feat(backup): daily server and user backups, restore by section (backend)

Admins switch automatic backups on, pick the time and the retention
(default 03:00, 3 days). Each run writes a gzip snapshot of the whole
database (VACUUM INTO, consistent while others write) and one MindSift
backup ZIP per active user below $DATA_DIR/backups, then deletes files
past the retention. A restart after the time catches up on that day.
Admins list, download and trigger runs; users list, download and restore
their own backups.

Import and restore can be limited to sections (notes, tasks, lists,
inbox, themes): restore only empties the chosen sections. Export and
import now carry custom themes. File names are checked against a fixed
pattern, so no other file can be fetched through the API.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/backups.go

@@ -0,0 +1,168 @@
+package api
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/sandrodach/mindsift/internal/auth"
+	"github.com/sandrodach/mindsift/internal/storage"
+)
+
+// Automatic backups (see storage/backup.go): daily at the configured time a snapshot of the whole
+// database for the admin and one MindSift backup per active user, both kept for the configured number
+// of days. Admins can also start a run by hand; users list, download and restore their own backups.
+
+var backupRunMu sync.Mutex
+
+func (s *Server) backupRoot() string {
+	return filepath.Join(filepath.Dir(s.cfg.DatabasePath), "backups")
+}
+
+// runBackups makes one full run; returns the name of the system snapshot.
+func (s *Server) runBackups() (string, error) {
+	backupRunMu.Lock()
+	defer backupRunMu.Unlock()
+	now := time.Now()
+	root := s.backupRoot()
+	sys, _ := s.store.GetSystemSettings()
+	keep := storage.DefaultBackupRetentionDays
+	if sys != nil && sys.BackupRetentionDays > 0 {
+		keep = sys.BackupRetentionDays
+	}
+
+	name, err := s.store.WriteSystemSnapshot(filepath.Join(root, "system"), now)
+	if err != nil {
+		return "", err
+	}
+	_ = storage.PruneBackups(filepath.Join(root, "system"), keep, now)
+
+	users, err := s.store.GetAllUsers()
+	if err != nil {
+		return name, err
+	}
+	failed := 0
+	for _, u := range users {
+		if !u.IsActive {
+			continue
+		}
+		dir := storage.UserBackupDir(root, u.ID)
+		if _, err := s.store.WriteUserBackup(u.ID, dir, now); err != nil {
+			failed++
+			slog.Error("Benutzer-Backup fehlgeschlagen", "user_id", u.ID, "error", err)
+			continue
+		}
+		_ = storage.PruneBackups(dir, keep, now)
+	}
+	slog.Info("Backups erstellt", "system", name, "users", len(users), "failed", failed)
+	if failed > 0 {
+		return name, fmt.Errorf("%d Benutzer-Backups fehlgeschlagen (siehe Server-Log)", failed)
+	}
+	return name, nil
+}
+
+// startBackupScheduler runs the backups once a day at the configured time (server time zone). After a
+// restart past that time on a day without a run, it catches up.
+func (s *Server) startBackupScheduler() {
+	ticker := time.NewTicker(time.Minute)
+	defer ticker.Stop()
+	lastRun := ""
+	if files, err := storage.ListBackups(filepath.Join(s.backupRoot(), "system")); err == nil && len(files) > 0 {
+		lastRun = strings.TrimPrefix(files[0].Name, "mindsift-db-")[:10] // date of the newest snapshot
+	}
+	for range ticker.C {
+		sys, err := s.store.GetSystemSettings()
+		if err != nil || sys == nil || !sys.BackupEnabled {
+			continue
+		}
+		now := time.Now()
+		today := now.Format("2006-01-02")
+		if lastRun == today || now.Format("15:04") < sys.BackupTime {
+			continue
+		}
+		lastRun = today
+		if _, err := s.runBackups(); err != nil {
+			slog.Error("Automatisches Backup fehlgeschlagen", "error", err)
+		}
+	}
+}
+
+func (s *Server) handleAdminListBackups(w http.ResponseWriter, r *http.Request) {
+	files, err := storage.ListBackups(filepath.Join(s.backupRoot(), "system"))
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, files)
+}
+
+func (s *Server) handleAdminRunBackup(w http.ResponseWriter, r *http.Request) {
+	if _, err := s.runBackups(); err != nil {
+		writeError(w, http.StatusInternalServerError, "Backup fehlgeschlagen: "+err.Error())
+		return
+	}
+	s.handleAdminListBackups(w, r)
+}
+
+func (s *Server) handleAdminDownloadBackup(w http.ResponseWriter, r *http.Request) {
+	serveBackupFile(w, r, filepath.Join(s.backupRoot(), "system"), chi.URLParam(r, "name"), "application/gzip")
+}
+
+func (s *Server) handleListMyBackups(w http.ResponseWriter, r *http.Request) {
+	files, err := storage.ListBackups(storage.UserBackupDir(s.backupRoot(), auth.GetUserID(r.Context())))
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, files)
+}
+
+func (s *Server) handleDownloadMyBackup(w http.ResponseWriter, r *http.Request) {
+	dir := storage.UserBackupDir(s.backupRoot(), auth.GetUserID(r.Context()))
+	serveBackupFile(w, r, dir, chi.URLParam(r, "name"), "application/zip")
+}
+
+// handleRestoreMyBackup imports one of the user's server backups: mode=merge (add next to the data)
+// or mode=restore (empty the chosen sections first), sections=notes,tasks,lists,inbox,themes.
+func (s *Server) handleRestoreMyBackup(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
+	path, err := storage.BackupPath(storage.UserBackupDir(s.backupRoot(), userID), chi.URLParam(r, "name"))
+	if err != nil {
+		writeError(w, http.StatusNotFound, err.Error())
+		return
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	plan, err := storage.PlanMindSiftImport(data, filepath.Base(path))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	sections := storage.NormalizeSections(strings.Split(r.URL.Query().Get("sections"), ","))
+	plan = plan.Only(sections)
+	if r.URL.Query().Get("preview") == "1" {
+		writeJSON(w, http.StatusOK, plan.Summary(false))
+		return
+	}
+	s.applyImport(w, userID, plan, sections, r.URL.Query().Get("mode") == "restore")
+}
+
+func serveBackupFile(w http.ResponseWriter, r *http.Request, dir, name, contentType string) {
+	path, err := storage.BackupPath(dir, name)
+	if err != nil {
+		writeError(w, http.StatusNotFound, err.Error())
+		return
+	}
+	w.Header().Set("Content-Type", contentType)
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, name))
+	http.ServeFile(w, r, path)
+}

internal/api/backups_test.go

@@ -0,0 +1,91 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/sandrodach/mindsift/internal/auth"
+	"github.com/sandrodach/mindsift/internal/storage"
+)
+
+func TestBackupsRunListDownloadAndRestoreSections(t *testing.T) {
+	srv, store, token := setupTestServer(t)
+	router := srv.Router()
+	claims, _ := auth.ValidateToken(testJWTSecret, token)
+	uid := claims.UserID
+	_, _ = store.CreateDocument(uid, "", "Notiz vom Montag", "📝", "", nil, nil, false)
+	list, _ := store.CreateList(uid, "Einkauf", "🛒", "shopping")
+	_, _ = store.CreateListItem(list.ID, "Milch", "", "", 0, uid)
+	_, _ = store.SaveUserTheme(uid, "", "Mein Theme", ":root[data-theme=\"x\"] { --accent-primary: #f00; }")
+
+	call := func(method, path string) *httptest.ResponseRecorder {
+		req := httptest.NewRequest(method, path, nil)
+		req.Header.Set("Authorization", "Bearer "+token)
+		rec := httptest.NewRecorder()
+		router.ServeHTTP(rec, req)
+		return rec
+	}
+
+	// Admin starts a run: one database snapshot plus a backup for the user
+	rec := call("POST", "/api/v1/admin/backups")
+	if rec.Code != http.StatusOK {
+		t.Fatalf("run backups: %d %s", rec.Code, rec.Body.String())
+	}
+	var sysFiles []storage.BackupFile
+	_ = json.Unmarshal(rec.Body.Bytes(), &sysFiles)
+	if len(sysFiles) != 1 || !strings.HasSuffix(sysFiles[0].Name, ".db.gz") || sysFiles[0].Size == 0 {
+		t.Fatalf("expected one snapshot, got %+v", sysFiles)
+	}
+	if rec := call("GET", "/api/v1/admin/backups/"+sysFiles[0].Name); rec.Code != http.StatusOK || rec.Body.Len() == 0 {
+		t.Fatalf("download snapshot: %d", rec.Code)
+	}
+	if rec := call("GET", "/api/v1/admin/backups/..%2F..%2Fmindsift.db"); rec.Code != http.StatusNotFound {
+		t.Fatalf("path tricks must be refused, got %d", rec.Code)
+	}
+
+	var mine []storage.BackupFile
+	_ = json.Unmarshal(call("GET", "/api/v1/backups").Body.Bytes(), &mine)
+	if len(mine) != 1 {
+		t.Fatalf("expected one user backup, got %+v", mine)
+	}
+
+	// Lose data, then restore only the lists: notes stay as they are now
+	listsBefore, _ := store.GetAllListsForUser(uid)
+	docsBefore, _ := store.GetDocuments(uid)
+	_ = store.PurgeUserSections(uid, map[string]bool{storage.SectionLists: true, storage.SectionThemes: true})
+	_, _ = store.CreateDocument(uid, "", "Notiz vom Dienstag", "📝", "", nil, nil, false)
+	rec = call("POST", "/api/v1/backups/"+mine[0].Name+"/restore?mode=restore&sections=lists,themes")
+	if rec.Code != http.StatusOK {
+		t.Fatalf("restore: %d %s", rec.Code, rec.Body.String())
+	}
+	lists, _ := store.GetAllListsForUser(uid)
+	themes, _ := store.GetUserThemes(uid)
+	docs, _ := store.GetDocuments(uid)
+	if len(lists) != len(listsBefore) || len(themes) != 1 {
+		t.Fatalf("lists and themes should be back: %d of %d lists, %d themes", len(lists), len(listsBefore), len(themes))
+	}
+	if len(docs) != len(docsBefore)+1 {
+		t.Fatalf("notes were not selected and must stay untouched (plus Dienstag), got %d of %d", len(docs), len(docsBefore)+1)
+	}
+
+	// Retention: old files go
+	dir := filepath.Join(srv.backupRoot(), "system")
+	old := filepath.Join(dir, "mindsift-db-2000-01-01-0300.db.gz")
+	_ = os.WriteFile(old, []byte("x"), 0o600)
+	_ = os.Chtimes(old, mustTime("2000-01-01"), mustTime("2000-01-01"))
+	_, _ = srv.runBackups()
+	if _, err := os.Stat(old); !os.IsNotExist(err) {
+		t.Fatalf("backups older than the retention must be deleted")
+	}
+}
+
+func mustTime(day string) (t time.Time) {
+	t, _ = time.Parse("2006-01-02", day)
+	return t
+}

internal/api/handlers_account.go

@@ -82,15 +82,21 @@ func (s *Server) runImport(w http.ResponseWriter, r *http.Request, plan *storage
 		writeError(w, http.StatusBadRequest, err.Error())
 		return
 	}
+	// sections=notes,tasks,…: only these parts of a MindSift backup (all when not given)
+	sections := storage.NormalizeSections(strings.Split(r.URL.Query().Get("sections"), ","))
+	plan = plan.Only(sections)
 	if r.URL.Query().Get("preview") == "1" {
 		writeJSON(w, http.StatusOK, plan.Summary(false))
 		return
 	}
-	userID := auth.GetUserID(r.Context())
-	// mode=restore (MindSift data only): replace everything instead of adding next to it. The plan is
-	// fully read and validated at this point, so a broken file never wipes anything.
-	if r.URL.Query().Get("mode") == "restore" && strings.HasSuffix(r.URL.Path, "/mindsift") {
-		if err := s.store.PurgeUserData(userID); err != nil {
+	s.applyImport(w, auth.GetUserID(r.Context()), plan, sections, r.URL.Query().Get("mode") == "restore" && strings.HasSuffix(r.URL.Path, "/mindsift"))
+}
+
+// applyImport adds the plan to the user's data; with restore the chosen sections are emptied first.
+// The plan is fully read and validated at this point, so a broken file never wipes anything.
+func (s *Server) applyImport(w http.ResponseWriter, userID string, plan *storage.ImportPlan, sections map[string]bool, restore bool) {
+	if restore {
+		if err := s.store.PurgeUserSections(userID, sections); err != nil {
 			writeError(w, http.StatusInternalServerError, "Wiederherstellen abgebrochen: "+err.Error())
 			return
 		}

internal/api/server.go

@@ -56,6 +56,9 @@ func NewServer(cfg *config.Config, store *storage.Store, wsHub *ws.Hub, staticFS
 	if cfg.DemoMode && cfg.DemoResetMinutes > 0 {
 		go srv.startDemoResetTicker()
 	}
+	if !cfg.DemoMode {
+		go srv.startBackupScheduler()
+	}
 	return srv
 }
 
@@ -130,6 +133,9 @@ func (s *Server) Router() http.Handler {
 		r.Get("/api/v1/stats", s.handleStats)
 		r.Get("/api/v1/search", s.handleSearch)
 		r.Get("/api/v1/export", s.handleExport)
+		r.Get("/api/v1/backups", s.handleListMyBackups)
+		r.Get("/api/v1/backups/{name}", s.handleDownloadMyBackup)
+		r.Post("/api/v1/backups/{name}/restore", s.handleRestoreMyBackup)
 		r.Get("/api/v1/export/markdown", s.handleExportMarkdown)
 		r.Post("/api/v1/import/mindsift", s.handleImportMindSift)
 		r.Delete("/api/v1/user/data", s.handlePurgeOwnData)
@@ -256,6 +262,9 @@ func (s *Server) Router() http.Handler {
 		r.Group(func(r chi.Router) {
 			r.Use(s.adminMiddleware)
 			r.Get("/api/v1/admin/settings", s.handleAdminGetSettings)
+			r.Get("/api/v1/admin/backups", s.handleAdminListBackups)
+			r.Post("/api/v1/admin/backups", s.handleAdminRunBackup)
+			r.Get("/api/v1/admin/backups/{name}", s.handleAdminDownloadBackup)
 			r.Put("/api/v1/admin/settings", s.handleAdminUpdateSettings)
 			r.Get("/api/v1/admin/settings/sharing-impact", s.handleAdminSharingImpact)