package db

import (
	_"github.com/go-sql-driver/mysql"
  "database/sql"
	"fmt"
	"strings"
)
// 教程
// https://www.jianshu.com/p/ee87e989f149
//数据库配置
const (
    userName = "go_test"
    password = "R4MSD57Gmr42CRTw"
    ip = "27.102.70.190"
    port = "3306"
    dbName = "go_test"
)
//Db数据库连接池
var DB *sql.DB

//注意方法名大写，就是public
func InitDB() bool {
    //构建连接："用户名:密码@tcp(IP:端口)/数据库?charset=utf8"
    path := strings.Join([]string{userName, ":", password, "@tcp(",ip, ":", port, ")/", dbName, "?charset=utf8"}, "")

    //打开数据库,前者是驱动名，所以要导入： _ "github.com/go-sql-driver/mysql"
    DB, _ = sql.Open("mysql", path)
    //设置数据库最大连接数
    DB.SetConnMaxLifetime(100)
    //设置上数据库最大闲置连接数
    DB.SetMaxIdleConns(10)
    //验证连接
    if err := DB.Ping(); err != nil{
        fmt.Println("opon database fail",err)
        return false
    }
		fmt.Println("connnect success")
		return true
}

type User struct {
	Id int
	UserName string
	Password string
}

func InsertUser(user User) (bool){
	//开启事务
	tx, err := DB.Begin()
	if err != nil{
			fmt.Println("tx fail")
			return false
	}
	//准备sql语句
	stmt, err := tx.Prepare("INSERT INTO nk_user (`name`, `password`) VALUES (?, ?)")
	if err != nil{
			fmt.Println("Prepare fail")
			return false
	}
	//将参数传递到sql语句中并且执行
	res, err := stmt.Exec(user.UserName, user.Password)
	if err != nil{
			fmt.Println("Exec fail")
			return false
	}
	//将事务提交
	tx.Commit()
	//获得上一个插入自增的id
	fmt.Println(res.LastInsertId())
	return true
}

func SelectAllUser() ([]User) {
	//执行查询语句
	rows, err := DB.Query("SELECT * from nk_user")
	if err != nil{
			fmt.Println("查询出错了")    
	}
	var users []User
	//循环读取结果
	for rows.Next(){
			var user User
			//将每一行的结果都赋值到一个user对象中
			err := rows.Scan(&user.Id, &user.UserName, &user.Password)
			if err != nil {
					fmt.Println("rows fail")
			}
			//将user追加到users的这个数组中
			users = append(users, user)
	}
	return users
}