feat: 代码片段功能与 Markdown 内嵌片段渲染、文档截图等

backend/handler/chat.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/freefire/jiang13-bbs/middleware"
@@ -240,11 +241,32 @@ func (h *Handlers) JoinChatRoom(c *gin.Context) {
 	if !ok {
 		return
 	}
-	_, _, err := h.Chat.Join(claims.ID, roomID)
+	member, joined, err := h.Chat.Join(claims.ID, roomID)
 	if err != nil {
 		c.JSON(chatErrToStatus(err), gin.H{"error": err.Error()})
 		return
 	}
+	// 首次加入则向房间广播系统提示 + 成员变更
+	if joined && member != nil {
+		displayName := h.Chat.DisplayName(claims.ID)
+		if displayName != "" {
+			sysMsg, _ := h.Chat.SendSystemMessage(roomID, displayName+" 加入了群聊")
+			if sysMsg != nil && sysMsg.ID > 0 {
+				h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+					Type: realtime.EventChatMessage,
+					Data: sysMsg,
+				})
+			}
+		}
+		h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+			Type: realtime.EventChatMembership,
+			Data: gin.H{
+				"room_id": roomID,
+				"status":  "joined",
+				"user_id": claims.ID,
+			},
+		})
+	}
 	c.JSON(http.StatusOK, gin.H{"ok": true})
 }
 
@@ -300,6 +322,35 @@ func (h *Handlers) InviteChatMembers(c *gin.Context) {
 			Data: gin.H{"room_id": roomID, "status": "invited"},
 		})
 	}
+	// 被邀请者入群时向房间广播系统提示 + 成员变更
+	if len(added) > 0 {
+		var names []string
+		for _, uid := range added {
+			if n := h.Chat.DisplayName(uid); n != "" {
+				names = append(names, n)
+			}
+		}
+		if len(names) > 0 {
+			content := strings.Join(names, "、") + " 加入了群聊"
+			sysMsg, _ := h.Chat.SendSystemMessage(roomID, content)
+			if sysMsg != nil && sysMsg.ID > 0 {
+				h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+					Type: realtime.EventChatMessage,
+					Data: sysMsg,
+				})
+			}
+		}
+		for _, uid := range added {
+			h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+				Type: realtime.EventChatMembership,
+				Data: gin.H{
+					"room_id": roomID,
+					"status":  "joined",
+					"user_id": uid,
+				},
+			})
+		}
+	}
 	c.JSON(http.StatusOK, gin.H{"added": added})
 }