<?php
namespace wcf\system\cronjob;
use wcf\data\cronjob\Cronjob;
use wcf\data\streaming\partner\StreamingPartnerAction;
use wcf\data\streaming\partner\StreamingPartnerList;
use wcf\util\HTTPRequest;
use wcf\util\JSON;
use wcf\util\StringUtil;

class StreamingPartnerRefreshStreamDataCronjob extends AbstractCronjob {
    /**
     * Twitch.tv API base url
     * @var string
     */
    const API_BASE = 'https://api.twitch.tv/helix';

    /**
     * @inheritDoc
     */
    protected $maxLifetime = 3600;

    /**
     * Array of channel names
     * @var array
     */
    public $channels = [];

    /**
     * @inheritDoc
     */
    public function execute(Cronjob $cronjob) {
        parent::execute($cronjob);

        if (!MODULE_STREAMING_PARTNER || StringUtil::trim(STREAMING_PARTNER_TWITCH_CLIENT_ID) == '') {
            return;
        }

        $this->getChannelNames();

        if (empty($this->channels)) {
            return;
        }

        $this->fetchChannelData();
        $this->fetchStreamData();
        $this->prepareData();
        $this->updatePartners();
    }

    /**
     * Returns an array of Twitch.tv channel names
     */
    private function getChannelNames() {
        $partnerList = new StreamingPartnerList();
        $partnerList->readObjects();
        $partners = $partnerList->getObjects();

        foreach ($partners as $partner) {
            $channel = $partner->twitchUsername;
            $name = StringUtil::trim(preg_replace('~https?://(?:www\.)twitch\.tv/(#?[a-zA-Z0-9][\w]{2,24}).*~i', '\1', mb_strtolower($channel)));

            if (!empty($name)) {
                $index = count($this->channels);
                $this->channels[$index] = ['data' => [
                    'partnerID' => $partner->partnerID,
                    'name' => $name
                ]];
            }
        }
    }

    /**
     * Fetches Twitch.tv channel data.
     */
    private function fetchChannelData() {
        if (empty($this->channels)) {
            return;
        }

        foreach ($this->channels as $channelID => $channelData) {
            $request = new HTTPRequest(self::API_BASE . '/users/?id' . $channelData['data']['name'],
                [
                    'method' => 'GET'
            ],);
            $request->addHeader('Client-ID:', STREAMING_PARTNER_TWITCH_CLIENT_ID);
            $request->addHeader('Accept:', 'application/vnd.twitchtv.v5+json');
            try {
                $request->execute();
            }
            catch (HTTPException $e) {
                throw new SystemException("unexpected response from server: ".print_r($e->getExtraInformation(), 1), $e->getCode(), $e->getDescription(), $e);
            }

            $reply = $request->getReply();
            $channelData = JSON::decode(StringUtil::trim($reply['body']));


            if (!is_array($channelData) || empty($channelData['_id'])) {
                unset($this->channels[$channelID]);
                continue;
            }

            // Remove unneccessary stuff
            unset($channelData['_links']);

            $this->channels[$channelID]['data'] = array_merge($this->channels[$channelID]['data'], $channelData);
        }
    }

    /**
     * Fetches Twitch.tv channel data.
     */
    private function fetchStreamData() {
        if (empty($this->channels)) {
            return;
        }

        $channelNames = [];

        foreach ($this->channels as $channelID => $channelData) {
            $channelNames[$channelID] = $channelData['data']['name'];
        }

        foreach (array_chunk($channelNames, 25, true) as $channels) {
            $streams = [];

            $request = new HTTPRequest(self::API_BASE . '/streams/?login=' . implode('&login=', $channels),
                [
                    'method' => 'GET'
            ],);
            $request->addHeader('Client-ID', STREAMING_PARTNER_TWITCH_CLIENT_ID);
            $request->addHeader('Accept:', 'application/vnd.twitchtv.v5+json');
            try {
                $request->execute();
            }
            catch (HTTPException $e) {
                throw new SystemException("unexpected response from server: ".print_r($e->getExtraInformation(), 1), $e->getCode(), $e->getDescription(), $e);
            }

            $reply = $request->getReply();
            $streams = JSON::decode(StringUtil::trim($reply['body']))['streams'];

            if (!is_array($streams) || empty($streams)) {
                continue;
            }

            foreach ($streams as $streamData) {
                if (empty($streamData['_id'])) {
                    continue;
                }

                $channelID = array_search($streamData['channel']['name'], $channels);

                // Remove unneccessary stuff
                unset($streamData['_links']);
                unset($streamData['channel']);

                if (isset($this->channels[$channelID])) {
                    $this->channels[$channelID]['stream'] = $streamData;
                }
            }
        }
    }

    /**
     * Set stream status.
     */
    private function prepareData() {
        if (empty($this->channels)) {
            return;
        }

        // set stream status
        foreach ($this->channels as $k => $v) {
            if (empty($v['stream']['_id'])) {
                $this->channels[$k]['stream']['status'] = 'offline';
            }
            else {
                $this->channels[$k]['stream']['status'] = 'online';
            }
        }
    }

    /**
     * Update partner stream data
     */
    private function updatePartners() {
        if (empty($this->channels)) {
            return;
        }

        foreach ($this->channels as $partner) {
            $lastStreamDate = [];

            if ($partner['stream']['status'] == 'online') {
                $lastStreamDate = ['lastStreamDate' => TIME_NOW];
            }

            $objectAction = new StreamingPartnerAction([$partner['data']['partnerID']], 'update', ['data' => array_merge([
                'twitchUsername' => $partner['data']['display_name'],
                'followerCount' => $partner['data']['followers'],
                'streamStatus' => $partner['stream']['status'],
                'streamTitle' => !empty($partner['data']['status']) ? $partner['data']['status'] : '',
                'gameName' => !empty($partner['data']['game']) ? $partner['data']['game'] : '',
                'lastUpdate' => TIME_NOW
            ], $lastStreamDate)]);
            $objectAction->executeAction();
        }
    }
}