feat: WS handler 接入 SessionManager，main.go 注入依赖 + 健康检查获取活跃会话数

backend/cmd/server/main.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/hhs/camtalk/internal/config"
 	"github.com/hhs/camtalk/internal/logger"
+	"github.com/hhs/camtalk/internal/session"
 	"github.com/hhs/camtalk/internal/ws"
 )
 
@@ -33,6 +34,12 @@ func main() {
 		"addr", cfg.Server.Addr(),
 	)
 
+	// 初始化 Session Manager（MVP 默认内存实现）
+	var sessionMgr session.Manager
+	// TODO: 当 Redis 配置非空时切换为 RedisManager
+	sessionMgr = session.NewMemoryManager(30*time.Minute, 20)
+	defer sessionMgr.(*session.MemoryManager).Stop()
+
 	// Gin 模式
 	if cfg.App.Env == "prod" {
 		gin.SetMode(gin.ReleaseMode)
@@ -44,11 +51,11 @@ func main() {
 	// REST API
 	api := r.Group("/api")
 	{
-		api.GET("/health", healthHandler)
+		api.GET("/health", healthHandler(sessionMgr))
 	}
 
 	// WebSocket
-	r.GET("/ws", ws.ServeWS)
+	r.GET("/ws", ws.ServeWS(sessionMgr))
 
 	// HTTP Server
 	srv := &http.Server{
@@ -82,11 +89,13 @@ func main() {
 }
 
 // healthHandler 健康检查。
-func healthHandler(c *gin.Context) {
+func healthHandler(sessionMgr session.Manager) gin.HandlerFunc {
+	return func(c *gin.Context) {
 		c.JSON(200, gin.H{
 			"status":          "ok",
 			"version":         "0.1.0",
 			"uptime":          time.Since(startTime).String(),
-		"active_sessions": 0, // TODO: 接入 Session Manager
+			"active_sessions": sessionMgr.ActiveCount(),
 		})
 	}
+}

backend/internal/ws/handler.go

@@ -1,17 +1,19 @@
 package ws
 
 import (
+	"context"
 	"encoding/json"
 	"net/http"
 	"sync"
 	"time"
 
 	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
 	"github.com/gorilla/websocket"
 
+	"github.com/hhs/camtalk/internal/errors"
 	"github.com/hhs/camtalk/internal/logger"
 	"github.com/hhs/camtalk/internal/models"
+	"github.com/hhs/camtalk/internal/session"
 )
 
 var upgrader = websocket.Upgrader{
@@ -25,14 +27,21 @@ type Client struct {
 	mu        sync.Mutex
 }
 
-func (c *Client) sendJSON(v any) error {
+// SendJSON 向客户端发送 JSON 消息（公开以便 errors 包调用）。
+func (c *Client) SendJSON(v any) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	return c.conn.WriteJSON(v)
 }
 
 // ServeWS 处理 WebSocket 升级请求。
-func ServeWS(c *gin.Context) {
+func ServeWS(sessionMgr session.Manager) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		serveWS(c, sessionMgr)
+	}
+}
+
+func serveWS(c *gin.Context, sessionMgr session.Manager) {
 	conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
 	if err != nil {
 		logger.Log.Errorw("websocket upgrade failed", "error", err)
@@ -40,11 +49,17 @@ func ServeWS(c *gin.Context) {
 	}
 	defer conn.Close()
 
-	sessionID := uuid.New().String()
+	// 创建会话
+	sessionID, err := sessionMgr.Create(context.Background(), models.DefaultConfig())
+	if err != nil {
+		logger.Log.Errorw("create session failed", "error", err)
+		return
+	}
+
 	client := &Client{conn: conn, sessionID: sessionID}
 
 	// 发送 connected 消息
-	_ = client.sendJSON(models.WsConnected{
+	_ = client.SendJSON(models.WsConnected{
 		Type:          "connected",
 		SessionID:     sessionID,
 		ServerVersion: "0.1.0",
@@ -92,51 +107,67 @@ func ServeWS(c *gin.Context) {
 			Type string `json:"type"`
 		}
 		if err := json.Unmarshal(message, &envelope); err != nil {
-			_ = client.sendJSON(models.WsError{
+			errors.SendWSError(client, errors.CodeInvalidMessage, "", err)
-				Type:    "error",
-				Code:    "INVALID_MESSAGE",
-				Message: "invalid JSON",
-			})
 			continue
 		}
 
 		switch envelope.Type {
 		case "ping":
-			_ = client.sendJSON(models.WsPong{Type: "pong"})
+			_ = client.SendJSON(models.WsPong{Type: "pong"})
 
 		case "query":
 			var msg models.WsQuery
 			if err := json.Unmarshal(message, &msg); err != nil {
-				_ = client.sendJSON(models.WsError{
+				errors.SendWSError(client, errors.CodeInvalidMessage, msg.RequestID, err)
-					Type:      "error",
-					Code:      "INVALID_MESSAGE",
-					Message:   "invalid query message",
-					RequestID: msg.RequestID,
-				})
 				continue
 			}
 			logger.Log.Infow("query received", "session", sessionID, "request", msg.RequestID)
-			// TODO: 调用 AI 编排流程（STT → LLM → TTS）
+
+			// 刷新会话 TTL
+			if err := sessionMgr.Touch(context.Background(), sessionID); err != nil {
+				logger.Log.Warnw("touch session failed", "session", sessionID, "error", err)
+			}
+
+			// 标记活跃请求
+			if err := sessionMgr.SetActiveRequest(context.Background(), sessionID, msg.RequestID); err != nil {
+				logger.Log.Warnw("set active request failed", "session", sessionID, "error", err)
+			}
+
+			// 获取对话历史（供后续 Orchestrator 使用）
+			_, _ = sessionMgr.GetHistory(context.Background(), sessionID, 20)
+
+			// TODO: 解码 audio Base64 → 启动 orchestrator.ProcessQuery goroutine
 
 		case "config":
 			var msg models.WsConfig
 			if err := json.Unmarshal(message, &msg); err != nil {
-				_ = client.sendJSON(models.WsError{
+				errors.SendWSError(client, errors.CodeInvalidMessage, "", err)
-					Type:    "error",
-					Code:    "INVALID_MESSAGE",
-					Message: "invalid config message",
-				})
 				continue
 			}
-			logger.Log.Infow("config update", "session", sessionID)
+
-			// TODO: 更新会话配置
+			patch := models.SessionConfigPatch{
+				TTSEnabled:  msg.Payload.TTSEnabled,
+				DetailLevel: msg.Payload.DetailLevel,
+				Language:    msg.Payload.Language,
+			}
+			if err := sessionMgr.UpdateConfig(context.Background(), sessionID, patch); err != nil {
+				errors.SendWSError(client, errors.CodeInternalError, "", err)
+				continue
+			}
+			logger.Log.Infow("config updated", "session", sessionID)
 
 		case "interrupt":
 			logger.Log.Infow("interrupt received", "session", sessionID)
-			// TODO: 中断当前 AI 响应
+
+			// 获取活跃请求 ID（实际 cancel 在 Phase 5 接入 orchestrator 后实现）
+			reqID, _ := sessionMgr.GetActiveRequestID(context.Background(), sessionID)
+			if reqID != "" {
+				_ = sessionMgr.ClearActiveRequest(context.Background(), sessionID)
+				// TODO: 取消对应 context cancel func
+			}
 
 		default:
-			_ = client.sendJSON(models.WsError{
+			_ = client.SendJSON(models.WsError{
 				Type:    "error",
 				Code:    "INVALID_MESSAGE",
 				Message: "unknown message type: " + envelope.Type,
@@ -145,5 +176,7 @@ func ServeWS(c *gin.Context) {
 	}
 
 	close(done)
+
+	// 断开连接时不销毁会话，让其自然过期（支持重连恢复）
 	logger.Log.Infow("client disconnected", "session", sessionID)
 }