feat: persist pinned libraries per user with cross-device sync (#20)

Store pinned library IDs on the user record and expose GET/PUT
/me/pinned-libraries endpoints. The web client now loads and saves pins
through the API, migrates legacy localStorage data once, and applies
pinned ordering on both the libraries and home pages.

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: truewhile <truewhile@users.noreply.github.com>

internal/service/profile.go

@@ -3,6 +3,7 @@ package service
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"strings"
 
@@ -81,6 +82,106 @@ func (p *ProfileService) UpdateProfile(ctx context.Context, userID string, patch
 	return p.repo.User.FindByID(ctx, userID)
 }
 
+// GetPinnedLibraryIDs returns the user's pinned library IDs, filtered to libraries
+// they can still access.
+func (p *ProfileService) GetPinnedLibraryIDs(ctx context.Context, userID string) ([]string, error) {
+	user, err := p.repo.User.FindByID(ctx, userID)
+	if err != nil {
+		return nil, err
+	}
+	if user == nil {
+		return nil, errors.New("user not found")
+	}
+	visibility := UserDefaultMediaVisibility(ctx, p.repo, userID)
+	accessible, err := p.accessibleLibraryIDSet(ctx, visibility)
+	if err != nil {
+		return nil, err
+	}
+	return filterPinnedLibraryIDs(user.DecodePinnedLibraryIDs(), accessible), nil
+}
+
+// SetPinnedLibraryIDs persists the user's pinned library order after filtering to
+// accessible, enabled libraries.
+func (p *ProfileService) SetPinnedLibraryIDs(ctx context.Context, userID string, ids []string) ([]string, error) {
+	if userID == "" {
+		return nil, errors.New("missing user id")
+	}
+	user, err := p.repo.User.FindByID(ctx, userID)
+	if err != nil {
+		return nil, err
+	}
+	if user == nil {
+		return nil, errors.New("user not found")
+	}
+	visibility := UserDefaultMediaVisibility(ctx, p.repo, userID)
+	accessible, err := p.accessibleLibraryIDSet(ctx, visibility)
+	if err != nil {
+		return nil, err
+	}
+	normalized := filterPinnedLibraryIDs(normalizePinnedLibraryIDs(ids), accessible)
+	raw, err := json.Marshal(normalized)
+	if err != nil {
+		return nil, err
+	}
+	if err := p.repo.User.UpdateFields(ctx, userID, map[string]any{
+		"pinned_library_ids": string(raw),
+	}); err != nil {
+		return nil, err
+	}
+	return normalized, nil
+}
+
+func (p *ProfileService) accessibleLibraryIDSet(ctx context.Context, visibility MediaVisibility) (map[string]struct{}, error) {
+	libs, err := p.repo.Library.List(ctx)
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[string]struct{})
+	for _, lib := range libs {
+		if !lib.Enabled {
+			continue
+		}
+		if !LibraryVisibleForUser(ctx, p.repo, lib, visibility) {
+			continue
+		}
+		out[lib.ID] = struct{}{}
+	}
+	return out, nil
+}
+
+func normalizePinnedLibraryIDs(ids []string) []string {
+	if len(ids) == 0 {
+		return nil
+	}
+	seen := make(map[string]struct{}, len(ids))
+	out := make([]string, 0, len(ids))
+	for _, id := range ids {
+		trimmed := strings.TrimSpace(id)
+		if trimmed == "" {
+			continue
+		}
+		if _, ok := seen[trimmed]; ok {
+			continue
+		}
+		seen[trimmed] = struct{}{}
+		out = append(out, trimmed)
+	}
+	return out
+}
+
+func filterPinnedLibraryIDs(ids []string, accessible map[string]struct{}) []string {
+	if len(ids) == 0 {
+		return nil
+	}
+	out := make([]string, 0, len(ids))
+	for _, id := range ids {
+		if _, ok := accessible[id]; ok {
+			out = append(out, id)
+		}
+	}
+	return out
+}
+
 // AdminUpdateRole lets administrators promote / demote another user. The
 // caller is expected to gate the route with AdminRequired.
 func (p *ProfileService) AdminUpdateRole(ctx context.Context, userID, role string) (*model.User, error) {

internal/service/profile_pinned_test.go

@@ -0,0 +1,61 @@
+package service
+
+import (
+	"testing"
+
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"go.uber.org/zap"
+)
+
+func TestProfilePinnedLibrariesFiltersInaccessibleAndPreservesOrder(t *testing.T) {
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&model.User{}, &model.Library{}); err != nil {
+		t.Fatal(err)
+	}
+	repos := repository.New(db)
+	svc := NewProfileService(zap.NewNop(), repos)
+
+	user := &model.User{Username: "viewer", PasswordHash: "hash", Role: "user"}
+	if err := repos.User.Create(t.Context(), user); err != nil {
+		t.Fatal(err)
+	}
+	libA := &model.Library{Name: "Movies", Path: "/media/movies", Type: "movie", Enabled: true}
+	libB := &model.Library{Name: "TV", Path: "/media/tv", Type: "tv", Enabled: true}
+	libHidden := &model.Library{Name: "Adult", Path: "/media/adult", Type: "movie", Enabled: true}
+	for _, lib := range []*model.Library{libA, libB, libHidden} {
+		if err := repos.Library.Create(t.Context(), lib); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := repos.User.UpdateFields(t.Context(), user.ID, map[string]any{
+		"allowed_library_ids": `["` + libA.ID + `","` + libB.ID + `"]`,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := svc.SetPinnedLibraryIDs(t.Context(), user.ID, []string{
+		libB.ID, libHidden.ID, libA.ID, libB.ID, "missing",
+	})
+	if err != nil {
+		t.Fatalf("SetPinnedLibraryIDs: %v", err)
+	}
+	want := []string{libB.ID, libA.ID}
+	if len(got) != len(want) || got[0] != want[0] || got[1] != want[1] {
+		t.Fatalf("SetPinnedLibraryIDs = %v, want %v", got, want)
+	}
+
+	loaded, err := svc.GetPinnedLibraryIDs(t.Context(), user.ID)
+	if err != nil {
+		t.Fatalf("GetPinnedLibraryIDs: %v", err)
+	}
+	if len(loaded) != len(want) || loaded[0] != want[0] || loaded[1] != want[1] {
+		t.Fatalf("GetPinnedLibraryIDs = %v, want %v", loaded, want)
+	}
+}