package dao

import (
	"GolangLearnPractice1/bookstore2/model"
	"GolangLearnPractice1/bookstore2/utils"
	"crypto/md5"
	"crypto/rand"
	"encoding/base64"
	"errors"
	"fmt"
	"time"
)

//CheckUserNameAndPassword 检查用户名称和密码
func CheckUserNameAndPassword(userName, initPassword string) error {
	user, _ := GetUserByUserName(userName)
	if user == nil {
		//没有此用户
		err := errors.New("用户与密码不匹配")
		return err
	}
	//以盐值对初始密码进行加密后得到密码
	md5Inst := md5.New()
	initPassword = initPassword + user.Salt
	md5Inst.Write([]byte(initPassword))
	passwordBytes := md5Inst.Sum([]byte([]byte(user.Salt)))
	password := fmt.Sprintf("%q", passwordBytes)
	//那加密处理后密码与数据库的密码比较
	if password == user.Password {
		//用户与密码匹配
		return nil
	}
	//密码不正确
	err := errors.New("用户与密码不匹配")
	return err

}

//GetUserByID 通过ID得到用户的名称和密码
func GetUserByID(userID int64) (*model.User, error) {
	user := &model.User{}
	sqlStr := "select id,userName,password,salt,email,userStatus,createTime from users where id=?"
	row := utils.Db.QueryRow(sqlStr, userID)
	err := row.Scan(&user.UserID, &user.UserName, &user.Password, &user.Salt, &user.Email, &user.UserStatus, &user.CreateTime)
	if err != nil {
		return nil, err
	}
	return user, nil
}

//InsertUser 插入用户信息
func InsertUser(userName, initPassword, email string) error {
	sqlStr := "insert into users(userName,password,salt,email,userStatus,createTime) values(?,?,?,?,?,?)"
	//生成加盐
	p, _ := rand.Prime(rand.Reader, 60) //n代表位数，比如3为2位，127为7位
	b := p.Bytes()
	salt := base64.URLEncoding.EncodeToString(b)
	//对密码根据盐值进行加密,得到密码
	md5Inst := md5.New()
	initPassword = initPassword + salt
	md5Inst.Write([]byte(initPassword))
	passwordBytes := md5Inst.Sum([]byte(salt))
	password := fmt.Sprintf("%q", passwordBytes)

	//生成时间
	createTime := time.Now().Format("2006-01-02 15:04:05")
	//将用户信息插入数据库
	_, err := utils.Db.Exec(sqlStr, userName, password, salt, email, 0, createTime)
	if err != nil {
		fmt.Println("数据库插入错误。")
		return err
	}
	return nil

}

//GetUserByUserName 根据用户名称找用户
func GetUserByUserName(userName string) (*model.User, error) {
	sqlStr := "select id,userName,password,salt,email,userStatus,createTime from users where userName=?"
	row := utils.Db.QueryRow(sqlStr, userName)
	user := &model.User{}
	err := row.Scan(&user.UserID, &user.UserName, &user.Password, &user.Salt, &user.Email, &user.UserStatus, &user.CreateTime)
	if err != nil {
		return nil, err
	}
	return user, nil
}