feat(logging): implement client log streaming and management

- Added log streaming functionality for clients, allowing real-time log access via SSE.
- Introduced LogHandler to manage log streaming requests and responses.
- Implemented LogSessionManager to handle active log sessions and listeners.
- Enhanced protocol with log-related message types and structures.
- Created Logger for client-side logging, supporting various log levels and file output.
- Developed LogViewer component for the web interface to display and filter logs.
- Updated API to support log stream creation and management.
- Added support for querying logs by level and searching through log messages.

internal/client/tunnel/logger.go

@@ -0,0 +1,240 @@
+package tunnel
+
+import (
+	"container/ring"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"github.com/gotunnel/pkg/protocol"
+)
+
+const (
+	maxBufferSize  = 1000              // 环形缓冲区最大条目数
+	logFilePattern = "client.%s.log"   // 日志文件名模式
+)
+
+// LogLevel 日志级别
+type LogLevel int
+
+const (
+	LevelDebug LogLevel = iota
+	LevelInfo
+	LevelWarn
+	LevelError
+)
+
+// Logger 客户端日志收集器
+type Logger struct {
+	dataDir     string
+	buffer      *ring.Ring
+	bufferMu    sync.RWMutex
+	file        *os.File
+	fileMu      sync.Mutex
+	fileDate    string
+	subscribers map[string]chan protocol.LogEntry
+	subMu       sync.RWMutex
+}
+
+// NewLogger 创建新的日志收集器
+func NewLogger(dataDir string) (*Logger, error) {
+	l := &Logger{
+		dataDir:     dataDir,
+		buffer:      ring.New(maxBufferSize),
+		subscribers: make(map[string]chan protocol.LogEntry),
+	}
+
+	// 确保日志目录存在
+	logDir := filepath.Join(dataDir, "logs")
+	if err := os.MkdirAll(logDir, 0755); err != nil {
+		return nil, err
+	}
+
+	return l, nil
+}
+
+// Printf 记录日志 (兼容 log.Printf)
+func (l *Logger) Printf(format string, args ...interface{}) {
+	l.log(LevelInfo, "client", format, args...)
+}
+
+// Infof 记录信息日志
+func (l *Logger) Infof(format string, args ...interface{}) {
+	l.log(LevelInfo, "client", format, args...)
+}
+
+// Warnf 记录警告日志
+func (l *Logger) Warnf(format string, args ...interface{}) {
+	l.log(LevelWarn, "client", format, args...)
+}
+
+// Errorf 记录错误日志
+func (l *Logger) Errorf(format string, args ...interface{}) {
+	l.log(LevelError, "client", format, args...)
+}
+
+// Debugf 记录调试日志
+func (l *Logger) Debugf(format string, args ...interface{}) {
+	l.log(LevelDebug, "client", format, args...)
+}
+
+// PluginLog 记录插件日志
+func (l *Logger) PluginLog(pluginName, level, format string, args ...interface{}) {
+	var lvl LogLevel
+	switch level {
+	case "debug":
+		lvl = LevelDebug
+	case "warn":
+		lvl = LevelWarn
+	case "error":
+		lvl = LevelError
+	default:
+		lvl = LevelInfo
+	}
+	l.log(lvl, "plugin:"+pluginName, format, args...)
+}
+
+func (l *Logger) log(level LogLevel, source, format string, args ...interface{}) {
+	entry := protocol.LogEntry{
+		Timestamp: time.Now().UnixMilli(),
+		Level:     levelToString(level),
+		Message:   fmt.Sprintf(format, args...),
+		Source:    source,
+	}
+
+	// 输出到标准输出
+	fmt.Printf("%s [%s] [%s] %s\n",
+		time.Now().Format("2006-01-02 15:04:05"),
+		entry.Level,
+		entry.Source,
+		entry.Message)
+
+	// 添加到环形缓冲区
+	l.bufferMu.Lock()
+	l.buffer.Value = entry
+	l.buffer = l.buffer.Next()
+	l.bufferMu.Unlock()
+
+	// 写入文件
+	l.writeToFile(entry)
+
+	// 通知订阅者
+	l.notifySubscribers(entry)
+}
+
+// Subscribe 订阅日志流
+func (l *Logger) Subscribe(sessionID string) <-chan protocol.LogEntry {
+	ch := make(chan protocol.LogEntry, 100)
+	l.subMu.Lock()
+	l.subscribers[sessionID] = ch
+	l.subMu.Unlock()
+	return ch
+}
+
+// Unsubscribe 取消订阅
+func (l *Logger) Unsubscribe(sessionID string) {
+	l.subMu.Lock()
+	if ch, ok := l.subscribers[sessionID]; ok {
+		close(ch)
+		delete(l.subscribers, sessionID)
+	}
+	l.subMu.Unlock()
+}
+
+// GetRecentLogs 获取最近的日志
+func (l *Logger) GetRecentLogs(lines int, level string) []protocol.LogEntry {
+	l.bufferMu.RLock()
+	defer l.bufferMu.RUnlock()
+
+	var entries []protocol.LogEntry
+	l.buffer.Do(func(v interface{}) {
+		if v == nil {
+			return
+		}
+		entry := v.(protocol.LogEntry)
+		// 应用级别过滤
+		if level != "" && entry.Level != level {
+			return
+		}
+		entries = append(entries, entry)
+	})
+
+	// 如果指定了行数，返回最后 N 行
+	if lines > 0 && len(entries) > lines {
+		entries = entries[len(entries)-lines:]
+	}
+
+	return entries
+}
+
+// Close 关闭日志收集器
+func (l *Logger) Close() {
+	l.fileMu.Lock()
+	if l.file != nil {
+		l.file.Close()
+		l.file = nil
+	}
+	l.fileMu.Unlock()
+
+	l.subMu.Lock()
+	for _, ch := range l.subscribers {
+		close(ch)
+	}
+	l.subscribers = make(map[string]chan protocol.LogEntry)
+	l.subMu.Unlock()
+}
+
+func (l *Logger) writeToFile(entry protocol.LogEntry) {
+	l.fileMu.Lock()
+	defer l.fileMu.Unlock()
+
+	today := time.Now().Format("2006-01-02")
+	if l.fileDate != today {
+		if l.file != nil {
+			l.file.Close()
+		}
+
+		logPath := filepath.Join(l.dataDir, "logs", fmt.Sprintf(logFilePattern, today))
+		f, err := os.OpenFile(logPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+		if err != nil {
+			return
+		}
+		l.file = f
+		l.fileDate = today
+	}
+
+	if l.file != nil {
+		fmt.Fprintf(l.file, "%d|%s|%s|%s\n",
+			entry.Timestamp, entry.Level, entry.Source, entry.Message)
+	}
+}
+
+func (l *Logger) notifySubscribers(entry protocol.LogEntry) {
+	l.subMu.RLock()
+	defer l.subMu.RUnlock()
+
+	for _, ch := range l.subscribers {
+		select {
+		case ch <- entry:
+		default:
+			// 订阅者太慢，丢弃日志
+		}
+	}
+}
+
+func levelToString(level LogLevel) string {
+	switch level {
+	case LevelDebug:
+		return "debug"
+	case LevelInfo:
+		return "info"
+	case LevelWarn:
+		return "warn"
+	case LevelError:
+		return "error"
+	default:
+		return "info"
+	}
+}