MetaLab/internal/service/auth_service.go

package service

import (
	"regexp"

	"metazone.cc/metalab/internal/common"
	"metazone.cc/metalab/internal/config"
	"metazone.cc/metalab/internal/model"
	"metazone.cc/metalab/internal/repository"

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

// AuthService 认证业务逻辑
type AuthService struct {
	userRepo     *repository.UserRepo
	tokenService *TokenService
	cfg          *config.Config
}

// NewAuthService 构造函数
func NewAuthService(userRepo *repository.UserRepo, tokenSvc *TokenService, cfg *config.Config) *AuthService {
	return &AuthService{userRepo: userRepo, tokenService: tokenSvc, cfg: cfg}
}

var (
	ErrEmailExists      = common.ErrEmailExists
	ErrUsernameTaken    = common.ErrUsernameTaken
	ErrInvalidCred      = common.ErrInvalidCred
	ErrUserNotFound     = common.ErrUserNotFound
	ErrUserBanned       = common.ErrUserBanned
	ErrUserLocked       = common.ErrUserLocked
	ErrUserDeleted      = common.ErrUserDeleted
	ErrWeakPassword     = common.ErrWeakPassword
	ErrTokenExpired     = common.ErrTokenExpired
	ErrTokenInvalid     = common.ErrTokenInvalid
	ErrTokenRevoked     = common.ErrTokenRevoked
	ErrPermissionDenied = common.ErrPermissionDenied
)

var pwLetter = regexp.MustCompile(`[a-zA-Z]`)
var pwDigit = regexp.MustCompile(`\d`)

// dummyHash 防时序攻击：当用户不存在时，仍对虚拟哈希执行完整的 bcrypt 比对
// 在 init() 中按当前 bcrypt 成本生成，确保时序与真实校验一致
var dummyHash []byte

func init() {
	hash, err := bcrypt.GenerateFromPassword([]byte("metazone-dummy-hash-2026"), 12)
	if err != nil {
		panic("failed to generate bcrypt dummy hash: " + err.Error())
	}
	dummyHash = hash
}

// validatePassword 密码强度：至少 8 位 + 包含字母 + 包含数字
func validatePassword(pw string) error {
	if len(pw) < 8 || !pwLetter.MatchString(pw) || !pwDigit.MatchString(pw) {
		return ErrWeakPassword
	}
	return nil
}

// Register 注册
// 流程：密码强度 → 邮箱查重 → 哈希 → 生成唯一用户名 → 创建 → access JWT + refresh JWT
// rememberMe=true: refresh Cookie 持久化（30天）；false: session cookie（关浏览器即清除）
func (s *AuthService) Register(req model.RegisterRequest) (string, string, *model.User, error) {
	// 1. 密码强度
	if err := validatePassword(req.Password); err != nil {
		return "", "", nil, err
	}

	// 2. 检查邮箱
	exists, err := s.userRepo.ExistsByEmail(req.Email)
	if err != nil {
		return "", "", nil, err
	}
	if exists {
		return "", "", nil, ErrEmailExists
	}

	// 3. 哈希密码
	hash, err := common.HashPassword(req.Password, s.cfg.Bcrypt.Cost)
	if err != nil {
		return "", "", nil, err
	}

	// 4. 生成唯一用户名
	username, err := common.GenerateUsername(s.userRepo, 20)
	if err != nil {
		return "", "", nil, err
	}

	// 5. 创建用户
	user := &model.User{
		Email:        req.Email,
		PasswordHash: hash,
		Username:     username,
		Role:         model.RoleUser,
		Status:       model.StatusActive,
	}
	if err := s.userRepo.Create(user); err != nil {
		return "", "", nil, err
	}

	// 6. 生成 access JWT
	accessToken, err := s.tokenService.BuildAccessToken(user)
	if err != nil {
		return "", "", nil, err
	}

	// 7. 生成 refresh JWT（不勾选"记住我"也用 session cookie，关浏览器即清除）
	refreshToken, err := s.tokenService.BuildRefreshToken(user, req.RememberMe)
	if err != nil {
		return "", "", nil, err
	}

	return accessToken, refreshToken, user, nil
}

// Login 登录
// 流程：按邮箱查找 → 检查状态 → 验证密码 → access JWT + refresh JWT
// 防时序攻击：邮箱不存在时仍执行完整 bcrypt 比对
// rememberMe=true: refresh Cookie 持久化（30天）；false: session cookie（关浏览器即清除）
func (s *AuthService) Login(req model.LoginRequest) (string, string, *model.User, error) {
	user, err := s.userRepo.FindByEmail(req.Email)
	if err != nil {
		_ = bcrypt.CompareHashAndPassword(dummyHash, []byte(req.Password))
		return "", "", nil, ErrInvalidCred
	}

	// 已注销（deleted）→ 自动恢复
	if user.Status == model.StatusDeleted {
		user.Status = model.StatusActive
		user.DeletedAt = gorm.DeletedAt{}
		if err := s.userRepo.Update(user); err != nil {
			return "", "", nil, err
		}
		// 恢复后继续正常登录流程
	}

	// 永久锁定
	if user.Status == model.StatusLocked {
		_ = bcrypt.CompareHashAndPassword(dummyHash, []byte(req.Password))
		return "", "", nil, ErrUserLocked
	}

	// 封禁
	if user.Status == model.StatusBanned {
		return "", "", nil, ErrUserBanned
	}

	if !common.CheckPassword(req.Password, user.PasswordHash) {
		return "", "", nil, ErrInvalidCred
	}

	// 生成 access JWT
	accessToken, err := s.tokenService.BuildAccessToken(user)
	if err != nil {
		return "", "", nil, err
	}

	// 生成 refresh JWT（不勾选"记住我"也生成，Cookie 用 session 模式）
	refreshToken, err := s.tokenService.BuildRefreshToken(user, req.RememberMe)
	if err != nil {
		return "", "", nil, err
	}

	return accessToken, refreshToken, user, nil
}

// CheckEmail 检查邮箱是否已被注册（无需认证的轻量检查）
func (s *AuthService) CheckEmail(email string) (bool, error) {
	return s.userRepo.ExistsByEmail(email)
}

// InvalidateSessions 吊销某用户所有 JWT（递增 token_version，强制所有设备重新登录）
// 适用场景：修改密码、账号被盗、管理员强制下线
func (s *AuthService) InvalidateSessions(userID uint) error {
	return s.userRepo.IncrementTokenVersion(userID)
}