<?php

namespace OpenMind\System;

use DB\SQL\Mapper;

class Notifications extends Mapper
{
	public const FB_GENERIC = 0x01;
	public const FB_IMPORT = 0x02;
	public const FB_ADMIN = 0x03;
	public const FB_NOTALIVE = 0x0B;

	/**
	 * If you need custom notification or to simply send a command to client use
	 * FB_CUSTOM_NOTIFICATION+xxx where xxx is a number that identify your notification.
	 */
	public const FB_CUSTOM_NOTIFICATION = 0x4000;
	public const FB_REFRESH_FILTERS = self::FB_CUSTOM_NOTIFICATION + 1;

	private const TABLE_NAME = 'notifications';
	private const CODE_CONDITION = 'code=?';

	/**
	 * Initialize the notification mapper.
	 *
	 * @side-effects Connects the mapper to the configured database.
	 */
	public function __construct()
	{
		global $f3;

		parent::__construct($f3->get('DB'), self::TABLE_NAME);
	}

	/**
	 * Remove all notifications matching the supplied code.
	 *
	 * @param int $code Notification code to remove from the database.
	 * @return void
	 * @side-effects Deletes matching notification records.
	 */
	public function Remove(int $code)
	{
		$this->reset();
		$this->erase([self::CODE_CONDITION, $code]);
	}

	/**
	 * Remove every notification from the table.
	 *
	 * @return void
	 * @side-effects Truncates the notifications table.
	 */
	public function emptyAll()
	{
		global $f3;

		$f3->get('DB')->exec('TRUNCATE TABLE ' . self::TABLE_NAME);
	}

	/**
	 * Send a custom notification to the system.
	 *
	 * @param int $code Notification code, such as FB_GENERIC or FB_IMPORT.
	 * @param string|null $caption Notification caption.
	 * @param mixed $link Optional notification link.
	 * @return void
	 * @side-effects Persists the notification when the code is allowed.
	 */
	public function notify(int $code, string $caption = null, $link = null)
	{
		if ($code === $this::FB_GENERIC || $this->check($code)) {
			$this->reset();
			$this->code = $code;
			$this->caption = $caption;
			$this->link = $link;
			$this->save();
		}
	}

	/**
	 * Check whether a notification with the supplied code exists.
	 *
	 * @param int $code Notification code to check.
	 * @return bool Whether a matching notification exists.
	 * @side-effects Loads matching records into the mapper.
	 */
	public function check(int $code)
	{
		$this->load([self::CODE_CONDITION, $code]);
		return $this->dry();
	}
}