path: root/ratatoeskr/frontend.php

<?php
/*
 * File: ratatoeskr/frontend.php
 * All the stuff for the frontend (i.e. what the visitor of the website sees).
 *
 * License:
 * This file is part of Ratatöskr.
 * Ratatöskr is licensed unter the MIT / X11 License.
 * See "ratatoeskr/licenses/ratatoeskr" for more information.
 */

use r7r\ste;
use r7r\cms\sys\Env;
use r7r\cms\sys\Esc;

require_once(dirname(__FILE__) . "/sys/utils.php");
require_once(dirname(__FILE__) . "/languages.php");
require_once(dirname(__FILE__) . "/config.php");
require_once(dirname(__FILE__) . "/sys/models.php");
require_once(dirname(__FILE__) . "/sys/textprocessors.php");

/** @var ste\STECore $ste */
assert(isset($ste));

/*
 * Function: section_transform_ste
 * Transforms an <Section> object to an array, so it can be accessed via a STE template.
 *
 * Parameters:
 *  $section - <Section> object.
 *  $lang - The current language.
 *
 * Returns:
 *  Array with these fields:
 *  * id    - The ID of the section.
 *  * name  - The name of the section.
 *  * title - The title of the section in the current language
 *  * __obj - The <Section> object. Useful for plugins, so they do not need to fetch the object from the database again.
 */
function section_transform_ste($section, $lang)
{
    return [
        "id"    => $section->get_id(),
        "name"  => $section->name,
        "title" => $section->title[$lang]->text,
        "__obj" => $section
    ];
}

/*
 * Function: tag_transform_ste
 * Transforms an <Tag> object to an array, so it can be accessed via a STE template.
 *
 * Parameters:
 *  $section - <Tag> object.
 *  $lang - The current language.
 *
 * Returns:
 *  Array with these fields:
 *  * id    - The ID of the tag.
 *  * name  - The name of the tag.
 *  * title - The title in the current language.
 *  * __obj - The <Tag> object. Useful for plugins, so they do not need to fetch the object from the database again.
 */
function tag_transform_ste($tag, $lang)
{
    try {
        return [
            "id"    => $tag->get_id(),
            "name"  => $tag->name,
            "title" => $tag->title[$lang]->text,
            "__obj" => $tag
        ];
    } catch (DoesNotExistError $e) {
        return false;
    }
}

/*
 * Function: article_transform_ste
 * Transforms an <Article> object to an array, so it can be accessed via a STE template.
 *
 * Parameters:
 *  $article - <Article> object.
 *  $lang - The current language.
 *
 * Returns:
 *  Array with these fields:
 *  * id
 *  * urlname
 *  * fullurl
 *  * title
 *  * text
 *  * excerpt
 *  * custom (array: name=>value)
 *  * status (numeric)
 *  * section (sub-fields: <section_transform_ste>)
 *  * timestamp
 *  * tags (array(sub-fields: <tag_transform_ste>))
 *  * languages (array: language name=>url)
 *  * comments_allowed
 *  * __obj - Useful for plugins, so they do not need to fetch the object from the database again.
 */
function article_transform_ste($article, $lang)
{
    global $rel_path_to_root;

    $textprocessors = Env::getGlobal()->textprocessors();

    $languages = [];
    $a_section = $article->get_section();
    foreach ($article->title as $language => $_) {
        $languages[$language] = "$rel_path_to_root/$language/{$a_section->name}/{$article->urlname}";
    }

    return [
        "id"               => $article->get_id(),
        "urlname"          => $article->urlname,
        "fullurl"          => Esc::esc("$rel_path_to_root/$lang/{$a_section->name}/{$article->urlname}"),
        "title"            => Esc::esc($article->title[$lang]->text),
        "text"             => $textprocessors->mustApply(str_replace("%root%", $rel_path_to_root, $article->text[$lang]->text), $article->text[$lang]->texttype),
        "excerpt"          => $textprocessors->mustApply(str_replace("%root%", $rel_path_to_root, $article->excerpt[$lang]->text), $article->excerpt[$lang]->texttype),
        "custom"           => $article->custom,
        "status"           => $article->status,
        "section"          => section_transform_ste($a_section, $lang),
        "timestamp"        => $article->timestamp,
        "tags"             => array_filter(array_map(function ($tag) use ($lang) {
            return tag_transform_ste($tag, $lang);
        }, $article->get_tags())),
        "languages"        => $languages,
        "comments_allowed" => $article->allow_comments,
        "__obj"            => $article
    ];
}

/*
 * Function: comment_transform_ste
 * Transforms an <Comment> object to an array, so it can be accessed via a STE template.
 *
 * Parameters:
 *  $comment - <Comment> object.
 *
 * Returns:
 *  Array with these fields:
 *  * id
 *  * text
 *  * author
 *  * timestamp
 */
function comment_transform_ste($comment)
{
    return [
        "id"        => $comment->get_id(),
        "text"      => $comment->create_html(),
        "author"    => Esc::esc($comment->author_name),
        "timestamp" => $comment->get_timestamp(),
        "__obj"     => $comment
    ];
}

/* Register some tags for the template engine */
/*
 * STETag: articles_get
 * Get articles by custom criterias. Will only get articles, that are available in the current language ($language).
 * The fields of an article can be looked up at <article_transform_ste>.
 *
 * Parameters:
 *  var        - (mandatory) The name of the variable, where the current article should be stored at.
 *  id         - (optional)  Filter by ID.
 *  urlname    - (optional)  Filter by urlname.
 *  section    - (optional)  Filter by section (section name).
 *  sectionvar - (optional)  Filter by section (Name of variable that contains a section).
 *  status     - (optional)  Filter by status (numeric, <Article::STATUS_>).
 *  tag        - (optional)  Filter by tag (tag name).
 *  tagvar     - (optional)  Filter by tag (Name of variable that contains a tag).
 *  sort       - (optional)  How to sort. Format: "fieldname direction" where fieldname is one of [id, urlname, title, timestamp] and direction is one of [asc, desc].
 *  perpage    - (optional)  How many articles should be shown per page (default unlimited).
 *  page       - (optional)  On which page are we (starting with 1). Useful in combination with $current[page], <page_prev> and <page_next>. (Default: 1)
 *  maxpage    - (optional)  (variable name) If given, the number of pages are stored in this variable.
 *  skip       - (optional)  How many articles should be skipped? (Default: none)
 *  count      - (optional)  How many articles to output. (Default unlimited)
 *
 * Tag Content:
 *  The tag's content will be executed for every article. The current article will be written to the variable specified by the var parameter before.
 *
 * Returns:
 *  All results from the tag content.
 */
$ste->register_tag("articles_get", function ($ste, $params, $sub) {
    $lang = $ste->vars["language"];

    if (!isset($params["var"])) {
        throw new ste\RuntimeError("Parameter var is needed in article_get!");
    }

    $criterias = ["langavail" => $lang, "onlyvisible" => true];
    if (isset($params["id"])) {
        $criterias["id"] = $params["id"];
    }
    if (isset($params["urlname"])) {
        $criterias["urlname"];
    }
    if (isset($params["status"])) {
        $criterias["status"] = $params["status"];
    }
    if (isset($params["sectionvar"])) {
        $sectionvar = $ste->get_var_by_name($params["sectionvar"]);
        $criterias["section"] = $sectionvar["__obj"];
    } elseif (isset($params["section"])) {
        try {
            $criterias["section"] = Section::by_name($params["section"]);
        } catch (DoesNotExistError $e) {
        }
    }
    if (isset($params["tagvar"])) {
        $tagvar = $ste->get_var_by_name($params["tagvar"]);
        $criterias["tag"] = $tagvar["__obj"];
    }
    if (isset($params["tag"])) {
        try {
            $criterias["tag"] = Tag::by_name($params["tag"]);
        } catch (DoesNotExistError $e) {
        }
    }

    $field     = null;
    $direction = null;
    if (isset($params["sort"])) {
        list($field, $direction) = explode(" ", $params["sort"]);
        if ($direction === null) {
            $field = null;
        }
        $direction = strtoupper($direction);
    }

    $result = Article::by_multi($criterias, $field, $direction, @$params["count"], @$params["skip"], @$params["perpage"], @$params["page"], $maxpage);

    $result = array_map(function ($article) use ($lang) {
        return article_transform_ste($article, $lang);
    }, $result);

    if (isset($params["perpage"]) and isset($params["maxpage"])) {
        $ste->set_var_by_name($params["maxpage"], $maxpage == 0 ? 1 : $maxpage);
    }

    $output = "";
    foreach ($result as $article) {
        $ste->set_var_by_name($params["var"], $article);
        $output .= $sub($ste);
    }
    return $output;
});

/*
 * STETag: section_list
 * Iterate over all sections.
 * The fields of a section can be looked up at <section_transform_ste>.
 *
 * Parameters:
 *  var             - (mandatory) The name of the variable, where the current section should be stored at.
 *  exclude         - (optional)  Sections to exclude
 *  include_default - (optional)  Should the default section be included (default: No).
 *
 * Tag Content:
 *  The tag's content will be executed for every section. The current section will be written to the variable specified by the var parameter before.
 *
 * Returns:
 *  All results from the tag content.
 */
$ste->register_tag("section_list", function ($ste, $params, $sub) {
    global $ratatoeskr_settings;
    $lang = $ste->vars["language"];

    $default_section = $ratatoeskr_settings["default_section"];

    if (!isset($params["var"])) {
        throw new ste\RuntimeException("Parameter var is needed in article_get!");
    }

    $result = Section::all();

    if (isset($params["exclude"])) {
        $exclude = explode(",", $params["exclude"]);
        $result = array_filter($result, function ($section) use ($exclude) {
            return !in_array($section->name, $exclude);
        });
    }

    $result = array_filter($result, function ($section) use ($default_section) {
        return $section->get_id() != $default_section;
    });

    $result = array_map(function ($section) use ($lang) {
        return section_transform_ste($section, $lang);
    }, $result);

    if ($ste->evalbool($params["include_default"])) {
        $default = section_transform_ste(Section::by_id($default_section), $lang);
        array_unshift($result, $default);
    }

    $output = "";
    foreach ($result as $section) {
        $ste->set_var_by_name($params["var"], $section);
        $output .= $sub($ste);
    }
    return $output;
});

/*
 * STETag: article_comments_count
 * Get the number of comments for an article.
 *
 * Parameters:
 *  article - (mandatory) The name of the variable, where the article is stored at.
 *
 * Returns:
 *  The number of comments.
 */
$ste->register_tag("article_comments_count", function ($ste, $params, $sub) {
    if (!isset($params["article"])) {
        throw new ste\RuntimeException("Need parameter 'article' in ste:article_comments_count.");
    }
    $tpl_article = $ste->get_var_reference($params["article"], false);
    $lang = $ste->vars["language"];

    if (isset($tpl_article["__obj"])) {
        $article = $tpl_article["__obj"];
    } else {
        try {
            $article = Article::by_id(@$tpl_article["id"]);
        } catch (DoesNotExistError $e) {
            return 0;
        }
    }
    $comments = $article->get_comments($lang, true);
    $tpl_article["__comments"] = $comments;
    return count($comments);
});

/*
 * STETag: article_comments
 * List all comments for an article.
 * The fields of a comment can be looked up at <comment_transform_ste>.
 *
 * Parameters:
 *  var     - (mandatory) The name of the variable, where the current comment should be stored at.
 *  article - (mandatory) The name of the variable, where the article is stored at.
 *  sort    - (optional)  Should the comments be sorted chronologically (asc) or inverse (desc)? Default: asc
 *
 * Tag Content:
 *  The tag's content will be executed for every comment. The current comment will be written to the variable specified by the var parameter before.
 *
 * Returns:
 *  All results from the tag content.
 */
$ste->register_tag("article_comments", function ($ste, $params, $sub) {
    if (!isset($params["var"])) {
        throw new ste\RuntimeException("Need parameter 'var' in ste:article_comments.");
    }
    if (!isset($params["article"])) {
        throw new ste\RuntimeException("Need parameter 'article' in ste:article_comments.");
    }
    $tpl_article = $ste->get_var_reference($params["article"], false);
    $lang = $ste->vars["language"];

    if (isset($tpl_article["__comments"])) {
        $comments = $tpl_article["__comments"];
    } else {
        if (isset($tpl_article["__obj"])) {
            $article = $tpl_article["__obj"];
        } else {
            try {
                $article = Article::by_id(@$tpl_article["id"]);
            } catch (DoesNotExistError $e) {
                return "";
            }
        }

        $comments = $article->get_comments($lang, true);
    }

    $sortdir = (@$params["sort"] == "desc") ? -1 : 1;
    usort($comments, function ($a, $b) use ($sortdir) {
        return ($a->get_timestamp() <=> $b->get_timestamp()) * $sortdir;
    });

    $comments = array_map("comment_transform_ste", $comments);

    $output = "";
    foreach ($comments as $comment) {
        $ste->set_var_by_name($params["var"], $comment);
        $output .= $sub($ste);
    }
    return $output;
});

/*
 * STETag: comment_form
 * Generates a HTML form tag that allows the visitor to write a comment.
 *
 * Parameters:
 *  article    - (mandatory) The name of the variable, where the article is stored at.
 *  default    - (optional)  If not empty, a default formular with the mandatory fields will be generated.
 *  previewbtn - (optional)  If not empty and default form is choosen, a preview button will also be generated.
 *
 * Tag Content:
 *  The tag's content will be written into the HTML form tag.
 *  You have at least to define these fields:
 *
 *  * <input type="text" name="author_name" />    - The Name of the author.
 *  * <input type="text" name="author_mail" />    - The E-Mailaddress of the author.
 *  * <textarea name="comment_text"></textarea>   - The Text of the comment.
 *  * <input type="submit" name="post_comment" /> - Submit button.
 *
 *  You might also want to define this:
 *
 *  * <input type="submit" name="preview_comment" /> - For a preview of the comment.
 *
 *  If the parameter default is not empty, the tag's content will be thrown away.
 *
 * Returns:
 *  The finished HTML form.
 *
 * See Also:
 *  The "prevcomment" field in <$current>.
 */
$ste->register_tag("comment_form", function ($ste, $params, $sub) {
    global $translation;
    if (!isset($params["article"])) {
        throw new ste\RuntimeException("Need parameter 'article' in ste:comment_form.");
    }
    $tpl_article = $ste->get_var_reference($params["article"], false);

    if (isset($tpl_article["__obj"])) {
        $article = $tpl_article["__obj"];
    } else {
        try {
            $article = Article::by_id(@$tpl_article["id"]);
        } catch (DoesNotExistError $e) {
            return "";
        }
    }

    if (!$article->allow_comments) {
        return "";
    }

    /* A token protects from double sending of the same form and is also a simple protection from stupid spambots. */
    $token = uniqid("", true);
    $_SESSION["ratatoeskr_comment_tokens"][$token] = time();

    $form_header = "<form action=\"{$tpl_article["fullurl"]}?comment\" method=\"post\" accept-charset=\"UTF-8\"><input type=\"hidden\" name=\"comment_token\" value=\"$token\" />";

    $previewbtn = $ste->evalbool(@$params["previewbtn"]) ? " <input type=\"submit\" name=\"preview_comment\" value=\"{$translation["comment_form_preview"]}\" />" : "";

    if ($ste->evalbool(@$params["default"])) {
        $form_body = "<p>{$translation["comment_form_name"]}: <input type=\"text\" name=\"author_name\" value=\"" . Esc::esc((string)$_POST["author_name"] ?? '') . "\" /></p>
<p>{$translation["comment_form_mail"]}: <input type=\"text\" name=\"author_mail\" value=\"" . Esc::esc((string)$_POST["author_mail"] ?? '') . "\" /></p>
<p>{$translation["comment_form_text"]}:<br /><textarea name=\"comment_text\" cols=\"50\" rows=\"10\">" . Esc::esc((string)@$_POST["comment_text"] ?? '') . "</textarea></p>
<p><input type=\"submit\" name=\"post_comment\" value=\"{$translation["comment_form_submit"]}\" />$previewbtn</p>";
    } else {
        $ste->vars["current"]["oldcomment"] = [
            "name" => @$_POST["author_name"],
            "mail" => @$_POST["author_mail"],
            "text" => @$_POST["comment_text"]
        ];
        $form_body = $sub($ste);
        unset($ste->vars["current"]["oldcomment"]);
    }

    return "$form_header\n$form_body\n</form>";
});

/*
 * STETags: Page control
 * These tags can create links to the previous/next page.
 *
 * page_prev - Link to the previous page (if available).
 * page_next - Link to the next page (if available).
 *
 * Parameters:
 *  current - (mandatory) The current page number.
 *  maxpage - (mandatory) How many pages in total?
 *  default - (optional)  If not empty, a default localized link text will be used.
 *
 * Tag Content:
 *  The tag's content will be used as the link text.
 *
 * Returns:
 *  A Link to the previous / next page.
 */

$ste->register_tag("page_prev", function ($ste, $params, $sub) {
    global $translation;
    if (!isset($params["current"])) {
        throw new ste\RuntimeException("Need parameter 'current' in ste:page_prev.");
    }
    if (!isset($params["maxpage"])) {
        throw new ste\RuntimeException("Need parameter 'maxpage' in ste:page_prev.");
    }

    if ($params["current"] == 1) {
        return "";
    }

    parse_str(parse_url($_SERVER["REQUEST_URI"], PHP_URL_QUERY), $query);
    $query["page"] = $params["current"] - 1;
    $url = $_SERVER["REDIRECT_URL"] . "?" . http_build_query($query);
    return "<a href=\"" . Esc::esc($url) . "\">" . (($ste->evalbool(@$params["default"])) ? $translation["page_prev"] : $sub($ste)) . "</a>";
});

$ste->register_tag("page_next", function ($ste, $params, $sub) {
    global $translation;
    if (!isset($params["current"])) {
        throw new ste\RuntimeException("Need parameter 'current' in ste:page_next.");
    }
    if (!isset($params["maxpage"])) {
        throw new ste\RuntimeException("Need parameter 'maxpage' in ste:page_next.");
    }

    if ($params["current"] == $params["maxpage"]) {
        return "";
    }

    parse_str(parse_url($_SERVER["REQUEST_URI"], PHP_URL_QUERY), $query);
    $query["page"] = $params["current"] + 1;
    $url = $_SERVER["REDIRECT_URL"] . "?" . http_build_query($query);
    return "<a href=\"" . Esc::esc($url) . "\">" . (($ste->evalbool(@$params["default"])) ? $translation["page_next"] : $sub($ste)) . "</a>";
});

/*
 * STETag: languages
 * List all languages available in the current context.
 *
 * Parameters:
 *  var - (mandatory) The name of the variable, where the current language information should be stored at.
 *
 * Sub-fields of var:
 *  short    - 2 letter code of language
 *  fullname - The full name of the language
 *  url      - URL to the current page in this language
 *
 * Tag Content:
 *  The tag's content will be executed for every language. The current language will be written to the variable specified by the var parameter before.
 *
 * Returns:
 *  All results from the tag content.
 */
$ste->register_tag("languages", function ($ste, $params, $sub) {
    global $languages, $ratatoeskr_settings, $rel_path_to_root;

    if (!isset($params["var"])) {
        throw new Exception("Need parameter 'var' in ste:languages.");
    }

    $langs = [];
    if (isset($ste->vars["current"]["article"])) {
        if (isset($ste->vars["current"]["article"]["__obj"])) {
            $article = $ste->vars["current"]["article"]["__obj"];
        } else {
            try {
                $article = Article::by_id($ste->vars["current"]["article"]["id"]);
            } catch (DoesNotExistError $e) {
            }
        }
        foreach ($article->title as $lang => $_) {
            $langs[] = $lang;
        }
    } else {
        foreach ($ratatoeskr_settings["languages"] as $lang) {
            $langs[] = $lang;
        }
    }

    $output = "";
    foreach ($langs as $lang) {
        $ste->set_var_by_name($params["var"], [
            "short"    => $lang,
            "fullname" => Esc::esc($languages[$lang]["language"]),
            "url"      => Esc::esc("$rel_path_to_root/$lang/" . implode("/", array_slice($ste->vars["current"]["url_fragments"], 1)))
        ]);
        $output .= $sub($ste);
    }
    return $output;
});

/*
 * STETag: styles_load
 * Load all current styles.
 *
 * Parameters:
 *  mode - (optional) Either "embed" or "link". Default: link
 *
 * Returns:
 *  The current styles (either linked or embedded)
 */
$ste->register_tag("styles_load", function ($ste, $params, $sub) {
    global $rel_path_to_root;
    if (isset($params["mode"]) and (($params["mode"] == "embed") or ($params["mode"] == "link"))) {
        $mode = $params["mode"];
    } else {
        $mode = "link";
    }

    if ($mode == "embed") {
        $output = "";
        if (isset($ste->vars["current"]["__style_objs"])) {
            foreach ($ste->vars["current"]["__style_objs"] as $style) {
                $output .= "/* Style: {$style->name} */\n" . $style->code . "\n";
            }
        } else {
            foreach ($ste->vars["current"]["styles"] as $stylename) {
                try {
                    $style = Style::by_name($stylename);
                    $output .= "/* Style: $stylename */\n" . str_replace("%root%", $rel_path_to_root, $style->code) . "\n";
                } catch (DoesNotExistError $e) {
                    $output .= "/* Warning: Failed to load style: $stylename */\n";
                }
            }
        }
        $output = "<style type=\"text/css\">\n" . Esc::esc($output) . "</style>";
    } else {
        $output = "";
        foreach ($ste->vars["current"]["styles"] as $stylename) {
            $output .= "<link rel=\"stylesheet\" type=\"text/css\" href=\"$rel_path_to_root/css.php?name=" . Esc::esc($stylename) . "\" />\n";
        }
    }
    return $output;
});

/*
 * STETag: title
 * Generate a HTML title tag for your site.
 *
 * Tag Content:
 *  The name of your site.
 *
 * Returns:
 *  A HTML title tag that describes the current (sub)page.
 */
$ste->register_tag("title", function ($ste, $params, $sub) {
    $pagetitle = $sub($ste);
    if (isset($ste->vars["current"]["article"])) {
        return "<title>" . Esc::esc($ste->vars["current"]["article"]["title"]) . " – $pagetitle" . "</title>";
    }
    if (isset($ste->vars["current"]["section"])) {
        return "<title>" . Esc::esc($ste->vars["current"]["section"]["title"]) . " – $pagetitle" . "</title>";
    }
    return "<title>$pagetitle</title>";
});

function make_on_anything_tag($field)
{
    return function ($ste, $params, $sub) use ($field) {
        if ($ste->evalbool(@$ste->vars["current"][$field])) {
            if (!empty($params["var"])) {
                $ste->set_var_by_name($params["var"], $ste->vars["current"][$field]);
            }
            return $sub($ste);
        }
        return "";
    };
}

/*
 * STETag: on_article
 * Execute tag content, if currently an article is requested.
 *
 * Parameters:
 *  var - (optional) If set, the article will be stored in the variable with that name (see <article_transform_ste> for sub-fields).
 *
 * Returns:
 *  The executed tag content, if an article was requested.
 */
$ste->register_tag("on_article", make_on_anything_tag("article"));

/*
 * STETag: on_tag
 * Execute tag content, if currently a tag is requested.
 *
 * Parameters:
 *  var - (optional) If set, the tag will be stored in the variable with that name (see <tag_transform_ste> for sub-fields).
 *
 * Returns:
 *  The executed tag content, if a tag was requested.
 */
$ste->register_tag("on_tag", make_on_anything_tag("tag"));

/*
 * STETag: on_section
 * Execute tag content, if currently a section is requested.
 *
 * Parameters:
 *  var - (optional) If set, the section will be stored in the variable with that name (see <section_transform_ste> for sub-fields).
 *
 * Returns:
 *  The executed tag content, if a section was requested.
 */
$ste->register_tag("on_section", make_on_anything_tag("section"));

/*
 * STEVar: $current
 * Holds information about the current page in the frontend (the part of the webpage, the visitor sees).
 *
 * $current has these fields:
 *  * article       - Only set if a single article is shown. Holds information about an article. (sub-fields are described at <article_transform_ste>).
 *  * section       - Only set if a whole section is shown. Holds information about an section. (sub-fields are described at <section_transform_ste>).
 *  * tag           - Only set if all articles with the same tag should be shown (pseudo section _tags). Holds information about a tag. (sub-fields are described at <tag_transform_ste>).
 *  * page          - Which subpage is shown? Useful with <page_prev>, <page_next> and the page parameter of <articles_get>. Default: 1
 *  * commented     - True, if the visitor has successfully written a comment.
 *  * comment_fail  - If the user tried to comment, but the system rejected the comment, this will be set and will contain the error message.
 *  * comment_prev  - If the user wanted to preview the article, this will be set and contain the HTML code of the comment.
 *  * styles        - The styles, that should be loaded. You can also just use <styles_load>.
 *  * url_fragments - Array of URL parts. Mainly used internally, so you *really* should not modify this one...
 *  * oldcomment    - The data of the previously sent formular (subfields: name, mail, text). Only set inside the <comment_form> tag.
 *
 *  Plugins might insert their own $current fields.
 */

/*
 * STEVar: $language
 * The short form (e.g. "en" for English, "de" for German, ...) of the current language.
 */

$comment_validators = [
    function () /* Basic validator. Checks, if all mandatory fields are set and if the form token is okay. Also provides some stupid spambot protection...  */ {
        global $translation;
        if (empty($_POST["author_name"])) {
            throw new CommentRejected($translation["author_name_missing"]);
        }
        if (empty($_POST["author_mail"])) {
            throw new CommentRejected($translation["author_email_missing"]);
        }
        if (empty($_POST["comment_text"])) {
            throw new CommentRejected($translation["comment_text_missing"]);
        }
        if (!isset($_POST["comment_token"])) {
            throw new CommentRejected($translation["comment_form_invalid"]);
        }
        if (!isset($_SESSION["ratatoeskr_comment_tokens"][$_POST["comment_token"]])) {
            throw new CommentRejected($translation["comment_form_invalid"]);
        }
        if (time() - $_SESSION["ratatoeskr_comment_tokens"][$_POST["comment_token"]] < 10) { /* Comment filled in in under 10 seconds? Most likely a spambot. */
            throw new CommentRejected($translation["comment_too_fast"]);
        }
        unset($_SESSION["ratatoeskr_comment_tokens"][$_POST["comment_token"]]);
    }
];

$on_comment_store = [];

/*
 * Function: frontend_url_handler
 */
function frontend_url_handler(&$data, $url_now, &$url_next)
{
    global $ste, $ratatoeskr_settings, $languages, $comment_validators, $on_comment_store;
    $path = array_merge([$url_now], $url_next);
    $url_next = [];

    /* If no language or an invalid language was given, fix it. */
    if ((count($path) == 0) or (!isset($languages[$path[0]]))) {
        if (count($path) > 0) {
            array_shift($path);
        }
        array_unshift($path, $ratatoeskr_settings["default_language"]);
    }

    $ste->vars["current"]["url_fragments"] = $path;

    $lang = array_shift($path);
    $ste->vars["language"] = $lang;
    load_language($languages[$lang]["translation_exist"] ? $lang : "en"); /* English is always available */

    if (count($path) != 0) {
        $section_name = array_shift($path);
    } else {
        $section_name = null;
    }

    if ($section_name == "_tags") {
        try {
            $tag = Tag::by_name(array_shift($path));
        } catch (DoesNotExistError $e) {
            throw new NotFoundError();
        }
        $ste->vars["current"]["tag"] = tag_transform_ste($tag, $lang);
    } else {
        if ($section_name === null) {
            $section = Section::by_id($ratatoeskr_settings["default_section"]);
        } else {
            try {
                $section = Section::by_name($section_name);
            } catch (DoesNotExistError $e) {
                throw new NotFoundError();
            }
        }

        if (count($path)== 0) {
            $ste->vars["current"]["section"] = section_transform_ste($section, $lang);
        } else {
            try {
                $article = Article::by_urlname(array_shift($path));
            } catch (DoesNotExistError $e) {
                throw new NotFoundError();
            }
            $ste->vars["current"]["article"] = article_transform_ste($article, $lang);

            if (isset($_GET["comment"])) {
                if (isset($_POST["preview_comment"])) {
                    $ste->vars["current"]["comment_prev"] = Comment::htmlize_comment_text($_POST["comment_text"]);
                } elseif (isset($_POST["post_comment"])) {
                    $rejected = false;
                    try {
                        foreach ($comment_validators as $validator) {
                            call_user_func($validator);
                        }
                    } catch (CommentRejected $e) {
                        $ste->vars["current"]["comment_fail"] = Esc::esc($e->getMessage());
                        $rejected = true;
                    }
                    if (!$rejected) {
                        $comment = Comment::create($article, $lang);
                        $comment->author_name = $_POST["author_name"];
                        $comment->author_mail = $_POST["author_mail"];
                        $comment->text        = $_POST["comment_text"];
                        $comment->save();
                        $ste->vars["current"]["commented"] = "Yes";
                        foreach ($on_comment_store as $ocs_fx) {
                            call_user_func($ocs_fx, $comment);
                        }
                    }
                }
            }
        }
    }

    $ste->vars["current"]["page"] = (isset($_GET["page"]) and is_numeric($_GET["page"])) ? $_GET["page"] : 1;

    if (!isset($section)) {
        $section = Section::by_id($ratatoeskr_settings["default_section"]);
    }

    foreach ($section->get_styles() as $style) {
        $ste->vars["current"]["styles"][] = $style->name;
        $ste->vars["current"]["__style_objs"][] = $style;
    }
    echo $ste->exectemplate("/usertemplates/" . $section->template);
}

/*
 * Class: CommentRejected
 * An Exeption a comment validator can throw, if the validation failed.
 *
 * See Also:
 *  <register_comment_validator>
 */
class CommentRejected extends Exception
{
}