<?php

/**
 * Utilities for handling pagenames
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Andreas Gohr <andi@splitbrain.org>
 * @todo       Combine similar functions like {wiki,media,meta}FN()
 */

use dokuwiki\Utf8\PhpString;
use dokuwiki\Utf8\Clean;
use dokuwiki\File\Resolver;
use dokuwiki\Extension\Event;
use dokuwiki\ChangeLog\MediaChangeLog;
use dokuwiki\ChangeLog\PageChangeLog;
use dokuwiki\File\MediaResolver;
use dokuwiki\File\PageResolver;

/**
 * Fetch the an ID from request
 *
 * Uses either standard $_REQUEST variable or extracts it from
 * the full request URI when userewrite is set to 2
 *
 * For $param='id' $conf['start'] is returned if no id was found.
 * If the second parameter is true (default) the ID is cleaned.
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 *
 * @param string $param  the $_REQUEST variable name, default 'id'
 * @param bool   $clean  if true, ID is cleaned
 * @return string
 */
function getID($param = 'id', $clean = true)
{
    /** @var Input $INPUT */
    global $INPUT;
    global $conf;
    global $ACT;

    $id = $INPUT->str($param);

    //construct page id from request URI
    if (empty($id) && $conf['userewrite'] == 2) {
        $request = $INPUT->server->str('REQUEST_URI');
        $script = '';

        //get the script URL
        if ($conf['basedir']) {
            $relpath = '';
            if ($param != 'id') {
                $relpath = 'lib/exe/';
            }
            $script = $conf['basedir'] . $relpath .
                PhpString::basename($INPUT->server->str('SCRIPT_FILENAME'));
        } elseif ($INPUT->server->str('PATH_INFO')) {
            $request = $INPUT->server->str('PATH_INFO');
        } elseif ($INPUT->server->str('SCRIPT_NAME')) {
            $script = $INPUT->server->str('SCRIPT_NAME');
        } elseif ($INPUT->server->str('DOCUMENT_ROOT') && $INPUT->server->str('SCRIPT_FILENAME')) {
            $script = preg_replace(
                '/^' . preg_quote($INPUT->server->str('DOCUMENT_ROOT'), '/') . '/',
                '',
                $INPUT->server->str('SCRIPT_FILENAME')
            );
            $script = '/' . $script;
        }

        //clean script and request (fixes a windows problem)
        $script  = preg_replace('/\/\/+/', '/', $script);
        $request = preg_replace('/\/\/+/', '/', $request);

        //remove script URL and Querystring to gain the id
        if (preg_match('/^' . preg_quote($script, '/') . '(.*)/', $request, $match)) {
            $id = preg_replace('/\?.*/', '', $match[1]);
        }
        $id = urldecode($id);
        //strip leading slashes
        $id = preg_replace('!^/+!', '', $id);
    }

    // Namespace autolinking from URL
    if (str_ends_with($id, ':') || ($conf['useslash'] && str_ends_with($id, '/'))) {
        if (page_exists($id . $conf['start'])) {
            // start page inside namespace
            $id .= $conf['start'];
        } elseif (page_exists($id . noNS(cleanID($id)))) {
            // page named like the NS inside the NS
            $id .= noNS(cleanID($id));
        } elseif (page_exists($id)) {
            // page like namespace exists
            $id = substr($id, 0, -1);
        } else {
            // fall back to default
            $id .= $conf['start'];
        }
        if (isset($ACT) && $ACT === 'show') {
            $urlParameters = $_GET;
            if (isset($urlParameters['id'])) {
                unset($urlParameters['id']);
            }
            send_redirect(wl($id, $urlParameters, true, '&'));
        }
    }
    if ($clean) $id = cleanID($id);
    if ($id === '' && $param == 'id') $id = $conf['start'];

    return $id;
}

/**
 * Remove unwanted chars from ID
 *
 * Cleans a given ID to only use allowed characters. Accented characters are
 * converted to unaccented ones
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 *
 * @param  string  $raw_id    The pageid to clean
 * @param  boolean $ascii     Force ASCII
 * @return string cleaned id
 */
function cleanID($raw_id, $ascii = false)
{
    global $conf;
    static $sepcharpat = null;

    global $cache_cleanid;
    $cache = & $cache_cleanid;

    // check if it's already in the memory cache
    if (!$ascii && isset($cache[(string)$raw_id])) {
        return $cache[(string)$raw_id];
    }

    $sepchar = $conf['sepchar'];
    if ($sepcharpat == null) // build string only once to save clock cycles
        $sepcharpat = '#\\' . $sepchar . '+#';

    $id = trim((string)$raw_id);
    $id = PhpString::strtolower($id);

    //alternative namespace seperator
    if ($conf['useslash']) {
        $id = strtr($id, ';/', '::');
    } else {
        $id = strtr($id, ';/', ':' . $sepchar);
    }

    if ($conf['deaccent'] == 2 || $ascii) $id = Clean::romanize($id);
    if ($conf['deaccent'] || $ascii) $id = Clean::deaccent($id, -1);

    //remove specials
    $id = Clean::stripspecials($id, $sepchar, '\*');

    if ($ascii) $id = Clean::strip($id);

    //clean up
    $id = preg_replace($sepcharpat, $sepchar, $id);
    $id = preg_replace('#:+#', ':', $id);
    $id = trim($id, ':._-');
    $id = preg_replace('#:[:\._\-]+#', ':', $id);
    $id = preg_replace('#[:\._\-]+:#', ':', $id);

    if (!$ascii) $cache[(string)$raw_id] = $id;
    return($id);
}

/**
 * Return namespacepart of a wiki ID
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 *
 * @param string $id
 * @return string|false the namespace part or false if the given ID has no namespace (root)
 */
function getNS($id)
{
    $pos = strrpos((string)$id, ':');
    if ($pos !== false) {
        return substr((string)$id, 0, $pos);
    }
    return false;
}

/**
 * Returns the ID without the namespace
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 *
 * @param string $id
 * @return string
 */
function noNS($id)
{
    $pos = strrpos($id, ':');
    if ($pos !== false) {
        return substr($id, $pos + 1);
    } else {
        return $id;
    }
}

/**
 * Returns the current namespace
 *
 * @author Nathan Fritz <fritzn@crown.edu>
 *
 * @param string $id
 * @return string
 */
function curNS($id)
{
    return noNS(getNS($id));
}

/**
 * Returns the ID without the namespace or current namespace for 'start' pages
 *
 * @author Nathan Fritz <fritzn@crown.edu>
 *
 * @param string $id
 * @return string
 */
function noNSorNS($id)
{
    global $conf;

    $p = noNS($id);
    if (in_array($p, [$conf['start'], false, ''], true)) {
        $p = curNS($id);
        if ($p === false || $p === '') {
            return $conf['start'];
        }
    }
    return $p;
}

/**
 * Creates a XHTML valid linkid from a given headline title
 *
 * @param string  $title   The headline title
 * @param array|bool   $check   Existing IDs
 * @return string the title
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function sectionID($title, &$check)
{
    $title = str_replace([':', '.'], '', cleanID($title));
    $new = ltrim($title, '0123456789_-');
    if (empty($new)) {
        $title = 'section' . preg_replace('/[^0-9]+/', '', $title); //keep numbers from headline
    } else {
        $title = $new;
    }

    if (is_array($check)) {
        $suffix = 0;
        $candidateTitle = $title;
        while (in_array($candidateTitle, $check)) {
            $candidateTitle = $title . ++$suffix;
        }
        $check [] = $candidateTitle;
        return $candidateTitle;
    } else {
        return $title;
    }
}

/**
 * Wiki page existence check
 *
 * parameters as for wikiFN
 *
 * @author Chris Smith <chris@jalakai.co.uk>
 *
 * @param string $id page id
 * @param string|int $rev empty or revision timestamp
 * @param bool $clean flag indicating that $id should be cleaned (see wikiFN as well)
 * @param bool $date_at
 * @return bool exists?
 */
function page_exists($id, $rev = '', $clean = true, $date_at = false)
{
    $id = (explode('#', $id, 2))[0]; // #3608

    if ($rev !== '' && $date_at) {
        $pagelog = new PageChangeLog($id);
        $pagelog_rev = $pagelog->getLastRevisionAt($rev);
        if ($pagelog_rev !== false)
            $rev = $pagelog_rev;
    }
    return file_exists(wikiFN($id, $rev, $clean));
}

/**
 * Media existence check
 *
 * @param string $id page id
 * @param string|int $rev empty or revision timestamp
 * @param bool $clean flag indicating that $id should be cleaned (see mediaFN as well)
 * @param bool $date_at
 * @return bool exists?
 */
function media_exists($id, $rev = '', $clean = true, $date_at = false)
{
    if ($rev !== '' && $date_at) {
        $changeLog = new MediaChangeLog($id);
        $changelog_rev = $changeLog->getLastRevisionAt($rev);
        if ($changelog_rev !== false) {
            $rev = $changelog_rev;
        }
    }
    return file_exists(mediaFN($id, $rev, $clean));
}

/**
 * returns the full path to the datafile specified by ID and optional revision
 *
 * The filename is URL encoded to protect Unicode chars
 *
 * @param  $raw_id  string   id of wikipage
 * @param  $rev     int|string   page revision, empty string for current
 * @param  $clean   bool     flag indicating that $raw_id should be cleaned.  Only set to false
 *                           when $id is guaranteed to have been cleaned already.
 * @return string full path
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function wikiFN($raw_id, $rev = '', $clean = true)
{
    global $conf;

    global $cache_wikifn;
    $cache = & $cache_wikifn;

    $id = $raw_id;
    $rev = (int) $rev; // any falsy rev will be rev 0 in the cache

    if ($clean) $id = cleanID($id);
    $id = str_replace(':', '/', $id);

    if (isset($cache[$id]) && isset($cache[$id][$rev])) {
        return $cache[$id][$rev];
    }

    if (empty($rev)) {
        $fn = $conf['datadir'] . '/' . utf8_encodeFN($id) . '.txt';
    } else {
        $fn = $conf['olddir'] . '/' . utf8_encodeFN($id) . '.' . $rev . '.txt';
        if ($conf['compression']) {
            //test for extensions here, we want to read both compressions
            if (file_exists($fn . '.gz')) {
                $fn .= '.gz';
            } elseif (file_exists($fn . '.bz2')) {
                $fn .= '.bz2';
            } else {
                //file doesnt exist yet, so we take the configured extension
                $fn .= '.' . $conf['compression'];
            }
        }
    }

    if (!isset($cache[$id])) {
        $cache[$id] = [];
    }
    $cache[$id][$rev] = $fn;
    return $fn;
}

/**
 * Returns the full path to the file for locking the page while editing.
 *
 * @author Ben Coburn <btcoburn@silicodon.net>
 *
 * @param string $id page id
 * @return string full path
 */
function wikiLockFN($id)
{
    global $conf;
    return $conf['lockdir'] . '/' . md5(cleanID($id)) . '.lock';
}


/**
 * returns the full path to the meta file specified by ID and extension
 *
 * @author Steven Danz <steven-danz@kc.rr.com>
 *
 * @param string $id   page id
 * @param string $ext  file extension
 * @return string full path
 */
function metaFN($id, $ext)
{
    global $conf;
    $id = cleanID($id);
    $id = str_replace(':', '/', $id);

    $fn = $conf['metadir'] . '/' . utf8_encodeFN($id) . $ext;
    return $fn;
}

/**
 * returns the full path to the media's meta file specified by ID and extension
 *
 * @author Kate Arzamastseva <pshns@ukr.net>
 *
 * @param string $id   media id
 * @param string $ext  extension of media
 * @return string
 */
function mediaMetaFN($id, $ext)
{
    global $conf;
    $id = cleanID($id);
    $id = str_replace(':', '/', $id);

    $fn = $conf['mediametadir'] . '/' . utf8_encodeFN($id) . $ext;
    return $fn;
}

/**
 * returns an array of full paths to all metafiles of a given ID
 *
 * @author Esther Brunner <esther@kaffeehaus.ch>
 * @author Michael Hamann <michael@content-space.de>
 *
 * @param string $id page id
 * @return array
 */
function metaFiles($id)
{
    $basename = metaFN($id, '');
    $files    = glob($basename . '.*', GLOB_MARK);
    // filter files like foo.bar.meta when $id == 'foo'
    return    $files ? preg_grep('/^' . preg_quote($basename, '/') . '\.[^.\/]*$/u', $files) : [];
}

/**
 * returns the full path to the mediafile specified by ID
 *
 * The filename is URL encoded to protect Unicode chars
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 * @author Kate Arzamastseva <pshns@ukr.net>
 *
 * @param string     $id  media id
 * @param string|int $rev empty string or revision timestamp
 * @param bool $clean
 *
 * @return string full path
 */
function mediaFN($id, $rev = '', $clean = true)
{
    global $conf;
    if ($clean) $id = cleanID($id);
    $id = str_replace(':', '/', $id);
    if (empty($rev)) {
        $fn = $conf['mediadir'] . '/' . utf8_encodeFN($id);
    } else {
        $ext = mimetype($id);
        $name = substr($id, 0, -1 * strlen($ext[0]) - 1);
        $fn = $conf['mediaolddir'] . '/' . utf8_encodeFN($name . '.' . ( (int) $rev ) . '.' . $ext[0]);
    }
    return $fn;
}

/**
 * Returns the full filepath to a localized file if local
 * version isn't found the english one is returned
 *
 * @param  string $id  The id of the local file
 * @param  string $ext The file extension (usually txt)
 * @return string full filepath to localized file
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function localeFN($id, $ext = 'txt')
{
    global $conf;
    $file = DOKU_CONF . 'lang/' . $conf['lang'] . '/' . $id . '.' . $ext;
    if (!file_exists($file)) {
        $file = DOKU_INC . 'inc/lang/' . $conf['lang'] . '/' . $id . '.' . $ext;
        if (!file_exists($file)) {
            //fall back to english
            $file = DOKU_INC . 'inc/lang/en/' . $id . '.' . $ext;
        }
    }
    return $file;
}

/**
 * Resolve relative paths in IDs
 *
 * Do not call directly use resolve_mediaid or resolve_pageid
 * instead
 *
 * Partyly based on a cleanPath function found at
 * http://php.net/manual/en/function.realpath.php#57016
 *
 * @deprecated 2020-09-30
 * @param string $ns     namespace which is context of id
 * @param string $id     relative id
 * @param bool   $clean  flag indicating that id should be cleaned
 * @return string
 */
function resolve_id($ns, $id, $clean = true)
{
    global $conf;
    dbg_deprecated(Resolver::class . ' and its children');

    // some pre cleaning for useslash:
    if ($conf['useslash']) $id = str_replace('/', ':', $id);

    // if the id starts with a dot we need to handle the
    // relative stuff
    if ($id && $id[0] == '.') {
        // normalize initial dots without a colon
        $id = preg_replace('/^((\.+:)*)(\.+)(?=[^:\.])/', '\1\3:', $id);
        // prepend the current namespace
        $id = $ns . ':' . $id;

        // cleanup relatives
        $result = [];
        $pathA  = explode(':', $id);
        if (!$pathA[0]) $result[] = '';
        foreach ($pathA as $dir) {
            if ($dir == '..') {
                if (end($result) == '..') {
                    $result[] = '..';
                } elseif (!array_pop($result)) {
                    $result[] = '..';
                }
            } elseif ($dir && $dir != '.') {
                $result[] = $dir;
            }
        }
        if (!end($pathA)) $result[] = '';
        $id = implode(':', $result);
    } elseif ($ns !== false && !str_contains($id, ':')) {
        //if link contains no namespace. add current namespace (if any)
        $id = $ns . ':' . $id;
    }

    if ($clean) $id = cleanID($id);
    return $id;
}

/**
 * Returns a full media id
 *
 * @param string $ns namespace which is context of id
 * @param string &$media (reference) relative media id, updated to resolved id
 * @param bool &$exists (reference) updated with existance of media
 * @param int|string $rev
 * @param bool $date_at
 * @deprecated 2020-09-30
 */
function resolve_mediaid($ns, &$media, &$exists, $rev = '', $date_at = false)
{
    dbg_deprecated(MediaResolver::class);
    $resolver = new MediaResolver("$ns:deprecated");
    $media = $resolver->resolveId($media, $rev, $date_at);
    $exists = media_exists($media, $rev, false, $date_at);
}

/**
 * Returns a full page id
 *
 * @deprecated 2020-09-30
 * @param string $ns namespace which is context of id
 * @param string &$page (reference) relative page id, updated to resolved id
 * @param bool &$exists (reference) updated with existance of media
 * @param string $rev
 * @param bool $date_at
 */
function resolve_pageid($ns, &$page, &$exists, $rev = '', $date_at = false)
{
    dbg_deprecated(PageResolver::class);

    global $ID;
    if (getNS($ID) == $ns) {
        $context = $ID; // this is usually the case
    } else {
        $context = "$ns:deprecated"; // only used when a different context namespace was given
    }

    $resolver = new PageResolver($context);
    $page = $resolver->resolveId($page, $rev, $date_at);
    $exists = page_exists($page, $rev, false, $date_at);
}

/**
 * Returns the name of a cachefile from given data
 *
 * The needed directory is created by this function!
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 *
 * @param string $data  This data is used to create a unique md5 name
 * @param string $ext   This is appended to the filename if given
 * @return string       The filename of the cachefile
 */
function getCacheName($data, $ext = '')
{
    global $conf;
    $md5  = md5($data);
    $file = $conf['cachedir'] . '/' . $md5[0] . '/' . $md5 . $ext;
    io_makeFileDir($file);
    return $file;
}

/**
 * Checks a pageid against $conf['hidepages']
 *
 * @author Andreas Gohr <gohr@cosmocode.de>
 *
 * @param string $id page id
 * @return bool
 */
function isHiddenPage($id)
{
    $data = ['id' => $id, 'hidden' => false];
    Event::createAndTrigger('PAGEUTILS_ID_HIDEPAGE', $data, '_isHiddenPage');
    return $data['hidden'];
}

/**
 * callback checks if page is hidden
 *
 * @param array $data event data    - see isHiddenPage()
 */
function _isHiddenPage(&$data)
{
    global $conf;
    global $ACT;

    if ($data['hidden']) return;
    if (empty($conf['hidepages'])) return;
    if ($ACT == 'admin') return;

    if (preg_match('/' . $conf['hidepages'] . '/ui', ':' . $data['id'])) {
        $data['hidden'] = true;
    }
}

/**
 * Reverse of isHiddenPage
 *
 * @author Andreas Gohr <gohr@cosmocode.de>
 *
 * @param string $id page id
 * @return bool
 */
function isVisiblePage($id)
{
    return !isHiddenPage($id);
}

/**
 * Format an id for output to a user
 *
 * Namespaces are denoted by a trailing “:*”. The root namespace is
 * “*”. Output is escaped.
 *
 * @author Adrian Lang <lang@cosmocode.de>
 *
 * @param string $id page id
 * @return string
 */
function prettyprint_id($id)
{
    if (!$id || $id === ':') {
        return '*';
    }
    if (str_ends_with($id, ':')) {
        $id .= '*';
    }
    return hsc($id);
}

/**
 * Encode a UTF-8 filename to use on any filesystem
 *
 * Uses the 'fnencode' option to determine encoding
 *
 * When the second parameter is true the string will
 * be encoded only if non ASCII characters are detected -
 * This makes it safe to run it multiple times on the
 * same string (default is true)
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 * @see    urlencode
 *
 * @param string $file file name
 * @param bool   $safe if true, only encoded when non ASCII characters detected
 * @return string
 */
function utf8_encodeFN($file, $safe = true)
{
    global $conf;
    if ($conf['fnencode'] == 'utf-8') return $file;

    if ($safe && preg_match('#^[a-zA-Z0-9/_\-\.%]+$#', $file)) {
        return $file;
    }

    if ($conf['fnencode'] == 'safe') {
        return SafeFN::encode($file);
    }

    $file = urlencode($file);
    $file = str_replace('%2F', '/', $file);
    return $file;
}

/**
 * Decode a filename back to UTF-8
 *
 * Uses the 'fnencode' option to determine encoding
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 * @see    urldecode
 *
 * @param string $file file name
 * @return string
 */
function utf8_decodeFN($file)
{
    global $conf;
    if ($conf['fnencode'] == 'utf-8') return $file;

    if ($conf['fnencode'] == 'safe') {
        return SafeFN::decode($file);
    }

    return urldecode($file);
}

/**
 * Find a page in the current namespace (determined from $ID) or any
 * higher namespace that can be accessed by the current user,
 * this condition can be overriden by an optional parameter.
 *
 * Used for sidebars, but can be used other stuff as well
 *
 * @todo   add event hook
 *
 * @param  string $page the pagename you're looking for
 * @param bool $useacl only return pages readable by the current user, false to ignore ACLs
 * @return false|string the full page id of the found page, false if any
 */
function page_findnearest($page, $useacl = true)
{
    if ((string) $page === '') return false;
    global $ID;

    $ns = $ID;
    do {
        $ns = getNS($ns);
        $pageid = cleanID("$ns:$page");
        if (page_exists($pageid) && (!$useacl || auth_quickaclcheck($pageid) >= AUTH_READ)) {
            return $pageid;
        }
    } while ($ns !== false);

    return false;
}
