<?php
/*
 * Name: Image Ratings
 * Author: Shish <webmaster@shishnet.org>
 * Link: http://code.shishnet.org/shimmie2/
 * License: GPLv2
 * Description: Allow users to rate images "safe", "questionable" or "explicit"
 * Documentation:
 *  This shimmie extension provides filter:
 *  <ul>
 *    <li>rating = (safe|questionable|explicit|unknown)
 *      <ul>
 *        <li>rating=s -- safe images
 *        <li>rating=q -- questionable images
 *        <li>rating=e -- explicit images
 *        <li>rating=u -- Unknown rating
 *        <li>rating=sq -- safe and questionable images
 *      </ul>
 *  </ul>
 */

class RatingSetEvent extends Event
{
    /** @var Image */
    public $image;
    /** @var string  */
    public $rating;

    public function __construct(Image $image, string $rating)
    {
        assert(in_array($rating, ["s", "q", "e", "u"]));

        $this->image = $image;
        $this->rating = $rating;
    }
}

class Ratings extends Extension
{
    protected $db_support = [DatabaseDriver::MYSQL, DatabaseDriver::PGSQL];

    public function get_priority(): int
    {
        return 50;
    }

    public function onInitExt(InitExtEvent $event)
    {
        global $config;
        
        if ($config->get_int("ext_ratings2_version") < 2) {
            $this->install();
        }

        $config->set_default_string("ext_rating_anon_privs", 'squ');
        $config->set_default_string("ext_rating_user_privs", 'sqeu');
        $config->set_default_string("ext_rating_admin_privs", 'sqeu');
    }
    
    public function onSetupBuilding(SetupBuildingEvent $event)
    {
        $privs = [];
        $privs['Safe Only'] = 's';
        $privs['Safe and Unknown'] = 'su';
        $privs['Safe and Questionable'] = 'sq';
        $privs['Safe, Questionable, Unknown'] = 'squ';
        $privs['All'] = 'sqeu';

        $sb = new SetupBlock("Image Ratings");
        $sb->add_choice_option("ext_rating_anon_privs", $privs, "Anonymous: ");
        $sb->add_choice_option("ext_rating_user_privs", $privs, "<br>Users: ");
        $sb->add_choice_option("ext_rating_admin_privs", $privs, "<br>Admins: ");
        $event->panel->add_block($sb);
    }
    
    // public function onPostListBuilding(PostListBuildingEvent $event)
    // {
    //     global $user;
    //     if ($user->is_admin() && !empty($event->search_terms)) {
    //         $this->theme->display_bulk_rater(Tag::implode($event->search_terms));
    //     }
    // }

    
    public function onDisplayingImage(DisplayingImageEvent $event)
    {
        global $user, $page;
        /**
         * Deny images upon insufficient permissions.
         **/
        $user_view_level = Ratings::get_user_privs($user);
        $user_view_level = preg_split('//', $user_view_level, -1);
        if (!in_array($event->image->rating, $user_view_level)) {
            $page->set_mode(PageMode::REDIRECT);
            $page->set_redirect(make_link("post/list"));
        }
    }
    
    public function onRatingSet(RatingSetEvent $event)
    {
        if (empty($event->image->rating)) {
            $old_rating = "";
        } else {
            $old_rating = $event->image->rating;
        }
        $this->set_rating($event->image->id, $event->rating, $old_rating);
    }
    
    public function onImageInfoBoxBuilding(ImageInfoBoxBuildingEvent $event)
    {
        $event->add_part($this->theme->get_rater_html($event->image->id, $event->image->rating, $this->can_rate()), 80);
    }
    
    public function onImageInfoSet(ImageInfoSetEvent $event)
    {
        if ($this->can_rate() && isset($_POST["rating"])) {
            $rating = $_POST["rating"];
            if (Ratings::rating_is_valid($rating)) {
                send_event(new RatingSetEvent($event->image, $rating));
            }
        }
    }

    public function onParseLinkTemplate(ParseLinkTemplateEvent $event)
    {
        $event->replace('$rating', $this->rating_to_human($event->image->rating));
    }

    public function onSearchTermParse(SearchTermParseEvent $event)
    {
        global $user;
        
        $matches = [];
        if (is_null($event->term) && $this->no_rating_query($event->context)) {
            $set = Ratings::privs_to_sql(Ratings::get_user_privs($user));
            $event->add_querylet(new Querylet("rating IN ($set)"));
        }
        if (preg_match("/^rating[=|:](?:([sqeu]+)|(safe|questionable|explicit|unknown))$/D", strtolower($event->term), $matches)) {
            $ratings = $matches[1] ? $matches[1] : $matches[2][0];
            $ratings = array_intersect(str_split($ratings), str_split(Ratings::get_user_privs($user)));
            $set = "'" . join("', '", $ratings) . "'";
            $event->add_querylet(new Querylet("rating IN ($set)"));
        }
    }

    public function onTagTermParse(TagTermParseEvent $event)
    {
        $matches = [];

        if (preg_match("/^rating[=|:](?:([sqeu]+)|(safe|questionable|explicit|unknown))$/D", strtolower($event->term), $matches) && $event->parse) {
            $ratings = $matches[1] ? $matches[1] : $matches[2][0];
            $ratings = array_intersect(str_split($ratings), str_split(Ratings::get_user_privs($user)));

            $rating = $ratings[0];
            
            $image = Image::by_id($event->id);

            $re = new RatingSetEvent($image, $rating);

            send_event($re);
        }

        if (!empty($matches)) {
            $event->metatag = true;
        }
    }
    
    public function onBulkActionBlockBuilding(BulkActionBlockBuildingEvent $event)
    {
        global $user;

        if ($user->can("bulk_edit_image_rating")) {
            $event->add_action("bulk_rate","Set (R)ating", "r","",$this->theme->get_selection_rater_html("u","bulk_rating"));
        }
    }

    public function onBulkAction(BulkActionEvent $event)
    {
        global $user;

        switch ($event->action) {
            case "bulk_rate":
                if (!isset($_POST['bulk_rating'])) {
                    return;
                }
                if ($user->can("bulk_edit_image_rating")) {
                    $rating = $_POST['bulk_rating'];
                    $total = 0;
                    foreach ($event->items as $image) {
                        send_event(new RatingSetEvent($image, $rating));
                        $total++;
                    }
                    flash_message("Rating set for $total items");
                }
                break;
        }
    }

    public function onPageRequest(PageRequestEvent $event)
    {
        global $user, $page;
        
        if ($event->page_matches("admin/bulk_rate")) {
            if (!$user->can("bulk_edit_image_rating")) {
                throw new PermissionDeniedException();
            } else {
                $n = 0;
                while (true) {
                    $images = Image::find_images($n, 100, Tag::explode($_POST["query"]));
                    if (count($images) == 0) {
                        break;
                    }
                    
                    reset($images); // rewind to first element in array.
                    
                    foreach ($images as $image) {
                        send_event(new RatingSetEvent($image, $_POST['rating']));
                    }
                    $n += 100;
                }
                #$database->execute("
                #	update images set rating=? where images.id in (
                #		select image_id from image_tags join tags
                #		on image_tags.tag_id = tags.id where tags.tag = ?);
                #	", array($_POST["rating"], $_POST["tag"]));
                $page->set_mode(PageMode::REDIRECT);
                $page->set_redirect(make_link("post/list"));
            }
        }
    }

    public static function get_user_privs(User $user): string
    {
        global $config;

        if ($user->is_anonymous()) {
            $sqes = $config->get_string("ext_rating_anon_privs");
        } elseif ($user->is_admin()) {
            $sqes = $config->get_string("ext_rating_admin_privs");
        } else {
            $sqes = $config->get_string("ext_rating_user_privs");
        }
        return $sqes;
    }

    public static function privs_to_sql(string $sqes): string
    {
        $arr = [];
        $length = strlen($sqes);
        for ($i=0; $i<$length; $i++) {
            $arr[] = "'" . $sqes[$i] . "'";
        }
        $set = join(', ', $arr);
        return $set;
    }

    public static function rating_to_human(string $rating): string
    {
        switch ($rating) {
            case "s": return "Safe";
            case "q": return "Questionable";
            case "e": return "Explicit";
            default:  return "Unknown";
        }
    }

    public static function rating_is_valid(string $rating): bool
    {
        switch ($rating) {
            case "s":
            case "q":
            case "e":
            case "u":
                return true;
            default:
                return false;
        }
    }

    /**
     * FIXME: this is a bit ugly and guessey, should have proper options
     */
    private function can_rate(): bool
    {
        global $config, $user;
        if ($user->is_anonymous() && $config->get_string("ext_rating_anon_privs") == "sqeu") {
            return false;
        }
        if ($user->is_admin()) {
            return true;
        }
        if (!$user->is_anonymous() && $config->get_string("ext_rating_user_privs") == "sqeu") {
            return true;
        }
        return false;
    }

    /**
     * #param string[] $context
     */
    private function no_rating_query(array $context): bool
    {
        foreach ($context as $term) {
            if (preg_match("/^rating[=|:]/", $term)) {
                return false;
            }
        }
        return true;
    }

    private function install()
    {
        global $database, $config;

        if ($config->get_int("ext_ratings2_version") < 1) {
            $database->Execute("ALTER TABLE images ADD COLUMN rating CHAR(1) NOT NULL DEFAULT 'u'");
            $database->Execute("CREATE INDEX images__rating ON images(rating)");
            $config->set_int("ext_ratings2_version", 3);
        }

        if ($config->get_int("ext_ratings2_version") < 2) {
            $database->Execute("CREATE INDEX images__rating ON images(rating)");
            $config->set_int("ext_ratings2_version", 2);
        }

        if ($config->get_int("ext_ratings2_version") < 3) {
            $database->Execute("UPDATE images SET rating = 'u' WHERE rating is null");
            switch ($database->get_driver_name()) {
                case DatabaseDriver::MYSQL:
                    $database->Execute("ALTER TABLE images CHANGE rating rating CHAR(1) NOT NULL DEFAULT 'u'");
                    break;
                case DatabaseDriver::PGSQL:
                    $database->Execute("ALTER TABLE images ALTER COLUMN rating SET DEFAULT 'u'");
                    $database->Execute("ALTER TABLE images ALTER COLUMN rating SET NOT NULL");
                    break;
            }
            $config->set_int("ext_ratings2_version", 3);
        }
    }

    private function set_rating(int $image_id, string $rating, string $old_rating)
    {
        global $database;
        if ($old_rating != $rating) {
            $database->Execute("UPDATE images SET rating=? WHERE id=?", [$rating, $image_id]);
            log_info("rating", "Rating for Image #{$image_id} set to: ".$this->rating_to_human($rating));
        }
    }
}