<?php

/*
 * Chill is a software for social workers
 * Copyright (C) 2019 Champs Libres <info@champs-libres.coop>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

namespace Chill\EventBundle\Timeline;

use Chill\EventBundle\Entity\Event;
use Chill\MainBundle\Entity\Scope;
use Chill\MainBundle\Timeline\TimelineProviderInterface;
use Doctrine\ORM\EntityManager;
use Chill\MainBundle\Security\Authorization\AuthorizationHelper;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
use Symfony\Component\Security\Core\Role\Role;
use Doctrine\ORM\Mapping\ClassMetadata;
use Chill\PersonBundle\Entity\Person;
use Chill\MainBundle\Entity\User;

/**
 * Class TimelineEventProvider
 *
 * @package Chill\EventBundle\Timeline
 * @author  Mathieu Jaumotte jaum_mathieu@collectifs.net
 */
class TimelineEventProvider implements TimelineProviderInterface
{
    /**
     * @var EntityManager
     */
    protected $em;
    
    /**
     * @var AuthorizationHelper
     */
    protected $helper;
    
    /**
     * @var User
     */
    protected $user;
    
    /**
     * TimelineEventProvider constructor.
     *
     * @param EntityManager $em
     * @param AuthorizationHelper $helper
     * @param TokenStorageInterface $storage
     */
    public function __construct(
        EntityManager $em,
        AuthorizationHelper $helper,
        TokenStorageInterface $storage
    ) {
        $this->em = $em;
        $this->helper = $helper;
        if (!$storage->getToken()->getUser() instanceof User) {
            throw new \RuntimeException('A user should be authenticated !');
        }
        $this->user = $storage->getToken()->getUser();
    }
    
    /**
     * @param string $context
     * @param array $args
     * @return array|string[]
     * @throws \Doctrine\ORM\Mapping\MappingException
     */
    public function fetchQuery($context, array $args)
    {
        $this->checkContext($context);
        
        $metadataEvent = $this->em->getClassMetadata('ChillEventBundle:Event');
        $metadataParticipation = $this->em->getClassMetadata('ChillEventBundle:Participation');
        $metadataPerson = $this->em->getClassMetadata('ChillPersonBundle:Person');
        
        $query = array(
            'id' => $metadataEvent->getTableName().'.'.$metadataEvent->getColumnName('id'),
            'type' => 'event',
            'date' => $metadataEvent->getTableName().'.'.$metadataEvent->getColumnName('date'),
            'FROM' => $this->getFromClause($metadataEvent, $metadataParticipation, $metadataPerson),
            'WHERE' => $this->getWhereClause($metadataEvent, $metadataParticipation, $metadataPerson, $args['person'])
        );
        
        return $query;
    }
    
    /**
     * @param ClassMetadata $metadataEvent
     * @param ClassMetadata $metadataParticipation
     * @param ClassMetadata $metadataPerson
     * @return string
     * @throws \Doctrine\ORM\Mapping\MappingException
     */
    private function getFromClause(
        ClassMetadata $metadataEvent,
        ClassMetadata $metadataParticipation,
        ClassMetadata $metadataPerson
    ) {
        $eventParticipationMapping = $metadataParticipation->getAssociationMapping('event');
        $participationPersonMapping = $metadataParticipation->getAssociationMapping('person');
        
        return $metadataEvent->getTableName()

            .' JOIN '.$metadataParticipation->getTableName()
            .' ON '  .$metadataParticipation->getTableName()
            .'.'     .$eventParticipationMapping['joinColumns'][0]['name']
            .' = '   .$metadataEvent->getTableName()
            .'.'     .$eventParticipationMapping['joinColumns'][0]['referencedColumnName']

            .' JOIN '.$metadataPerson->getTableName()
            .' ON '  .$metadataPerson->getTableName()
            .'.'     .$participationPersonMapping['joinColumns'][0]['referencedColumnName']
            .' = '   .$metadataParticipation->getTableName()
            .'.'     .$participationPersonMapping['joinColumns'][0]['name']
            ;
    }
    
    /**
     * @param ClassMetadata $metadataEvent
     * @param ClassMetadata $metadataParticipation
     * @param ClassMetadata $metadataPerson
     * @param Person $person
     * @return string
     * @throws \Doctrine\ORM\Mapping\MappingException
     */
    private function getWhereClause(
        ClassMetadata $metadataEvent,
        ClassMetadata $metadataParticipation,
        ClassMetadata $metadataPerson,
        Person $person
    ) {
        $role = new Role('CHILL_EVENT_SEE');
        
        $reachableCenters = $this->helper->getReachableCenters($this->user, $role);
        $associationMapping = $metadataParticipation->getAssociationMapping('person');
        
        if (count($reachableCenters) === 0) {
            return 'FALSE = TRUE';
        }
    
        $whereClause = sprintf( '%s = %d',
            $associationMapping['joinColumns'][0]['name'],
            $person->getId());
        
        // and
        $centerAndScopeLines = array();
        foreach ($reachableCenters as $center) {
            $reachableCircleId = array_map(
                function (Scope $scope) { return $scope->getId(); },
                $this->helper->getReachableCircles($this->user, $role, $person->getCenter())
            );
            $centerAndScopeLines[] = sprintf(
                '(%s = %d AND %s IN (%s))',
                $metadataPerson->getTableName() . '.' .
                $metadataPerson->getAssociationMapping('center')['joinColumns'][0]['name'],
                $center->getId(),
                $metadataEvent->getTableName() . '.' .
                $metadataEvent->getAssociationMapping('circle')['joinColumns'][0]['name'],
                implode(',', $reachableCircleId)
            );
        }
        $whereClause .= ' AND ('. implode(' OR ', $centerAndScopeLines) .')';
        
        return $whereClause;
    }
    
    /**
     * check if the context is supported
     *
     * @param string $context
     * @throws \LogicException if the context is not supported
     */
    private function checkContext($context)
    {
        if ($context !== 'person') {
            throw new \LogicException("The context '$context' is not "
                . "supported. Currently only 'person' is supported");
        }
    }
    
    /**
     * @param string $type
     * @return bool
     */
    public function supportsType($type)
    {
        return $type === 'event';
    }
    
    /**
     * @param array $ids
     * @return array|mixed[]
     */
    public function getEntities(array $ids) {
    
        $events = $this->em->getRepository(Event::class)
            ->findBy(array('id' => $ids));
        
        $result = array();
        foreach ($events as $event) {
            $result[$event->getId()] = $event;
        }
        return $result;
    }
    
    /**
     * @param Event $entity
     * @param string $context
     * @param array $args
     * @return array|mixed[]
     */
    public function getEntityTemplate($entity, $context, array $args) {
    
        $this->checkContext($context);
        
        return array(
            'template' => 'ChillEventBundle:Timeline:event_person_context.html.twig',
            'template_data' => array(
                'event' => $entity,
                'person' => $args['person'],
                'user' => $this->user
            )
        );
    }
    
}