<?php
namespace FeedReaderCentral\Domain;

use DateTimeImmutable;
use Exception;
use FeedReaderCentral\Data;
use FeedReaderCentral\Key;

/**
 * An RSS or Atom feed
 */
class Feed
{
    /** @var int The ID of the feed */
    public int $id = 0;

    /** @var int The ID of the user to whom this subscription belongs */
    public int $user_id = 0;

    /** @var string The URL of the feed */
    public string $url = '';

    /** @var string|null The title of this feed */
    public ?string $title = null;

    /** @var string|null The date/time items in this feed were last updated */
    public ?string $updated_on = null;

    /** @var string|null The date/time this feed was last checked */
    public ?string $checked_on = null;

    /**
     * The date/time items in this feed were last updated
     *
     * @return DateTimeImmutable|null The updated date, or null if it is not set
     * @throws Exception If the date/time is an invalid format
     */
    public function updatedOn(): ?DateTimeImmutable
    {
        return is_null($this->updated_on) ? null : new DateTimeImmutable($this->updated_on);
    }

    /**
     * The date/time this feed was last checked
     *
     * @return DateTimeImmutable|null The last checked date, or null if it is not set
     * @throws Exception If the date/time is an invalid format
     */
    public function checkedOn(): ?DateTimeImmutable
    {
        return is_null($this->checked_on) ? null : new DateTimeImmutable($this->checked_on);
    }

    /**
     * Create a document from the parsed feed
     *
     * @param \FeedReaderCentral\Feed $feed The parsed feed
     * @return static The document constructed from the parsed feed
     */
    public static function fromParsed(\FeedReaderCentral\Feed $feed): static
    {
        $it = new static();
        $it->user_id =    $_SESSION[Key::USER_ID];
        $it->url     = $feed->url;
        $it->title   = $feed->title;
        $it->updated_on = $feed->updatedOn;
        $it->checked_on = Data::formatDate('now');

        return $it;
    }
}