<?php

declare(strict_types=1);

namespace Chill\Migrations\Person;

use Doctrine\DBAL\Schema\Schema;
use Doctrine\Migrations\AbstractMigration;

/**
 * Change model relation between Person and AccompagnyingPeriod
 * Migrate datas into new join table
 *
 * @author Mathieu Jaumotte mathieu.jaumotte@champs-libres.coop
 */
final class Version20210326113045 extends AbstractMigration
{
    private $datas = [];
    
    public function getDescription() : string
    {
        return 'Change model relation between Person and AccompagnyingPeriod, without losing datas when going up';
    }
    
    /**
     *  In these direction, there is no loss.
     */
    public function up(Schema $schema) : void
    {
        // create join table
        $this->addSql('CREATE TABLE persons_accompanying_periods (person_id INT NOT NULL, accompanyingperiod_id INT NOT NULL, PRIMARY KEY(person_id, accompanyingperiod_id))');
        $this->addSql('CREATE INDEX IDX_49A3871F217BBB47 ON persons_accompanying_periods (person_id)');
        $this->addSql('CREATE INDEX IDX_49A3871F550B0C53 ON persons_accompanying_periods (accompanyingperiod_id)');
        $this->addSql('ALTER TABLE persons_accompanying_periods ADD CONSTRAINT FK_49A3871F217BBB47 FOREIGN KEY (person_id) REFERENCES chill_person_person (id) ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE');
        $this->addSql('ALTER TABLE persons_accompanying_periods ADD CONSTRAINT FK_49A3871F550B0C53 FOREIGN KEY (accompanyingperiod_id) REFERENCES chill_person_accompanying_period (id) ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE');
    
        // insert datas in new join table
        $this->addSql('INSERT INTO persons_accompanying_periods (person_id, accompanyingperiod_id) '
            . 'SELECT person_id, id as accompagnying_period_id FROM chill_person_accompanying_period WHERE person_id IS NOT NULL');
        
        // drop column
        $this->addSql('DROP INDEX idx_64a4a621217bbb47');
        $this->addSql('ALTER TABLE chill_person_accompanying_period DROP CONSTRAINT fk_64a4a621217bbb47');
        $this->addSql('ALTER TABLE chill_person_accompanying_period DROP person_id');
    }
    
    /**
     *  The distinct clause makes that for each group of duplicates, it keeps only the first row in the returned result set.
     *  Then we have only few lost datas. Lost datas: when many persons for one AccompanyingPeriod (keep only first person)
     */
    public function down(Schema $schema) : void
    {
        // add column
        $this->addSql('ALTER TABLE chill_person_accompanying_period ADD person_id INT DEFAULT NULL');
        $this->addSql('ALTER TABLE chill_person_accompanying_period ADD CONSTRAINT fk_64a4a621217bbb47 FOREIGN KEY (person_id) REFERENCES chill_person_person (id) NOT DEFERRABLE INITIALLY IMMEDIATE');
        $this->addSql('CREATE INDEX idx_64a4a621217bbb47 ON chill_person_accompanying_period (person_id)');

        // insert datas in existing table
        $this->addSql('UPDATE chill_person_accompanying_period AS ap '
            . 'SET person_id = jt.person_id '
            . 'FROM ( '
            .   'SELECT DISTINCT ON (accompanyingperiod_id) accompanyingperiod_id AS id, person_id FROM persons_accompanying_periods '
            .   'ORDER BY id, person_id ASC '
            . ') AS jt '
            . 'WHERE ap.id = jt.id');
        
        // drop join table
        $this->addSql('DROP TABLE persons_accompanying_periods');
    }
}