<?php

class RemoveImageHashBanEvent extends Event
{
    public $hash;

    public function __construct(string $hash)
    {
        $this->hash = $hash;
    }
}

class AddImageHashBanEvent extends Event
{
    public $hash;
    public $reason;

    public function __construct(string $hash, string $reason)
    {
        $this->hash = $hash;
        $this->reason = $reason;
    }
}

class ImageBan extends Extension
{
    public function onDatabaseUpgrade(DatabaseUpgradeEvent $event)
    {
        global $config, $database;
        if ($config->get_int("ext_imageban_version") < 1) {
            $database->create_table("image_bans", "
				id SCORE_AIPK,
				hash CHAR(32) NOT NULL,
				date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
				reason TEXT NOT NULL
			");
            $config->set_int("ext_imageban_version", 1);
        }
    }

    public function onDataUpload(DataUploadEvent $event)
    {
        global $database;
        $row = $database->get_row("SELECT * FROM image_bans WHERE hash = :hash", ["hash"=>$event->hash]);
        if ($row) {
            log_info("image_hash_ban", "Attempted to upload a blocked image ({$event->hash} - {$row['reason']})");
            throw new UploadException("Image ".html_escape($row["hash"])." has been banned, reason: ".format_text($row["reason"]));
        }
    }

    public function onPageRequest(PageRequestEvent $event)
    {
        global $database, $page, $user;

        if ($event->page_matches("image_hash_ban")) {
            if ($user->can(Permissions::BAN_IMAGE)) {
                if ($event->get_arg(0) == "add") {
                    $image = isset($_POST['image_id']) ? Image::by_id(int_escape($_POST['image_id'])) : null;
                    $hash = isset($_POST["hash"]) ? $_POST["hash"] : $image->hash;
                    $reason = isset($_POST['reason']) ? $_POST['reason'] : "DNP";

                    if ($hash) {
                        send_event(new AddImageHashBanEvent($hash, $reason));
                        flash_message("Image ban added");

                        if ($image) {
                            send_event(new ImageDeletionEvent($image));
                            flash_message("Image deleted");
                        }

                        $page->set_mode(PageMode::REDIRECT);
                        $page->set_redirect($_SERVER['HTTP_REFERER']);
                    }
                } elseif ($event->get_arg(0) == "remove") {
                    if (isset($_POST['hash'])) {
                        send_event(new RemoveImageHashBanEvent($_POST['hash']));

                        flash_message("Image ban removed");
                        $page->set_mode(PageMode::REDIRECT);
                        $page->set_redirect($_SERVER['HTTP_REFERER']);
                    }
                } elseif ($event->get_arg(0) == "list") {
                    $page_num = 0;
                    if ($event->count_args() == 2) {
                        $page_num = int_escape($event->get_arg(1));
                    }
                    $page_size = 100;
                    $page_count = ceil($database->get_one("SELECT COUNT(id) FROM image_bans")/$page_size);
                    $this->theme->display_Image_hash_Bans($page, $page_num, $page_count, $this->get_image_hash_bans($page_num, $page_size));
                }
            }
        }
    }

    public function onPageSubNavBuilding(PageSubNavBuildingEvent $event)
    {
        global $user;
        if ($event->parent==="system") {
            if ($user->can(Permissions::BAN_IMAGE)) {
                $event->add_nav_link("image_bans", new Link('image_hash_ban/list/1'), "Image Bans", NavLink::is_active(["image_hash_ban"]));
            }
        }
    }


    public function onUserBlockBuilding(UserBlockBuildingEvent $event)
    {
        global $user;
        if ($user->can(Permissions::BAN_IMAGE)) {
            $event->add_link("Image Bans", make_link("image_hash_ban/list/1"));
        }
    }

    public function onAddImageHashBan(AddImageHashBanEvent $event)
    {
        global $database;
        $database->Execute(
            "INSERT INTO image_bans (hash, reason, date) VALUES (?, ?, now())",
            [$event->hash, $event->reason]
        );
        log_info("image_hash_ban", "Banned hash {$event->hash} because '{$event->reason}'");
    }

    public function onRemoveImageHashBan(RemoveImageHashBanEvent $event)
    {
        global $database;
        $database->Execute("DELETE FROM image_bans WHERE hash = ?", [$event->hash]);
    }

    public function onImageAdminBlockBuilding(ImageAdminBlockBuildingEvent $event)
    {
        global $user;
        if ($user->can(Permissions::BAN_IMAGE)) {
            $event->add_part($this->theme->get_buttons_html($event->image));
        }
    }

    // DB funness

    public function get_image_hash_bans(int $page, int $size=100): array
    {
        global $database;

        // FIXME: many
        $size_i = int_escape($size);
        $offset_i = int_escape($page-1)*$size_i;
        $where = ["(1=1)"];
        $args = [];
        if (!empty($_GET['hash'])) {
            $where[] = 'hash = ?';
            $args[] = $_GET['hash'];
        }
        if (!empty($_GET['reason'])) {
            $where[] = 'reason SCORE_ILIKE ?';
            $args[] = "%".$_GET['reason']."%";
        }
        $where = implode(" AND ", $where);
        $bans = $database->get_all($database->scoreql_to_sql("
			SELECT *
			FROM image_bans
			WHERE $where
			ORDER BY id DESC
			LIMIT $size_i
			OFFSET $offset_i
			"), $args);
        if ($bans) {
            return $bans;
        } else {
            return [];
        }
    }

    // in before resolution limit plugin
    public function get_priority(): int
    {
        return 30;
    }
}