fix: prevent concurrent transcription races and mask API key

app.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"sort"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -37,6 +38,7 @@ type App struct {
 	wasMediaPlaying  bool
 	whisperManager   *whisper.Manager
 	tempDir          string
+	transcribing     int32 // atomic: 1 = transcription in progress, prevents concurrent
 }
 
 // NewApp creates a new App application struct
@@ -236,6 +238,8 @@ func (a *App) StartRecording() {
 			err = a.audioRecorder.Start(a.recordingPath)
 		}
 		if err != nil {
+			// Clean up the orphaned temp file since recording failed to start
+			os.Remove(a.recordingPath)
 			if a.overlay != nil {
 				a.overlay.Hide()
 			}
@@ -268,23 +272,25 @@ func (a *App) StopRecording() {
 	}
 
 	if a.audioRecorder == nil {
-		atomic.StoreInt32(&a.recording, 0)
 		return
 	}
 
+	// Capture the path BEFORE stopping the recorder, so it can't be
+	// overwritten by a concurrent StartRecording (which sets a.recordingPath).
+	pathToProcess := a.recordingPath
+
 	err := a.audioRecorder.Stop()
 	if err != nil {
 		logger.Error("Failed to stop recording: %v", err)
 		return
 	}
 
-	// Capture the path before it can be overwritten by another immediate start
-	pathToProcess := a.recordingPath
 	// Transcribe in a goroutine to avoid blocking
 	go a.processRecording(pathToProcess)
 }
 
-// processRecording handles transcription and pasting
+// processRecording handles transcription and pasting.
+// Uses an atomic guard to prevent concurrent transcriptions.
 func (a *App) processRecording(recordingPath string) {
 	if recordingPath == "" {
 		logger.Error("No recording path set")
@@ -295,6 +301,15 @@ func (a *App) processRecording(recordingPath string) {
 		return
 	}
 
+	// Prevent concurrent transcriptions: only one goroutine can process at a time.
+	// If another transcription is already in progress, discard this recording.
+	if !atomic.CompareAndSwapInt32(&a.transcribing, 0, 1) {
+		logger.Info("Another transcription already in progress, discarding recording: %s", recordingPath)
+		os.Remove(recordingPath)
+		return
+	}
+	defer atomic.StoreInt32(&a.transcribing, 0)
+
 	// IDIOT-PROOFING: Ignore extremely short recordings (less than ~100ms or ~3KB)
 	// that are likely accidental clicks or hardware glitches.
 	stat, statErr := os.Stat(recordingPath)
@@ -407,7 +422,17 @@ func (a *App) processRecording(recordingPath string) {
 // GetSettings returns the current configuration
 func (a *App) GetSettings() map[string]interface{} {
 	conf := make(map[string]interface{})
-	conf["api_key"] = a.config.APIKey
+	// Mask the API key: only reveal the last 4 characters so the user can verify
+	// which key is configured without exposing the full secret to the frontend.
+	if a.config.APIKey != "" {
+		key := a.config.APIKey
+		if len(key) > 4 {
+			key = "****" + key[len(key)-4:]
+		}
+		conf["api_key"] = key
+	} else {
+		conf["api_key"] = ""
+	}
 	conf["shortcut"] = a.config.Shortcut
 	conf["whisper_model"] = a.config.WhisperModel
 	conf["ai_model"] = a.config.AIModel
@@ -433,8 +458,13 @@ func (a *App) GetSettings() map[string]interface{} {
 // SaveSettings updates the configuration
 func (a *App) SaveSettings(settings map[string]interface{}) string {
 	if val, ok := settings["api_key"].(string); ok {
+		// Only update the API key if it's not the masked value returned by GetSettings.
+		// GetSettings masks the key as "****abcd" so the frontend can show the last 4 chars.
+		// If the user didn't change it and sent back the masked value, preserve the real key.
+		if !strings.HasPrefix(val, "****") {
 			a.config.APIKey = val
 		}
+	}
 	// PLATFORM NOTE: Shortcut saving is disabled on Linux because Linux uses
 	// the `--press` daemon approach (GNOME custom shortcuts) instead of the
 	// built-in hotkey listener. On Windows, we allow the user to configure
@@ -502,7 +532,9 @@ func (a *App) SaveSettings(settings map[string]interface{}) string {
 		return fmt.Sprintf("Error saving settings: %v", err)
 	}
 
-	// Re-init transcriber with new settings
+	// Re-init transcriber with new settings.
+	// Note: a.config.APIKey is already updated by the api_key field above.
+	// Since GetSettings masks the key, we only update if it's not still the masked value.
 	a.transcriber = transcriber.NewClient(
 		a.config.APIKey,
 		a.config.WhisperModel,
@@ -668,6 +700,8 @@ func (a *App) Shutdown(ctx context.Context) {
 	if a.overlay != nil {
 		a.overlay.Close()
 	}
+	// Gracefully shut down the Linux press daemon HTTP server (no-op on Windows)
+	stopLinuxPressDaemon()
 	logger.Close()
 }
 
@@ -681,21 +715,31 @@ func (a *App) CheckOnline() bool {
 	return whisper.CheckOnline()
 }
 
-// IsWhisperInstalled checks if offline whisper is installed
+// IsWhisperInstalled checks if offline whisper is installed.
+// Reuses the cached whisperManager if available.
 func (a *App) IsWhisperInstalled() bool {
-	mgr, err := whisper.NewManager()
+	mgr := a.whisperManager
+	if mgr == nil {
+		var err error
+		mgr, err = whisper.NewManager()
 		if err != nil {
 			return false
 		}
+	}
 	return mgr.IsInstalled()
 }
 
-// GetWhisperInfo returns information about installed whisper
+// GetWhisperInfo returns information about installed whisper.
+// Reuses the cached whisperManager if available.
 func (a *App) GetWhisperInfo() map[string]interface{} {
-	mgr, err := whisper.NewManager()
+	mgr := a.whisperManager
+	if mgr == nil {
+		var err error
+		mgr, err = whisper.NewManager()
 		if err != nil {
 			return map[string]interface{}{"installed": false}
 		}
+	}
 
 	if !mgr.IsInstalled() {
 		return map[string]interface{}{"installed": false}
@@ -741,10 +785,18 @@ func (a *App) UninstallWhisper() string {
 	return "Whisper uninstalled successfully"
 }
 
-// GetAvailableWhisperModels returns list of available whisper models
+// GetAvailableWhisperModels returns list of available whisper models,
+// sorted by name for consistent UI display.
 func (a *App) GetAvailableWhisperModels() []map[string]string {
-	var models []map[string]string
-	for name, info := range whisper.Models {
+	var names []string
+	for name := range whisper.Models {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	models := make([]map[string]string, 0, len(names))
+	for _, name := range names {
+		info := whisper.Models[name]
 		models = append(models, map[string]string{
 			"name": name,
 			"size": info.Size,

internal/audio/recorder/recorder.go

@@ -262,14 +262,22 @@ func (r *AudioRecorder) Cleanup() {
 }
 
 // onAudioData is called by miniaudio when audio data is available.
-// Safe to call without r.mu because atomic writing flag prevents writes
-// after Stop() clears the flag.
+// Safe to call without r.mu: the atomic writing flag prevents writes after
+// Stop() clears it, and r.device.Stop() waits for in-flight callbacks to
+// complete before returning, so r.outputFile is guaranteed valid here.
 func (r *AudioRecorder) onAudioData(_, inputSamples []byte, _ uint32) {
-	if atomic.LoadInt32(&r.writing) == 0 || r.outputFile == nil || len(inputSamples) == 0 {
+	if atomic.LoadInt32(&r.writing) == 0 || len(inputSamples) == 0 {
 		return
 	}
 
-	n, err := r.outputFile.Write(inputSamples)
+	// Double-check outputFile under the assumption that Stop() has already
+	// set writing=0 before touching the file handle.
+	f := r.outputFile
+	if f == nil {
+		return
+	}
+
+	n, err := f.Write(inputSamples)
 	if err == nil {
 		atomic.AddUint32(&r.dataSize, uint32(n))
 	}

internal/config/config.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
+	"sync"
 )
 
 // Application defaults
@@ -43,6 +44,9 @@ type Config struct {
 const CurrentConfigVersion = 1
 const MaxHistoryItems = 100
 
+// saveMu protects concurrent writes to the config file.
+var saveMu sync.Mutex
+
 // DefaultConfig returns a new configuration with sensible default values.
 func DefaultConfig() *Config {
 	return &Config{
@@ -91,7 +95,11 @@ func (c *Config) migrate() {
 
 // Save writes the configuration to the specified file path.
 // If configPath is empty, it uses the default configuration path.
+// It uses atomic writes (write-to-temp then rename) to prevent corruption.
 func Save(c *Config, configPath string) error {
+	saveMu.Lock()
+	defer saveMu.Unlock()
+
 	if configPath == "" {
 		var err error
 		configPath, err = GetConfigPath()
@@ -111,7 +119,13 @@ func Save(c *Config, configPath string) error {
 		return err
 	}
 
-	return os.WriteFile(configPath, data, 0600)
+	// Atomic write: write to temp file, then rename to prevent corruption
+	// if the app crashes mid-write.
+	tmpPath := configPath + ".tmp"
+	if err := os.WriteFile(tmpPath, data, 0600); err != nil {
+		return err
+	}
+	return os.Rename(tmpPath, configPath)
 }
 
 // GetConfigPath returns the default configuration file path.

internal/logger/logger.go

@@ -54,12 +54,13 @@ func Init() error {
 	return nil
 }
 
-// Close closes the log file handle.
+// Close flushes buffered writes and closes the log file handle.
 func Close() {
 	logMutex.Lock()
 	defer logMutex.Unlock()
 
 	if logFile != nil {
+		logFile.Sync() // Flush buffered writes so the last log entries are not lost
 		logFile.Close()
 		logFile = nil
 	}

internal/services/whisper/whisper.go

@@ -2,6 +2,7 @@
 package whisper
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -295,7 +296,10 @@ func (m *Manager) Transcribe(audioPath string, language string) (string, error)
 
 	// Run whisper with simple arguments: ./main -m model.bin -l language -f audio.wav
 	// Vulkan build uses GPU by default, no need for -ngl
-	cmd := exec.Command(binaryPath, "-m", modelPath, "-l", language, "-f", audioPath)
+	// Use a 5-minute timeout to prevent infinite hangs on long audio or stuck processes
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, binaryPath, "-m", modelPath, "-l", language, "-f", audioPath)
 
 	// Set working directory to the binary's location so it can find DLLs
 	cmd.Dir = filepath.Dir(binaryPath)
@@ -419,7 +423,10 @@ func CheckOnline() bool {
 	}
 	defer resp.Body.Close()
 
-	return true
+	// Drain the response body to allow connection reuse and prevent resource leak
+	io.Copy(io.Discard, resp.Body)
+
+	return resp.StatusCode == http.StatusOK
 }
 
 // DownloadProgress represents download progress
@@ -437,6 +444,10 @@ func downloadFile(url, dest string, progress chan<- DownloadProgress) error {
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("download failed: server returned HTTP %d", resp.StatusCode)
+	}
+
 	out, err := os.Create(dest)
 	if err != nil {
 		return err

internal/ui/tray/tray.go

@@ -13,6 +13,7 @@ import (
 	"runtime"
 	"strings"
 	"sync"
+	"sync/atomic"
 
 	"wis-free-v3/internal/config"
 	"wis-free-v3/internal/logger"
@@ -47,7 +48,7 @@ var trayLabel = "wis-free-v3"
 // Menu item references for dynamic updates
 var statusMenuItem *systray.MenuItem
 var triggerCountItem *systray.MenuItem
-var triggerCount int
+var triggerCount int32
 var iconsInitOnce sync.Once
 var startupMenuItem *systray.MenuItem
 
@@ -233,10 +234,13 @@ func icoToPNG(data []byte) ([]byte, error) {
 	return nil, fmt.Errorf("no PNG image found in ico")
 }
 
+var statusMu sync.Mutex
 var lastStatus string
 
 // UpdateStatus updates the status text displayed in the tray menu.
 func UpdateStatus(status string) {
+	statusMu.Lock()
+	defer statusMu.Unlock()
 	if statusMenuItem != nil && status != lastStatus {
 		lastStatus = status
 		statusMenuItem.SetTitle("Status: " + status)
@@ -255,9 +259,9 @@ func UpdateStatus(status string) {
 
 // IncrementTriggerCount increments the troubleshooting counter in the tray.
 func IncrementTriggerCount() {
-	triggerCount++
+	count := atomic.AddInt32(&triggerCount, 1)
 	if triggerCountItem != nil {
-		triggerCountItem.SetTitle(fmt.Sprintf("Shortcut detected: %d times", triggerCount))
+		triggerCountItem.SetTitle(fmt.Sprintf("Shortcut detected: %d times", count))
 	}
 }
 

internal/windows/overlay.go

@@ -99,6 +99,8 @@ type Overlay struct {
 	mu             sync.RWMutex
 	stopCh         chan struct{}
 	bgBrush        syscall.Handle
+	barBrushWhite  syscall.Handle // Pre-created GDI brush for white bars (recording animation)
+	barBrushOrange syscall.Handle // Pre-created GDI brush for orange bars (transcribing animation)
 	hFont          syscall.Handle
 	volume         uint64 // atomic: float64 stored via math.Float64bits
 	smoothedVolume uint64 // atomic: float64 stored via math.Float64bits
@@ -171,6 +173,12 @@ func (o *Overlay) Close() {
 	if o.hFont != 0 {
 		procDeleteObject.Call(uintptr(o.hFont))
 	}
+	if o.barBrushWhite != 0 {
+		procDeleteObject.Call(uintptr(o.barBrushWhite))
+	}
+	if o.barBrushOrange != 0 {
+		procDeleteObject.Call(uintptr(o.barBrushOrange))
+	}
 	close(o.stopCh)
 }
 
@@ -193,6 +201,12 @@ func (o *Overlay) run() {
 	brushRec, _, _ := procCreateSolidBrush.Call(COLOR_BG_DARK)
 	o.bgBrush = syscall.Handle(brushRec)
 
+	whiteRec, _, _ := procCreateSolidBrush.Call(uintptr(COLOR_WHITE))
+	o.barBrushWhite = syscall.Handle(whiteRec)
+
+	orangeRec, _, _ := procCreateSolidBrush.Call(uintptr(COLOR_MIC_ORANGE))
+	o.barBrushOrange = syscall.Handle(orangeRec)
+
 	fontName := syscall.StringToUTF16Ptr("Segoe UI")
 	fontRec, _, _ := procCreateFontW.Call(
 		18, 0, 0, 0, 600,

linux_press_daemon.go

@@ -76,6 +76,9 @@ func sendLinuxPressPing() error {
 	return nil
 }
 
+// linuxPressServer holds the HTTP server reference for graceful shutdown.
+var linuxPressServer *http.Server
+
 func (a *App) startLinuxPressDaemon() {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/press", func(w http.ResponseWriter, r *http.Request) {
@@ -100,7 +103,9 @@ func (a *App) startLinuxPressDaemon() {
 			Addr:              linuxPressAddr,
 			Handler:           mux,
 			ReadHeaderTimeout: 2 * time.Second,
+			IdleTimeout:       5 * time.Second,
 		}
+		linuxPressServer = server
 		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
 			logger.Error("Linux press daemon stopped: %v", err)
 		}

linux_press_daemon_stub.go

@@ -9,3 +9,5 @@
 package main
 
 func (a *App) startLinuxPressDaemon() {}
+
+func stopLinuxPressDaemon() {}

text_insert_nonlinux.go

@@ -28,13 +28,15 @@ func (a *App) insertTranscription(text string) {
 	// Paste
 	a.pasteText()
 
-	// Restore old clipboard after a short delay, but ONLY if the user
-	// hasn't manually copied something else or another burst hasn't finished.
+	// Restore old clipboard after a delay, but ONLY if the clipboard still
+	// contains our transcribed text (i.e. user hasn't copied something else).
 	if clipErr == nil && oldClip != "" {
 		go func() {
-			time.Sleep(1000 * time.Millisecond)
-			current, _ := wailsruntime.ClipboardGetText(a.ctx)
-			if current == text {
+			time.Sleep(1500 * time.Millisecond)
+			current, currentErr := wailsruntime.ClipboardGetText(a.ctx)
+			// Only restore if no error reading AND clipboard still holds our text
+			// AND it hasn't been modified by another goroutine
+			if currentErr == nil && current == text {
 				wailsruntime.ClipboardSetText(a.ctx, oldClip)
 				logger.Info("Clipboard history restored")
 			}