fix(setup): 数据库有用户时跳过管理员引导

backend/internal/setup/setup.go

@@ -10,6 +10,7 @@ import (
 	"log"
 	"os"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/repository"
@@ -103,6 +104,36 @@ type JWTConfig struct {
 	ExpireHour int    `json:"expire_hour" yaml:"expire_hour"`
 }
 
+const (
+	adminBootstrapReasonEmptyDatabase          = "empty_database"
+	adminBootstrapReasonAdminExists            = "admin_exists"
+	adminBootstrapReasonUsersExistWithoutAdmin = "users_exist_without_admin"
+)
+
+type adminBootstrapDecision struct {
+	shouldCreate bool
+	reason       string
+}
+
+func decideAdminBootstrap(totalUsers, adminUsers int64) adminBootstrapDecision {
+	if adminUsers > 0 {
+		return adminBootstrapDecision{
+			shouldCreate: false,
+			reason:       adminBootstrapReasonAdminExists,
+		}
+	}
+	if totalUsers > 0 {
+		return adminBootstrapDecision{
+			shouldCreate: false,
+			reason:       adminBootstrapReasonUsersExistWithoutAdmin,
+		}
+	}
+	return adminBootstrapDecision{
+		shouldCreate: true,
+		reason:       adminBootstrapReasonEmptyDatabase,
+	}
+}
+
 // NeedsSetup checks if the system needs initial setup
 // Uses multiple checks to prevent attackers from forcing re-setup by deleting config
 func NeedsSetup() bool {
@@ -262,8 +293,8 @@ func Install(cfg *SetupConfig) error {
 		return fmt.Errorf("database initialization failed: %w", err)
 	}
 
-	// Create admin user
+	// Create admin user (only when database is empty and no admin exists).
-	if err := createAdminUser(cfg); err != nil {
+	if _, _, err := createAdminUser(cfg); err != nil {
 		return fmt.Errorf("admin user creation failed: %w", err)
 	}
 
@@ -309,7 +340,7 @@ func initializeDatabase(cfg *SetupConfig) error {
 	return repository.ApplyMigrations(migrationCtx, db)
 }
 
-func createAdminUser(cfg *SetupConfig) error {
+func createAdminUser(cfg *SetupConfig) (bool, string, error) {
 	dsn := fmt.Sprintf(
 		"host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
 		cfg.Database.Host, cfg.Database.Port, cfg.Database.User,
@@ -318,7 +349,7 @@ func createAdminUser(cfg *SetupConfig) error {
 
 	db, err := sql.Open("postgres", dsn)
 	if err != nil {
-		return err
+		return false, "", err
 	}
 
 	defer func() {
@@ -331,13 +362,27 @@ func createAdminUser(cfg *SetupConfig) error {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
-	// Check if admin already exists
+	var totalUsers int64
-	var count int64
+	if err := db.QueryRowContext(ctx, "SELECT COUNT(1) FROM users").Scan(&totalUsers); err != nil {
-	if err := db.QueryRowContext(ctx, "SELECT COUNT(1) FROM users WHERE role = $1", service.RoleAdmin).Scan(&count); err != nil {
+		return false, "", err
-		return err
 	}
-	if count > 0 {
+	var adminUsers int64
-		return nil // Admin already exists
+	if err := db.QueryRowContext(ctx, "SELECT COUNT(1) FROM users WHERE role = $1", service.RoleAdmin).Scan(&adminUsers); err != nil {
+		return false, "", err
+	}
+	decision := decideAdminBootstrap(totalUsers, adminUsers)
+	if !decision.shouldCreate {
+		return false, decision.reason, nil
+	}
+
+	if strings.TrimSpace(cfg.Admin.Password) == "" {
+		password, genErr := generateSecret(16)
+		if genErr != nil {
+			return false, "", fmt.Errorf("failed to generate admin password: %w", genErr)
+		}
+		cfg.Admin.Password = password
+		fmt.Printf("Generated admin password (one-time): %s\n", cfg.Admin.Password)
+		fmt.Println("IMPORTANT: Save this password! It will not be shown again.")
 	}
 
 	admin := &service.User{
@@ -351,7 +396,7 @@ func createAdminUser(cfg *SetupConfig) error {
 	}
 
 	if err := admin.SetPassword(cfg.Admin.Password); err != nil {
-		return err
+		return false, "", err
 	}
 
 	_, err = db.ExecContext(
@@ -367,7 +412,10 @@ func createAdminUser(cfg *SetupConfig) error {
 		admin.CreatedAt,
 		admin.UpdatedAt,
 	)
-	return err
+	if err != nil {
+		return false, "", err
+	}
+	return true, decision.reason, nil
 }
 
 func writeConfigFile(cfg *SetupConfig) error {
@@ -528,17 +576,6 @@ func AutoSetupFromEnv() error {
 		log.Println("Warning: JWT secret auto-generated. Consider setting a fixed secret for production.")
 	}
 
-	// Generate admin password if not provided
-	if cfg.Admin.Password == "" {
-		password, err := generateSecret(16)
-		if err != nil {
-			return fmt.Errorf("failed to generate admin password: %w", err)
-		}
-		cfg.Admin.Password = password
-		fmt.Printf("Generated admin password (one-time): %s\n", cfg.Admin.Password)
-		fmt.Println("IMPORTANT: Save this password! It will not be shown again.")
-	}
-
 	// Test database connection
 	log.Println("Testing database connection...")
 	if err := TestDatabaseConnection(&cfg.Database); err != nil {
@@ -562,10 +599,22 @@ func AutoSetupFromEnv() error {
 
 	// Create admin user
 	log.Println("Creating admin user...")
-	if err := createAdminUser(cfg); err != nil {
+	created, reason, err := createAdminUser(cfg)
+	if err != nil {
 		return fmt.Errorf("admin user creation failed: %w", err)
 	}
+	if created {
 		log.Printf("Admin user created: %s", cfg.Admin.Email)
+	} else {
+		switch reason {
+		case adminBootstrapReasonAdminExists:
+			log.Println("Admin user already exists, skipping admin bootstrap")
+		case adminBootstrapReasonUsersExistWithoutAdmin:
+			log.Println("Database already has user data; skipping auto admin bootstrap to avoid password overwrite")
+		default:
+			log.Println("Admin bootstrap skipped")
+		}
+	}
 
 	// Write config file
 	log.Println("Writing configuration file...")

backend/internal/setup/setup_test.go

@@ -0,0 +1,51 @@
+package setup
+
+import "testing"
+
+func TestDecideAdminBootstrap(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name       string
+		totalUsers int64
+		adminUsers int64
+		should     bool
+		reason     string
+	}{
+		{
+			name:       "empty database should create admin",
+			totalUsers: 0,
+			adminUsers: 0,
+			should:     true,
+			reason:     adminBootstrapReasonEmptyDatabase,
+		},
+		{
+			name:       "admin exists should skip",
+			totalUsers: 10,
+			adminUsers: 1,
+			should:     false,
+			reason:     adminBootstrapReasonAdminExists,
+		},
+		{
+			name:       "users exist without admin should skip",
+			totalUsers: 5,
+			adminUsers: 0,
+			should:     false,
+			reason:     adminBootstrapReasonUsersExistWithoutAdmin,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			got := decideAdminBootstrap(tc.totalUsers, tc.adminUsers)
+			if got.shouldCreate != tc.should {
+				t.Fatalf("shouldCreate=%v, want %v", got.shouldCreate, tc.should)
+			}
+			if got.reason != tc.reason {
+				t.Fatalf("reason=%q, want %q", got.reason, tc.reason)
+			}
+		})
+	}
+}