Fixed dark and light themes, ui.theme auto/dark/light

Colors no longer come from the terminal's palette, whose color 0 many
color themes set to a grey that is not their background. A theme sets
tview's default styles and the color names used in texts, all chosen from
entries 16-255 of the 256-color table so terminals without 24-bit color
show them exactly. "auto" picks light or dark from the background color
the terminal reports. Settable in the Config view, applied at the next
start (widgets copy their colors when created). Replaces using the
terminal's own background and text colors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019reK4DUGYqDUjniWYJvwUW

internal/ui/settings.go

@@ -24,16 +24,23 @@ type settingsValues struct {
 	covers                                            bool
 	coverStyle                                        string
 	notify, bell                                      bool
+	theme                                             string
 }
 
-var coverStyles = []string{"auto", "kitty", "sextant", "quadrant", "cells"}
+var (
+	coverStyles = []string{"auto", "kitty", "sextant", "quadrant", "cells"}
+	themes      = []string{"auto", "dark", "light"}
+)
 
 // settingsFrom reads the settings in use.
 func settingsFrom(c *config.Config) settingsValues {
-	style := c.UI.CoverStyle
+	style, th := c.UI.CoverStyle, c.UI.Theme
 	if style == "" {
 		style = "auto"
 	}
+	if th == "" {
+		th = "auto"
+	}
 	return settingsValues{
 		radarrURL: c.Radarr.URL, radarrKey: c.Radarr.APIKey,
 		radarrProfile: c.Radarr.DefaultQualityProfile, radarrFolder: c.Radarr.DefaultRootFolder,
@@ -43,6 +50,7 @@ func settingsFrom(c *config.Config) settingsValues {
 		refresh: strconv.Itoa(c.UI.RefreshSeconds),
 		covers:  c.UI.ShowCovers(), coverStyle: style,
 		notify: c.UI.ShouldNotifyDownloads(), bell: c.UI.Bell,
+		theme: th,
 	}
 }
 
@@ -80,6 +88,10 @@ func applySettings(raw config.Config, v settingsValues, overridden map[string]st
 	if v.coverStyle == "auto" {
 		raw.UI.CoverStyle = ""
 	}
+	raw.UI.Theme = v.theme
+	if v.theme == "auto" {
+		raw.UI.Theme = ""
+	}
 
 	if _, err := raw.Effective(os.Getenv); err != nil {
 		return raw, err
@@ -97,7 +109,7 @@ func boolSetting(old *bool, value, def bool) *bool {
 }
 
 // settingsView edits the configuration file's settings. Everything except
-// the cover style of already open panes applies right after saving.
+// the theme applies right after saving; the theme at the next start.
 type settingsView struct {
 	app  *App
 	root *tview.Flex
@@ -112,6 +124,7 @@ type settingsView struct {
 	refresh    *tview.InputField
 	covers     *tview.Checkbox
 	style      *tview.DropDown
+	theme      *tview.DropDown
 	notify     *tview.Checkbox
 	bell       *tview.Checkbox
 	showKeys   *tview.Checkbox
@@ -171,6 +184,8 @@ func newSettingsView(app *App) *settingsView {
 	f.AddFormItem(v.covers)
 	v.style = tview.NewDropDown().SetLabel("Poster style").SetOptions(coverStyles, func(string, int) { v.edited() })
 	f.AddFormItem(v.style)
+	v.theme = tview.NewDropDown().SetLabel("Theme (at the next start)").SetOptions(themes, func(string, int) { v.edited() })
+	f.AddFormItem(v.theme)
 	v.notify = tview.NewCheckbox().SetLabel("Notify about finished downloads").SetChangedFunc(func(bool) { v.edited() })
 	f.AddFormItem(v.notify)
 	v.bell = tview.NewCheckbox().SetLabel("Ring the terminal bell too").SetChangedFunc(func(bool) { v.edited() })
@@ -289,6 +304,11 @@ func (v *settingsView) fill(s settingsValues) {
 			v.style.SetCurrentOption(i)
 		}
 	}
+	for i, name := range themes {
+		if name == s.theme {
+			v.theme.SetCurrentOption(i)
+		}
+	}
 	v.notify.SetChecked(s.notify)
 	v.bell.SetChecked(s.bell)
 	v.dirty = false
@@ -302,6 +322,10 @@ func (v *settingsView) read() settingsValues {
 	if i >= 0 && i < len(coverStyles) {
 		style = coverStyles[i]
 	}
+	th := "auto"
+	if i, _ := v.theme.GetCurrentOption(); i >= 0 && i < len(themes) {
+		th = themes[i]
+	}
 	return settingsValues{
 		radarrURL: text("radarr.url"), radarrKey: text("radarr.apikey"),
 		radarrProfile: text("radarr.profile"), radarrFolder: text("radarr.folder"),
@@ -311,6 +335,7 @@ func (v *settingsView) read() settingsValues {
 		refresh: v.refresh.GetText(),
 		covers:  v.covers.IsChecked(), coverStyle: style,
 		notify: v.notify.IsChecked(), bell: v.bell.IsChecked(),
+		theme: th,
 	}
 }
 
@@ -322,7 +347,7 @@ func (v *settingsView) describe() {
 	} else {
 		b.WriteString("Config file: " + tview.Escape(v.app.cfgPath) + "\n")
 	}
-	b.WriteString("Changes take effect when you save; nothing needs a restart.\n")
+	b.WriteString("Changes take effect when you save; only the theme waits for the next start.\n")
 	if len(v.overridden) > 0 {
 		var names []string
 		for _, env := range v.overridden {
@@ -412,9 +437,13 @@ func (v *settingsView) save() {
 		v.report("[red]Saved, but not applied: " + tview.Escape(err.Error()) + "[-]")
 		return
 	}
+	themeChanged := effective.UI.Theme != v.app.cfg.UI.Theme
 	v.app.cfgFile = &raw
 	v.app.applyConfig(effective)
 	v.dirty = false
 	v.report("[green]Saved to " + tview.Escape(v.app.cfgPath) + " and applied.[-]")
+	if themeChanged {
+		v.report("The new theme is used from the next start.")
+	}
 	v.app.Notify(levelSuccess, "Settings saved")
 }