<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Serializer\Normalizer;

use Symfony\Component\Serializer\Exception\InvalidArgumentException;
use Symfony\Component\Serializer\Exception\NotNormalizableValueException;

/**
 * Normalizes an object implementing the {@see \DateTimeInterface} to a date string.
 * Denormalizes a date string to an instance of {@see \DateTime} or {@see \DateTimeImmutable}.
 *
 * @author Kévin Dunglas <dunglas@gmail.com>
 */
class DateTimeNormalizer implements NormalizerInterface, DenormalizerInterface, CacheableSupportsMethodInterface
{
    public const FORMAT_KEY = 'datetime_format';
    public const TIMEZONE_KEY = 'datetime_timezone';

    private $defaultContext = [
        self::FORMAT_KEY => \DateTime::RFC3339,
        self::TIMEZONE_KEY => null,
    ];

    private const SUPPORTED_TYPES = [
        \DateTimeInterface::class => true,
        \DateTimeImmutable::class => true,
        \DateTime::class => true,
    ];

    public function __construct(array $defaultContext = [])
    {
        $this->defaultContext = array_merge($this->defaultContext, $defaultContext);
    }

    /**
     * {@inheritdoc}
     *
     * @throws InvalidArgumentException
     *
     * @return string
     */
    public function normalize($object, string $format = null, array $context = [])
    {
        if (!$object instanceof \DateTimeInterface) {
            throw new InvalidArgumentException('The object must implement the "\DateTimeInterface".');
        }

        $dateTimeFormat = $context[self::FORMAT_KEY] ?? $this->defaultContext[self::FORMAT_KEY];
        $timezone = $this->getTimezone($context);

        if (null !== $timezone) {
            $object = clone $object;
            $object = $object->setTimezone($timezone);
        }

        return $object->format($dateTimeFormat);
    }

    /**
     * {@inheritdoc}
     */
    public function supportsNormalization($data, string $format = null)
    {
        return $data instanceof \DateTimeInterface;
    }

    /**
     * {@inheritdoc}
     *
     * @throws NotNormalizableValueException
     *
     * @return \DateTimeInterface
     */
    public function denormalize($data, string $type, string $format = null, array $context = [])
    {
        $dateTimeFormat = $context[self::FORMAT_KEY] ?? null;
        $timezone = $this->getTimezone($context);

        if ('' === $data || null === $data) {
            throw new NotNormalizableValueException('The data is either an empty string or null, you should pass a string that can be parsed with the passed format or a valid DateTime string.');
        }

        if (null !== $dateTimeFormat) {
            $object = \DateTime::class === $type ? \DateTime::createFromFormat($dateTimeFormat, $data, $timezone) : \DateTimeImmutable::createFromFormat($dateTimeFormat, $data, $timezone);

            if (false !== $object) {
                return $object;
            }

            $dateTimeErrors = \DateTime::class === $type ? \DateTime::getLastErrors() : \DateTimeImmutable::getLastErrors();

            throw new NotNormalizableValueException(sprintf('Parsing datetime string "%s" using format "%s" resulted in %d errors: ', $data, $dateTimeFormat, $dateTimeErrors['error_count'])."\n".implode("\n", $this->formatDateTimeErrors($dateTimeErrors['errors'])));
        }

        try {
            return \DateTime::class === $type ? new \DateTime($data, $timezone) : new \DateTimeImmutable($data, $timezone);
        } catch (\Exception $e) {
            throw new NotNormalizableValueException($e->getMessage(), $e->getCode(), $e);
        }
    }

    /**
     * {@inheritdoc}
     */
    public function supportsDenormalization($data, string $type, string $format = null)
    {
        return isset(self::SUPPORTED_TYPES[$type]);
    }

    /**
     * {@inheritdoc}
     */
    public function hasCacheableSupportsMethod(): bool
    {
        return __CLASS__ === static::class;
    }

    /**
     * Formats datetime errors.
     *
     * @return string[]
     */
    private function formatDateTimeErrors(array $errors): array
    {
        $formattedErrors = [];

        foreach ($errors as $pos => $message) {
            $formattedErrors[] = sprintf('at position %d: %s', $pos, $message);
        }

        return $formattedErrors;
    }

    private function getTimezone(array $context): ?\DateTimeZone
    {
        $dateTimeZone = $context[self::TIMEZONE_KEY] ?? $this->defaultContext[self::TIMEZONE_KEY];

        if (null === $dateTimeZone) {
            return null;
        }

        return $dateTimeZone instanceof \DateTimeZone ? $dateTimeZone : new \DateTimeZone($dateTimeZone);
    }
}