feat(websocket): integrate WebSocket support and refactor SSE handling

- Added WebSocket support by introducing a new WSHandler and related infrastructure.
- Replaced SSE implementations with WebSocket equivalents across message and QR code handlers.
- Updated service and repository layers to utilize WebSocket for real-time messaging.
- Removed obsolete SSE hub and related code, streamlining the application for WebSocket usage.
- Enhanced router to include WebSocket endpoints for real-time communication.

internal/handler/message_handler.go

@@ -2,10 +2,7 @@ package handler
 
 import (
 	"context"
-	"fmt"
-	"net/http"
 	"strconv"
-	"time"
 
 	"github.com/gin-gonic/gin"
 
@@ -13,7 +10,7 @@ import (
 	"carrot_bbs/internal/model"
 	"carrot_bbs/internal/pkg/cursor"
 	"carrot_bbs/internal/pkg/response"
-	"carrot_bbs/internal/pkg/sse"
+	"carrot_bbs/internal/pkg/ws"
 	"carrot_bbs/internal/service"
 )
 
@@ -23,95 +20,17 @@ type MessageHandler struct {
 	messageService *service.MessageService
 	userService    service.UserService
 	groupService   service.GroupService
-	sseHub         *sse.Hub
+	wsHub          *ws.Hub
 }
 
 // NewMessageHandler 创建消息处理器
-func NewMessageHandler(chatService service.ChatService, messageService *service.MessageService, userService service.UserService, groupService service.GroupService, sseHub *sse.Hub) *MessageHandler {
+func NewMessageHandler(chatService service.ChatService, messageService *service.MessageService, userService service.UserService, groupService service.GroupService, wsHub *ws.Hub) *MessageHandler {
 	return &MessageHandler{
 		chatService:    chatService,
 		messageService: messageService,
 		userService:    userService,
 		groupService:   groupService,
-		sseHub:         sseHub,
-	}
-}
-
-// HandleSSE 实时消息订阅（SSE）
-// GET /api/v1/realtime/sse
-func (h *MessageHandler) HandleSSE(c *gin.Context) {
-	userID := c.GetString("user_id")
-	if userID == "" {
-		response.Unauthorized(c, "")
-		return
-	}
-	if h.sseHub == nil {
-		response.InternalServerError(c, "sse hub not available")
-		return
-	}
-
-	lastID := sse.ParseEventID(c.GetHeader("Last-Event-ID"))
-	if lastID == 0 {
-		lastID = sse.ParseEventID(c.Query("last_event_id"))
-	}
-	ch, cancel, replay := h.sseHub.Subscribe(userID, lastID)
-	defer cancel()
-
-	w := c.Writer
-	flusher, ok := w.(http.Flusher)
-	if !ok {
-		response.InternalServerError(c, "streaming unsupported")
-		return
-	}
-
-	w.Header().Set("Content-Type", "text/event-stream")
-	w.Header().Set("Cache-Control", "no-cache, no-transform")
-	w.Header().Set("Connection", "keep-alive")
-	w.Header().Set("X-Accel-Buffering", "no")
-	c.Status(http.StatusOK)
-	flusher.Flush()
-
-	writeEvent := func(ev sse.Event) bool {
-		data, err := sse.EncodeData(ev)
-		if err != nil {
-			return false
-		}
-		if _, err := fmt.Fprintf(w, "id: %d\nevent: %s\ndata: %s\n\n", ev.ID, ev.Event, data); err != nil {
-			return false
-		}
-		flusher.Flush()
-		return true
-	}
-
-	for _, ev := range replay {
-		if !writeEvent(ev) {
-			return
-		}
-	}
-
-	// Use a shorter heartbeat interval to survive common 50-60s proxy idle timeout.
-	heartbeat := time.NewTicker(10 * time.Second)
-	defer heartbeat.Stop()
-
-	for {
-		select {
-		case <-c.Request.Context().Done():
-			return
-		case ev, ok := <-ch:
-			if !ok || !writeEvent(ev) {
-				return
-			}
-		case <-heartbeat.C:
-			// Comment keepalive line for SSE intermediaries/proxies.
-			if _, err := fmt.Fprint(w, ": keepalive\n\n"); err != nil {
-				return
-			}
-			flusher.Flush()
-			if _, err := fmt.Fprint(w, "event: heartbeat\ndata: {}\n\n"); err != nil {
-				return
-			}
-			flusher.Flush()
-		}
+		wsHub:          wsHub,
 	}
 }