = $this->onAfterValidation($action, $request, $_format, $entity, $errors, [$postedData]);
        if ($response instanceof Response) {
            return $response;
        }

        if ($errors->count() > 0) {
            // only format accepted
            return $this->json($errors, 422);
        }

        if ($forcePersist && $request->getMethod() === Request::METHOD_POST) {
            $this->getDoctrine()->getManager()->persist($postedData);
        }

        $this->getDoctrine()->getManager()->flush();


        $response = $this->onAfterFlush($action, $request, $_format, $entity, $errors, [$postedData]);
        if ($response instanceof Response) {
            return $response;
        }

        switch ($request->getMethod()) {
            case Request::METHOD_DELETE:
                return $this->json('', Response::HTTP_OK);
            case Request::METHOD_POST:
                return $this->json(
                    $postedData,
                    Response::HTTP_OK,
                    [], 
                    $this->getContextForSerializationPostAlter($action, $request, $_format, $entity, [$postedData])
                );
        }
    }
    
    /**
     * Serialize collections
     *
     */
    protected function serializeCollection(string $action, Request $request, string $_format, PaginatorInterface $paginator, $entities): Response
    {
        $model = new Collection($entities, $paginator);

        $context = $this->getContextForSerialization($action, $request, $_format, $entities);

        return $this->json($model, Response::HTTP_OK, [], $context);
    }
    

    protected function getContextForSerialization(string $action, Request $request, string $_format, $entity): array
    {
        switch ($request->getMethod()) {
            case Request::METHOD_GET:
                return [ 'groups' => [ 'read' ]];
            case Request::METHOD_PUT:
            case Request::METHOD_PATCH:
            case Request::METHOD_POST:
                return [ 'groups' => [ 'write' ]];
            default:
                throw new \LogicException("get context for serialization is not implemented for this method");
        }
    }

    /**
     * Get the context for serialization post alter query (in case of 
     * PATCH, PUT, or POST method)
     *
     * This is called **after** the entity was altered.
     */
    protected function getContextForSerializationPostAlter(string $action, Request $request, string $_format, $entity, array $more = []): array
    {
        return [ 'groups' => [ 'read' ]];
    }

    /**
     * get the role given from the config.
     */
    protected function getRoleFor(string $action, Request $request, $entity, $_format): string
    {
        $actionConfig = $this->getActionConfig($action);

        if (NULL !== $actionConfig['roles'][$request->getMethod()]) {
            return $actionConfig['roles'][$request->getMethod()];
        }

        if ($this->crudConfig['base_role']) {
            return $this->crudConfig['base_role'];
        }

        throw new \RuntimeException(sprintf("the config does not have any role for the ".
            "method %s nor a global role for the whole action. Add those to your ".
            "configuration or override the required method", $request->getMethod()));
        
    }

    protected function getSerializer(): SerializerInterface
    {
        return $this->get('serializer');
    }
}