feat: 新增Chat会话和群聊API

- 新增chat_session相关模型、仓库和服务
- 新增chat_group相关模型、仓库和服务
- 新增session_handler和chat_group_handler
- 实现会话管理和群聊功能

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/internal/handler/chat_group_handler.go

@@ -0,0 +1,149 @@
+package handler
+
+import (
+	"net/http"
+	"strconv"
+
+	"x-agents/server/internal/model"
+	"x-agents/server/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ChatGroupHandler 群聊处理器
+type ChatGroupHandler struct {
+	groupService *service.ChatGroupService
+}
+
+// NewChatGroupHandler 创建群聊处理器
+func NewChatGroupHandler(groupService *service.ChatGroupService) *ChatGroupHandler {
+	return &ChatGroupHandler{
+		groupService: groupService,
+	}
+}
+
+// CreateGroup 创建群聊
+func (h *ChatGroupHandler) CreateGroup(c *gin.Context) {
+	var req model.CreateGroupRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	// 从上下文获取用户ID
+	userID, exists := c.Get("user_id")
+	if exists {
+		req.UserID = userID.(string)
+	}
+
+	group, err := h.groupService.CreateGroup(req)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusCreated, group)
+}
+
+// ListGroups 获取群聊列表
+func (h *ChatGroupHandler) ListGroups(c *gin.Context) {
+	userID := c.Query("user_id")
+	if userID == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "user_id is required"})
+		return
+	}
+
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
+	offset, _ := strconv.Atoi(c.DefaultQuery("offset", "0"))
+
+	groups, total, err := h.groupService.ListGroups(userID, limit, offset)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"list": groups, "total": total})
+}
+
+// GetGroup 获取群聊详情
+func (h *ChatGroupHandler) GetGroup(c *gin.Context) {
+	id := c.Param("id")
+
+	group, err := h.groupService.GetGroup(id)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "Group not found"})
+		return
+	}
+
+	c.JSON(http.StatusOK, group)
+}
+
+// UpdateGroup 更新群聊
+func (h *ChatGroupHandler) UpdateGroup(c *gin.Context) {
+	id := c.Param("id")
+
+	var req model.UpdateGroupRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	group, err := h.groupService.UpdateGroup(id, req)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, group)
+}
+
+// DeleteGroup 删除群聊
+func (h *ChatGroupHandler) DeleteGroup(c *gin.Context) {
+	id := c.Param("id")
+
+	err := h.groupService.DeleteGroup(id)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"success": true})
+}
+
+// GroupChat 群聊对话
+func (h *ChatGroupHandler) GroupChat(c *gin.Context) {
+	id := c.Param("id")
+
+	// 获取群聊信息
+	group, err := h.groupService.GetGroup(id)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "Group not found"})
+		return
+	}
+
+	var req model.GroupChatRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	// 获取用户ID
+	userID := ""
+	if uid, exists := c.Get("user_id"); exists {
+		userID = uid.(string)
+	}
+
+	// 如果没有提供 Agent IDs，使用群聊中配置的
+	agentIDs := req.AgentIDs
+	if agentIDs == "" {
+		agentIDs = group.AgentIDs
+	}
+
+	response, err := h.groupService.GroupChat(userID, req.Message, agentIDs, req.SessionID)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, response)
+}