<?php

/**
 * Kunena Component
 *
 * @package        Kunena.Framework
 *
 * @copyright      Copyright (C) 2008 - @currentyear@ Kunena Team. All rights reserved.
 * @license        https://www.gnu.org/copyleft/gpl.html GNU/GPL
 * @link           https://www.kunena.org
 **/

namespace Kunena\Forum\Libraries;

\defined('_JEXEC') or die();

use Joomla\CMS\Factory;

/**
 * Class KunenaInstaller
 *
 * @since   Kunena 6.0
 */
class KunenaInstaller
{
    /**
     * @var     array
     * @since   Kunena 6.0
     */
    protected static $downgrade = ['3.1' => '3.0.95'];

    /**
     * @var     null
     * @since   Kunena 6.0
     */
    protected static $tables = null;

    /**
     * Check if we are allowed to downgrade from the new to the old version.
     *
     * @param   string  $version  version
     *
     * @return bool True if version can be safely downgraded.
     *
     * @since   Kunena 6.0
     */
    public static function canDowngrade(string $version): bool
    {
        if ($version == '@' . 'kunenaversion' . '@') {
            return true;
        }

        foreach (self::$downgrade as $major => $minor) {
            if (version_compare($version, $major, "<")) {
                continue;
            }

            if (version_compare($version, $minor, ">=")) {
                return true;
            }
        }

        return true;
    }

    /**
     * Get Kunena database schema version.
     *
     * @return  string  Version number or null.
     *
     * @since   Kunena 6.0
     */
    public static function getSchemaVersion()
    {
        // Check if Kunena can be found from the database.
        if (!self::detectTable('kunena_version')) {
            return false;
        }

        // Get installed version.
        $db    = Factory::getContainer()->get('DatabaseDriver');
        $query = $db->createQuery();
        $query->select('version')
            ->from($db->quoteName('#__kunena_version'))
            ->where($db->quoteName('state') . "=''")
            ->order($db->quoteName('id') . ' DESC');
        $query->setLimit(1);
        $db->setQuery($query);

        return $db->loadResult();
    }

    /**
     * Detect if table exists in the database.
     *
     * @param   string  $table   Table name to be found.
     * @param   string  $prefix  Database prefix.
     * @param   bool    $reload  Reload all tables.
     *
     * @return  boolean  True if the table exists in the database.
     *
     * @since   Kunena 6.0
     */
    public static function detectTable(string $table, $prefix = '#__', $reload = false): bool
    {
        $db = Factory::getContainer()->get('DatabaseDriver');

        if (self::$tables === null || $reload) {
            $list = $db->getTableList();

            self::$tables = [];

            foreach ($list as $item) {
                self::$tables[$item] = false;
            }
        }

        if ($prefix == '#__') {
            $prefix = $db->getPrefix();
        }

        $table = $prefix . $table;

        return isset(self::$tables[$table]);
    }

    /**
     * Get column type in the table.
     *
     * @param   string   $table   Table name to be found.
     * @param   string   $column  Table column to be searched.
     * @param   string   $prefix  Database prefix.
     * @param   boolean  $reload  Reload all tables.
     *
     * @return  boolean|null Column type or NULL if either table or column does not exist.
     *
     * @since   Kunena 6.0
     */
    public static function getTableColumn(string $table, string $column, $prefix = '#__', $reload = false): ?bool
    {
        if (!self::detectTable($table, $prefix, $reload)) {
            return false;
        }

        $db = Factory::getContainer()->get('DatabaseDriver');

        if ($prefix == '#__') {
            $prefix = $db->getPrefix();
        }

        $table = $prefix . $table;

        if (!isset(self::$tables[$table]['columns'])) {
            self::$tables[$table]['columns'] = $db->getTableColumns($table);
        }

        return isset(self::$tables[$table]['columns'][$column]) ? self::$tables[$table]['columns'][$column] : null;
    }
}