#include "line.h"

Line *Line::getInstance()
{
    static Line linedb;
    return &linedb;
}

Line::Line()
{
    //先判断连接是否存在
    if(QSqlDatabase::contains("linesql"))
    {
        db_ = QSqlDatabase::addDatabase("linesql");
    }
    else
    {
        //1.加载数据库驱动
        db_ = QSqlDatabase::addDatabase("QSQLITE", "linesql");
        qDebug () << db_.connectionName();//打印连接名称

        //2.设置数据库名
        db_.setDatabaseName("line.db");
        qDebug () << db_.databaseName();
    }

    //3.打开数据库
    if(db_.open())
    {
        qDebug() << "open success";
    }
    else
    {
        qDebug() << "open:" << db_.lastError().text();
        return;
    }

    QString sql = "create table if not exists table_line(number varchar(10) primary key,state varchar(3));";

    QSqlQuery query(db_);
    if (query.exec(sql))
    {
        qDebug() << "linedb success.";
    }
    db_.close();
}

QString Line::findCode(QString number)
{
    QString sql = QString("select from table_line where name = :name;");
    //打开数据库
    if(!db_.open())
    {
        qDebug() << "open fail" << db_.lastError().text();
        exit(-1);
    }

    //执行插入操作
    QSqlQuery query(db_);
    query.prepare(sql);
    query.bindValue(":number",QVariant(number));
    query.exec();
    QString linecode;

    //查询成功
    if(query.next())
    {
        linecode = query.value(1).toString();
        qDebug() << "linecode:" << linecode;

    }

    db_.close();

    return linecode;

}

QString Line::choose()
{
    QString sql = QString("select from table_line where state = :state limit 1;");
    QSqlQuery query(db_);
    query.prepare(sql);
    query.bindValue(":state",QVariant("000"));  //选择未占用的车位
    query.exec();
    if(query.next())
    {
        QString number = query.value(0).toString();
        return number;
    }
}


void Line::setState(QString number)
{
    QString sql = QString("update table_line set state=:state where number=:number");
    QSqlQuery query(db_);
    query.prepare(sql);
    query.bindValue(":number",QVariant(number));
    query.bindValue(":state",QVariant("111"));  //已占用的话为111
    query.exec();
}

void Line::resetState(QString number)
{
    QString sql = QString("update table_line set state=:state where number=:number");
    QSqlQuery query(db_);
    query.prepare(sql);
    query.bindValue(":number",QVariant(number));
    query.bindValue(":state",QVariant("000"));   //状态初始值为000
    query.exec();
}