Trakt lists: keep the Radarr/Sonarr lookups of their titles on disk

Library membership is asked every time via movie?tmdbId= / series?tvdbId=;
only the lookups of titles not in the library are stored (3 days).

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

internal/radarr/radarr.go

@@ -102,6 +102,19 @@ func (c *Client) Movies(ctx context.Context) ([]Movie, error) {
 	return movies, err
 }
 
+// MovieByTMDB returns the library movie with the TMDb id, ok=false if the
+// library has none. Unlike a lookup it does not ask the metadata provider.
+func (c *Client) MovieByTMDB(ctx context.Context, tmdbID int) (Movie, bool, error) {
+	var movies []Movie
+	err := c.Do(ctx, http.MethodGet, "movie", url.Values{"tmdbId": {strconv.Itoa(tmdbID)}}, nil, &movies)
+	for _, m := range movies { // checked: a version that ignores the filter sends the whole library
+		if m.TMDBID == tmdbID && m.InLibrary() {
+			return m, true, err
+		}
+	}
+	return Movie{}, false, err
+}
+
 // AddOptions are the choices from the add form.
 type AddOptions struct {
 	QualityProfileID    int

internal/sonarr/sonarr.go

@@ -111,6 +111,19 @@ func (c *Client) Series(ctx context.Context) ([]Series, error) {
 	return series, err
 }
 
+// SeriesByTVDB returns the library series with the TVDB id, ok=false if the
+// library has none. Unlike a lookup it does not ask the metadata provider.
+func (c *Client) SeriesByTVDB(ctx context.Context, tvdbID int) (Series, bool, error) {
+	var series []Series
+	err := c.Do(ctx, http.MethodGet, "series", url.Values{"tvdbId": {strconv.Itoa(tvdbID)}}, nil, &series)
+	for _, s := range series { // checked: a version that ignores the filter sends the whole library
+		if s.TVDBID == tvdbID && s.InLibrary() {
+			return s, true, err
+		}
+	}
+	return Series{}, false, err
+}
+
 // AddOptions are the choices from the add form.
 type AddOptions struct {
 	QualityProfileID int

internal/ui/app.go

@@ -37,7 +37,8 @@ type App struct {
 	theme        theme         // the colors in use
 	trakt        *trakt.Client // trending, most watched and anticipated lists, casts
 	people       *peopleCache  // casts loaded from Trakt
-	disk         *diskCache    // posters and casts kept between runs
+	disk         *diskCache    // posters, casts and lookups kept between runs
+	lookups      *lookupStore  // Radarr/Sonarr lookups of Trakt list titles
 	// Called (on the UI goroutine) a moment after a release was grabbed.
 	afterGrab []func()
 	// The Movies and Series views, to refresh their Trakt lists.
@@ -188,8 +189,9 @@ func New(cfg *config.Config) *App {
 	if u := os.Getenv("ARR_TUI_TRAKT_URL"); u != "" {
 		a.trakt.SetBaseURL(u) // another Trakt API, for development (dev/screenshots)
 	}
-	movies := newSearchView(a, radarrBackend{radarrClient})
-	series := newSearchView(a, sonarrBackend{sonarrClient})
+	a.lookups = newLookupStore(a.disk)
+	movies := newSearchView(a, radarrBackend{radarrClient, a.lookups})
+	series := newSearchView(a, sonarrBackend{sonarrClient, a.lookups})
 	a.searches = []*searchView{movies, series}
 	a.views = []view{
 		{key: '1', name: "Movies", body: movies.root, onShow: movies.activate, hints: searchHints},
@@ -463,6 +465,7 @@ func (a *App) Run() error {
 		if a.people.dirty { // casts fetched in the last seconds
 			_ = a.disk.savePeople(a.peopleSnapshot())
 		}
+		_ = a.lookups.save()
 	}()
 	go a.disk.prunePosters()
 	// The screen draws through the theme (see themedScreen).

internal/ui/backend.go

@@ -72,7 +72,10 @@ func (m movieResult) withID(id int) result {
 	return m
 }
 
-type radarrBackend struct{ c *radarr.Client }
+type radarrBackend struct {
+	c       *radarr.Client
+	lookups *lookupStore
+}
 
 func (b radarrBackend) name() string              { return "Radarr" }
 func (b radarrBackend) noun() string              { return "Movies" }
@@ -91,14 +94,30 @@ func (b radarrBackend) search(ctx context.Context, term string) ([]result, error
 func (radarrBackend) lists() []trakt.List { return trakt.MovieLists }
 
 func (b radarrBackend) resolve(ctx context.Context, e trakt.Entry) (result, error) {
-	if e.IDs.TMDB == 0 {
+	id := e.IDs.TMDB
+	if id == 0 {
 		return nil, errNotListed
 	}
-	found, err := b.search(ctx, radarr.TMDBTerm(e.IDs.TMDB))
-	if err != nil || len(found) == 0 {
+	if m, ok, err := b.c.MovieByTMDB(ctx, id); err != nil {
+		return nil, err
+	} else if ok {
+		return movieResult{Movie: m, poster: coverFor(b.c.Client, m.Images, true)}, nil
+	}
+	// Not in the library: the lookup from an earlier run, if fresh.
+	key := radarr.TMDBTerm(id)
+	var m radarr.Movie
+	if b.lookups.get(key, &m) {
+		return movieResult{Movie: m, poster: coverFor(b.c.Client, m.Images, false)}, nil
+	}
+	movies, err := b.c.Lookup(ctx, key)
+	if err != nil || len(movies) == 0 {
 		return nil, err
 	}
-	return found[0], nil
+	m = movies[0]
+	if !m.InLibrary() {
+		b.lookups.put(key, m)
+	}
+	return movieResult{Movie: m, poster: coverFor(b.c.Client, m.Images, m.InLibrary())}, nil
 }
 
 func (b radarrBackend) add(ctx context.Context, r result, c addChoice) (int, error) {
@@ -136,7 +155,10 @@ func (s seriesResult) withID(id int) result {
 	return s
 }
 
-type sonarrBackend struct{ c *sonarr.Client }
+type sonarrBackend struct {
+	c       *sonarr.Client
+	lookups *lookupStore
+}
 
 func (b sonarrBackend) name() string     { return "Sonarr" }
 func (b sonarrBackend) noun() string     { return "Series" }
@@ -165,14 +187,30 @@ func (b sonarrBackend) search(ctx context.Context, term string) ([]result, error
 func (sonarrBackend) lists() []trakt.List { return trakt.ShowLists }
 
 func (b sonarrBackend) resolve(ctx context.Context, e trakt.Entry) (result, error) {
-	if e.IDs.TVDB == 0 {
+	id := e.IDs.TVDB
+	if id == 0 {
 		return nil, errNotListed
 	}
-	found, err := b.search(ctx, "tvdb:"+itoa(e.IDs.TVDB))
-	if err != nil || len(found) == 0 {
+	if s, ok, err := b.c.SeriesByTVDB(ctx, id); err != nil {
+		return nil, err
+	} else if ok {
+		return seriesResult{Series: s, poster: coverFor(b.c.Client, s.Images, true)}, nil
+	}
+	// Not in the library: the lookup from an earlier run, if fresh.
+	key := "tvdb:" + itoa(id)
+	var s sonarr.Series
+	if b.lookups.get(key, &s) {
+		return seriesResult{Series: s, poster: coverFor(b.c.Client, s.Images, false)}, nil
+	}
+	series, err := b.c.Lookup(ctx, key)
+	if err != nil || len(series) == 0 {
 		return nil, err
 	}
-	return found[0], nil
+	s = series[0]
+	if !s.InLibrary() {
+		b.lookups.put(key, s)
+	}
+	return seriesResult{Series: s, poster: coverFor(b.c.Client, s.Images, s.InLibrary())}, nil
 }
 
 func (b sonarrBackend) add(ctx context.Context, r result, c addChoice) (int, error) {

internal/ui/diskcache.go

@@ -169,6 +169,42 @@ func (d *diskCache) savePeople(all map[string]savedPeople) error {
 	return writeAtomic(d.peoplePath(), data)
 }
 
+func (d *diskCache) lookupsPath() string { return filepath.Join(d.dir, "lookups.json") }
+
+// loadLookups reads the stored Radarr/Sonarr lookups that are not too old.
+func (d *diskCache) loadLookups() map[string]savedLookup {
+	out := map[string]savedLookup{}
+	if d.dir == "" {
+		return out
+	}
+	data, err := os.ReadFile(d.lookupsPath())
+	if err != nil {
+		return out
+	}
+	var all map[string]savedLookup
+	if json.Unmarshal(data, &all) != nil {
+		return out // unreadable: start afresh, it is only a cache
+	}
+	for k, l := range all {
+		if time.Since(l.Saved) <= lookupTTL {
+			out[k] = l
+		}
+	}
+	return out
+}
+
+// saveLookups writes the lookups.
+func (d *diskCache) saveLookups(all map[string]savedLookup) error {
+	if d.dir == "" {
+		return nil
+	}
+	data, err := json.Marshal(all)
+	if err != nil {
+		return err
+	}
+	return writeAtomic(d.lookupsPath(), data)
+}
+
 // writeAtomic writes a file through a temporary file and a rename, creating
 // the directory (private) if needed.
 func writeAtomic(path string, data []byte) error {

internal/ui/lookups.go

@@ -0,0 +1,95 @@
+package ui
+
+import (
+	"encoding/json"
+	"maps"
+	"slices"
+	"sync"
+	"time"
+)
+
+const (
+	lookupTTL       = 3 * 24 * time.Hour // a stored lookup is used this long
+	maxLookupsSaved = 2000               // lookups kept (in memory and on disk)
+	lookupSaveDelay = 5 * time.Second    // new lookups are written to disk this long after the last one
+)
+
+// lookupStore keeps the Radarr/Sonarr lookups of Trakt list titles that are
+// not in the library, so a list shows at once after a restart: a lookup asks
+// the metadata provider and takes about a second, while whether a title is
+// in the library is asked of the server every time (that is quick, and must
+// not be stale). Safe for use from any goroutine; read from disk on first use.
+type lookupStore struct {
+	disk *diskCache
+
+	mu      sync.Mutex
+	loaded  bool
+	entries map[string]savedLookup
+	dirty   bool
+	timer   *time.Timer
+}
+
+// savedLookup is one lookup result as Radarr/Sonarr sent it.
+type savedLookup struct {
+	Saved time.Time       `json:"saved"`
+	Data  json.RawMessage `json:"data"`
+}
+
+func newLookupStore(disk *diskCache) *lookupStore { return &lookupStore{disk: disk} }
+
+func (s *lookupStore) load() {
+	if !s.loaded {
+		s.loaded, s.entries = true, s.disk.loadLookups()
+	}
+}
+
+// get decodes the stored lookup of key into v, if there is a fresh one.
+func (s *lookupStore) get(key string, v any) bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.load()
+	e, ok := s.entries[key]
+	if !ok || time.Since(e.Saved) > lookupTTL {
+		return false
+	}
+	return json.Unmarshal(e.Data, v) == nil
+}
+
+// put stores a lookup, dropping the oldest ones beyond maxLookupsSaved, and
+// has it written to disk soon.
+func (s *lookupStore) put(key string, v any) {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.load()
+	s.entries[key] = savedLookup{Saved: time.Now(), Data: data}
+	if len(s.entries) > maxLookupsSaved {
+		keys := slices.SortedFunc(maps.Keys(s.entries), func(x, y string) int {
+			return s.entries[x].Saved.Compare(s.entries[y].Saved)
+		})
+		for _, k := range keys[:len(keys)-maxLookupsSaved] {
+			delete(s.entries, k)
+		}
+	}
+	s.dirty = true
+	if s.timer != nil {
+		s.timer.Stop()
+	}
+	s.timer = time.AfterFunc(lookupSaveDelay, func() { _ = s.save() })
+}
+
+// save writes the lookups to disk if there are new ones.
+func (s *lookupStore) save() error {
+	s.mu.Lock()
+	if !s.dirty {
+		s.mu.Unlock()
+		return nil
+	}
+	s.dirty = false
+	all := maps.Clone(s.entries)
+	s.mu.Unlock()
+	return s.disk.saveLookups(all)
+}

internal/ui/lookups_test.go

@@ -0,0 +1,63 @@
+package ui
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+
+	"git.stinnesbeck.com/nils/arr-tui/internal/radarr"
+	"git.stinnesbeck.com/nils/arr-tui/internal/trakt"
+)
+
+func TestListLookupsKeptOnDisk(t *testing.T) {
+	var lookups, libraryAsks atomic.Int32
+	inLibrary := false
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/v3/movie":
+			libraryAsks.Add(1)
+			if inLibrary && r.URL.Query().Get("tmdbId") == "949" {
+				w.Write([]byte(`[{"id":7,"title":"Heat","year":1995,"tmdbId":949}]`))
+				return
+			}
+			w.Write([]byte(`[{"id":3,"title":"Other","tmdbId":1}]`)) // ignores the filter
+		case "/api/v3/movie/lookup":
+			lookups.Add(1)
+			w.Write([]byte(`[{"title":"Heat","year":1995,"tmdbId":949,"overview":"Cops and robbers."}]`))
+		}
+	}))
+	defer srv.Close()
+	disk := &diskCache{dir: t.TempDir()}
+	entry := trakt.Entry{Title: "Heat", IDs: trakt.IDs{TMDB: 949}}
+	resolve := func() result {
+		t.Helper()
+		store := newLookupStore(disk) // a new run
+		b := radarrBackend{radarr.NewClient(srv.URL, "k"), store}
+		r, err := b.resolve(context.Background(), entry)
+		if err != nil || r == nil {
+			t.Fatalf("resolve: %v %v", r, err)
+		}
+		if err := store.save(); err != nil {
+			t.Fatal(err)
+		}
+		return r
+	}
+
+	if r := resolve(); r.inLibrary() || lookups.Load() != 1 {
+		t.Fatalf("first run: in library %v, %d lookups", r.inLibrary(), lookups.Load())
+	}
+	r := resolve()
+	if lookups.Load() != 1 || r.details().plot != "Cops and robbers." {
+		t.Errorf("second run: %d lookups, plot %q", lookups.Load(), r.details().plot)
+	}
+	// Added meanwhile (elsewhere): the library answer wins over the stored lookup.
+	inLibrary = true
+	if r := resolve(); !r.inLibrary() || lookups.Load() != 1 {
+		t.Errorf("after adding: in library %v, %d lookups", r.inLibrary(), lookups.Load())
+	}
+	if libraryAsks.Load() != 3 {
+		t.Errorf("library asked %d times", libraryAsks.Load())
+	}
+}