Add the Config view: edit and save the settings, applied without a restart

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

internal/arr/client.go

@@ -11,16 +11,34 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
+	"sync"
 	"time"
 )
 
 // Client is a minimal JSON client for the Radarr/Sonarr v3 API.
 type Client struct {
+	mu      sync.RWMutex // guards baseURL and apiKey, which Reconfigure can change
 	baseURL string
 	apiKey  string
 	http    *http.Client
 }
 
+// settings returns the current base URL and API key.
+func (c *Client) settings() (baseURL, apiKey string) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.baseURL, c.apiKey
+}
+
+// Reconfigure points the client at another instance or key. Requests already
+// in flight are not affected.
+func (c *Client) Reconfigure(baseURL, apiKey string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.baseURL = strings.TrimRight(baseURL, "/")
+	c.apiKey = apiKey
+}
+
 // NewClient returns a client for the instance at baseURL (without /api/v3).
 func NewClient(baseURL, apiKey string) *Client {
 	return &Client{
@@ -46,7 +64,8 @@ func (e *APIError) Error() string {
 // Do sends a request to /api/v3/<path>. body (if non-nil) is JSON-encoded and
 // the response is decoded into out (if non-nil).
 func (c *Client) Do(ctx context.Context, method, path string, query url.Values, body, out any) error {
-	u := c.baseURL + "/api/v3/" + strings.TrimLeft(path, "/")
+	base, apiKey := c.settings()
+	u := base + "/api/v3/" + strings.TrimLeft(path, "/")
 	if len(query) > 0 {
 		u += "?" + query.Encode()
 	}
@@ -64,7 +83,7 @@ func (c *Client) Do(ctx context.Context, method, path string, query url.Values,
 	if err != nil {
 		return err
 	}
-	req.Header.Set("X-Api-Key", c.apiKey)
+	req.Header.Set("X-Api-Key", apiKey)
 	req.Header.Set("Accept", "application/json")
 	if body != nil {
 		req.Header.Set("Content-Type", "application/json")

internal/arr/image.go

@@ -26,7 +26,8 @@ func (c *Client) Poster(images []Image, inLibrary bool) (key string, fetch func(
 		}
 		if inLibrary && img.URL != "" {
 			local := img.URL
-			return c.baseURL + "|" + local, func(ctx context.Context) ([]byte, error) {
+			base, _ := c.settings()
+			return base + "|" + local, func(ctx context.Context) ([]byte, error) {
 				// MediaCover has poster-250.jpg next to poster.jpg; fall back to the original.
 				if small := smallVariant(local); small != local {
 					if data, err := c.GetBytes(ctx, small); err == nil {
@@ -68,21 +69,23 @@ func (c *Client) GetBytes(ctx context.Context, ref string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("X-Api-Key", c.apiKey)
+	_, apiKey := c.settings()
+	req.Header.Set("X-Api-Key", apiKey)
 	return doImage(c.http, req)
 }
 
 // resolve joins a server-relative path to the base URL. Radarr/Sonarr include
 // their URL base in image paths, so it must not be added twice.
 func (c *Client) resolve(ref string) (string, error) {
-	base, err := url.Parse(c.baseURL)
+	baseURL, _ := c.settings()
+	base, err := url.Parse(baseURL)
 	if err != nil {
 		return "", err
 	}
 	if base.Path != "" && base.Path != "/" && strings.HasPrefix(ref, strings.TrimRight(base.Path, "/")+"/") {
 		return base.Scheme + "://" + base.Host + ref, nil
 	}
-	return c.baseURL + ref, nil
+	return baseURL + ref, nil
 }
 
 var imageClient = &http.Client{Timeout: 20 * time.Second}

internal/arr/update_test.go

@@ -46,3 +46,39 @@ func TestSetSeasonMonitoredUnknownSeason(t *testing.T) {
 		t.Error("want error")
 	}
 }
+
+func TestReconfigureSwitchesInstanceAndKey(t *testing.T) {
+	var gotKey, gotHost string
+	mk := func(host string) *httptest.Server {
+		return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			gotKey, gotHost = r.Header.Get("X-Api-Key"), host
+			io.WriteString(w, `{"version":"1"}`)
+		}))
+	}
+	a, b := mk("a"), mk("b")
+	defer a.Close()
+	defer b.Close()
+
+	c := NewClient(a.URL, "key-a")
+	var out struct{ Version string }
+	if err := c.Do(context.Background(), http.MethodGet, "system/status", nil, nil, &out); err != nil || gotHost != "a" || gotKey != "key-a" {
+		t.Fatalf("before: host=%q key=%q err=%v", gotHost, gotKey, err)
+	}
+	c.Reconfigure(b.URL+"/", "key-b") // a trailing slash is trimmed like in NewClient
+	if err := c.Do(context.Background(), http.MethodGet, "system/status", nil, nil, &out); err != nil || gotHost != "b" || gotKey != "key-b" {
+		t.Fatalf("after: host=%q key=%q err=%v", gotHost, gotKey, err)
+	}
+	// Used from many goroutines while being changed (run with -race to see it matter).
+	done := make(chan bool)
+	go func() {
+		for i := 0; i < 50; i++ {
+			c.Reconfigure(a.URL, "k")
+			c.Reconfigure(b.URL, "k")
+		}
+		done <- true
+	}()
+	for i := 0; i < 50; i++ {
+		_ = c.Do(context.Background(), http.MethodGet, "system/status", nil, nil, &out)
+	}
+	<-done
+}

internal/config/config.go

@@ -103,14 +103,54 @@ func Load(path string) (*Config, []string, error) {
 // Parse decodes config JSON, applies environment overrides and defaults, and
 // validates the result. Unknown fields are rejected to catch typos.
 func Parse(data []byte) (*Config, error) {
+	raw, err := parseRaw(data)
+	if err != nil {
+		return nil, err
+	}
+	return raw.Effective(os.Getenv)
+}
+
+// parseRaw decodes config JSON as it stands in the file: no environment
+// overrides, no defaults, no validation.
+func parseRaw(data []byte) (*Config, error) {
 	var cfg Config
 	dec := json.NewDecoder(bytes.NewReader(data))
 	dec.DisallowUnknownFields()
 	if err := dec.Decode(&cfg); err != nil {
 		return nil, fmt.Errorf("parsing config: %w", err)
 	}
+	return &cfg, nil
+}
 
-	cfg.applyEnv(os.Getenv)
+// LoadFile reads the config at path exactly as written: no environment
+// overrides, no defaults, no validation. It is what an editor of the file must
+// start from, so values that only came from the environment are not written
+// back to disk.
+func LoadFile(path string) (*Config, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("reading config: %w", err)
+	}
+	cfg, err := parseRaw(data)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", path, err)
+	}
+	return cfg, nil
+}
+
+// Effective returns the configuration the program runs with: a copy with the
+// environment overrides and defaults applied, validated.
+func (c *Config) Effective(env func(string) string) (*Config, error) {
+	cfg := *c
+	if c.UI.Covers != nil {
+		v := *c.UI.Covers
+		cfg.UI.Covers = &v
+	}
+	if c.UI.NotifyDownloads != nil {
+		v := *c.UI.NotifyDownloads
+		cfg.UI.NotifyDownloads = &v
+	}
+	cfg.applyEnv(env)
 	cfg.applyDefaults()
 	if err := cfg.Validate(); err != nil {
 		return nil, err
@@ -118,6 +158,66 @@ func Parse(data []byte) (*Config, error) {
 	return &cfg, nil
 }
 
+// envVars maps the settings that can be overridden by the environment to the
+// variable that does it.
+var envVars = map[string]string{
+	"radarr.url":     "ARR_TUI_RADARR_URL",
+	"radarr.apikey":  "ARR_TUI_RADARR_APIKEY",
+	"sonarr.url":     "ARR_TUI_SONARR_URL",
+	"sonarr.apikey":  "ARR_TUI_SONARR_APIKEY",
+	"sabnzbd.url":    "ARR_TUI_SABNZBD_URL",
+	"sabnzbd.apikey": "ARR_TUI_SABNZBD_APIKEY",
+}
+
+// Overrides returns, for every setting that the environment currently
+// overrides, the name of the variable. Keys look like "radarr.url".
+func Overrides(env func(string) string) map[string]string {
+	out := map[string]string{}
+	for key, name := range envVars {
+		if env(name) != "" {
+			out[key] = name
+		}
+	}
+	return out
+}
+
+// Save writes the config to path as indented JSON. The file is replaced
+// atomically (a temporary file in the same directory, then a rename) and keeps
+// the permissions of the existing file, or is private (0600) when new: it
+// holds API keys.
+func Save(path string, cfg *Config) error {
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		return err
+	}
+	data = append(data, '\n')
+
+	mode := os.FileMode(0o600)
+	if info, err := os.Stat(path); err == nil {
+		mode = info.Mode().Perm()
+	}
+	tmp, err := os.CreateTemp(filepath.Dir(path), ".config-*.tmp")
+	if err != nil {
+		return fmt.Errorf("saving config: %w", err)
+	}
+	defer os.Remove(tmp.Name()) // no-op after a successful rename
+	if err := tmp.Chmod(mode); err != nil {
+		tmp.Close()
+		return fmt.Errorf("saving config: %w", err)
+	}
+	if _, err := tmp.Write(data); err != nil {
+		tmp.Close()
+		return fmt.Errorf("saving config: %w", err)
+	}
+	if err := tmp.Close(); err != nil {
+		return fmt.Errorf("saving config: %w", err)
+	}
+	if err := os.Rename(tmp.Name(), path); err != nil {
+		return fmt.Errorf("saving config: %w", err)
+	}
+	return nil
+}
+
 func (c *Config) applyEnv(get func(string) string) {
 	override := func(dst *string, key string) {
 		if v := get(key); v != "" {

internal/config/config_test.go

@@ -109,3 +109,82 @@ func TestCoverStyleValidation(t *testing.T) {
 		t.Error("unknown style accepted")
 	}
 }
+
+func TestSaveRoundTripAndPermissions(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "config.json")
+	covers := false
+	cfg := &Config{
+		Radarr:  Arr{Service: Service{URL: "http://r:7878", APIKey: "rk"}, DefaultQualityProfile: "HD-1080p"},
+		Sonarr:  Arr{Service: Service{URL: "http://s:8989", APIKey: "sk"}},
+		SABnzbd: Service{URL: "http://a:8080", APIKey: "ak"},
+		UI:      UI{RefreshSeconds: 5, Covers: &covers, CoverStyle: "sextant", Bell: true},
+	}
+	if err := Save(path, cfg); err != nil {
+		t.Fatal(err)
+	}
+	info, err := os.Stat(path)
+	if err != nil || info.Mode().Perm() != 0o600 {
+		t.Fatalf("new file mode = %v, want 0600 (it holds API keys): %v", info.Mode().Perm(), err)
+	}
+	got, err := LoadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Radarr.DefaultQualityProfile != "HD-1080p" || got.UI.RefreshSeconds != 5 || got.UI.Covers == nil || *got.UI.Covers || got.UI.CoverStyle != "sextant" || !got.UI.Bell {
+		t.Errorf("round trip lost values: %+v", got)
+	}
+	// Unset optional settings stay out of the file.
+	if data, _ := os.ReadFile(path); strings.Contains(string(data), "notify_downloads") || strings.Contains(string(data), "default_root_folder") {
+		t.Errorf("unset settings written:\n%s", data)
+	}
+
+	// An existing file keeps its permissions and no temporary file is left behind.
+	if err := os.Chmod(path, 0o640); err != nil {
+		t.Fatal(err)
+	}
+	if err := Save(path, cfg); err != nil {
+		t.Fatal(err)
+	}
+	if info, _ := os.Stat(path); info.Mode().Perm() != 0o640 {
+		t.Errorf("existing mode changed to %v", info.Mode().Perm())
+	}
+	entries, _ := os.ReadDir(dir)
+	if len(entries) != 1 {
+		t.Errorf("leftover files in the config directory: %v", entries)
+	}
+}
+
+func TestLoadFileIgnoresEnvironmentAndDefaults(t *testing.T) {
+	t.Setenv("ARR_TUI_RADARR_APIKEY", "from-env")
+	path := filepath.Join(t.TempDir(), "config.json")
+	os.WriteFile(path, []byte(`{"radarr":{"url":"http://r/","apikey":"from-file"},"sonarr":{"url":"http://s","apikey":"k"},"sabnzbd":{"url":"http://a","apikey":"k"}}`), 0o600)
+
+	raw, err := LoadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if raw.Radarr.APIKey != "from-file" || raw.Radarr.URL != "http://r/" || raw.UI.RefreshSeconds != 0 {
+		t.Errorf("raw = %+v: environment, trailing slash trimming and defaults must not be applied", raw)
+	}
+	eff, err := raw.Effective(os.Getenv)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if eff.Radarr.APIKey != "from-env" || eff.Radarr.URL != "http://r" || eff.UI.RefreshSeconds != 3 {
+		t.Errorf("effective = %+v", eff)
+	}
+	if raw.Radarr.APIKey != "from-file" {
+		t.Error("Effective must not modify the raw config")
+	}
+	if got := Overrides(os.Getenv); len(got) != 1 || got["radarr.apikey"] != "ARR_TUI_RADARR_APIKEY" {
+		t.Errorf("overrides = %v", got)
+	}
+}
+
+func TestEffectiveValidates(t *testing.T) {
+	raw := &Config{Radarr: Arr{Service: Service{URL: "ftp://x", APIKey: "k"}}}
+	if _, err := raw.Effective(func(string) string { return "" }); err == nil {
+		t.Error("an invalid config must not become effective")
+	}
+}

internal/sabnzbd/sabnzbd.go

@@ -11,16 +11,26 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
 // Client talks to a SABnzbd instance.
 type Client struct {
+	mu      sync.RWMutex // guards baseURL and apiKey, which Reconfigure can change
 	baseURL string
 	apiKey  string
 	http    *http.Client
 }
 
+// Reconfigure points the client at another instance or key.
+func (c *Client) Reconfigure(baseURL, apiKey string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.baseURL = strings.TrimRight(baseURL, "/")
+	c.apiKey = apiKey
+}
+
 // NewClient returns a client for the instance at baseURL.
 func NewClient(baseURL, apiKey string) *Client {
 	return &Client{
@@ -159,9 +169,12 @@ func boolParam(b bool) string {
 // {"status": false, "error": "..."}, which is turned into an error here.
 func (c *Client) call(ctx context.Context, params url.Values, out any) error {
 	params.Set("output", "json")
-	params.Set("apikey", c.apiKey)
+	c.mu.RLock()
+	baseURL, apiKey := c.baseURL, c.apiKey
+	c.mu.RUnlock()
+	params.Set("apikey", apiKey)
 
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.baseURL+"/api?"+params.Encode(), nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, baseURL+"/api?"+params.Encode(), nil)
 	if err != nil {
 		return stripURL(err)
 	}

internal/sabnzbd/sabnzbd_test.go

@@ -122,3 +122,22 @@ func TestTransportErrorHidesAPIKey(t *testing.T) {
 		t.Errorf("error leaks API key: %v", err)
 	}
 }
+
+func TestReconfigure(t *testing.T) {
+	var gotKey string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotKey = r.URL.Query().Get("apikey")
+		w.Write([]byte(`{"version":"5.1"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("http://127.0.0.1:1", "old") // unreachable until reconfigured
+	if _, err := c.Version(context.Background()); err == nil {
+		t.Fatal("expected a connection error")
+	}
+	c.Reconfigure(srv.URL+"/", "new")
+	v, err := c.Version(context.Background())
+	if err != nil || v != "5.1" || gotKey != "new" {
+		t.Errorf("version=%q key=%q err=%v", v, gotKey, err)
+	}
+}

internal/ui/app.go

@@ -25,6 +25,9 @@ type view struct {
 	onShow, onHide func()
 	// hints lists the keys that work in this view (shown in the status bar).
 	hints func() string
+	// captureKeys makes the global single-key shortcuts (q, ?) stand back
+	// while this view is shown, because its fields take typed text.
+	captureKeys bool
 }
 
 // App is the top-level arr-tui application.
@@ -46,8 +49,18 @@ type App struct {
 	state    map[string]serviceState // keyed by service name
 	probes   []probe
 
-	screen     tcell.Screen // remembered at the first draw, for the bell
+	screen     tcell.Screen   // remembered at the first draw, for the bell
+	cfg        *config.Config // the settings in use (file, environment and defaults combined)
+	cfgPath    string         // the config file, empty if unknown
+	cfgFile    *config.Config // the file's contents as written, for saving
+	radarr     *radarr.Client
+	sonarr     *sonarr.Client
 	sab        *sabnzbd.Client
+	downloads  *downloadsView
+	settings   *settingsView
+	panes      []*detailPane // every detail pane, to restyle posters when settings change
+	reconnect  []func()      // run after the service addresses or keys changed
+	watchStop  context.CancelFunc
 	notifyDone bool // announce finished downloads
 	bell       bool
 	covers     bool // poster thumbnails enabled
@@ -111,8 +124,10 @@ func New(cfg *config.Config) *App {
 		a.gfx = newKittyGraphics(a.writeTerminal)
 	}
 
+	a.cfg = cfg
 	radarrClient := radarr.NewClient(cfg.Radarr.URL, cfg.Radarr.APIKey)
 	sonarrClient := sonarr.NewClient(cfg.Sonarr.URL, cfg.Sonarr.APIKey)
+	a.radarr, a.sonarr = radarrClient, sonarrClient
 	a.logs = newLogView(a)
 	sabClient := sabnzbd.NewClient(cfg.SABnzbd.URL, cfg.SABnzbd.APIKey)
 	a.sab = sabClient
@@ -127,6 +142,8 @@ func New(cfg *config.Config) *App {
 		}},
 		{"SABnzbd", sabClient.Version},
 	}
+	settings := newSettingsView(a)
+	a.settings = settings
 	calendar := newCalendarView(a, radarrClient, sonarrClient)
 	library := newLibraryView(a, radarrClient, sonarrClient)
 	downloads := newDownloadsView(a, sabClient,
@@ -135,13 +152,15 @@ func New(cfg *config.Config) *App {
 			{name: "Sonarr", queue: sonarrClient.Queue, remove: sonarrClient.RemoveQueueItem},
 		},
 		time.Duration(cfg.UI.RefreshSeconds)*time.Second)
+	a.downloads = downloads
 	a.views = []view{
-		{key: '1', name: "Movies", body: newSearchView(a, radarrBackend{radarrClient}, cfg.Radarr).root, hints: searchHints},
-		{key: '2', name: "Series", body: newSearchView(a, sonarrBackend{sonarrClient}, cfg.Sonarr).root, hints: searchHints},
+		{key: '1', name: "Movies", body: newSearchView(a, radarrBackend{radarrClient}).root, hints: searchHints},
+		{key: '2', name: "Series", body: newSearchView(a, sonarrBackend{sonarrClient}).root, hints: searchHints},
 		{key: '3', name: "Library", body: library.root, onShow: library.activate, hints: libraryHints},
 		{key: '4', name: "Downloads", body: downloads.root, onShow: downloads.activate, onHide: downloads.deactivate, hints: downloads.hints},
 		{key: '5', name: "Calendar", body: calendar.root, onShow: calendar.activate, hints: calendarHints},
 		{key: '6', name: "Log", body: a.logs.root, onShow: a.logs.onShow, hints: logHints},
+		{key: '7', name: "Config", body: settings.root, onShow: settings.activate, hints: settingsHints, captureKeys: true},
 	}
 	for i, v := range a.views {
 		a.pages.AddPage(v.name, v.body, true, i == 0)
@@ -236,6 +255,7 @@ func (a *App) setNarrow(narrow bool) {
 	a.narrow = narrow
 	a.topBar.ResizeItem(a.services, servicesWidth(narrow), 0)
 	a.renderServices()
+	a.renderTabs()
 }
 
 func (a *App) renderServices() {
@@ -295,27 +315,31 @@ func (a *App) Run() error {
 		}
 	}()
 	go a.watchServices(stop)
-	if a.notifyDone {
-		ctx, cancel := context.WithCancel(context.Background())
-		defer cancel()
-		go a.watchDownloads(ctx, a.sab, a.bell)
-	}
+	a.setNotifyDownloads(a.notifyDone)
+	defer a.setNotifyDownloads(false)
 	return a.app.Run()
 }
 
+// setNotifyDownloads starts or stops the background watch for finished downloads.
+func (a *App) setNotifyDownloads(on bool) {
+	a.notifyDone = on
+	if a.watchStop != nil {
+		a.watchStop()
+		a.watchStop = nil
+	}
+	if on {
+		ctx, cancel := context.WithCancel(context.Background())
+		a.watchStop = cancel
+		go a.watchDownloads(ctx, a.sab)
+	}
+}
+
 // watchServices checks all services now and then every heartbeat until stop is closed.
 func (a *App) watchServices(stop <-chan struct{}) {
 	tick := time.NewTicker(heartbeat)
 	defer tick.Stop()
 	for {
-		for _, p := range a.probes {
-			go func() {
-				ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-				defer cancel()
-				version, err := p.check(ctx)
-				a.post(func() { a.SetService(p.name, version, err) })
-			}()
-		}
+		a.probeAll()
 		select {
 		case <-tick.C:
 		case <-stop:
@@ -324,15 +348,34 @@ func (a *App) watchServices(stop <-chan struct{}) {
 	}
 }
 
+// probeAll checks every service in the background and updates the indicators.
+func (a *App) probeAll() {
+	for _, p := range a.probes {
+		go func() {
+			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+			defer cancel()
+			version, err := p.check(ctx)
+			a.post(func() { a.SetService(p.name, version, err) })
+		}()
+	}
+}
+
 func (a *App) renderStatus() {
 	var hints string
 	if n := len(a.overlays); n > 0 {
 		hints = a.overlays[n-1].hints + " · Ctrl+C quit"
 	} else {
-		if h := a.views[a.active].hints; h != nil {
-			hints = h() + " · "
+		v := a.views[a.active]
+		var parts []string
+		if v.hints != nil {
+			parts = append(parts, v.hints())
 		}
-		hints += "? help · F1-F6 · q quit"
+		if v.captureKeys { // q and ? are text there
+			parts = append(parts, "F9 help · F1-F7 views")
+		} else {
+			parts = append(parts, "? help · F1-F7 · q quit")
+		}
+		hints = strings.Join(parts, " · ")
 	}
 	a.status.SetText("[gray]" + hints)
 }
@@ -419,7 +462,7 @@ func (a *App) onlyFullOverlays() bool {
 // typing reports whether keystrokes belong to a text field or dialog and must
 // not trigger global shortcuts.
 func (a *App) typing() bool {
-	if len(a.overlays) > 0 {
+	if len(a.overlays) > 0 || a.views[a.active].captureKeys {
 		return true
 	}
 	_, isInput := a.app.GetFocus().(*tview.InputField)
@@ -483,9 +526,14 @@ func (a *App) switchTo(i int) {
 func (a *App) renderTabs() {
 	var s string
 	for i, v := range a.views {
-		if i == a.active {
+		switch {
+		case a.narrow && i == a.active:
+			s += fmt.Sprintf("[black:white]%c %s[-:-] ", v.key, v.name)
+		case a.narrow:
+			s += fmt.Sprintf("[gray]%c %s[-] ", v.key, v.name)
+		case i == a.active:
 			s += fmt.Sprintf("[black:white] %c %s [-:-] ", v.key, v.name)
-		} else {
+		default:
 			s += fmt.Sprintf("[gray] %c %s [-]", v.key, v.name)
 		}
 	}

internal/ui/app_test.go

@@ -22,7 +22,7 @@ func newTestApp(t *testing.T) *App {
 
 func TestOnlyFunctionKeysSwitchViews(t *testing.T) {
 	a := newTestApp(t)
-	for _, r := range "123456\t" {
+	for _, r := range "1234567\t" {
 		key := tcell.NewEventKey(tcell.KeyRune, r, 0)
 		if r == '\t' {
 			key = tcell.NewEventKey(tcell.KeyTab, 0, 0)
@@ -32,7 +32,7 @@ func TestOnlyFunctionKeysSwitchViews(t *testing.T) {
 			t.Fatalf("key %q switched to view %d", r, a.active)
 		}
 	}
-	for i, k := range []tcell.Key{tcell.KeyF1, tcell.KeyF2, tcell.KeyF3, tcell.KeyF4, tcell.KeyF5, tcell.KeyF6} {
+	for i, k := range []tcell.Key{tcell.KeyF1, tcell.KeyF2, tcell.KeyF3, tcell.KeyF4, tcell.KeyF5, tcell.KeyF6, tcell.KeyF7} {
 		if a.handleKey(tcell.NewEventKey(k, 0, 0)) != nil || a.active != i {
 			t.Errorf("F%d: active view %d, want %d", i+1, a.active, i)
 		}

internal/ui/calendar.go

@@ -209,6 +209,7 @@ func newCalendarView(app *App, r *radarr.Client, s *sonarr.Client) *calendarView
 	v.table.SetSelectionChangedFunc(func(int, int) { v.renderDetails() })
 	v.table.SetSelectedFunc(func(int, int) { v.open() })
 	v.table.SetInputCapture(v.handleKey)
+	app.reconnect = append(app.reconnect, func() { v.entries, v.loaded = nil, false })
 	v.render()
 	return v
 }

internal/ui/configapply.go

@@ -0,0 +1,66 @@
+package ui
+
+import (
+	"os"
+	"time"
+
+	"git.stinnesbeck.com/nils/arr-tui/internal/config"
+)
+
+// SetConfigSource tells the app which file the settings came from and what that
+// file contains, so the Config view can save changes. raw is the file as
+// written (see config.LoadFile), not the effective settings.
+func (a *App) SetConfigSource(path string, raw *config.Config) {
+	a.cfgPath, a.cfgFile = path, raw
+	if a.settings != nil {
+		a.settings.describe()
+	}
+}
+
+// applyConfig puts new settings into effect without a restart.
+func (a *App) applyConfig(c *config.Config) {
+	old := a.cfg
+	a.cfg = c
+
+	if old.Radarr.Service != c.Radarr.Service || old.Sonarr.Service != c.Sonarr.Service || old.SABnzbd != c.SABnzbd {
+		a.radarr.Reconfigure(c.Radarr.URL, c.Radarr.APIKey)
+		a.sonarr.Reconfigure(c.Sonarr.URL, c.Sonarr.APIKey)
+		a.sab.Reconfigure(c.SABnzbd.URL, c.SABnzbd.APIKey)
+		a.probeAll() // the indicators, right away
+		for _, f := range a.reconnect {
+			f()
+		}
+	}
+	if old.UI.RefreshSeconds != c.UI.RefreshSeconds {
+		a.downloads.setInterval(time.Duration(c.UI.RefreshSeconds) * time.Second)
+	}
+	a.bell = c.UI.Bell
+	if c.UI.ShouldNotifyDownloads() != a.notifyDone {
+		a.setNotifyDownloads(c.UI.ShouldNotifyDownloads())
+	}
+	if old.UI.ShowCovers() != c.UI.ShowCovers() || old.UI.CoverStyle != c.UI.CoverStyle {
+		a.covers = c.UI.ShowCovers()
+		a.restyleCovers()
+	}
+}
+
+// restyleCovers applies a changed poster style or switch to every detail pane.
+func (a *App) restyleCovers() {
+	blocks, graphics := resolveCovers(a.cfg.UI.CoverStyle, os.Getenv)
+	if a.gfx != nil {
+		a.gfx.deleteAll() // the terminal's copies belong to the old images
+	}
+	a.coverStyle = blocks
+	switch {
+	case graphics && a.gfx == nil:
+		a.gfx = newKittyGraphics(a.writeTerminal)
+	case !graphics:
+		a.gfx = nil
+	}
+	a.coverCache = newCoverCache() // stored copies depend on the style (their height)
+	for _, p := range a.panes {
+		p.cover.style, p.cover.gfx = blocks, a.gfx
+		p.cover.cells = nil
+		p.Show(p.detail, p.lastRef) // fetch the poster again for the new style
+	}
+}

internal/ui/cover_test.go

@@ -7,6 +7,7 @@ import (
 	"image/color"
 	"image/jpeg"
 	"image/png"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -158,11 +159,11 @@ func TestCoverViewDraws(t *testing.T) {
 
 func TestLoadCoverCachesAndDedupes(t *testing.T) {
 	a := newTestApp(t)
-	fetches := 0
+	var fetches atomic.Int32
 	var buf bytes.Buffer
 	png.Encode(&buf, stripes(10, 20))
 	ref := coverRef{key: "k", fetch: func(context.Context) ([]byte, error) {
-		fetches++
+		fetches.Add(1)
 		return buf.Bytes(), nil
 	}}
 
@@ -173,8 +174,8 @@ func TestLoadCoverCachesAndDedupes(t *testing.T) {
 	if len(a.coverCache.waiting["k"]) != 2 {
 		t.Fatalf("waiters = %d, want 2", len(a.coverCache.waiting["k"]))
 	}
-	if fetches > 1 {
-		t.Errorf("fetched %d times", fetches)
+	if n := fetches.Load(); n > 1 {
+		t.Errorf("fetched %d times", n)
 	}
 }
 

internal/ui/detail.go

@@ -27,8 +27,9 @@ type detailPane struct {
 	cover       *coverView
 
 	detail   detailText
-	want     string // key of the poster that should be shown
-	hasCover bool   // a poster (or its loading note) is part of the content
+	lastRef  coverRef // the poster of the current detail, to fetch it again after a style change
+	want     string   // key of the poster that should be shown
+	hasCover bool     // a poster (or its loading note) is part of the content
 
 	// What the text was last wrapped for.
 	laidOut struct {
@@ -47,12 +48,13 @@ func newDetailPane(app *App) *detailPane {
 	}
 	d.AddItem(d.text, 0, 1, false)
 	d.SetBorder(true).SetTitle(" Details ")
+	app.panes = append(app.panes, d)
 	return d
 }
 
 // Show displays the text and, if there is one, the poster.
 func (d *detailPane) Show(text detailText, ref coverRef) {
-	d.detail = text
+	d.detail, d.lastRef = text, ref
 	d.laidOut.valid = false
 	if !d.app.covers || ref.fetch == nil {
 		d.want, d.hasCover = "", false

internal/ui/downloads.go

@@ -134,6 +134,14 @@ func (v *downloadsView) nextPanel(dir int) {
 	v.app.app.SetFocus(v.panels[0])
 }
 
+// setInterval changes the polling interval, also while polling.
+func (v *downloadsView) setInterval(d time.Duration) {
+	v.interval = d
+	if v.cancel != nil {
+		v.activate()
+	}
+}
+
 // activate starts polling; called when the view becomes visible.
 func (v *downloadsView) activate() {
 	v.deactivate()

internal/ui/form.go

@@ -51,9 +51,24 @@ func arrowNavigation(f *tview.Form, cancel func(), hooks *browseHooks) {
 		}
 		switch ev.Key() {
 		case tcell.KeyDown:
+			if pos == total-1 && hooks != nil && hooks.edge != nil && hooks.edge(true) {
+				return nil
+			}
 			f.SetFocus(min(pos+1, total-1))
 		case tcell.KeyUp:
+			if pos == 0 && hooks != nil && hooks.edge != nil && hooks.edge(false) {
+				return nil
+			}
 			f.SetFocus(max(pos-1, 0))
+		case tcell.KeyTab, tcell.KeyBacktab:
+			dir := 1
+			if ev.Key() == tcell.KeyBacktab {
+				dir = -1
+			}
+			if hooks != nil && hooks.tab != nil && hooks.tab(dir) {
+				return nil
+			}
+			return ev
 		case tcell.KeyLeft, tcell.KeyRight:
 			step := 1
 			if ev.Key() == tcell.KeyLeft {
@@ -118,6 +133,11 @@ func bindSearchNow(box *tview.Checkbox, searchable func() bool, blocked func())
 type browseHooks struct {
 	browse func(dd *tview.DropDown, index int) // the highlight moved to entry index
 	abort  func()                              // the list was closed without selecting
+	// edge is called when Down is pressed on the last field or Up on the first;
+	// it returns true if it moved the focus elsewhere.
+	edge func(down bool) bool
+	// tab is called for Tab (dir 1) and Shift+Tab (dir -1); true if handled.
+	tab func(dir int) bool
 }
 
 // browser mirrors the highlight of an open dropdown list, which tview does

internal/ui/help.go

@@ -6,7 +6,7 @@ import (
 )
 
 const helpText = `[yellow]Global[-]
-  F1-F6                  switch view (also from the release and episode lists)
+  F1-F7                  switch view (also from the release and episode lists)
   Tab, Shift+Tab         switch panel within a view
   ?, F9                  this help (F9 works while typing)
   q, Ctrl+C              quit
@@ -67,6 +67,14 @@ const helpText = `[yellow]Global[-]
   Popups fade away by themselves; everything they said is kept here.
   ↑↓, PgUp/PgDn          scroll        G  follow new entries        c  clear
 
+[yellow]Config (F7)[-]
+  Edit the settings of the config file: service addresses and API keys, add-form
+  defaults, refresh interval, posters, notifications.
+  ↑↓ move, Tab next section, Space toggles, Enter presses a button
+  Test connections checks the three services with the values typed in
+  Save writes the file and applies everything at once; Revert discards edits
+  Letters such as q and ? are typed here; F9 opens this help
+
 [yellow]Connections[-]
 `
 

internal/ui/library.go

@@ -263,6 +263,14 @@ func newLibraryView(app *App, r *radarr.Client, s *sonarr.Client) *libraryView {
 		v.render()
 	})
 	v.input.SetDoneFunc(func(tcell.Key) { v.app.app.SetFocus(v.pane().table) })
+	app.reconnect = append(app.reconnect, func() {
+		// Another server: forget what the old one said, reload when shown.
+		v.seriesFiles = map[int]seriesFiles{}
+		for _, p := range v.panes {
+			p.all, p.shown, p.loaded, p.err = nil, nil, false, nil
+		}
+		v.render()
+	})
 	v.render()
 	return v
 }

internal/ui/search.go

@@ -25,7 +25,6 @@ const (
 type searchView struct {
 	app *App
 	be  backend
-	cfg config.Arr
 
 	root    *tview.Flex
 	input   *tview.InputField
@@ -46,11 +45,10 @@ type searchView struct {
 	loaded   bool
 }
 
-func newSearchView(app *App, be backend, cfg config.Arr) *searchView {
+func newSearchView(app *App, be backend) *searchView {
 	v := &searchView{
 		app:     app,
 		be:      be,
-		cfg:     cfg,
 		input:   tview.NewInputField().SetLabel("Search: "),
 		list:    tview.NewList().ShowSecondaryText(false),
 		details: newDetailPane(app),
@@ -106,10 +104,27 @@ func newSearchView(app *App, be backend, cfg config.Arr) *searchView {
 		return ev
 	})
 
+	app.reconnect = append(app.reconnect, v.reloadOptions)
 	go v.loadOptions()
 	return v
 }
 
+// defaults returns the add-form defaults of the service, as currently configured.
+func (v *searchView) defaults() config.Arr {
+	if v.be.name() == "Radarr" {
+		return v.app.cfg.Radarr
+	}
+	return v.app.cfg.Sonarr
+}
+
+// reloadOptions fetches the profiles and folders again, after the service changed.
+func (v *searchView) reloadOptions() {
+	v.mu.Lock()
+	v.loaded = false
+	v.mu.Unlock()
+	go v.loadOptions()
+}
+
 // loadOptions checks the connection and fetches the data the add form needs.
 func (v *searchView) loadOptions() {
 	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
@@ -301,8 +316,8 @@ func (v *searchView) add(i int) {
 		lSearch  = "Search now"
 	)
 	form := tview.NewForm().
-		AddDropDown(lProfile, profileNames, profileIndex(profiles, v.cfg.DefaultQualityProfile), nil).
-		AddDropDown(lFolder, folderPaths, folderIndex(folders, v.cfg.DefaultRootFolder), nil)
+		AddDropDown(lProfile, profileNames, profileIndex(profiles, v.defaults().DefaultQualityProfile), nil).
+		AddDropDown(lFolder, folderPaths, folderIndex(folders, v.defaults().DefaultRootFolder), nil)
 	height := 13
 	if len(modes) > 0 {
 		form.AddDropDown(lEpisode, modeNames, 0, nil)

internal/ui/settings.go

@@ -0,0 +1,419 @@
+package ui
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/rivo/tview"
+
+	"git.stinnesbeck.com/nils/arr-tui/internal/arr"
+	"git.stinnesbeck.com/nils/arr-tui/internal/config"
+	"git.stinnesbeck.com/nils/arr-tui/internal/sabnzbd"
+)
+
+// settingsValues are the settings as shown in the Config view.
+type settingsValues struct {
+	radarrURL, radarrKey, radarrProfile, radarrFolder string
+	sonarrURL, sonarrKey, sonarrProfile, sonarrFolder string
+	sabURL, sabKey                                    string
+	refresh                                           string // seconds, as typed
+	covers                                            bool
+	coverStyle                                        string
+	notify, bell                                      bool
+}
+
+var coverStyles = []string{"auto", "kitty", "sextant", "quadrant"}
+
+// settingsFrom reads the settings in use.
+func settingsFrom(c *config.Config) settingsValues {
+	style := c.UI.CoverStyle
+	if style == "" {
+		style = "auto"
+	}
+	return settingsValues{
+		radarrURL: c.Radarr.URL, radarrKey: c.Radarr.APIKey,
+		radarrProfile: c.Radarr.DefaultQualityProfile, radarrFolder: c.Radarr.DefaultRootFolder,
+		sonarrURL: c.Sonarr.URL, sonarrKey: c.Sonarr.APIKey,
+		sonarrProfile: c.Sonarr.DefaultQualityProfile, sonarrFolder: c.Sonarr.DefaultRootFolder,
+		sabURL: c.SABnzbd.URL, sabKey: c.SABnzbd.APIKey,
+		refresh: strconv.Itoa(c.UI.RefreshSeconds),
+		covers:  c.UI.ShowCovers(), coverStyle: style,
+		notify: c.UI.ShouldNotifyDownloads(), bell: c.UI.Bell,
+	}
+}
+
+// applySettings returns raw (the config file's contents) with the edited
+// values. Settings the environment overrides are left as the file has them, so
+// a value that only came from the environment is never written to disk. The
+// result is checked the way the program checks its configuration.
+func applySettings(raw config.Config, v settingsValues, overridden map[string]string) (config.Config, error) {
+	set := func(key string, dst *string, value string) {
+		if _, env := overridden[key]; !env {
+			*dst = strings.TrimSpace(value)
+		}
+	}
+	set("radarr.url", &raw.Radarr.URL, v.radarrURL)
+	set("radarr.apikey", &raw.Radarr.APIKey, v.radarrKey)
+	set("sonarr.url", &raw.Sonarr.URL, v.sonarrURL)
+	set("sonarr.apikey", &raw.Sonarr.APIKey, v.sonarrKey)
+	set("sabnzbd.url", &raw.SABnzbd.URL, v.sabURL)
+	set("sabnzbd.apikey", &raw.SABnzbd.APIKey, v.sabKey)
+	raw.Radarr.DefaultQualityProfile = strings.TrimSpace(v.radarrProfile)
+	raw.Radarr.DefaultRootFolder = strings.TrimSpace(v.radarrFolder)
+	raw.Sonarr.DefaultQualityProfile = strings.TrimSpace(v.sonarrProfile)
+	raw.Sonarr.DefaultRootFolder = strings.TrimSpace(v.sonarrFolder)
+
+	n, err := strconv.Atoi(strings.TrimSpace(v.refresh))
+	if err != nil || n < 1 || n > 3600 {
+		return raw, fmt.Errorf("refresh interval: %q is not a number of seconds between 1 and 3600", v.refresh)
+	}
+	raw.UI.RefreshSeconds = n
+	// Defaults stay out of the file unless the file already named them.
+	raw.UI.Covers = boolSetting(raw.UI.Covers, v.covers, true)
+	raw.UI.NotifyDownloads = boolSetting(raw.UI.NotifyDownloads, v.notify, true)
+	raw.UI.Bell = v.bell
+	raw.UI.CoverStyle = v.coverStyle
+	if v.coverStyle == "auto" {
+		raw.UI.CoverStyle = ""
+	}
+
+	if _, err := raw.Effective(os.Getenv); err != nil {
+		return raw, err
+	}
+	return raw, nil
+}
+
+// boolSetting keeps an optional boolean out of the file while it equals its
+// default and was not in the file before.
+func boolSetting(old *bool, value, def bool) *bool {
+	if old == nil && value == def {
+		return nil
+	}
+	return &value
+}
+
+// settingsView edits the configuration file's settings. Everything except
+// the cover style of already open panes applies right after saving.
+type settingsView struct {
+	app  *App
+	root *tview.Flex
+
+	radarr, sonarr, sab, ui, actions *tview.Form
+	groups                           []*tview.Form // keyboard order
+	status                           *tview.TextView
+
+	inputs     map[string]*tview.InputField // by setting key, e.g. "radarr.url"
+	refresh    *tview.InputField
+	covers     *tview.Checkbox
+	style      *tview.DropDown
+	notify     *tview.Checkbox
+	bell       *tview.Checkbox
+	showKeys   *tview.Checkbox
+	overridden map[string]string
+	dirty      bool
+	filling    bool // set while the fields are filled, so that does not count as an edit
+}
+
+func settingsHints() string {
+	return "↑↓ move · Tab next section · Space toggles · Enter presses a button"
+}
+
+func newSettingsView(app *App) *settingsView {
+	v := &settingsView{app: app, inputs: map[string]*tview.InputField{}, overridden: config.Overrides(os.Getenv)}
+
+	section := func(title string) *tview.Form {
+		f := tview.NewForm().SetItemPadding(0)
+		f.SetBorder(true).SetTitle(" " + title + " ")
+		f.SetBorderPadding(0, 0, 1, 1) // one row per field
+		return f
+	}
+	input := func(f *tview.Form, label, key string, width int) {
+		in := tview.NewInputField().SetLabel(label).SetFieldWidth(width)
+		in.SetLabelWidth(24) // the same column in every section
+		if strings.HasSuffix(key, ".apikey") {
+			in.SetMaskCharacter('*')
+		}
+		if _, ok := v.overridden[key]; ok {
+			in.SetLabel(label + " (env)")
+			in.SetDisabled(true)
+		}
+		in.SetChangedFunc(func(string) { v.edited() })
+		f.AddFormItem(in)
+		v.inputs[key] = in
+	}
+	service := func(f *tview.Form, name string, withDefaults bool) {
+		input(f, "Address", name+".url", 0)
+		input(f, "API key", name+".apikey", 0)
+		if withDefaults {
+			input(f, "Default quality profile", name+".profile", 0)
+			input(f, "Default root folder", name+".folder", 0)
+		}
+	}
+	v.radarr, v.sonarr, v.sab = section("Radarr"), section("Sonarr"), section("SABnzbd")
+	service(v.radarr, "radarr", true)
+	service(v.sonarr, "sonarr", true)
+	service(v.sab, "sabnzbd", false)
+
+	v.ui = section("Interface")
+	v.refresh = tview.NewInputField().SetLabel("Downloads refresh (seconds)").SetFieldWidth(6)
+	v.refresh.SetChangedFunc(func(string) { v.edited() })
+	v.ui.AddFormItem(v.refresh)
+	v.ui.AddCheckbox("Posters", true, func(bool) { v.edited() })
+	v.ui.AddDropDown("Poster style", coverStyles, 0, func(string, int) { v.edited() })
+	v.ui.AddCheckbox("Notify about finished downloads", true, func(bool) { v.edited() })
+	v.ui.AddCheckbox("Ring the terminal bell too", false, func(bool) { v.edited() })
+	v.ui.AddCheckbox("Show API keys", false, func(shown bool) { v.maskKeys(!shown) })
+	v.covers = v.ui.GetFormItem(1).(*tview.Checkbox)
+	v.style = v.ui.GetFormItem(2).(*tview.DropDown)
+	v.notify = v.ui.GetFormItem(3).(*tview.Checkbox)
+	v.bell = v.ui.GetFormItem(4).(*tview.Checkbox)
+	v.showKeys = v.ui.GetFormItem(5).(*tview.Checkbox)
+
+	v.actions = tview.NewForm().SetItemPadding(0)
+	v.actions.SetBorder(true).SetTitle(" Actions ")
+	v.actions.SetBorderPadding(0, 0, 1, 1)
+	v.actions.AddButton("Test connections", v.test)
+	v.actions.AddButton("Save", v.save)
+	v.actions.AddButton("Revert", v.revert)
+
+	v.status = tview.NewTextView().SetDynamicColors(true).SetWordWrap(true)
+	v.status.SetBorder(true).SetTitle(" Result ")
+
+	left := tview.NewFlex().SetDirection(tview.FlexRow).
+		AddItem(v.radarr, 6, 0, true).
+		AddItem(v.sonarr, 6, 0, false).
+		AddItem(v.sab, 4, 0, false)
+	right := tview.NewFlex().SetDirection(tview.FlexRow).
+		AddItem(v.ui, 8, 0, false).
+		AddItem(v.actions, 4, 0, false).
+		AddItem(v.status, 0, 1, false)
+	v.root = tview.NewFlex().AddItem(left, 0, 1, true).AddItem(right, 0, 1, false)
+
+	v.groups = []*tview.Form{v.radarr, v.sonarr, v.sab, v.ui, v.actions}
+	for i, g := range v.groups {
+		i := i
+		arrowNavigation(g, func() {}, &browseHooks{
+			edge: func(down bool) bool {
+				if down && i+1 < len(v.groups) {
+					v.focusGroup(i+1, false)
+					return true
+				}
+				if !down && i > 0 {
+					v.focusGroup(i-1, true)
+					return true
+				}
+				return false
+			},
+			tab: func(dir int) bool {
+				v.focusGroup((i+dir+len(v.groups))%len(v.groups), false)
+				return true
+			},
+		})
+	}
+	v.fill(settingsFrom(app.cfg))
+	v.maskKeys(true)
+	v.describe()
+	return v
+}
+
+// focusGroup moves the focus to a section, to its first or last field.
+func (v *settingsView) focusGroup(i int, last bool) {
+	// tview only blurs the leaf that had the focus, not the other items of a
+	// form or the form itself; a form that keeps thinking it has focus would
+	// take the key presses.
+	for j, other := range v.groups {
+		if j != i {
+			blurForm(other)
+		}
+	}
+	g := v.groups[i]
+	idx := 0
+	if last {
+		idx = g.GetFormItemCount() + g.GetButtonCount() - 1
+	}
+	g.SetFocus(idx)
+	v.app.app.SetFocus(g)
+}
+
+// blurForm takes the focus away from a form and everything in it.
+func blurForm(f *tview.Form) {
+	for i := 0; i < f.GetFormItemCount(); i++ {
+		f.GetFormItem(i).Blur()
+	}
+	for i := 0; i < f.GetButtonCount(); i++ {
+		f.GetButton(i).Blur()
+	}
+	f.Blur()
+}
+
+func (v *settingsView) edited() {
+	if !v.filling {
+		v.dirty = true
+	}
+}
+
+// maskKeys hides or shows the API keys.
+func (v *settingsView) maskKeys(hide bool) {
+	for key, in := range v.inputs {
+		if strings.HasSuffix(key, ".apikey") {
+			if hide {
+				in.SetMaskCharacter('*')
+			} else {
+				in.SetMaskCharacter(0)
+			}
+		}
+	}
+}
+
+// fill puts the values into the fields.
+func (v *settingsView) fill(s settingsValues) {
+	v.filling = true
+	defer func() { v.filling = false }()
+	set := map[string]string{
+		"radarr.url": s.radarrURL, "radarr.apikey": s.radarrKey, "radarr.profile": s.radarrProfile, "radarr.folder": s.radarrFolder,
+		"sonarr.url": s.sonarrURL, "sonarr.apikey": s.sonarrKey, "sonarr.profile": s.sonarrProfile, "sonarr.folder": s.sonarrFolder,
+		"sabnzbd.url": s.sabURL, "sabnzbd.apikey": s.sabKey,
+	}
+	for key, value := range set {
+		v.inputs[key].SetText(value)
+	}
+	v.refresh.SetText(s.refresh)
+	v.covers.SetChecked(s.covers)
+	for i, name := range coverStyles {
+		if name == s.coverStyle {
+			v.style.SetCurrentOption(i)
+		}
+	}
+	v.notify.SetChecked(s.notify)
+	v.bell.SetChecked(s.bell)
+	v.dirty = false
+}
+
+// read collects the values from the fields.
+func (v *settingsView) read() settingsValues {
+	text := func(key string) string { return v.inputs[key].GetText() }
+	i, _ := v.style.GetCurrentOption()
+	style := "auto"
+	if i >= 0 && i < len(coverStyles) {
+		style = coverStyles[i]
+	}
+	return settingsValues{
+		radarrURL: text("radarr.url"), radarrKey: text("radarr.apikey"),
+		radarrProfile: text("radarr.profile"), radarrFolder: text("radarr.folder"),
+		sonarrURL: text("sonarr.url"), sonarrKey: text("sonarr.apikey"),
+		sonarrProfile: text("sonarr.profile"), sonarrFolder: text("sonarr.folder"),
+		sabURL: text("sabnzbd.url"), sabKey: text("sabnzbd.apikey"),
+		refresh: v.refresh.GetText(),
+		covers:  v.covers.IsChecked(), coverStyle: style,
+		notify: v.notify.IsChecked(), bell: v.bell.IsChecked(),
+	}
+}
+
+// describe writes the standing information into the result box.
+func (v *settingsView) describe() {
+	var b strings.Builder
+	if v.app.cfgPath == "" {
+		b.WriteString("[yellow]No config file is known, changes cannot be saved.[-]\n")
+	} else {
+		b.WriteString("Config file: " + tview.Escape(v.app.cfgPath) + "\n")
+	}
+	b.WriteString("Changes take effect when you save; nothing needs a restart.\n")
+	if len(v.overridden) > 0 {
+		var names []string
+		for _, env := range v.overridden {
+			names = append(names, env)
+		}
+		b.WriteString("[gray]Greyed-out fields come from the environment (" + strings.Join(names, ", ") + ") and are not written to the file.[-]\n")
+	}
+	v.status.SetText(b.String())
+}
+
+// activate refreshes the fields when the view is shown, unless they hold unsaved edits.
+func (v *settingsView) activate() {
+	if !v.dirty {
+		v.fill(settingsFrom(v.app.cfg))
+	}
+	v.focusGroup(0, false)
+}
+
+// report appends a line to the result box.
+func (v *settingsView) report(line string) {
+	fmt.Fprintln(v.status, line)
+	v.status.ScrollToEnd()
+}
+
+func (v *settingsView) revert() {
+	v.fill(settingsFrom(v.app.cfg))
+	v.describe()
+	v.report("[green]Reverted to the saved settings.[-]")
+}
+
+// test checks the three services with the values in the fields, without saving.
+func (v *settingsView) test() {
+	s := v.read()
+	v.describe()
+	v.report("Testing the connections…")
+	type probeFn func(ctx context.Context) (string, error)
+	tests := []struct {
+		name string
+		run  probeFn
+	}{
+		{"Radarr", func(ctx context.Context) (string, error) {
+			st, err := arr.NewClient(strings.TrimSpace(s.radarrURL), strings.TrimSpace(s.radarrKey)).SystemStatus(ctx)
+			return st.Version, err
+		}},
+		{"Sonarr", func(ctx context.Context) (string, error) {
+			st, err := arr.NewClient(strings.TrimSpace(s.sonarrURL), strings.TrimSpace(s.sonarrKey)).SystemStatus(ctx)
+			return st.Version, err
+		}},
+		{"SABnzbd", func(ctx context.Context) (string, error) {
+			return sabnzbd.NewClient(strings.TrimSpace(s.sabURL), strings.TrimSpace(s.sabKey)).Version(ctx)
+		}},
+	}
+	for _, t := range tests {
+		go func() {
+			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+			defer cancel()
+			version, err := t.run(ctx)
+			v.app.post(func() {
+				if err != nil {
+					v.report("[red]✗ " + t.name + ": " + tview.Escape(err.Error()) + "[-]")
+					return
+				}
+				v.report("[green]✓ " + t.name + " " + tview.Escape(version) + " answers[-]")
+			})
+		}()
+	}
+}
+
+// save writes the config file and applies the settings.
+func (v *settingsView) save() {
+	v.describe()
+	if v.app.cfgPath == "" || v.app.cfgFile == nil {
+		v.report("[red]There is no config file to save to.[-]")
+		return
+	}
+	raw, err := applySettings(*v.app.cfgFile, v.read(), v.overridden)
+	if err != nil {
+		v.report("[red]Not saved: " + tview.Escape(err.Error()) + "[-]")
+		return
+	}
+	if err := config.Save(v.app.cfgPath, &raw); err != nil {
+		v.report("[red]Not saved: " + tview.Escape(err.Error()) + "[-]")
+		return
+	}
+	effective, err := raw.Effective(os.Getenv)
+	if err != nil { // cannot happen: applySettings validated it
+		v.report("[red]Saved, but not applied: " + tview.Escape(err.Error()) + "[-]")
+		return
+	}
+	v.app.cfgFile = &raw
+	v.app.applyConfig(effective)
+	v.dirty = false
+	v.report("[green]Saved to " + tview.Escape(v.app.cfgPath) + " and applied.[-]")
+	v.app.Notify(levelSuccess, "Settings saved")
+}

internal/ui/settings_test.go

@@ -0,0 +1,233 @@
+package ui
+
+import (
+	"github.com/gdamore/tcell/v2"
+	"github.com/rivo/tview"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync/atomic"
+	"testing"
+
+	"git.stinnesbeck.com/nils/arr-tui/internal/config"
+)
+
+func baseRaw() config.Config {
+	return config.Config{
+		Radarr:  config.Arr{Service: config.Service{URL: "http://r:7878", APIKey: "rk"}},
+		Sonarr:  config.Arr{Service: config.Service{URL: "http://s:8989", APIKey: "sk"}},
+		SABnzbd: config.Service{URL: "http://a:8080", APIKey: "ak"},
+	}
+}
+
+func TestApplySettings(t *testing.T) {
+	raw := baseRaw()
+	v := settingsFrom(mustEffective(t, raw))
+	if v.refresh != "3" || !v.covers || !v.notify || v.bell || v.coverStyle != "auto" {
+		t.Fatalf("defaults shown wrong: %+v", v)
+	}
+
+	// Unchanged settings add nothing but the refresh interval to the file.
+	got, err := applySettings(raw, v, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.UI.Covers != nil || got.UI.NotifyDownloads != nil || got.UI.CoverStyle != "" || got.UI.Bell {
+		t.Errorf("defaults written to the file: %+v", got.UI)
+	}
+
+	// Edits are applied and whitespace is trimmed.
+	v.radarrURL = "  http://new:7878  "
+	v.radarrProfile = " HD-1080p "
+	v.sabKey = "newkey"
+	v.refresh = "10"
+	v.covers = false
+	v.notify = false
+	v.bell = true
+	v.coverStyle = "quadrant"
+	got, err = applySettings(raw, v, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Radarr.URL != "http://new:7878" || got.Radarr.DefaultQualityProfile != "HD-1080p" || got.SABnzbd.APIKey != "newkey" ||
+		got.UI.RefreshSeconds != 10 || got.UI.Covers == nil || *got.UI.Covers || got.UI.NotifyDownloads == nil || *got.UI.NotifyDownloads || !got.UI.Bell || got.UI.CoverStyle != "quadrant" {
+		t.Errorf("edits lost: %+v", got)
+	}
+
+	// A setting that was explicit in the file stays explicit, even at its default.
+	yes := true
+	raw.UI.Covers = &yes
+	v.covers = true
+	got, _ = applySettings(raw, v, nil)
+	if got.UI.Covers == nil || !*got.UI.Covers {
+		t.Error("an explicit setting was dropped")
+	}
+}
+
+func TestApplySettingsValidates(t *testing.T) {
+	v := settingsFrom(mustEffective(t, baseRaw()))
+	for name, mutate := range map[string]func(*settingsValues){
+		"refresh not a number": func(v *settingsValues) { v.refresh = "often" },
+		"refresh zero":         func(v *settingsValues) { v.refresh = "0" },
+		"refresh too large":    func(v *settingsValues) { v.refresh = "99999" },
+		"address not http":     func(v *settingsValues) { v.sonarrURL = "ftp://x" },
+		"empty api key":        func(v *settingsValues) { v.radarrKey = "  " },
+		"empty address":        func(v *settingsValues) { v.sabURL = "" },
+	} {
+		w := v
+		mutate(&w)
+		if _, err := applySettings(baseRaw(), w, nil); err == nil {
+			t.Errorf("%s: accepted", name)
+		}
+	}
+}
+
+func TestApplySettingsKeepsEnvironmentValuesOutOfTheFile(t *testing.T) {
+	raw := baseRaw()
+	// The fields show the key from the environment...
+	shown := settingsFrom(mustEffective(t, raw))
+	shown.radarrKey = "secret-from-env"
+	shown.radarrURL = "http://typed-over-env"
+	got, err := applySettings(raw, shown, map[string]string{"radarr.apikey": "ARR_TUI_RADARR_APIKEY", "radarr.url": "ARR_TUI_RADARR_URL"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	// ...but the file keeps what it had.
+	if got.Radarr.APIKey != "rk" || got.Radarr.URL != "http://r:7878" {
+		t.Errorf("environment values leaked into the file: %+v", got.Radarr)
+	}
+}
+
+func mustEffective(t *testing.T, raw config.Config) *config.Config {
+	t.Helper()
+	eff, err := raw.Effective(func(string) string { return "" })
+	if err != nil {
+		t.Fatal(err)
+	}
+	return eff
+}
+
+func TestSettingsViewSavesAndAppliesLive(t *testing.T) {
+	t.Setenv("ARR_TUI_RADARR_APIKEY", "") // make sure the environment does not interfere
+	var gotKey atomic.Value               // the app also probes the server in the background
+	radarr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotKey.Store(r.Header.Get("X-Api-Key"))
+		w.Write([]byte(`{"version":"6.0"}`))
+	}))
+	defer radarr.Close()
+
+	a := newTestApp(t)
+	path := filepath.Join(t.TempDir(), "config.json")
+	raw := baseRaw()
+	if err := config.Save(path, &raw); err != nil {
+		t.Fatal(err)
+	}
+	loaded, _ := config.LoadFile(path)
+	a.SetConfigSource(path, loaded)
+	v := a.settings
+	v.fill(settingsFrom(a.cfg))
+
+	// Edit the fields like a user would and save.
+	v.inputs["radarr.url"].SetText(radarr.URL)
+	v.inputs["radarr.apikey"].SetText("brand-new-key")
+	v.inputs["sonarr.profile"].SetText("Any")
+	v.refresh.SetText("7")
+	v.bell.SetChecked(true)
+	if !v.dirty {
+		t.Error("editing must mark the form as changed")
+	}
+	v.save()
+
+	// 1. The file has the new values and stays private.
+	saved, err := config.LoadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if saved.Radarr.URL != radarr.URL || saved.Radarr.APIKey != "brand-new-key" || saved.Sonarr.DefaultQualityProfile != "Any" || saved.UI.RefreshSeconds != 7 || !saved.UI.Bell {
+		t.Errorf("file = %+v", saved)
+	}
+	if info, _ := os.Stat(path); info.Mode().Perm() != 0o600 {
+		t.Errorf("mode %v", info.Mode().Perm())
+	}
+	// 2. The running app uses them at once.
+	if a.cfg.Radarr.URL != radarr.URL || !a.bell || a.cfg.UI.RefreshSeconds != 7 {
+		t.Errorf("settings not applied: %+v", a.cfg)
+	}
+	if _, err := a.radarr.SystemStatus(t.Context()); err != nil || gotKey.Load() != "brand-new-key" {
+		t.Errorf("the client still talks to the old instance: key=%v err=%v", gotKey.Load(), err)
+	}
+	if got := a.downloads.interval.Seconds(); got != 7 {
+		t.Errorf("downloads interval = %v", got)
+	}
+	if v.dirty {
+		t.Error("saving must clear the changed mark")
+	}
+	if !strings.Contains(v.status.GetText(false), "Saved") {
+		t.Errorf("result box: %q", v.status.GetText(false))
+	}
+
+	// An invalid edit is refused and leaves the file alone.
+	before, _ := os.ReadFile(path)
+	v.refresh.SetText("soon")
+	v.save()
+	after, _ := os.ReadFile(path)
+	if string(before) != string(after) || !strings.Contains(v.status.GetText(false), "Not saved") {
+		t.Errorf("invalid settings were saved: %q", v.status.GetText(false))
+	}
+	// Revert goes back to what is in use.
+	v.revert()
+	if v.refresh.GetText() != "7" || v.dirty {
+		t.Errorf("revert: refresh=%q dirty=%v", v.refresh.GetText(), v.dirty)
+	}
+}
+
+func TestSettingsViewWithoutConfigFile(t *testing.T) {
+	a := newTestApp(t)
+	a.settings.save()
+	if !strings.Contains(a.settings.status.GetText(false), "no config file") {
+		t.Errorf("result box: %q", a.settings.status.GetText(false))
+	}
+}
+
+func TestSettingsViewFocusMovesBetweenSections(t *testing.T) {
+	a := newTestApp(t)
+	v := a.settings
+	var focus func(p tview.Primitive)
+	focus = func(p tview.Primitive) { p.Focus(focus) }
+
+	v.focusGroup(3, false) // Interface
+	for _, g := range v.groups {
+		g.Focus(focus)
+	}
+	// Whatever flags were left behind, moving to the actions must leave exactly one section focused.
+	v.focusGroup(4, false)
+	focused := 0
+	for _, g := range v.groups {
+		if g.HasFocus() {
+			focused++
+		}
+	}
+	if focused != 1 || !v.actions.HasFocus() {
+		t.Errorf("%d sections claim the focus, want only the actions", focused)
+	}
+
+	// Down on the last field of a section continues in the next one; Tab cycles.
+	v.focusGroup(0, false)
+	send := func(g *tview.Form, k tcell.Key) { g.GetInputCapture()(tcell.NewEventKey(k, 0, 0)) }
+	g := v.radarr
+	g.SetFocus(g.GetFormItemCount() - 1)
+	send(g, tcell.KeyDown)
+	if !v.sonarr.HasFocus() || v.radarr.HasFocus() {
+		t.Error("Down on the last field must move to the next section")
+	}
+	send(v.sonarr, tcell.KeyBacktab)
+	if !v.radarr.HasFocus() || v.sonarr.HasFocus() {
+		t.Error("Shift+Tab must move back a section")
+	}
+	send(v.radarr, tcell.KeyUp) // first section, first field: nothing before it
+	if !v.radarr.HasFocus() {
+		t.Error("Up on the first field of the first section must stay put")
+	}
+}

internal/ui/watch.go

@@ -41,7 +41,7 @@ func diffHistory(seen map[string]string, slots []sabnzbd.HistorySlot, baseline b
 // watchDownloads polls SABnzbd's history until ctx ends and reports finished
 // and failed downloads as popups (and a bell, if enabled). Errors are not
 // reported here: the connection indicator and the log already do that.
-func (a *App) watchDownloads(ctx context.Context, sab *sabnzbd.Client, bell bool) {
+func (a *App) watchDownloads(ctx context.Context, sab *sabnzbd.Client) {
 	seen := map[string]string{}
 	baseline := true
 	t := time.NewTicker(watchInterval)
@@ -54,7 +54,7 @@ func (a *App) watchDownloads(ctx context.Context, sab *sabnzbd.Client, bell bool
 			events := diffHistory(seen, slots, baseline)
 			baseline = false
 			if len(events) > 0 {
-				a.post(func() { a.announce(events, bell) })
+				a.post(func() { a.announce(events, a.bell) })
 			}
 		}
 		select {