<?php

/*
 * Chill is a software for social workers
 * Copyright (C) 2015 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\ReportBundle\Timeline;

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\Scope;
use Chill\CustomFieldsBundle\Service\CustomFieldsHelper;
use Chill\ReportBundle\Entity\Report;
use Symfony\Component\Security\Core\Security;
use Chill\MainBundle\Timeline\TimelineSingleQuery;

/**
 * Provide report for inclusion in timeline
 */
class TimelineReportProvider implements TimelineProviderInterface
{
    
    protected EntityManager $em;
    
    protected AuthorizationHelper $helper;
    
    protected CustomFieldsHelper $customFieldsHelper;
    
    protected $showEmptyValues;
    
    public function __construct(
        EntityManager $em,
        AuthorizationHelper $helper,
        Security $security,
        CustomFieldsHelper $customFieldsHelper,
        $showEmptyValues
    )
    {
        $this->em = $em;
        $this->helper = $helper;
        $this->security = $security;
        $this->customFieldsHelper = $customFieldsHelper;
        $this->showEmptyValues = $showEmptyValues;
    }
    
    /**
     * 
     * {@inheritDoc}
     */
    public function fetchQuery($context, array $args)
    {
        $this->checkContext($context);
        
        $report = $this->em->getClassMetadata(Report::class);
        [$where, $parameters] = $this->getWhereClause($context, $args);

        return TimelineSingleQuery::fromArray([
           'id' => $report->getTableName()
                .'.'.$report->getColumnName('id'),
           'type' => 'report',
           'date' => $report->getTableName()
                .'.'.$report->getColumnName('date'),
           'FROM' => $this->getFromClause($context),
           'WHERE' => $where,
           'parameters' => $parameters
       ]);
    }
    
    private function getWhereClause(string $context, array $args): array
    {
        switch ($context) {
            case 'person':
                return $this->getWhereClauseForPerson($context, $args);
            case 'center':
                return $this->getWhereClauseForCenter($context, $args);
            default:
                throw new \UnexpectedValueException("This context $context is not implemented");
        }
    }

    private function getWhereClauseForCenter(string $context, array $args): array
    {
        $report = $this->em->getClassMetadata(Report::class);
        $person = $this->em->getClassMetadata(Person::class);
        $role = new Role('CHILL_REPORT_SEE');
        $reachableCenters = $this->helper->getReachableCenters($this->security->getUser(), 
                $role);
        $reportPersonId = $report->getAssociationMapping('person')['joinColumns'][0]['name'];
        $reportScopeId = $report->getAssociationMapping('scope')['joinColumns'][0]['name'];
        $personCenterId = $person->getAssociationMapping('center')['joinColumns'][0]['name'];
        // parameters for the query, will be filled later
        $parameters = [];

        // the clause, that will be joined with an "OR"
        $centerScopesClause = "({person}.{center_id} = ? ".
            "AND {report}.{scopes_id} IN ({scopes_ids}))";
        // container for formatted clauses
        $formattedClauses = [];

        $askedCenters = $args['centers'];
        foreach ($reachableCenters as $center) {
            if (FALSE === \in_array($center, $askedCenters)) {
                continue;
            }

            // add the center id to the parameters
            $parameters[] = $center->getId(); 
            // loop over scopes
            $scopeIds = [];
            foreach ($this->helper->getReachableScopes($this->security->getUser(), 
                $role, $center) as $scope) {
                if (\in_array($scope->getId(), $scopeIds)) {
                    continue; 
                }
                $scopeIds[] = $scope->getId();
            }

            $formattedClauses[] = \strtr($centerScopesClause, [
                '{scopes_ids}' => \implode(', ', \array_fill(0, \count($scopeIds), '?'))
            ]);
            // append $scopeIds to parameters
            $parameters = \array_merge($parameters, $scopeIds);
        }

        if (0 === count($formattedClauses)) {
            return [ 'FALSE = TRUE', [] ];
        }

        return [
            \strtr(
                \implode(' OR ', $formattedClauses),
                [
                    '{person}' => $person->getTableName(),
                    '{center_id}' => $personCenterId,
                    '{report}' => $report->getTableName(),
                    '{scopes_id}' => $reportScopeId,
                ]
            ),
            $parameters
        ];
    }

    private function getWhereClauseForPerson(string $context, array $args): array
    {
        $report = $this->em->getClassMetadata(Report::class);
        $person = $this->em->getClassMetadata(Person::class);
        $role = new Role('CHILL_REPORT_SEE');
        $reportPersonId = $report->getAssociationMapping('person')['joinColumns'][0]['name'];
        $reportScopeId = $report->getAssociationMapping('scope')['joinColumns'][0]['name'];
        $personCenterId = $person->getAssociationMapping('center')['joinColumns'][0]['name'];
        // parameters for the query, will be filled later
        $parameters = [ $args['person']->getId() ];

        // this is the final clause  that we are going to fill
        $clause = "{report}.{person_id} = ? AND {report}.{scopes_id} IN ({scopes_ids})";
        // iterate over reachable scopes
        $scopes = $this->helper->getReachableScopes($this->security->getUser(), $role, 
            $args['person']->getCenter());

        foreach ($scopes as $scope) {
            if (\in_array($scope->getId(), $parameters)) {
                continue;
            }

            $parameters[] = $scope->getId();
        }

        if (1 === count($parameters)) {
            // nothing change, we simplify the clause
            $clause = "{report}.{person_id} = ? AND FALSE = TRUE";
        }

        return [
            \strtr(
                $clause,
                [
                    '{report}' => $report->getTableName(),
                    '{person_id}' => $reportPersonId, 
                    '{scopes_id}' => $reportScopeId,
                    '{scopes_ids}' => \implode(', ', 
                        \array_fill(0, \count($parameters)-1, '?'))
                ]
            ),
            $parameters
        ];
    }
    
    private function getFromClause(string $context): string
    {
        $report = $this->em->getClassMetadata(Report::class);
        $person = $this->em->getClassMetadata(Person::class);
        $reportPersonId = $report
            ->getAssociationMapping('person')['joinColumns'][0]['name']
            ;
        $personId = $report
            ->getAssociationMapping('person')['joinColumns'][0]['referencedColumnName']
            ;

        $clause = "{report} ".
            "JOIN {person} ON {report}.{person_id} = {person}.{id_person} ";

        return \strtr($clause,
            [
                '{report}' => $report->getTableName(),
                '{person}' => $person->getTableName(),
                '{person_id}' => $reportPersonId,
                '{id_person}' => $personId
            ]
        );
    }

    /**
     * 
     * {@inheritDoc}
     */
    public function getEntities(array $ids)
    {
        $reports = $this->em->getRepository('ChillReportBundle:Report')
              ->findBy(array('id' => $ids));
        
        $result = array();
        foreach($reports as $report) {
            $result[$report->getId()] = $report;
        }
        
        return $result;
    }

    /**
     * 
     * {@inheritDoc}
     */
    public function getEntityTemplate($entity, $context, array $args)
    {
        $this->checkContext($context);
        
        return array(
           'template' => 'ChillReportBundle:Timeline:report.html.twig',
           'template_data' => array(
               'report' => $entity,
               'context' => $context,
               'custom_fields_in_summary' => $this->getFieldsToRender($entity, $context),
           )
        );
    }
    
    protected function getFieldsToRender(Report $entity, $context, array $args = array())
    {
        //gather all custom fields which should appears in summary
        $gatheredFields = array();
        
        if (array_key_exists('summary_fields', $entity->getCFGroup()->getOptions())) {
            // keep in memory title
            $title = null;
            $subtitle = null;
            
            foreach ($entity->getCFGroup()->getCustomFields() as $customField) {
                if (in_array($customField->getSlug(), 
                      $entity->getCFGroup()->getOptions()['summary_fields'])) {
                    // if we do not want to show empty values
                    if ($this->showEmptyValues === false) {
                        if ($customField->getType() === 'title') {
                            $options = $customField->getOptions();
                            switch($options['type']) {
                                case 'title': $title = $customField; break;
                                case 'subtitle': $subtitle = $customField; break;
                            }
                        } else {
                            if ($this->customFieldsHelper->isEmptyValue($entity->getCFData(), $customField)
                                === false) {
                                if ($title !== NULL) {
                                    $gatheredFields[] = $title;
                                    $title = null;
                                }
                                if ($subtitle !== NULL) {
                                    $gatheredFields[] = $subtitle;
                                    $subtitle = null;
                                }
                            $gatheredFields[] = $customField;
                            }
                        }
                    } else {
                        $gatheredFields[] = $customField;
                    }
                }
            }
        }
        
        return $gatheredFields;
        
    }

    /**
     * 
     * {@inheritDoc}
     */
    public function supportsType($type)
    {
        return $type === 'report';
    }
    
    /**
     * check if the context is supported
     * 
     * @param string $context
     * @throws \LogicException if the context is not supported
     */
    private function checkContext($context)
    {
        if ($context !== 'person' && $context !== 'center') {
            throw new \LogicException("The context '$context' is not "
                  . "supported. Currently only 'person' and 'center' is supported");
        }
    }

}