<?php

namespace Doctrine\DBAL\Types;

use DateTime;
use DateTimeInterface;
use Doctrine\DBAL\Platforms\AbstractPlatform;

/**
 * DateTime type saving additional timezone information.
 *
 * Caution: Databases are not necessarily experts at storing timezone related
 * data of dates. First, of all the supported vendors only PostgreSQL and Oracle
 * support storing Timezone data. But those two don't save the actual timezone
 * attached to a DateTime instance (for example "Europe/Berlin" or "America/Montreal")
 * but the current offset of them related to UTC. That means depending on daylight saving times
 * or not you may get different offsets.
 *
 * This datatype makes only sense to use, if your application works with an offset, not
 * with an actual timezone that uses transitions. Otherwise your DateTime instance
 * attached with a timezone such as Europe/Berlin gets saved into the database with
 * the offset and re-created from persistence with only the offset, not the original timezone
 * attached.
 */
class DateTimeTzType extends Type implements PhpDateTimeMappingType
{
    /**
     * {@inheritdoc}
     */
    public function getName()
    {
        return Type::DATETIMETZ;
    }

    /**
     * {@inheritdoc}
     */
    public function getSQLDeclaration(array $fieldDeclaration, AbstractPlatform $platform)
    {
        return $platform->getDateTimeTzTypeDeclarationSQL($fieldDeclaration);
    }

    /**
     * {@inheritdoc}
     */
    public function convertToDatabaseValue($value, AbstractPlatform $platform)
    {
        if ($value === null) {
            return $value;
        }

        if ($value instanceof DateTimeInterface) {
            return $value->format($platform->getDateTimeTzFormatString());
        }

        throw ConversionException::conversionFailedInvalidType($value, $this->getName(), ['null', 'DateTime']);
    }

    /**
     * {@inheritdoc}
     */
    public function convertToPHPValue($value, AbstractPlatform $platform)
    {
        if ($value === null || $value instanceof DateTimeInterface) {
            return $value;
        }

        $val = DateTime::createFromFormat($platform->getDateTimeTzFormatString(), $value);
        if (! $val) {
            throw ConversionException::conversionFailedFormat($value, $this->getName(), $platform->getDateTimeTzFormatString());
        }

        return $val;
    }
}