<?php

declare(strict_types=1);

namespace OCA\RePod\Core\PodcastData;

use OCA\GPodderSync\Core\PodcastData\PodcastData as CorePodcastData;

/**
 * @psalm-type PodcastDataType = array{
 *  title: ?string,
 *  author: ?string,
 *  link: ?string,
 *  description: ?string,
 *  imageUrl: ?string,
 *  fetchedAtUnix: int,
 *  imageBlob: ?string,
 * 	atomLink: ?string
 * }
 */
class PodcastData extends CorePodcastData implements \JsonSerializable
{
	public function __construct(
		?string $title,
		?string $author,
		?string $link,
		?string $description,
		?string $imageUrl,
		int $fetchedAtUnix,
		?string $imageBlob = null,
		private ?string $atomLink
	) {
		parent::__construct(
			$title,
			$author,
			$link,
			$description,
			$imageUrl,
			$fetchedAtUnix,
			$imageBlob
		);
	}

	/**
	 * @throws \Exception if the XML data could not be parsed
	 */
	public static function parseRssXml(string $xmlString, ?int $fetchedAtUnix = null): PodcastData {
		$xml = new \SimpleXMLElement($xmlString);
		$channel = $xml->channel;

		return new PodcastData(
			self::stringOrNull($channel->title),
			self::getXPathContent($xml, '/rss/channel/itunes:author'),
			self::stringOrNull($channel->link),
			self::stringOrNull($channel->description),
			self::getXPathContent($xml, '/rss/channel/image/url')
				?? self::getXPathAttribute($xml, '/rss/channel/itunes:image/@href'),
			$fetchedAtUnix ?? (new \DateTime())->getTimestamp(),
			null,
			self::getXPathContent($xml, '/rss/channel/atom:link/@href')
		);
	}

	/**
	 * @param null|\SimpleXMLElement|string $value
	 */
	public static function stringOrNull($value): ?string {
		if ($value) {
			return (string) $value;
		}

		return null;
	}

	public function getAtomLink(): ?string {
		return $this->atomLink;
	}

	/**
	 * @return PodcastDataType
	 */
	public function toArrayWithExtras() {
		return array_merge(parent::toArray(), [
			'atomLink' => $this->atomLink,
		]);
	}

	private static function getXPathContent(\SimpleXMLElement $xml, string $xpath): ?string {
		$match = $xml->xpath($xpath);
		if ($match) {
			return (string) $match[0];
		}

		return null;
	}

	private static function getXPathAttribute(\SimpleXMLElement $xml, string $xpath): ?string {
		$match = $xml->xpath($xpath);
		if ($match) {
			return (string) $match[0][0];
		}

		return null;
	}
}