feat: add audit log with email notification (#26)

backend/internal/service/audit_log_service.go

@@ -0,0 +1,85 @@
+package service
+
+import (
+	userAgentParser "github.com/mileusna/useragent"
+	"github.com/stonith404/pocket-id/backend/internal/model"
+	"github.com/stonith404/pocket-id/backend/internal/utils"
+	"gorm.io/gorm"
+	"log"
+)
+
+type AuditLogService struct {
+	db               *gorm.DB
+	appConfigService *AppConfigService
+	emailService     *EmailService
+}
+
+func NewAuditLogService(db *gorm.DB, appConfigService *AppConfigService, emailService *EmailService) *AuditLogService {
+	return &AuditLogService{db: db, appConfigService: appConfigService, emailService: emailService}
+}
+
+// Create creates a new audit log entry in the database
+func (s *AuditLogService) Create(event model.AuditLogEvent, ipAddress, userAgent, userID string, data model.AuditLogData) model.AuditLog {
+	auditLog := model.AuditLog{
+		Event:     event,
+		IpAddress: ipAddress,
+		UserAgent: userAgent,
+		UserID:    userID,
+		Data:      data,
+	}
+
+	// Save the audit log in the database
+	if err := s.db.Create(&auditLog).Error; err != nil {
+		log.Printf("Failed to create audit log: %v\n", err)
+		return model.AuditLog{}
+	}
+
+	return auditLog
+}
+
+// CreateNewSignInWithEmail creates a new audit log entry in the database and sends an email if the device hasn't been used before
+func (s *AuditLogService) CreateNewSignInWithEmail(ipAddress, userAgent, userID string, data model.AuditLogData) model.AuditLog {
+	createdAuditLog := s.Create(model.AuditLogEventSignIn, ipAddress, userAgent, userID, data)
+
+	// Count the number of times the user has logged in from the same device
+	var count int64
+	err := s.db.Model(&model.AuditLog{}).Where("user_id = ? AND ip_address = ? AND user_agent = ?", userID, ipAddress, userAgent).Count(&count).Error
+	if err != nil {
+		log.Printf("Failed to count audit logs: %v\n", err)
+		return createdAuditLog
+	}
+
+	// If the user hasn't logged in from the same device before, send an email
+	if count <= 1 {
+		go func() {
+			var user model.User
+			s.db.Where("id = ?", userID).First(&user)
+
+			title := "New device login with " + s.appConfigService.DbConfig.AppName.Value
+			err := s.emailService.Send(user.Email, title, "login-with-new-device", map[string]interface{}{
+				"ipAddress":      ipAddress,
+				"device":         s.DeviceStringFromUserAgent(userAgent),
+				"dateTimeString": createdAuditLog.CreatedAt.UTC().Format("2006-01-02 15:04:05 UTC"),
+			})
+			if err != nil {
+				log.Printf("Failed to send email: %v\n", err)
+			}
+		}()
+	}
+
+	return createdAuditLog
+}
+
+// ListAuditLogsForUser retrieves all audit logs for a given user ID
+func (s *AuditLogService) ListAuditLogsForUser(userID string, page int, pageSize int) ([]model.AuditLog, utils.PaginationResponse, error) {
+	var logs []model.AuditLog
+	query := s.db.Model(&model.AuditLog{}).Where("user_id = ?", userID).Order("created_at desc")
+
+	pagination, err := utils.Paginate(page, pageSize, query, &logs)
+	return logs, pagination, err
+}
+
+func (s *AuditLogService) DeviceStringFromUserAgent(userAgent string) string {
+	ua := userAgentParser.Parse(userAgent)
+	return ua.Name + " on " + ua.OS + " " + ua.OSVersion
+}