feat(tui): add option to remember view state between sessions (#17)

2025-12-25 18:22:54 +01:00
parent 5414e39e61
commit 1cff272fff
7 changed files with 483 additions and 22 deletions
--- a/internal/state/state.go
+++ b/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,
+	}
+}
+