<?php

declare(strict_types=1);

class BpbMediathekSeriesBridge extends BridgeAbstract
{
    const NAME = 'bpb.de Mediathek Serien Bridge';
    const URI = 'https://www.bpb.de';
    const DESCRIPTION = 'Gibt die neuesten Episoden einer Serie aus der bpb.de Mediathek zurück.';
    const MAINTAINER = 'Akamaru';
    const CACHE_TIMEOUT = 3600; // 1 Stunde

    const PARAMETERS = [
        'Serie' => [
            'series_slug' => [
                'name' => 'Serien-Slug (z.B. "faketrain")',
                'type' => 'text',
                'required' => true,
                'exampleValue' => 'faketrain',
                'title' => 'Den Serien-Slug findest du in der URL: bpb.de/mediathek/reihen/SERIEN-SLUG/'
            ],
            'limit' => [
                'name' => 'Maximale Anzahl an Episoden',
                'type' => 'number',
                'required' => false,
                'defaultValue' => 20
            ],
            'fetch_details' => [
                'name' => 'Detaillierte Metadaten laden',
                'type' => 'checkbox',
                'required' => false,
                'defaultValue' => 'checked',
                'title' => 'Lädt JSON-LD Metadaten von Episodenseiten (Thumbnail, Beschreibung, Datum)'
            ]
        ]
    ];

    private $seriesTitle = '';

    public function collectData()
    {
        $seriesSlug = $this->getInput('series_slug');
        $limit = $this->getInput('limit') ?? 20;
        $fetchDetails = $this->getInput('fetch_details') ?? false;

        if (empty($seriesSlug)) {
            returnClientError('Serien-Slug ist erforderlich.');
        }

        // Build series listing URL
        $seriesUrl = self::URI . '/mediathek/reihen/' . $seriesSlug . '/';

        // Fetch HTML
        $html = getSimpleHTMLDOM($seriesUrl);
        if (!$html) {
            returnServerError('Konnte die Serien-Seite nicht laden: ' . $seriesUrl);
        }

        // Extract series title from page
        $titleTag = $html->find('h1', 0);
        if ($titleTag) {
            $this->seriesTitle = trim($titleTag->plaintext);
        } else {
            $this->seriesTitle = 'Unbekannte Serie';
        }

        // Find all episode entries (h3 tags with links)
        $episodeElements = $html->find('h3 a[href*="/mediathek/"]');

        if (empty($episodeElements)) {
            returnServerError('Keine Episoden gefunden.');
        }

        // Collect all episodes (no early limit for proper sorting)
        $episodes = [];

        foreach ($episodeElements as $episodeLink) {
            $episode = [];

            // Extract title
            $episode['title'] = trim($episodeLink->plaintext);

            // Extract URL
            $episode['url'] = $this->normalizeUrl($episodeLink->href);

            // If fetch_details is enabled, load individual episode page
            if ($fetchDetails) {
                $this->enrichEpisodeWithJsonLD($episode);
            } else {
                // Basic metadata only
                $episode['timestamp'] = 0; // Will be sorted to bottom
                $episode['thumbnail'] = null;
                $episode['description'] = '';
            }

            $episodes[] = $episode;
        }

        // Sort episodes: newest first (by timestamp)
        usort($episodes, function ($a, $b) {
            $timeA = $a['timestamp'] ?? 0;
            $timeB = $b['timestamp'] ?? 0;
            return $timeB <=> $timeA; // Descending order
        });

        // Apply limit after sorting
        $episodes = array_slice($episodes, 0, $limit);

        // Create RSS items from episodes
        foreach ($episodes as $episode) {
            $item = [];

            // Title: Episode title only
            $item['title'] = $episode['title'];

            // URL
            $item['uri'] = $episode['url'];

            // Unique ID
            $item['uid'] = md5($episode['url']);

            // Timestamp
            if (!empty($episode['timestamp'])) {
                $item['timestamp'] = $episode['timestamp'];
            }

            // Author
            $item['author'] = 'bpb.de';

            // Build content HTML (only image + description)
            $content = '';

            // Thumbnail
            if (!empty($episode['thumbnail'])) {
                $content .= '<img src="' . htmlspecialchars($episode['thumbnail']) . '" alt="' . htmlspecialchars($episode['title']) . '" /><br>';
                $item['enclosures'] = [$episode['thumbnail']];
            }

            // Description
            if (!empty($episode['description'])) {
                $content .= '<p>' . $episode['description'] . '</p>';
            }

            $item['content'] = $content;

            $this->items[] = $item;
        }
    }

    /**
     * Enriches episode data by fetching and parsing JSON-LD from episode page
     */
    private function enrichEpisodeWithJsonLD(&$episode)
    {
        try {
            $episodeHtml = getSimpleHTMLDOM($episode['url']);
            if (!$episodeHtml) {
                // Failed to load, use basic data
                $episode['timestamp'] = 0;
                $episode['thumbnail'] = null;
                $episode['description'] = '';
                return;
            }

            // Extract JSON-LD script tag
            $jsonLdScript = $episodeHtml->find('script[type="application/ld+json"]', 0);
            if (!$jsonLdScript) {
                $episode['timestamp'] = 0;
                $episode['thumbnail'] = null;
                $episode['description'] = '';
                return;
            }

            $jsonData = json_decode($jsonLdScript->innertext, true);
            if (!$jsonData || json_last_error() !== JSON_ERROR_NONE) {
                $episode['timestamp'] = 0;
                $episode['thumbnail'] = null;
                $episode['description'] = '';
                return;
            }

            // Parse VideoObject schema
            if (isset($jsonData['@type']) && $jsonData['@type'] === 'VideoObject') {
                // Thumbnail/image
                if (isset($jsonData['thumbnailUrl'])) {
                    $episode['thumbnail'] = is_array($jsonData['thumbnailUrl'])
                        ? $jsonData['thumbnailUrl'][0]
                        : $jsonData['thumbnailUrl'];
                } else {
                    $episode['thumbnail'] = null;
                }

                // Description
                if (isset($jsonData['description'])) {
                    $episode['description'] = $jsonData['description'];
                } else {
                    $episode['description'] = '';
                }

                // Upload/publish date
                if (isset($jsonData['uploadDate'])) {
                    $timestamp = strtotime($jsonData['uploadDate']);
                    if ($timestamp !== false) {
                        $episode['timestamp'] = $timestamp;
                    } else {
                        $episode['timestamp'] = 0;
                    }
                } elseif (isset($jsonData['datePublished'])) {
                    $timestamp = strtotime($jsonData['datePublished']);
                    if ($timestamp !== false) {
                        $episode['timestamp'] = $timestamp;
                    } else {
                        $episode['timestamp'] = 0;
                    }
                } else {
                    $episode['timestamp'] = 0;
                }
            } else {
                // Not a VideoObject, use defaults
                $episode['timestamp'] = 0;
                $episode['thumbnail'] = null;
                $episode['description'] = '';
            }
        } catch (Exception $e) {
            // Graceful degradation: Silent fail, use basic data
            $episode['timestamp'] = 0;
            $episode['thumbnail'] = null;
            $episode['description'] = '';
        }
    }

    /**
     * Normalizes relative URLs to absolute URLs
     */
    private function normalizeUrl($url)
    {
        if (strpos($url, 'http') === 0) {
            return $url;
        }

        return strpos($url, '/') === 0
            ? self::URI . $url
            : self::URI . '/' . $url;
    }

    public function getName()
    {
        if (!empty($this->seriesTitle)) {
            return $this->seriesTitle . ' - bpb.de Mediathek';
        }
        return parent::getName();
    }

    public function getURI()
    {
        $seriesSlug = $this->getInput('series_slug');

        if (!empty($seriesSlug)) {
            return self::URI . '/mediathek/reihen/' . $seriesSlug . '/';
        }

        return self::URI;
    }

    public function getIcon()
    {
        return 'https://www.google.com/s2/favicons?domain=www.bpb.de&sz=32';
    }

    public function detectParameters($url)
    {
        // Pattern: https://www.bpb.de/mediathek/reihen/SLUG/
        if (preg_match('#bpb\.de/mediathek/reihen/([a-z0-9-]+)/?#i', $url, $matches)) {
            return [
                'series_slug' => $matches[1]
            ];
        }

        return null;
    }
}