feat: Add pcap import, file browser, logging, local capture, and stable call ordering

internal/logger/logger.go

@@ -0,0 +1,113 @@
+package logger
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+var (
+	instance *Logger
+	once     sync.Once
+)
+
+// Logger handles application logging
+type Logger struct {
+	file *os.File
+	mu   sync.Mutex
+	path string
+}
+
+// Init initializes the logger with timestamp-based filename
+func Init() error {
+	var err error
+	once.Do(func() {
+		// Create logs directory
+		logsDir := "logs"
+		if mkErr := os.MkdirAll(logsDir, 0755); mkErr != nil {
+			err = mkErr
+			return
+		}
+
+		// Create log file with timestamp
+		timestamp := time.Now().Format("2006-01-02_15-04-05")
+		filename := filepath.Join(logsDir, fmt.Sprintf("%s.log", timestamp))
+
+		f, openErr := os.Create(filename)
+		if openErr != nil {
+			err = openErr
+			return
+		}
+
+		instance = &Logger{
+			file: f,
+			path: filename,
+		}
+
+		Info("Logger initialized: %s", filename)
+	})
+	return err
+}
+
+// Close closes the logger
+func Close() {
+	if instance != nil && instance.file != nil {
+		instance.file.Close()
+	}
+}
+
+// GetPath returns the log file path
+func GetPath() string {
+	if instance != nil {
+		return instance.path
+	}
+	return ""
+}
+
+// log writes a log entry
+func log(level, format string, args ...interface{}) {
+	if instance == nil {
+		return
+	}
+
+	instance.mu.Lock()
+	defer instance.mu.Unlock()
+
+	timestamp := time.Now().Format("15:04:05.000")
+	msg := fmt.Sprintf(format, args...)
+	line := fmt.Sprintf("[%s] [%s] %s\n", timestamp, level, msg)
+
+	instance.file.WriteString(line)
+	instance.file.Sync()
+}
+
+// Debug logs a debug message
+func Debug(format string, args ...interface{}) {
+	log("DEBUG", format, args...)
+}
+
+// Info logs an info message
+func Info(format string, args ...interface{}) {
+	log("INFO", format, args...)
+}
+
+// Warn logs a warning message
+func Warn(format string, args ...interface{}) {
+	log("WARN", format, args...)
+}
+
+// Error logs an error message
+func Error(format string, args ...interface{}) {
+	log("ERROR", format, args...)
+}
+
+// Writer returns an io.Writer that logs to the file
+func Writer() io.Writer {
+	if instance != nil {
+		return instance.file
+	}
+	return os.Stdout
+}