refactor: update logging paths to use dynamic log directory

openwrt/files/ua3f.init

@@ -10,8 +10,6 @@ PROG="/usr/bin/$NAME"
 start_service() {
     config_load "$NAME"
 
-    mkdir -p /var/log/ua3f && chmod o+w /var/log/ua3f
-
     local enabled
     config_get_bool enabled "enabled" "enabled" "0"
     [ "$enabled" -eq "1" ] || return 0

src/internal/log/log.go

@@ -11,12 +11,10 @@ import (
 	"gopkg.in/natefinch/lumberjack.v2"
 )
 
-const log_file = "/var/log/ua3f/ua3f.log"
-
 func SetLogConf(level string) {
 	writer2 := os.Stdout
 	writer3 := &lumberjack.Logger{
-		Filename:   log_file,
+		Filename:   GetLogFilePath(),
 		MaxSize:    5, // megabytes
 		MaxBackups: 5,
 		MaxAge:     7, // days
@@ -58,6 +56,7 @@ func SetLogConf(level string) {
 func LogHeader(version string, cfg *config.Config) {
 	slog.Info("UA3F started", "version", version, "", cfg)
 	slog.Info("OS Info", GetOSInfo()...)
+	slog.Info("Log file", "path", GetLogFilePath())
 }
 
 func LogDebugWithAddr(src string, dest string, msg string) {

src/internal/log/path.go

@@ -0,0 +1,81 @@
+package log
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+var (
+	logDir     string
+	logDirOnce bool
+)
+
+// GetLogDir returns the platform-specific log directory for UA3F.
+// - Linux: /var/log/ua3f/
+// - Windows: ~/.ua3f/
+// - Other (fallback): temp directory
+// The directory is created automatically with proper permissions if it doesn't exist.
+func GetLogDir() string {
+	if logDirOnce {
+		return logDir
+	}
+
+	logDir = determineLogDir()
+	logDirOnce = true
+
+	// Ensure the directory exists
+	if err := os.MkdirAll(logDir, 0755); err != nil {
+		// If creation fails, fall back to temp directory
+		logDir = filepath.Join(os.TempDir(), "ua3f")
+		_ = os.MkdirAll(logDir, 0755)
+	}
+
+	return logDir
+}
+
+func determineLogDir() string {
+	switch runtime.GOOS {
+	case "linux":
+		// Try /var/log/ua3f/ first for Linux
+		varLogDir := "/var/log/ua3f"
+		if err := os.MkdirAll(varLogDir, 0755); err == nil {
+			// Test write permission
+			testFile := filepath.Join(varLogDir, ".write_test")
+			if f, err := os.Create(testFile); err == nil {
+				_ = f.Close()
+				_ = os.Remove(testFile)
+				return varLogDir
+			}
+		}
+		// Fall through to user home directory
+		return getUserLogDir()
+	default:
+		// macOS, Windows, FreeBSD, etc. - try user home first
+		return getUserLogDir()
+	}
+}
+
+func getUserLogDir() string {
+	// Try user home directory
+	homeDir, err := os.UserHomeDir()
+	if err == nil {
+		userLogDir := filepath.Join(homeDir, ".ua3f")
+		if err := os.MkdirAll(userLogDir, 0755); err == nil {
+			return userLogDir
+		}
+	}
+
+	// Fallback to temp directory
+	return filepath.Join(os.TempDir(), "ua3f")
+}
+
+// GetLogFilePath returns the full path to the main log file.
+func GetLogFilePath() string {
+	return filepath.Join(GetLogDir(), "ua3f.log")
+}
+
+// GetStatsFilePath returns the full path to a stats file.
+func GetStatsFilePath(name string) string {
+	return filepath.Join(GetLogDir(), name)
+}

src/internal/statistics/statistics.go

@@ -1,5 +1,7 @@
 package statistics
 
+import "github.com/sunbk201/ua3f/internal/log"
+
 type Recorder struct {
 	RewriteRecordList     *RewriteRecordList
 	PassThroughRecordList *PassThroughRecordList
@@ -8,9 +10,9 @@ type Recorder struct {
 
 func New() *Recorder {
 	return &Recorder{
-		RewriteRecordList:     NewRewriteRecordList("/var/log/ua3f/rewrite_stats"),
-		PassThroughRecordList: NewPassThroughRecordList("/var/log/ua3f/pass_stats"),
-		ConnectionRecordList:  NewConnectionRecordList("/var/log/ua3f/conn_stats"),
+		RewriteRecordList:     NewRewriteRecordList(log.GetStatsFilePath("rewrite_stats")),
+		PassThroughRecordList: NewPassThroughRecordList(log.GetStatsFilePath("pass_stats")),
+		ConnectionRecordList:  NewConnectionRecordList(log.GetStatsFilePath("conn_stats")),
 	}
 }