Filter dialog: only offer options that yield results

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

internal/ui/library.go

@@ -208,6 +208,8 @@ type libraryView struct {
 	seriesFiles map[int]seriesFiles
 	fileGen     int // invalidates running fetches
 	filePending int
+
+	refreshDialog func() // re-evaluates the options of the open filter dialog
 }
 
 type seriesFiles struct {
@@ -271,7 +273,7 @@ func (v *libraryView) handleKey(ev *tcell.EventKey) *tcell.EventKey {
 			v.filter = (v.filter + 1) % len(libFilters)
 			v.render()
 		case 'F':
-			v.app.openAttrFilter(v.attr, languagesOf(v.panes[kindMovies].all, v.panes[kindSeries].all), v.setAttrFilter)
+			v.openFilterDialog()
 		case 'r':
 			v.seriesFiles = map[int]seriesFiles{} // a manual reload also refreshes file properties
 			v.reload()
@@ -334,7 +336,7 @@ func (v *libraryView) reloadPane(p *libPane) {
 			}
 			p.err = err
 			if err == nil && kind == kindSeries {
-				defer v.loadSeriesFiles()
+				defer v.loadSeriesFiles(false)
 			}
 			if err != nil {
 				// Keep showing the last good list; say why it is stale.
@@ -494,7 +496,29 @@ func (v *libraryView) run(doing, done string, fn func(ctx context.Context) error
 func (v *libraryView) setAttrFilter(f attrFilter) {
 	v.attr = f
 	v.render()
-	v.loadSeriesFiles()
+	v.loadSeriesFiles(false)
+}
+
+// openFilterDialog opens the property filter. The files of all series are read
+// so the dialog can leave out options that would match nothing.
+func (v *libraryView) openFilterDialog() {
+	v.refreshDialog = v.app.openAttrFilter(v.attr, v.filterPool, v.setAttrFilter, func() { v.refreshDialog = nil })
+	v.loadSeriesFiles(true)
+}
+
+// filterPool lists the files of the items that pass the status and text
+// filters, for the filter dialog.
+func (v *libraryView) filterPool() filterPool {
+	var p filterPool
+	for _, pane := range v.panes {
+		for _, it := range filterItems(pane.all, v.filter, v.input.GetText(), attrFilter{}) {
+			if !it.attrsKnown {
+				p.unknown = true
+			}
+			p.files = append(p.files, it.attrs)
+		}
+	}
+	return p
 }
 
 // withCachedFiles fills in the file properties of a series from the cache.
@@ -510,9 +534,10 @@ func (v *libraryView) withCachedFiles(it libItem) libItem {
 }
 
 // loadSeriesFiles fetches the file properties of all series that lack them,
-// but only while a property filter is active (it costs one request per series).
-func (v *libraryView) loadSeriesFiles() {
-	if !v.attr.active() {
+// but only while a property filter is active or the filter dialog is open
+// (it costs one request per series).
+func (v *libraryView) loadSeriesFiles(force bool) {
+	if !force && !v.attr.active() {
 		return
 	}
 	p := v.panes[kindSeries]
@@ -580,6 +605,9 @@ func (v *libraryView) loadSeriesFiles() {
 				}
 				if v.filePending%10 == 0 { // keep redraws cheap for big libraries
 					v.render()
+					if v.refreshDialog != nil {
+						v.refreshDialog()
+					}
 				}
 			})
 		}