<?php

use dokuwiki\Extension\SyntaxPlugin;

/**
 * Easily embed videos from various Video Sharing sites
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Andreas Gohr <andi@splitbrain.org>
 */
class syntax_plugin_vshare_video extends SyntaxPlugin
{
    protected $sites;

    protected $sizes = [
        'small' => [255, 143],
        'medium' => [425, 239],
        'large' => [520, 293],
        'full' => ['100%', ''],
        'half' => ['50%', ''],
    ];

    protected $alignments = [
        0 => 'none',
        1 => 'right',
        2 => 'left',
        3 => 'center',
    ];

    /**
     * Constructor.
     * Intitalizes the supported video sites
     */
    public function __construct()
    {
        $this->sites = helper_plugin_vshare::loadSites();
    }

    /** @inheritdoc */
    public function getType()
    {
        return 'substition';
    }

    /** @inheritdoc */
    public function getPType()
    {
        return 'block';
    }

    /** @inheritdoc */
    public function getSort()
    {
        return 159;
    }

    /** @inheritdoc */
    public function connectTo($mode)
    {
        $pattern = implode('|', array_keys($this->sites));
        $this->Lexer->addSpecialPattern('\{\{\s?(?:' . $pattern . ')>[^}]*\}\}', $mode, 'plugin_vshare_video');
    }

    /** @inheritdoc */
    public function handle($match, $state, $pos, Doku_Handler $handler)
    {
        $command = substr($match, 2, -2);

        // title
        [$command, $title] = sexplode('|', $command, 2, '');
        $title = trim($title);

        // alignment
        $align = 0;
        if (substr($command, 0, 1) == ' ') ++$align;
        if (substr($command, -1) == ' ') $align += 2;
        $command = trim($command);

        // get site and video
        [$site, $vid] = explode('>', $command);
        if (!$this->sites[$site]) return null; // unknown site
        if (!$vid) return null; // no video!?

        // what size?
        [$vid, $pstr] = sexplode('?', $vid, 2, '');
        parse_str($pstr, $userparams);
        [$width, $height] = $this->parseSize($userparams);

        // get URL
        $url = $this->insertPlaceholders($this->sites[$site]['url'], $vid, $width, $height);
        [$url, $urlpstr] = sexplode('?', $url, 2, '');
        parse_str($urlpstr, $urlparams);

        // merge parameters
        $params = array_merge($urlparams, $userparams);
        $url = $url . '?' . buildURLparams($params, '&');

        return [
            'site' => $site,
            'domain' => parse_url($url, PHP_URL_HOST),
            'video' => $vid,
            'url' => $url,
            'align' => $this->alignments[$align],
            'width' => $width,
            'height' => $height,
            'title' => $title
        ];
    }

    /** @inheritdoc */
    public function render($mode, Doku_Renderer $R, $data)
    {
        if ($mode != 'xhtml') return false;
        if (is_null($data)) return false;

        if (is_a($R, 'renderer_plugin_dw2pdf')) {
            $R->doc .= $this->pdf($data);
        } else {
            $R->doc .= $this->iframe($data, $this->getConf('gdpr') ? 'div' : 'iframe');
        }
        return true;
    }

    /**
     * Prepare the HTML for output of the embed iframe
     * @param array $data
     * @param string $element Can be used to not directly embed the iframe
     * @return string
     */
    public function iframe($data, $element = 'iframe')
    {
        $attributes = [
            'src' => $data['url'],
            'width' => $data['width'],
            'height' => $data['height'],
            'style' => $this->sizeToStyle($data['width'], $data['height']),
            'class' => 'vshare vshare__' . $data['align'],
            'allowfullscreen' => '',
            'frameborder' => 0,
            'scrolling' => 'no',
            'data-domain' => $data['domain'],
            'loading' => 'lazy',
        ];
        if ($this->getConf('extrahard')) {
            $attributes = array_merge($attributes, $this->hardenedIframeAttributes());
        }

        return "<$element "
            . buildAttributes($attributes)
            . '><h3>' . hsc($data['title']) . "</h3></$element>";
    }

    /**
     * Create a style attribute for the given size
     *
     * @param int|string $width
     * @param int|string $height
     * @return string
     */
    public function sizeToStyle($width, $height)
    {
        // no unit? use px
        if ($width && $width == (int)$width) {
            $width .= 'px';
        }
        // no unit? use px
        if ($height && $height == (int)$height) {
            $height .= 'px';
        }

        $style = '';
        if ($width) $style .= 'width:' . $width . ';';
        if ($height) $style .= 'height:' . $height . ';';
        return $style;
    }

    /**
     * Prepare the HTML for output in PDF exports
     *
     * @param array $data
     * @return string
     */
    public function pdf($data)
    {
        $html = '<div class="vshare vshare__' . $data['align'] . '"
                      width="' . $data['width'] . '"
                      height="' . $data['height'] . '">';

        $html .= '<a href="' . hsc($data['url']) . '" class="vshare">';
        $html .= '<img src="' . DOKU_BASE . 'lib/plugins/vshare/video.png" />';
        $html .= '</a>';

        $html .= '<br />';

        $html .= '<a href="' . hsc($data['url']) . '" class="vshare">';
        $html .= ($data['title'] ? hsc($data['title']) : 'Video');
        $html .= '</a>';

        $html .= '</div>';

        return $html;
    }

    /**
     * Fill the placeholders in the given URL
     *
     * @param string $url
     * @param string $vid
     * @param int|string $width
     * @param int|string $height
     * @return string
     */
    public function insertPlaceholders($url, $vid, $width, $height)
    {
        global $INPUT;
        $url = str_replace('@VIDEO@', rawurlencode($vid), $url);
        $url = str_replace('@DOMAIN@', rawurlencode($INPUT->server->str('HTTP_HOST')), $url);
        $url = str_replace('@WIDTH@', $width, $url);
        $url = str_replace('@HEIGHT@', $height, $url);

        return $url;
    }

    /**
     * Extract the wanted size from the parameter list
     *
     * @param array $params
     * @return int[]
     */
    public function parseSize(&$params)
    {
        $known = implode('|', array_keys($this->sizes));

        foreach (array_keys($params) as $key) {
            if (preg_match("/^((\d+)x(\d+))|($known)\$/i", $key, $m)) {
                unset($params[$key]);
                if (isset($m[4])) {
                    return $this->sizes[strtolower($m[4])];
                } else {
                    return [$m[2], $m[3]];
                }
            }
        }

        // default
        return $this->sizes['medium'];
    }

    /**
     * Get additional attributes to set on the iframe to harden
     *
     * @link https://dustri.org/b/youtube-video-embedding-harm-reduction.html
     * @return array
     */
    protected function hardenedIframeAttributes()
    {
        $disallow = [
            'accelerometer',
            'ambient-light-sensor',
            'autoplay',
            'battery',
            'browsing-topics',
            'camera',
            'display-capture',
            'domain-agent',
            'document-domain',
            'encrypted-media',
            'execution-while-not-rendered',
            'execution-while-out-of-viewport',
            'gamepad',
            'geolocation',
            'gyroscope',
            'hid',
            'identity-credentials-get',
            'idle-detection',
            'local-fonts',
            'magnetometer',
            'microphone',
            'midi',
            'otp-credentials',
            'payment',
            'picture-in-picture',
            'publickey-credentials-create',
            'publickey-credentials-get',
            'screen-wake-lock',
            'serial',
            'speaker-selection',
            'usb',
            'window-management',
            'xr-spatial-tracking',
        ];

        $disallow = implode('; ', array_map(static fn($v) => "$v 'none'", $disallow));

        return [
            'credentialless' => '',
            'sandbox' => 'allow-scripts allow-same-origin',
            'allow' => $disallow,
            'csp' => 'sandbox allow-scripts allow-same-origin',
            'referrerpolicy' => 'no-referrer',
        ];
    }
}
