<?php

use dokuwiki\Extension\SyntaxPlugin;
use dokuwiki\HTTP\DokuHTTPClient;

/**
 * DokuWiki Plugin gh (Syntax Component)
 *
 * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
 * @author  Andreas Gohr <andi@splitbrain.org>
 */
class syntax_plugin_gh extends SyntaxPlugin
{
    /**
     * Extension to highlighting language mapping
     *
     * When a extension is not found here it's assumed the extension name equals the language
     *
     * @var array
     */
    protected $ext2lang = [
        'as' => 'actionscript3',
        'bas' => 'gwbasic',
        'h' => 'c',
        'hpp' => 'cpp',
        'hs' => 'haskell',
        'htm' => 'html5',
        'html' => 'html5',
        'js' => 'javascript',
        'pas' => 'pascal',
        'pl' => 'perl6',
        'py' => 'python',
        'rb' => 'ruby',
        'sh' => 'bash',
        'yml' => 'yaml'
    ];

    /**
     * @return string Syntax mode type
     */
    public function getType()
    {
        return 'substition';
    }

    /**
     * @return string Paragraph type
     */
    public function getPType()
    {
        return 'block';
    }

    /**
     * @return int Sort order - Low numbers go before high numbers
     */
    public function getSort()
    {
        return 155;
    }

    /**
     * Connect lookup pattern to lexer.
     *
     * @param string $mode Parser mode
     */
    public function connectTo($mode)
    {
        $this->Lexer->addSpecialPattern('{{gh>[^}]*}}', $mode, 'plugin_gh');
    }

    /** @inheritDoc */
    public function handle($match, $state, $pos, Doku_Handler $handler)
    {
        $match = trim(substr($match, 5, -2));
        [$url, $lines] = sexplode(' ', $match, 2);
        [$from, $to] = sexplode('-', $lines, 2);

        $data = ['from' => (int)$from, 'to' => (int)$to];

        if (preg_match('/([\w.\-]+)\/([\w-]+\/[\w-]+(\/[\w-]+)?)\/blob\/([\w-]+)\/(.*)$/', $url, $m)) {
            $data['base'] = $m[1];
            $data['repo'] = $m[2];
            $data['blob'] = $m[4];
            $data['file'] = $m[5];
        }

        return $data;
    }

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

        if (!$data['base']) return false;
        if (!$data['repo']) return false;
        if (!$data['blob']) return false;
        if (!$data['file']) return false;

        global $ID;
        global $INPUT;

        if ($data['base'] == 'github.com') {
            $raw = 'https://raw.githubusercontent.com/' . $data['repo'] . '/' . $data['blob'] . '/' . $data['file'];
        } else {
            $raw = 'https://' . $data['base'] . '/' . $data['repo'] . '/raw/' . $data['blob'] . '/' . $data['file'];
        }
        $url = 'https://' . $data['base'] . '/' . $data['repo'] . '/blob/' . $data['blob'] . '/' . $data['file'];

        // check if there's a usable cache
        $text = false;
        $cache = getCacheName($raw, '.ghplugin');
        $tcache = @filemtime($cache);
        $tpage = @filemtime(wikiFN($ID));
        if ($tcache && $tpage && !$INPUT->bool('purge')) {
            $now = time();
            if ($now - $tcache < ($now - $tpage) * 2) {
                // use cache when it's younger than twice the age of the page
                $text = io_readFile($cache);
            }
        }

        // no cache loaded, get from HTTP
        if (!$text) {
            $http = new DokuHTTPClient();
            $text = $http->get($raw);

            if ($text) {
                // save to cache
                io_saveFile($cache, $text);
            } elseif ($tcache) {
                // HTTP failed but there's an old cache - use it
                $text = io_readFile($cache);
            }
        }

        // WTF? there's nothing. we're done here
        if (!$text) return true;

        // apply line ranges
        if ($data['from'] || $data['to']) {
            $len = $data['to'] - $data['from'];
            if ($len <= 0) $len = null;

            $lines = explode("\n", $text);
            $lines = array_slice($lines, $data['from'], $len);
            $text = implode("\n", $lines);
        }

        // add icon
        [$ext] = mimetype($data['file'], false);
        $class = preg_replace('/[^_\-a-z0-9]+/i', '_', $ext);
        $class = 'mediafile mf_' . $class;

        // add link
        $renderer->doc .= '<dl class="file">' . DOKU_LF;
        $renderer->doc .= '<dt><a href="' . $url . '" class="' . $class . '">';
        $renderer->doc .= hsc($data['file']);
        $renderer->doc .= '</a></dt>' . DOKU_LF . '<dd>';

        if (isset($this->ext2lang[$ext])) {
            $lang = $this->ext2lang[$ext];
        } else {
            $lang = $ext;
        }

        $renderer->file($text, $lang);
        $renderer->doc .= '</dd>';
        $renderer->doc .= '</dl>';
        return true;
    }
}