<?php
namespace app\models;

use app\components\helpers\ValueHelper;
use app\models\core\User;
use yii\behaviors\TimestampBehavior;
use yii\db\ActiveRecord;
use yii\db\Expression;
use yii\helpers\ArrayHelper;

/**
 * Class Session
 * @package app\models
 * @property integer $user_id
 * @property integer $duration
 * @property string $login_at
 * @property string $logout_at
 * @property string $seen_at
 */
class Session extends ActiveRecord
{
    /** @var integer token expiration, minutes */
    protected $tokenExpiration;

    const EXPIRES_DEFAULT = 60;

    public function init()
    {
        parent::init();

        $this->tokenExpiration = self::getTokenExpiration();
    }

    protected static function getTokenExpiration()
    {
        return ArrayHelper::getValue(\Yii::$app->params, 'session.expires', self::EXPIRES_DEFAULT);
    }

    public static function tableName()
    {
        return 'session';
    }

    public function behaviors()
    {
        return [
            [
                'class' => TimestampBehavior::className(),
                'createdAtAttribute' => 'login_at',
                'updatedAtAttribute' => null,
                'value' => ValueHelper::now(),
            ],
        ];
    }

    public static function start($attributes)
    {
        $session = new static($attributes);

        return $session->save();
    }

    public function beforeSave($insert)
    {
        if (!$this->logout_at) {
            $this->seen_at = ValueHelper::now();
        }

        return parent::beforeSave($insert);
    }

    public function stop()
    {
        if ($this->logout_at) {
            return true;
        }

        $period = $this->tokenExpiration * 60;
        $logout_at = <<<EXPR
        case when unix_timestamp() - unix_timestamp(seen_at) > {$period}
             then from_unixtime(unix_timestamp(seen_at) + {$period})
             else now()
        end
EXPR;
        $duration = <<<EXPR
        unix_timestamp($logout_at) - unix_timestamp(login_at)
EXPR;

        $this->logout_at = new Expression($logout_at);
        $this->duration = new Expression($duration);

        return $this->save();
    }

    public static function stopExpired()
    {
        /** @var Session $sessions */
        $sessions = static::find()
            ->andWhere([
                '>',
                new Expression('time_to_sec(timediff(now(), seen_at))'),
                self::getTokenExpiration() * 60
            ])
            ->andWhere(['logout_at' => null])
            ->all();

        foreach ($sessions as $session) {
            $session->stop();
        }
    }

    public function getUser()
    {
        return $this->hasOne(User::className(), ['id' => 'user_id']);
    }
}
/**
 * @SWG\Definition(
 *     definition="Session",
 *     type="object",
 *     description="Session model",
 *     allOf={
 *       @SWG\Schema(ref="#/definitions/Session"),
 *       @SWG\Schema(
 *           @SWG\Property(property="login", type="string", example="28/03/2018 09:12:33", description="Datetime the user has logged in"),
 *           @SWG\Property(property="logout", type="string", example="28/03/2018 09:13:44", description="Datetime the user has logged out"),
 *           @SWG\Property(property="duration", type="integer", example=71, description="The session duration"),
 *       )
 *     }
 * )
 */