config/services.yaml

@@ -23,7 +23,7 @@ services:
     # this creates a service per class whose id is the fully-qualified class name
     App\:
         resource: '../src/*'
-        exclude: '../src/{DependencyInjection,Entity,Model,Migrations,Tests,Functions,Kernel.php}'
+        exclude: '../src/{DependencyInjection,Exception,Modifiers,Entity,Model,Migrations,Tests,Functions,Kernel.php}'
 
     # controllers are imported separately to make sure services can be injected
     # as action arguments even if you don't extend any base controller class

resources/ts/components/picker.ts

@@ -80,7 +80,7 @@ export class FinderComponent extends Vue {
 
         this.state = 'fetching';
 
-        const response = await fetch(urls.prepare(urls.stops.grouped, { name: this.filter }));
+        const response = await fetch(urls.prepare(urls.stops.grouped, { name: this.filter, 'include-destinations': true }));
 
         if (response.ok) {
             this.found = (await response.json()).reduce((accumulator, { name, stops }) => Object.assign(accumulator, { [name]: stops }), {});

resources/ts/urls.ts

@@ -8,7 +8,11 @@ export function query(params: UrlParams = { }) {
     function *simplify(name: string, param: any): IterableIterator<ParamValuePair> {
         if (typeof param === 'string') {
             yield [ name, param ];
-        } else if (typeof param === 'number') {
+        } else if (typeof param === 'boolean') {
+            if (param) {
+                yield [ name, '1' ];
+            }
+        }  else if (typeof param === 'number') {
             yield [ name, param.toString() ];
         } else if (param instanceof Array) {
             for (let entry of param) {

src/Controller/Api/v1/DeparturesController.php

@@ -5,6 +5,7 @@ namespace App\Controller\Api\v1;
 
 use App\Controller\Controller;
 use App\Model\Departure;
+use App\Modifier\IdFilter;
 use App\Provider\DepartureRepository;
 use App\Provider\StopRepository;
 use App\Service\SerializerContextFactory;
@@ -34,7 +35,7 @@ class DeparturesController extends Controller
      */
     public function stop(DepartureRepository $departures, StopRepository $stops, $stop)
     {
-        $stop = $stops->getById($stop);
+        $stop = $stops->first(new IdFilter($stop));
 
         return $this->json($departures->getForStop($stop));
     }
@@ -65,7 +66,7 @@ class DeparturesController extends Controller
     public function stops(DepartureRepository $departures, StopRepository $stops, Request $request)
     {
         $stops = $stops
-            ->getManyById($request->query->get('stop'))
+            ->all(new IdFilter($request->query->get('stop')))
             ->flatMap(ref([ $departures, 'getForStop' ]))
             ->sortBy(property('departure'));
 

src/Controller/Api/v1/StopsController.php

@@ -1,12 +1,15 @@
 <?php
 
-
 namespace App\Controller\Api\v1;
 
 use App\Controller\Controller;
 use App\Model\Stop;
 use App\Model\Track;
 use App\Model\StopGroup;
+use App\Modifier\IdFilter;
+use App\Modifier\FieldFilter;
+use App\Modifier\IncludeDestinations;
+use App\Modifier\RelatedFilter;
 use App\Provider\StopRepository;
 use App\Provider\TrackRepository;
 use App\Service\Proxy\ReferenceFactory;
@@ -38,7 +41,8 @@ class StopsController extends Controller
      *     name="id",
      *     in="query",
      *     type="array",
-     *     description="Stop identificators to retrieve at once. Can be used to bulk load data. If not specified will return all data.",
+     *     description="Stop identificators to retrieve at once. Can be used to bulk load data. If not specified will
+     *     return all data.",
      *     @SWG\Items(type="string")
      * )
      *
@@ -46,16 +50,9 @@ class StopsController extends Controller
      */
     public function index(Request $request, StopRepository $stops)
     {
-        switch (true) {
-            case $request->query->has('id'):
-                $result = $stops->getManyById($request->query->get('id'));
-                break;
+        $modifiers = $this->getModifiersFromRequest($request);
 
-            default:
-                $result = $stops->getAll();
-        }
-
-        return $this->json($result->all());
+        return $this->json($stops->all(...$modifiers)->toArray());
     }
 
     /**
@@ -76,16 +73,9 @@ class StopsController extends Controller
      */
     public function groups(Request $request, StopRepository $stops)
     {
-        switch (true) {
-            case $request->query->has('name'):
-                $result = $stops->findByName($request->query->get('name'));
-                break;
+        $modifiers = $this->getModifiersFromRequest($request);
 
-            default:
-                $result = $stops->getAll();
-        }
-
-        return $this->json(static::group($result)->all());
+        return $this->json(static::group($stops->all(...$modifiers))->toArray());
     }
 
     /**
@@ -106,7 +96,7 @@ class StopsController extends Controller
      */
     public function one(Request $request, StopRepository $stops, $id)
     {
-        return $this->json($stops->getById($id));
+        return $this->json($stops->first(new IdFilter($id), new IncludeDestinations()));
     }
 
     /**
@@ -145,4 +135,19 @@ class StopsController extends Controller
             return $group;
         })->values();
     }
+
+    private function getModifiersFromRequest(Request $request)
+    {
+        if ($request->query->has('name')) {
+            yield FieldFilter::contains('name', $request->query->get('name'));
+        }
+
+        if ($request->query->has('id')) {
+            yield new IdFilter($request->query->get('id'));
+        }
+
+        if ($request->query->has('include-destinations')) {
+            yield new IncludeDestinations();
+        }
+    }
 }

src/Controller/Api/v1/TracksController.php

@@ -3,9 +3,13 @@
 namespace App\Controller\Api\v1;
 
 use App\Controller\Controller;
+use App\Model\Line;
 use App\Model\Stop;
 use App\Model\Track;
+use App\Modifier\IdFilter;
+use App\Modifier\RelatedFilter;
 use App\Provider\TrackRepository;
+use App\Service\IterableUtils;
 use Nelmio\ApiDocBundle\Annotation\Model;
 use Swagger\Annotations as SWG;
 use Symfony\Component\HttpFoundation\Request;
@@ -28,43 +32,31 @@ class TracksController extends Controller
      */
     public function index(Request $request, TrackRepository $repository)
     {
-        switch (true) {
-            case $request->query->has('stop'):
-                return $this->byStop($request, $repository);
-            case $request->query->has('line'):
-                return $this->byLine($request, $repository);
-            case $request->query->has('id'):
-                return $this->byId($request, $repository);
-            default:
-                throw new BadRequestHttpException(
-                    sprintf(
-                        'At least one parameter of %s must be set.',
-                        implode(', ', ['stop', 'line', 'id'])
-                    )
-                );
+        $modifiers = $this->getModifiersFromRequest($request);
+
+        return $this->json($repository->all(...$modifiers));
+    }
+
+    private function getModifiersFromRequest(Request $request)
+    {
+        if ($request->query->has('stop')) {
+            $stop = $request->query->get('stop');
+            $stop = Stop::reference($stop);
+
+            yield new RelatedFilter($stop);
+        }
+
+        if ($request->query->has('line')) {
+            $line = $request->query->get('line');
+            $line = Line::reference($line);
+
+            yield new RelatedFilter($line);
+        }
+
+        if ($request->query->has('id')) {
+            $id = encapsulate($request->query->get('id'));
+
+            yield new IdFilter($id);
         }
     }
-
-    private function byId(Request $request, TrackRepository $repository)
-    {
-        $id = encapsulate($request->query->get('id'));
-
-        return $this->json($repository->getManyById($id));
-    }
-
-    private function byStop(Request $request, TrackRepository $repository)
-    {
-        $stop = $request->query->get('stop');
-        $stop = array_map([Stop::class, 'reference'], encapsulate($stop));
-
-        return $this->json($repository->getByStop($stop));
-    }
-
-    private function byLine(Request $request, TrackRepository $repository)
-    {
-        $line = $request->query->get('line');
-        $line = array_map([Stop::class, 'reference'], encapsulate($line));
-
-        return $this->json($repository->getByLine($line));
-    }
-}
+}

src/Controller/Api/v1/TripController.php

@@ -4,6 +4,7 @@ namespace App\Controller\Api\v1;
 
 use App\Controller\Controller;
 use App\Model\Trip;
+use App\Modifier\IdFilter;
 use App\Provider\TripRepository;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
@@ -18,7 +19,7 @@ class TripController extends Controller
      */
     public function one($id, TripRepository $repository)
     {
-        $trip = $repository->getById($id);
+        $trip = $repository->all(new IdFilter($id));
 
         return $this->json($trip, Response::HTTP_OK, [], $this->serializerContextFactory->create(Trip::class));
     }

src/Event/HandleDatabaseModifierEvent.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Event;
+
+use App\Event\HandleModifierEvent;
+use App\Modifier\Modifier;
+use App\Provider\Repository;
+use Doctrine\ORM\QueryBuilder;
+
+class HandleDatabaseModifierEvent extends HandleModifierEvent
+{
+    private $builder;
+
+    public function __construct(
+        Modifier $modifier,
+        Repository $repository,
+        QueryBuilder $builder,
+        array $meta = []
+    ) {
+        parent::__construct($modifier, $repository, $meta);
+
+        $this->builder = $builder;
+    }
+
+    public function getBuilder(): QueryBuilder
+    {
+        return $this->builder;
+    }
+
+    public function replaceBuilder(QueryBuilder $builder): void
+    {
+        $this->builder = $builder;
+    }
+}

src/Event/HandleModifierEvent.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Event;
+
+use App\Modifier\Modifier;
+use App\Provider\Repository;
+
+class HandleModifierEvent
+{
+    private $repository;
+    private $modifier;
+    private $meta = [];
+
+    public function __construct(Modifier $modifier, Repository $repository, array $meta = [])
+    {
+        $this->repository = $repository;
+        $this->modifier   = $modifier;
+        $this->meta       = $meta;
+    }
+
+    public function getModifier(): Modifier
+    {
+        return $this->modifier;
+    }
+
+    public function getRepository()
+    {
+        return $this->repository;
+    }
+
+    public function getMeta(): array
+    {
+        return $this->meta;
+    }
+}

src/Event/PostProcessEvent.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Event;
+
+use App\Modifier\Modifier;
+use App\Provider\Repository;
+
+class PostProcessEvent extends HandleModifierEvent
+{
+    private $data;
+
+    public function __construct($data, Modifier $modifier, Repository $repository, array $meta = [])
+    {
+        parent::__construct($modifier, $repository, $meta);
+        $this->data = $data;
+    }
+
+    public function getData()
+    {
+        return $this->data;
+    }
+
+    public function setData($data): void
+    {
+        $this->data = $data;
+    }
+}

src/Exception/InvalidOptionException.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Exception;
+
+class InvalidOptionException extends \InvalidArgumentException
+{
+    public static function invalidType($parameter, $value, array $expected = [])
+    {
+        return new \InvalidArgumentException(
+            sprintf('Expected %s to be of type: %s. %s given.', $parameter, implode(', ', $expected), gettype($value))
+        );
+    }
+}

src/Exception/NonExistentServiceException.php

@@ -4,7 +4,6 @@
 namespace App\Exception;
 
 
-class NonExistentServiceException extends \Exception
+class NonExistentServiceException extends \LogicException
 {
-
-}
+}

src/Exception/NotSupportedException.php

@@ -2,6 +2,6 @@
 
 namespace App\Exception;
 
-class NotSupportedException extends \RuntimeException
+class NotSupportedException extends \LogicException
 {
-}
+}

src/Exception/UnsupportedModifierException.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace App\Exception;
+
+use App\Modifier\Modifier;
+use App\Provider\Repository;
+
+class UnsupportedModifierException extends \LogicException
+{
+    public static function createFromModifier(Modifier $modifier, Repository $repository)
+    {
+        return new static(sprintf("Modifier %s is not supported by %s.", get_class($modifier), get_class($repository)));
+    }
+}

src/Handler/Database/FieldFilterDatabaseHandler.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace App\Handler\Database;
+
+use App\Event\HandleDatabaseModifierEvent;
+use App\Event\HandleModifierEvent;
+use App\Handler\ModifierHandler;
+use App\Model\Stop;
+use App\Modifier\FieldFilter;
+use function App\Functions\encapsulate;
+
+class FieldFilterDatabaseHandler implements ModifierHandler
+{
+    protected $mapping = [
+        Stop::class => [
+            'name' => 'name',
+        ],
+    ];
+
+    public function process(HandleModifierEvent $event)
+    {
+        if (!$event instanceof HandleDatabaseModifierEvent) {
+            return;
+        }
+
+        /** @var FieldFilter $modifier */
+        $modifier = $event->getModifier();
+        $builder  = $event->getBuilder();
+        $alias    = $event->getMeta()['alias'];
+
+        $field    = $this->mapFieldName($event->getMeta()['type'], $modifier->getField());
+        $operator = $modifier->getOperator();
+        $value    = $modifier->getValue();
+
+        $parameter = sprintf(":%s_%s", $alias, $field);
+
+        if ($operator === 'in' || $operator === 'not in') {
+            $parameter = "($parameter)";
+            $value     = encapsulate($value);
+        }
+
+        $builder
+            ->andWhere(sprintf("%s.%s %s %s", $alias, $field, $operator, $parameter))
+            ->setParameter($parameter, $value)
+        ;
+    }
+
+    protected function mapFieldName(string $class, string $field)
+    {
+        if (!isset($this->mapping[$class][$field])) {
+            throw new \InvalidArgumentException(
+                sprintf("Unable to map field %s of %s into entity field.", $field, $class)
+            );
+        }
+
+        return $this->mapping[$class][$field];
+    }
+}

src/Handler/Database/IdFilterDatabaseHandler.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Handler\Database;
+
+use App\Handler\ModifierHandler;
+use App\Modifier\IdFilter;
+use App\Event\HandleDatabaseModifierEvent;
+use App\Event\HandleModifierEvent;
+use App\Service\IdUtils;
+use function Kadet\Functional\apply;
+
+class IdFilterDatabaseHandler implements ModifierHandler
+{
+    /**
+     * @var IdUtils
+     */
+    private $id;
+
+    public function __construct(IdUtils $id)
+    {
+        $this->id = $id;
+    }
+
+    public function process(HandleModifierEvent $event)
+    {
+        if (!$event instanceof HandleDatabaseModifierEvent) {
+            return;
+        }
+
+        /** @var IdFilter $modifier */
+        $modifier = $event->getModifier();
+        $builder  = $event->getBuilder();
+        $alias    = $event->getMeta()['alias'];
+        $provider = $event->getMeta()['provider'];
+
+        $id       = $modifier->getId();
+        $mapper   = apply([$this->id, 'generate'], $provider);
+
+        $builder
+            ->andWhere($modifier->isMultiple() ? "{$alias} in (:id)" : "{$alias} = :id")
+            ->setParameter(':id', $modifier->isMultiple() ? array_map($mapper, $id) : $mapper($id));
+        ;
+    }
+}

src/Handler/Database/IncludeDestinationsDatabaseHandler.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace App\Handler\Database;
+
+use App\Entity\TrackEntity;
+use App\Event\PostProcessEvent;
+use App\Handler\PostProcessingHandler;
+use App\Model\Destination;
+use App\Model\Stop;
+use App\Service\Converter;
+use App\Service\IdUtils;
+use Doctrine\ORM\EntityManagerInterface;
+use Tightenco\Collect\Support\Collection;
+use Kadet\Functional as f;
+use Kadet\Functional\Transforms as t;
+
+class IncludeDestinationsDatabaseHandler implements PostProcessingHandler
+{
+    private $em;
+    private $converter;
+    private $id;
+
+    public function __construct(EntityManagerInterface $entityManager, Converter $converter, IdUtils $id)
+    {
+        $this->em = $entityManager;
+        $this->converter = $converter;
+        $this->id = $id;
+    }
+
+    public function postProcess(PostProcessEvent $event)
+    {
+        $provider = $event->getMeta()['provider'];
+        $stops = $event
+            ->getData()
+            ->map(t\property('id'))
+            ->map(f\apply([$this->id, 'generate'], $provider))
+            ->all();
+
+        $destinations = collect($this->em->createQueryBuilder()
+            ->select('t', 'tl', 'f', 'fs', 'ts')
+            ->from(TrackEntity::class, 't')
+            ->join('t.stopsInTrack', 'ts')
+            ->join('t.line', 'tl')
+            ->where('ts.stop IN (:stops)')
+            ->join('t.final', 'f')
+            ->join('f.stop', 'fs')
+            ->getQuery()
+            ->execute(['stops' => $stops]))
+            ->reduce(function ($grouped, TrackEntity $track) {
+                foreach ($track->getStopsInTrack()->map(t\property('stop'))->map(t\property('id')) as $stop) {
+                    $grouped[$stop] = ($grouped[$stop] ?? collect())->add($track);
+                }
+
+                return $grouped;
+            }, collect())
+            ->map(function (Collection $tracks) {
+                return $tracks
+                    ->groupBy(function (TrackEntity $track) {
+                        return $track->getFinal()->getStop()->getId();
+                    })->map(function (Collection $tracks, $id) {
+                        return Destination::createFromArray([
+                            'stop'  => $this->converter->convert($tracks->first()->getFinal()->getStop()),
+                            'lines' => $tracks
+                                ->map(t\property('line'))
+                                ->unique(t\property('id'))
+                                ->map(f\ref([$this->converter, 'convert']))
+                                ->values(),
+                        ]);
+                    })->values();
+            });
+
+        $event->getData()->each(function (Stop $stop) use ($provider, $destinations) {
+            $stop->setDestinations($destinations[$this->id->generate($provider, $stop->getId())]);
+        });
+    }
+}

src/Handler/Database/LimitDatabaseHandler.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Handler\Database;
+
+use App\Event\HandleDatabaseModifierEvent;
+use App\Event\HandleModifierEvent;
+use App\Handler\ModifierHandler;
+use App\Modifier\Limit;
+
+class LimitDatabaseHandler implements ModifierHandler
+{
+    public function process(HandleModifierEvent $event)
+    {
+        if (!$event instanceof HandleDatabaseModifierEvent) {
+            return;
+        }
+
+        /** @var Limit $modifier */
+        $modifier = $event->getModifier();
+        $builder  = $event->getBuilder();
+
+        $builder
+            ->setFirstResult($modifier->getOffset())
+            ->setMaxResults($modifier->getCount())
+        ;
+    }
+}

src/Handler/Database/RelatedFilterDatabaseGenericHandler.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace App\Handler\Database;
+
+use App\Event\HandleDatabaseModifierEvent;
+use App\Event\HandleModifierEvent;
+use App\Handler\ModifierHandler;
+use App\Model\Line;
+use App\Model\Stop;
+use App\Model\Track;
+use App\Modifier\RelatedFilter;
+use App\Service\IdUtils;
+use App\Service\ReferenceFactory;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Container\ContainerInterface;
+use Symfony\Contracts\Service\ServiceSubscriberInterface;
+
+class RelatedFilterDatabaseGenericHandler implements ModifierHandler, ServiceSubscriberInterface
+{
+    protected $mapping = [
+        Track::class => [
+            Line::class => 'line',
+            Stop::class => TrackByStopDatabaseHandler::class,
+        ],
+    ];
+
+    private $em;
+    private $inner;
+    private $id;
+    private $references;
+
+    public function __construct(
+        ContainerInterface $inner,
+        EntityManagerInterface $em,
+        IdUtils $idUtils,
+        ReferenceFactory $references
+    ) {
+        $this->inner = $inner;
+        $this->em = $em;
+        $this->id = $idUtils;
+        $this->references = $references;
+    }
+
+    public function process(HandleModifierEvent $event)
+    {
+        if (!$event instanceof HandleDatabaseModifierEvent) {
+            return;
+        }
+
+        /** @var RelatedFilter $modifier */
+        $modifier = $event->getModifier();
+        $builder  = $event->getBuilder();
+        $alias    = $event->getMeta()['alias'];
+        $type     = $event->getMeta()['type'];
+
+        if (!array_key_exists($type, $this->mapping)) {
+            throw new \InvalidArgumentException(
+                sprintf("Relationship filtering for %s is not supported.", $type)
+            );
+        }
+
+        if (!array_key_exists($modifier->getRelationship(), $this->mapping[$type])) {
+            throw new \InvalidArgumentException(
+                sprintf("Relationship %s is not supported for .", $type)
+            );
+        }
+
+        $relationship = $this->mapping[$type][$modifier->getRelationship()];
+
+        if ($this->inner->has($relationship)) {
+            /** @var ModifierHandler $inner */
+            $inner = $this->inner->get($relationship);
+            $inner->process($event);
+            return;
+        }
+
+        $parameter = sprintf(":%s_%s", $alias, $relationship);
+        $reference = $this->references->create($modifier->getRelated(), $event->getMeta()['provider']);
+
+        $builder
+            ->join(sprintf('%s.%s', $alias, $relationship), $relationship)
+            ->andWhere(sprintf("%s = %s", $relationship, $parameter))
+            ->setParameter($parameter, $reference)
+        ;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public static function getSubscribedServices()
+    {
+        return [
+            TrackByStopDatabaseHandler::class,
+        ];
+    }
+}

src/Handler/Database/TrackByStopDatabaseHandler.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Handler\Database;
+
+use App\Entity\StopInTrack;
+use App\Event\HandleDatabaseModifierEvent;
+use App\Event\HandleModifierEvent;
+use App\Handler\ModifierHandler;
+use App\Modifier\RelatedFilter;
+use App\Service\ReferenceFactory;
+
+class TrackByStopDatabaseHandler implements ModifierHandler
+{
+    private $references;
+
+    public function __construct(ReferenceFactory $references)
+    {
+        $this->references = $references;
+    }
+
+    public function process(HandleModifierEvent $event)
+    {
+        if (!$event instanceof HandleDatabaseModifierEvent) {
+            return;
+        }
+
+        /** @var RelatedFilter $modifier */
+        $modifier = $event->getModifier();
+        $builder  = $event->getBuilder();
+        $alias    = $event->getMeta()['alias'];
+
+        $relationship = 'stopsInTrack';
+
+        $parameter = sprintf(":%s_%s", $alias, $relationship);
+        $reference = $this->references->create($modifier->getRelated(), $event->getMeta()['provider']);
+
+        $builder
+            ->join(sprintf("%s.%s", $alias, $relationship), 'stop_in_track')
+            ->andWhere(sprintf("stop_in_track.stop = %s", $parameter))
+            ->setParameter($parameter, $reference)
+        ;
+    }
+}

src/Handler/ModifierHandler.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace App\Handler;
+
+use App\Event\HandleModifierEvent;
+
+interface ModifierHandler
+{
+    public function process(HandleModifierEvent $event);
+}

src/Handler/PostProcessingHandler.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace App\Handler;
+
+use App\Event\PostProcessEvent;
+
+interface PostProcessingHandler
+{
+    public function postProcess(PostProcessEvent $event);
+}

src/Modifier/FieldFilter.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace App\Modifier;
+
+class FieldFilter implements Modifier
+{
+    private $field;
+    private $value;
+    private $operator;
+
+    public function __construct(string $field, $value, string $operator = '=')
+    {
+        $this->field    = $field;
+        $this->value    = $value;
+        $this->operator = $operator;
+    }
+
+    public static function contains(string $field, string $value)
+    {
+        return new static($field, "%$value%", 'LIKE');
+    }
+
+    public function getField(): string
+    {
+        return $this->field;
+    }
+
+    public function getValue()
+    {
+        return $this->value;
+    }
+
+    public function getOperator(): string
+    {
+        return $this->operator;
+    }
+}

src/Modifier/IdFilter.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Modifier;
+
+use App\Exception\InvalidOptionException;
+use App\Modifier\Modifier;
+
+class IdFilter implements Modifier
+{
+    /** @var string|array */
+    private $id;
+
+    public function __construct($id)
+    {
+        if (!is_iterable($id) && !is_string($id)) {
+            throw InvalidOptionException::invalidType('id', $id, ['string', 'array']);
+        }
+
+        $this->id = $id instanceof \Traversable ? iterator_to_array($id) : $id;
+    }
+
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    public function isMultiple()
+    {
+        return is_array($this->id);
+    }
+}

src/Modifier/IncludeDestinations.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace App\Modifier;
+
+class IncludeDestinations implements Modifier
+{
+}

src/Modifier/Limit.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Modifier;
+
+class Limit implements Modifier
+{
+    private $offset;
+    private $count;
+
+    public function __construct(int $offset = 0, ?int $count = null)
+    {
+        $this->offset = $offset;
+        $this->count  = $count;
+    }
+
+    public function getOffset()
+    {
+        return $this->offset;
+    }
+
+    public function getCount()
+    {
+        return $this->count;
+    }
+
+    public static function count(int $count)
+    {
+        return new static(0, $count);
+    }
+}

src/Modifier/Modifier.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace App\Modifier;
+
+interface Modifier
+{
+
+}

src/Modifier/RelatedFilter.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Modifier;
+
+use App\Model\Referable;
+
+class RelatedFilter implements Modifier
+{
+    private $relationship;
+    private $object;
+
+    public function __construct(Referable $object, ?string $relation = null)
+    {
+        $this->object       = $object;
+        $this->relationship = $relation ?: get_class($object);
+    }
+
+    public function getRelationship(): string
+    {
+        return $this->relationship;
+    }
+
+    public function getRelated(): Referable
+    {
+        return $this->object;
+    }
+}

src/Provider/Database/DatabaseRepository.php

@@ -2,15 +2,31 @@
 
 namespace App\Provider\Database;
 
-use App\Entity\Entity;
 use App\Entity\ProviderEntity;
+use App\Event\HandleDatabaseModifierEvent;
+use App\Event\PostProcessEvent;
+use App\Exception\UnsupportedModifierException;
+use App\Handler\Database\IdFilterDatabaseHandler;
+use App\Handler\Database\LimitDatabaseHandler;
+use App\Handler\Database\FieldFilterDatabaseHandler;
+use App\Handler\Database\RelatedFilterDatabaseGenericHandler;
+use App\Handler\ModifierHandler;
+use App\Handler\PostProcessingHandler;
 use App\Model\Referable;
+use App\Modifier\IdFilter;
+use App\Modifier\Limit;
+use App\Modifier\Modifier;
+use App\Modifier\FieldFilter;
+use App\Modifier\RelatedFilter;
+use App\Provider\Repository;
 use App\Service\Converter;
 use App\Service\IdUtils;
 use Doctrine\ORM\EntityManagerInterface;
-use Kadet\Functional as f;
+use Doctrine\ORM\QueryBuilder;
+use Psr\Container\ContainerInterface;
+use Symfony\Contracts\Service\ServiceSubscriberInterface;
 
-class DatabaseRepository
+abstract class DatabaseRepository implements ServiceSubscriberInterface, Repository
 {
     /** @var EntityManagerInterface */
     protected $em;
@@ -24,22 +40,30 @@ class DatabaseRepository
     /** @var Converter */
     protected $converter;
 
+    /** @var ContainerInterface */
+    protected $handlers;
+
     /**
      * DatabaseRepository constructor.
      *
      * @param EntityManagerInterface $em
      */
-    public function __construct(EntityManagerInterface $em, IdUtils $id, Converter $converter)
-    {
+    public function __construct(
+        EntityManagerInterface $em,
+        IdUtils $id,
+        Converter $converter,
+        ContainerInterface $handlers
+    ) {
         $this->em        = $em;
         $this->id        = $id;
         $this->converter = $converter;
+        $this->handlers  = $handlers;
     }
 
     /** @return static */
     public function withProvider(ProviderEntity $provider)
     {
-        $result = clone $this;
+        $result           = clone $this;
         $result->provider = $provider;
 
         return $result;
@@ -56,4 +80,87 @@ class DatabaseRepository
 
         return $this->em->getReference($class, $id);
     }
+
+    protected function processQueryBuilder(QueryBuilder $builder, iterable $modifiers, array $meta = [])
+    {
+        $reducers = [];
+
+        foreach ($modifiers as $modifier) {
+            $handler = $this->getHandler($modifier);
+
+            if ($handler instanceof ModifierHandler) {
+                $event = new HandleDatabaseModifierEvent($modifier, $this, $builder, array_merge([
+                    'provider' => $this->provider,
+                ], $meta));
+
+                $handler->process($event);
+            }
+
+            if ($handler instanceof PostProcessingHandler) {
+                $reducers[] = function ($result) use ($meta, $modifier, $handler) {
+                    $event = new PostProcessEvent($result, $modifier, $this, array_merge([
+                        'provider' => $this->provider,
+                    ], $meta));
+
+                    $handler->postProcess($event);
+
+                    return $event->getData();
+                };
+            }
+
+        }
+
+        return collect($reducers);
+    }
+
+    protected function allFromQueryBuilder(QueryBuilder $builder, iterable $modifiers, array $meta = [])
+    {
+        $reducers = $this->processQueryBuilder($builder, $modifiers, $meta);
+
+        return $reducers->reduce(function ($result, $reducer) {
+            return $reducer($result);
+        }, collect($builder->getQuery()->execute())->map(\Closure::fromCallable([$this, 'convert'])));
+    }
+
+    public function first(Modifier ...$modifiers)
+    {
+        return $this->all(Limit::count(1), ...$modifiers)->first();
+    }
+
+    protected function getHandler(Modifier $modifier)
+    {
+        $class = get_class($modifier);
+
+        if (!$this->handlers->has($class)) {
+            throw UnsupportedModifierException::createFromModifier($modifier, $this);
+        }
+
+        return $this->handlers->get($class);
+    }
+
+    /**
+     * Returns array describing handlers for each modifier type. Syntax is as follows:
+     * [ IdFilter::class => IdFilterDatabaseHandler::class ]
+     *
+     * It is internally used as part of service subscriber.
+     *
+     * @return array
+     */
+    protected static function getHandlers()
+    {
+        return [];
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public static function getSubscribedServices()
+    {
+        return array_merge([
+            IdFilter::class      => IdFilterDatabaseHandler::class,
+            Limit::class         => LimitDatabaseHandler::class,
+            FieldFilter::class   => FieldFilterDatabaseHandler::class,
+            RelatedFilter::class => RelatedFilterDatabaseGenericHandler::class,
+        ], static::getHandlers());
+    }
 }

src/Provider/Database/GenericLineRepository.php

@@ -3,34 +3,32 @@
 namespace App\Provider\Database;
 
 use App\Entity\LineEntity;
+use App\Event\HandleDatabaseModifierEvent;
+use App\Handler\Database\LimitDatabaseHandler;
+use App\Handler\Database\IdFilterDatabaseHandler;
+use App\Handler\ModifierHandler;
 use App\Model\Line;
+use App\Modifier\Limit;
+use App\Modifier\IdFilter;
 use App\Provider\LineRepository;
+use App\Modifier\Modifier;
 use Tightenco\Collect\Support\Collection;
 use Kadet\Functional as f;
 
 class GenericLineRepository extends DatabaseRepository implements LineRepository
 {
-    public function getAll(): Collection
+    public function all(Modifier ...$modifiers): Collection
     {
-        $repository = $this->em->getRepository(LineEntity::class);
-        $lines      = $repository->findAll();
+        $builder = $this->em
+            ->createQueryBuilder()
+            ->from(LineEntity::class, 'line')
+            ->select('line')
+        ;
 
-        return collect($lines)->map(f\ref([$this, 'convert']));
+        return $this->allFromQueryBuilder($builder, $modifiers, [
+            'alias'  => 'line',
+            'entity' => LineEntity::class,
+            'type'   => Line::class,
+        ]);
     }
-
-    public function getById($id): ?Line
-    {
-        $repository = $this->em->getRepository(LineEntity::class);
-        return $this->convert($repository->find($id));
-    }
-
-    public function getManyById($ids): Collection
-    {
-        $ids = collect($ids)->map(f\apply(f\ref([$this->id, 'generate']), $this->provider));
-
-        $repository = $this->em->getRepository(LineEntity::class);
-        $lines      = $repository->findBy(['id' => $ids->all()]);
-
-        return collect($lines)->map(f\ref([$this, 'convert']));
-    }
-}
+}

src/Provider/Database/GenericOperatorRepository.php

@@ -2,32 +2,26 @@
 
 namespace App\Provider\Database;
 
+use App\Entity\OperatorEntity;
 use App\Model\Operator;
+use App\Modifier\Modifier;
 use App\Provider\OperatorRepository;
 use Tightenco\Collect\Support\Collection;
 
 class GenericOperatorRepository extends DatabaseRepository implements OperatorRepository
 {
-    public function getAll(): Collection
+    public function all(Modifier ...$modifiers): Collection
     {
-        $repository = $this->em->getRepository(Operator::class);
-        $operators = $repository->findAll();
+        $builder = $this->em
+            ->createQueryBuilder()
+            ->from(OperatorEntity::class, 'operator')
+            ->select('operator')
+        ;
 
-        return collect($operators);
+        return $this->allFromQueryBuilder($builder, $modifiers, [
+            'alias'  => 'operator',
+            'entity' => OperatorEntity::class,
+            'type'   => Operator::class,
+        ]);
     }
-
-    public function getById($id): ?Operator
-    {
-        $repository = $this->em->getRepository(Operator::class);
-
-        return $repository->find($id);
-    }
-
-    public function getManyById($ids): Collection
-    {
-        $repository = $this->em->getRepository(Operator::class);
-        $operators  = $repository->findBy(['id' => $ids]);
-
-        return collect($operators);
-    }
-}
+}

src/Provider/Database/GenericScheduleRepository.php

@@ -70,4 +70,9 @@ class GenericScheduleRepository extends DatabaseRepository implements ScheduleRe
             ]);
         });
     }
+
+    protected static function getHandlers()
+    {
+        return [];
+    }
 }

src/Provider/Database/GenericStopRepository.php

@@ -3,84 +3,34 @@
 namespace App\Provider\Database;
 
 use App\Entity\StopEntity;
-use App\Entity\TrackEntity;
-use App\Model\Destination;
+use App\Handler\Database\IncludeDestinationsDatabaseHandler;
 use App\Model\Stop;
+use App\Modifier\Modifier;
+use App\Modifier\IncludeDestinations;
 use App\Provider\StopRepository;
-use Kadet\Functional as f;
-use Kadet\Functional\Transforms as t;
 use Tightenco\Collect\Support\Collection;
 
 class GenericStopRepository extends DatabaseRepository implements StopRepository
 {
-    public function getAll(): Collection
+    public function all(Modifier ...$modifiers): Collection
     {
-        $stops = $this->em->getRepository(StopEntity::class)->findAll();
+        $builder = $this->em
+            ->createQueryBuilder()
+            ->from(StopEntity::class, 'stop')
+            ->select('stop')
+        ;
 
-        return collect($stops)->map(f\ref([$this, 'convert']));
+        return $this->allFromQueryBuilder($builder, $modifiers, [
+            'alias'  => 'stop',
+            'entity' => StopEntity::class,
+            'type'   => Stop::class,
+        ]);
     }
 
-    public function getById($id): ?Stop
+    protected static function getHandlers()
     {
-        $id   = $this->id->generate($this->provider, $id);
-        $stop = $this->em->getRepository(StopEntity::class)->find($id);
-
-        return $this->convert($stop);
-    }
-
-    public function getManyById($ids): Collection
-    {
-        $ids   = collect($ids)->map(f\apply(f\ref([$this->id, 'generate']), $this->provider));
-        $stops = $this->em->getRepository(StopEntity::class)->findBy(['id' => $ids->all()]);
-
-        return collect($stops)->map(f\ref([$this, 'convert']));
-    }
-
-    public function findByName(string $name): Collection
-    {
-        $query = $this->em->createQueryBuilder()
-            ->select('s')
-            ->from(StopEntity::class, 's')
-            ->where('s.name LIKE :name')
-            ->getQuery();
-
-        $stops = collect($query->execute([':name' => "%$name%"]));
-
-        $destinations = collect($this->em->createQueryBuilder()
-            ->select('t', 'tl', 'f', 'fs', 'ts')
-            ->from(TrackEntity::class, 't')
-            ->join('t.stopsInTrack', 'ts')
-            ->join('t.line', 'tl')
-            ->where('ts.stop IN (:stops)')
-            ->join('t.final', 'f')
-            ->join('f.stop', 'fs')
-            ->getQuery()
-            ->execute(['stops' => $stops->map(t\property('id'))->all()]))
-            ->reduce(function ($grouped, TrackEntity $track) {
-                foreach ($track->getStopsInTrack()->map(t\property('stop'))->map(t\property('id')) as $stop) {
-                    $grouped[$stop] = ($grouped[$stop] ?? collect())->add($track);
-                }
-
-                return $grouped;
-            }, collect())
-            ->map(function (Collection $tracks) {
-                return $tracks
-                    ->groupBy(function (TrackEntity $track) {
-                        return $track->getFinal()->getStop()->getId();
-                    })->map(function (Collection $tracks, $id) {
-                        return Destination::createFromArray([
-                            'stop'  => $this->convert($tracks->first()->getFinal()->getStop()),
-                            'lines' => $tracks
-                                ->map(t\property('line'))
-                                ->unique(t\property('id'))
-                                ->map(f\ref([$this, 'convert']))
-                                ->values(),
-                        ]);
-                    })->values();
-            });
-
-        return collect($stops)->map(f\ref([$this, 'convert']))->each(function (Stop $stop) use ($destinations) {
-            $stop->setDestinations($destinations[$this->id->generate($this->provider, $stop->getId())]);
-        });
+        return array_merge(parent::getHandlers(), [
+            IncludeDestinations::class => IncludeDestinationsDatabaseHandler::class,
+        ]);
     }
 }

src/Provider/Database/GenericTrackRepository.php

@@ -2,36 +2,18 @@
 
 namespace App\Provider\Database;
 
-use App\Entity\LineEntity;
 use App\Entity\StopEntity;
 use App\Entity\StopInTrack;
 use App\Entity\TrackEntity;
-use function App\Functions\encapsulate;
-use App\Model\Stop;
+use App\Modifier\Modifier;
 use App\Model\Track;
 use App\Provider\TrackRepository;
 use Tightenco\Collect\Support\Collection;
 use Kadet\Functional as f;
+use function App\Functions\encapsulate;
 
 class GenericTrackRepository extends DatabaseRepository implements TrackRepository
 {
-    public function getAll(): Collection
-    {
-        $tracks = $this->em->getRepository(TrackEntity::class)->findAll();
-
-        return collect($tracks)->map(f\ref([$this, 'convert']));
-    }
-
-    public function getById($id): Track
-    {
-        // TODO: Implement getById() method.
-    }
-
-    public function getManyById($ids): Collection
-    {
-        // TODO: Implement getManyById() method.
-    }
-
     public function getByStop($stop): Collection
     {
         $reference = f\apply(f\ref([$this, 'reference']), StopEntity::class);
@@ -49,19 +31,17 @@ class GenericTrackRepository extends DatabaseRepository implements TrackReposito
         });
     }
 
-    public function getByLine($line): Collection
+    public function all(Modifier ...$modifiers): Collection
     {
-        $reference = f\apply(f\ref([$this, 'reference']), LineEntity::class);
+        $builder = $this->em
+            ->createQueryBuilder()
+            ->from(TrackEntity::class, 'track')
+            ->select('track');
 
-        $tracks = $this->em->createQueryBuilder()
-            ->from(StopInTrack::class, 'st')
-            ->join('st.track', 't')
-            ->join('t.stops', 's')
-            ->where('st.line in (:line)')
-            ->select(['st', 't', 's'])
-            ->getQuery()
-            ->execute(['stop' => array_map($reference, encapsulate($line))]);
-
-        return collect($tracks)->map(f\ref([$this, 'convert']));
+        return $this->allFromQueryBuilder($builder, $modifiers, [
+            'alias'  => 'track',
+            'entity' => TrackEntity::class,
+            'type'   => Track::class,
+        ]);
     }
-}
+}

src/Provider/Database/GenericTripRepository.php

@@ -4,25 +4,25 @@ namespace App\Provider\Database;
 
 use App\Entity\TripEntity;
 use App\Model\Trip;
+use App\Modifier\Modifier;
 use App\Provider\TripRepository;
+use Tightenco\Collect\Support\Collection;
 
 class GenericTripRepository extends DatabaseRepository implements TripRepository
 {
-    public function getById(string $id): Trip
+    public function all(Modifier ...$modifiers): Collection
     {
-        $id   = $this->id->generate($this->provider, $id);
-
-        $trip = $this->em
+        $builder = $this->em
             ->createQueryBuilder()
-            ->from(TripEntity::class, 't')
-            ->join('t.stops', 'ts')
+            ->from(TripEntity::class, 'trip')
+            ->join('trip.stops', 'ts')
             ->join('ts.stop', 's')
-            ->select('t', 'ts')
-            ->where('t.id = :id')
-            ->getQuery()
-            ->setParameter('id', $id)
-            ->getOneOrNullResult();
+            ->select('t', 'ts');
 
-        return $this->convert($trip);
+        return $this->allFromQueryBuilder($builder, $modifiers, [
+            'alias'  => 'trip',
+            'entity' => TripEntity::class,
+            'type'   => Trip::class,
+        ]);
     }
 }

src/Provider/Dummy/DummyStopRepository.php

@@ -3,6 +3,7 @@
 namespace App\Provider\Dummy;
 
 use App\Model\Stop;
+use App\Modifier\Modifier;
 use App\Provider\StopRepository;
 use App\Service\Proxy\ReferenceFactory;
 use Tightenco\Collect\Support\Collection;
@@ -41,4 +42,14 @@ class DummyStopRepository implements StopRepository
     {
         return collect();
     }
+
+    public function first(Modifier ...$modifiers)
+    {
+        // TODO: Implement first() method.
+    }
+
+    public function all(Modifier ...$modifiers): Collection
+    {
+        // TODO: Implement all() method.
+    }
 }

src/Provider/FluentRepository.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace App\Provider;
+
+use App\Modifier\Modifier;
+use Tightenco\Collect\Support\Collection;
+
+interface FluentRepository extends Repository
+{
+    public function first(Modifier ...$modifiers);
+    public function all(Modifier ...$modifiers): Collection;
+}

src/Provider/LineRepository.php

@@ -3,14 +3,6 @@
 
 namespace App\Provider;
 
-
-use App\Model\Line;
-use Tightenco\Collect\Support\Collection;
-
-interface LineRepository extends Repository
+interface LineRepository extends FluentRepository
 {
-    public function getAll(): Collection;
-
-    public function getById($id): ?Line;
-    public function getManyById($ids): Collection;
-}
+}

src/Provider/OperatorRepository.php

@@ -7,9 +7,6 @@ namespace App\Provider;
 use App\Model\Operator;
 use Tightenco\Collect\Support\Collection;
 
-interface OperatorRepository
+interface OperatorRepository extends FluentRepository
 {
-    public function getAll(): Collection;
-    public function getById($id): ?Operator;
-    public function getManyById($ids): Collection;
-}
+}

src/Provider/Repository.php

@@ -6,5 +6,4 @@ namespace App\Provider;
 
 interface Repository
 {
-
-}
+}

src/Provider/StopRepository.php

@@ -7,10 +7,6 @@ namespace App\Provider;
 use App\Model\Stop;
 use Tightenco\Collect\Support\Collection;
 
-interface StopRepository extends Repository
+interface StopRepository extends FluentRepository
 {
-    public function getAll(): Collection;
-    public function getById($id): ?Stop;
-    public function getManyById($ids): Collection;
-    public function findByName(string $name): Collection;
 }

src/Provider/TrackRepository.php

@@ -5,13 +5,7 @@ namespace App\Provider;
 use App\Model\Track;
 use Tightenco\Collect\Support\Collection;
 
-interface TrackRepository
+interface TrackRepository extends FluentRepository
 {
-    public function getAll(): Collection;
-
-    public function getById($id): Track;
-    public function getManyById($ids): Collection;
-
     public function getByStop($stop): Collection;
-    public function getByLine($line): Collection;
-}
+}

src/Provider/TripRepository.php

@@ -4,7 +4,6 @@ namespace App\Provider;
 
 use App\Model\Trip;
 
-interface TripRepository
+interface TripRepository extends FluentRepository
 {
-    public function getById(string $id): Trip;
 }

src/Provider/ZtmGdansk/ZtmGdanskDepartureRepository.php

@@ -6,6 +6,7 @@ use App\Model\Departure;
 use App\Model\Line;
 use App\Model\Stop;
 use App\Model\Vehicle;
+use App\Modifier\IdFilter;
 use App\Provider\Database\GenericScheduleRepository;
 use App\Provider\DepartureRepository;
 use App\Provider\LineRepository;
@@ -65,7 +66,8 @@ class ZtmGdanskDepartureRepository implements DepartureRepository
         $lines = $estimates->map(function ($delay) {
             return $delay['routeId'];
         })->unique();
-        $lines = $this->lines->getManyById($lines)->keyBy(t\property('id'));
+
+        $lines = $this->lines->all(new IdFilter($lines))->keyBy(t\property('id'));
 
         return collect($estimates)->map(function ($delay) use ($stop, $lines) {
             $scheduled = (new Carbon($delay['theoreticalTime'], 'Europe/Warsaw'))->tz('UTC');

src/Service/IdUtils.php

@@ -11,6 +11,7 @@ class IdUtils
 
     public function generate(ProviderEntity $provider, $id)
     {
+        // todo: use array cache if not fast enough
         return sprintf('%s%s%s', $provider->getId(), self::DELIMITER, $id);
     }
 
@@ -23,4 +24,4 @@ class IdUtils
     {
         return $this->strip($entity->getId());
     }
-}
+}

src/Service/ReferenceFactory.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace App\Service;
+
+use App\Entity\LineEntity;
+use App\Entity\ProviderEntity;
+use App\Entity\StopEntity;
+use App\Model\Line;
+use App\Model\Referable;
+use App\Model\Stop;
+use Doctrine\ORM\EntityManagerInterface;
+
+final class ReferenceFactory
+{
+    protected $mapping = [
+        Line::class => LineEntity::class,
+        Stop::class => StopEntity::class,
+    ];
+
+    private $em;
+    private $id;
+
+    public function __construct(EntityManagerInterface $em, IdUtils $id)
+    {
+        $this->em = $em;
+        $this->id = $id;
+    }
+
+    public function create(Referable $object, ProviderEntity $provider)
+    {
+        $class = get_class($object);
+
+        if (!array_key_exists($class, $this->mapping)) {
+            throw new \InvalidArgumentException(sprintf("Cannot make entity reference of %s.", $class));
+        }
+
+        return $this->em->getReference(
+            $this->mapping[$class],
+            $this->id->generate($provider, $object->getId())
+        );
+    }
+}