package main

import (
	"errors"

	"golang.org/x/crypto/bcrypt"
)

// 用户结构体
type User struct {
	Username     string
	PasswordHash []byte
}

// 模拟用户存储（实际应存入数据库）
var users = map[string]User{}

// 注册用户
func RegisterUser(username, password string) error {
	if _, exists := users[username]; exists {
		return errors.New("用户已存在")
	}
	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return err
	}
	users[username] = User{
		Username:     username,
		PasswordHash: hash,
	}
	return nil
}

// 用户登录验证
func AuthenticateUser(username, password string) error {
	user, exists := users[username]
	if !exists {
		return errors.New("用户不存在")
	}
	err := bcrypt.CompareHashAndPassword(user.PasswordHash, []byte(password))
	if err != nil {
		return errors.New("密码错误")
	}
	return nil
}