<?php

namespace Providers;

require_once('Rss.php');
require_once('../lib/php-youtube-api/src/autoload.php');

class Youtube extends Rss {

    const DEFAULT_MIN_DURATION = 60;

    public function __construct($feed, $options=[]) {
        parent::__construct($feed, $options);
        $config = json_decode(file_get_contents('../config/youtube.json'), TRUE);
        $this->_youtube = new \Madcoda\Youtube\Youtube([
            'key' => $config['key']
        ]);
    }

    protected function _getFeedUrl($feed) {
        return 'https://www.youtube.com/feeds/videos.xml?channel_id=' . $feed;
    }

    protected function _getCachePath() {
        return '../cache/youtube.%s';
    }

    protected function _mapRssItem($item) {
        $itemObj = parent::_mapRssItem($item);
        if (array_key_exists('descriptionlink', $this->_options)) {
            $linkConfig = explode(':', $this->_options['descriptionlink']);
            $linkDomain = NULL;
            if (!is_numeric($linkConfig[0])) {
                $linkDomain = array_shift($linkConfig);
                if (!$linkConfig) {
                    $linkConfig = ['1'];
                }
            }
            $linkIndex = intval($linkConfig[0]) - 1;
            $textLinks = [];
            if (preg_match_all('#(?:(?:https?|ftp):\/\/)?[\w/\-?=%.]+\.[\w/\-&?=%.]+#', $itemObj->Text, $textLinks)) {
                $textLinks = $textLinks[0];
                if ($linkDomain) {
                    $textLinks = array_values(array_filter($textLinks, function($link) use($linkDomain) {
                        if($linkParts = parse_url($link)) {
                            return $linkParts['host'] == $linkDomain;
                        }
                    }));
                }
                if (count($textLinks) > $linkIndex) {
                    $itemObj->Link = $textLinks[$linkIndex];
                }
            }
        }
        return $itemObj;
    }

    private function _getVideoMetadata($ids) {
        $cacheFile = sprintf($this->_getCachePath() . '.metadata', $this->_feed);
        $cacheData = [];
        if (file_exists($cacheFile)) {
            $cacheData = unserialize(file_get_contents($cacheFile));
        }
        $oldIDs = array_keys($cacheData);
        $newIDs = array_diff($ids, $oldIDs);
        if ($newIDs) {
            $metadata = $this->_youtube->getVideosInfo($newIDs);
            foreach ($metadata as $video) {
                $cacheData[$video->id] = $video;
            }
        }
        file_put_contents($cacheFile, serialize($cacheData));
        return array_filter($cacheData, function($item) use($ids) {
            return in_array($item->id, $ids);
        });
    }

    private function _getVideoDurations($ids) {
        $metadata = $this->_getVideoMetadata($ids);
        $return = [];
        foreach ($ids as $id) {
            $duration = new \DateInterval($metadata[$id]->contentDetails->duration);
            $return[$id] = $duration->h * 3600 + $duration->i * 60 + $duration->s;
        }
        return $return;
    }

    private function _getVideoID($item) {
        return preg_replace('/^yt:video:/', '', $item->ID);
    }

    protected function _filterItemContent($items) {
        $items = parent::_filterItemContent($items);

        if (array_key_exists('duration', $this->_options)) {
            $duration = intval($this->_options['duration']);
            $videoIDs = array_map(array($this, '_getVideoID'), $items);
            $durations = $this->_getVideoDurations($videoIDs);
            $minDuration = self::DEFAULT_MIN_DURATION;
            if (is_numeric($this->_options['duration'])) {
                $minDuration = intval($this->_options['duration']);
            }
            $items = array_filter($items, function($item) use($minDuration, $durations) {
                $videoID = $this->_getVideoID($item);
                return $durations[$videoID] >= $minDuration;
            });
        }

        return $items;
    }

}

?>