feat(tui): add option to remember view state between sessions

README.md

@@ -238,8 +238,23 @@ optional config file at `~/.config/snitch/snitch.toml`:
 numeric = false      # disable name resolution
 dns_cache = true     # cache dns lookups (set to false to disable)
 theme = "auto"       # color theme: auto, dark, light, mono
+
+[tui]
+remember_state = false   # remember view options between sessions
 ```
 
+### remembering view options
+
+when `remember_state = true`, the tui will save and restore:
+
+- filter toggles (tcp/udp, listen/established/other)
+- sort field and direction
+- address and port resolution settings
+
+state is saved to `$XDG_STATE_HOME/snitch/tui.json` (defaults to `~/.local/state/snitch/tui.json`).
+
+cli flags always take priority over saved state.
+
 ### environment variables
 
 ```bash

cmd/top.go

@@ -33,11 +33,12 @@ var topCmd = &cobra.Command{
 		resolver.SetNoCache(effectiveNoCache)
 
 		opts := tui.Options{
-			Theme:        theme,
-			Interval:     topInterval,
-			ResolveAddrs: resolveAddrs,
-			ResolvePorts: resolvePorts,
-			NoCache:      effectiveNoCache,
+			Theme:         theme,
+			Interval:      topInterval,
+			ResolveAddrs:  resolveAddrs,
+			ResolvePorts:  resolvePorts,
+			NoCache:       effectiveNoCache,
+			RememberState: cfg.TUI.RememberState,
 		}
 
 		// if any filter flag is set, use exclusive mode

internal/config/config.go

@@ -14,6 +14,12 @@ import (
 // Config represents the application configuration
 type Config struct {
 	Defaults DefaultConfig `mapstructure:"defaults"`
+	TUI      TUIConfig     `mapstructure:"tui"`
+}
+
+// TUIConfig contains TUI-specific configuration
+type TUIConfig struct {
+	RememberState bool `mapstructure:"remember_state"`
 }
 
 // DefaultConfig contains default values for CLI options
@@ -105,6 +111,9 @@ func setDefaults(v *viper.Viper) {
 	v.SetDefault("defaults.no_headers", false)
 	v.SetDefault("defaults.output_format", "table")
 	v.SetDefault("defaults.sort_by", "")
+
+	// tui settings
+	v.SetDefault("tui.remember_state", false)
 }
 
 func handleSpecialEnvVars(v *viper.Viper) {
@@ -146,6 +155,9 @@ func Get() *Config {
 					OutputFormat: "table",
 					SortBy:       "",
 				},
+				TUI: TUIConfig{
+					RememberState: false,
+				},
 			}
 		}
 		return config
@@ -199,6 +211,11 @@ ipv6 = false
 no_headers = false
 output_format = "table"
 sort_by = ""
+
+[tui]
+# remember view options (filters, sort, resolution) between sessions
+# state is saved to $XDG_STATE_HOME/snitch/tui.json
+remember_state = false
 `, themeList, theme.DefaultTheme)
 
 	// Ensure directory exists

internal/state/state.go

@@ -0,0 +1,133 @@
+package state
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/karol-broda/snitch/internal/collector"
+)
+
+// TUIState holds view options that can be persisted between sessions
+type TUIState struct {
+	ShowTCP         bool                `json:"show_tcp"`
+	ShowUDP         bool                `json:"show_udp"`
+	ShowListening   bool                `json:"show_listening"`
+	ShowEstablished bool                `json:"show_established"`
+	ShowOther       bool                `json:"show_other"`
+	SortField       collector.SortField `json:"sort_field"`
+	SortReverse     bool                `json:"sort_reverse"`
+	ResolveAddrs    bool                `json:"resolve_addrs"`
+	ResolvePorts    bool                `json:"resolve_ports"`
+}
+
+var (
+	saveMu   sync.Mutex
+	saveChan chan TUIState
+	once     sync.Once
+)
+
+// Path returns the XDG-compliant state file path
+func Path() string {
+	stateDir := os.Getenv("XDG_STATE_HOME")
+	if stateDir == "" {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return ""
+		}
+		stateDir = filepath.Join(home, ".local", "state")
+	}
+	return filepath.Join(stateDir, "snitch", "tui.json")
+}
+
+// Load reads the TUI state from disk.
+// returns nil if state file doesn't exist or can't be read.
+func Load() *TUIState {
+	path := Path()
+	if path == "" {
+		return nil
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil
+	}
+
+	var state TUIState
+	if err := json.Unmarshal(data, &state); err != nil {
+		return nil
+	}
+
+	return &state
+}
+
+// Save writes the TUI state to disk synchronously.
+// creates parent directories if needed.
+func Save(state TUIState) error {
+	path := Path()
+	if path == "" {
+		return nil
+	}
+
+	saveMu.Lock()
+	defer saveMu.Unlock()
+
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return err
+	}
+
+	data, err := json.MarshalIndent(state, "", "  ")
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(path, data, 0644)
+}
+
+// SaveAsync queues a state save to happen in the background.
+// only the most recent state is saved if multiple saves are queued.
+func SaveAsync(state TUIState) {
+	once.Do(func() {
+		saveChan = make(chan TUIState, 1)
+		go saveWorker()
+	})
+
+	// non-blocking send, replace pending save with newer state
+	select {
+	case saveChan <- state:
+	default:
+		// channel full, drain and replace
+		select {
+		case <-saveChan:
+		default:
+		}
+		select {
+		case saveChan <- state:
+		default:
+		}
+	}
+}
+
+func saveWorker() {
+	for state := range saveChan {
+		_ = Save(state)
+	}
+}
+
+// Default returns a TUIState with default values
+func Default() TUIState {
+	return TUIState{
+		ShowTCP:         true,
+		ShowUDP:         true,
+		ShowListening:   true,
+		ShowEstablished: true,
+		ShowOther:       true,
+		SortField:       collector.SortByLport,
+		SortReverse:     false,
+		ResolveAddrs:    false,
+		ResolvePorts:    false,
+	}
+}
+