Cyrene/backend/gateway/internal/handler/chat_handler.go

package handler

import (
	"bufio"
	"bytes"
	"crypto/rand"
	"encoding/base64"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gorilla/websocket"

	"github.com/yourname/cyrene-ai/gateway/internal/config"
	"github.com/yourname/cyrene-ai/gateway/internal/store"
	"github.com/yourname/cyrene-ai/gateway/internal/ws"
	"github.com/yourname/cyrene-ai/pkg/logger"
)

// ChatHandler 聊天处理器
type ChatHandler struct {
	cfg          *config.Config
	hub          *ws.Hub
	sessionStore *store.SessionStore
	upgrader     websocket.Upgrader
}

// NewChatHandler 创建聊天处理器
func NewChatHandler(cfg *config.Config, hub *ws.Hub, sessionStore *store.SessionStore) *ChatHandler {
	return &ChatHandler{
		cfg:          cfg,
		hub:          hub,
		sessionStore: sessionStore,
		upgrader: websocket.Upgrader{
			ReadBufferSize:  1024,
			WriteBufferSize: 1024,
			CheckOrigin: func(r *http.Request) bool {
				return true // 开发阶段允许所有来源
			},
		},
	}
}

// HandleWebSocket 处理WebSocket升级和消息路由
func (h *ChatHandler) HandleWebSocket(c *gin.Context) {
	// 从query参数获取token和session_id
	token := c.Query("token")
	sessionID := c.Query("session_id")
	clientID := c.Query("client_id")
	deviceName := c.Query("device_name")
	userAgent := c.Request.UserAgent()

	if token == "" {
		// 也尝试从Authorization头读取
		authHeader := c.GetHeader("Authorization")
		if len(authHeader) > 7 && authHeader[:7] == "Bearer " {
			token = authHeader[7:]
		}
	}

	if token == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "需要认证令牌"})
		return
	}

	// 验证token
	userID, err := h.cfg.ValidateToken(token)
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "认证令牌无效"})
		return
	}

	// 主对话仅限管理员访问
	if userID != "admin" {
		c.JSON(http.StatusForbidden, gin.H{
			"error":     "主对话仅限管理员使用",
			"errorType": "admin_only",
			"hint":      "请使用管理员账号登录以访问主对话功能",
		})
		return
	}

	if sessionID == "" {
		sessionID = "session_" + generateID()
	}

	// 升级WebSocket连接
	conn, err := h.upgrader.Upgrade(c.Writer, c.Request, nil)
	if err != nil {
		logger.Printf("[WS] 升级连接失败: %v", err)
		return
	}

	// 创建客户端
	client := ws.NewClient(h.hub, conn, userID, sessionID, clientID, deviceName, userAgent)

	// 注册到Hub
	h.hub.Register(client)

	// 启动读写协程
	go client.WritePump()
	go client.ReadPump(func(client *ws.Client, msg ws.ClientMessage) {
		h.handleMessage(client, msg)
	})
}

// handleMessage 处理WebSocket消息
func (h *ChatHandler) handleMessage(client *ws.Client, msg ws.ClientMessage) {
	switch msg.Type {
	case "message":
		h.handleChatMessage(client, msg)
	case "voice_input":
		h.handleVoiceInput(client, msg)
	case "history":
		h.handleHistoryRequest(client, msg)
	default:
		logger.Printf("[WS] 未知消息类型: %s from user=%s", msg.Type, client.UserID)
	}
}

// handleChatMessage 处理文字聊天消息 - 转发到 AI-Core（流式发送）
func (h *ChatHandler) handleChatMessage(client *ws.Client, msg ws.ClientMessage) {
	mode := msg.Mode
	if mode == "" {
		mode = "text"
	}

	// 持久化用户消息到数据库（在 WebSocket 发送之前）
	if h.sessionStore != nil && h.sessionStore.IsAvailable() {
		if err := h.sessionStore.AddMessage(client.SessionID, "user", "chat", msg.Content, client.ClientID); err != nil {
			logger.Printf("[chat] 持久化用户消息失败: %v", err)
		}
	}

	// 记录用户消息
	h.hub.RecordMessage(client.SessionID, "user", msg.Content)

	// 设置会话状态为 thinking
	h.hub.UpdateSessionState(client.SessionID, "thinking")

	// 构建 AI-Core 请求
	aiReq := map[string]interface{}{
		"user_id":    client.UserID,
		"session_id": client.SessionID,
		"message":    msg.Content,
		"mode":       mode,
	}
	if len(msg.Attachments) > 0 {
		aiReq["attachments"] = msg.Attachments
	}
	reqBody, err := json.Marshal(aiReq)
	if err != nil {
		logger.Printf("[chat] 序列化请求失败: %v", err)
		h.hub.UpdateSessionState(client.SessionID, "error")
		client.SendMessage(ws.ServerMessage{
			Type:      "error",
			MessageID: "msg_" + generateID(),
			Error:     "内部错误，请稍后重试",
			Timestamp: time.Now().UnixMilli(),
		})
		return
	}

	// 缓存用户消息（在 goroutine 前完成，避免竞态）
	userMsg := ws.Message{
		ID:        "msg_" + generateID(),
		Role:      "user",
		Content:   msg.Content,
		Timestamp: time.Now().UnixMilli(),
		ClientInfo: &ws.ClientInfo{
			ClientID:   client.ClientID,
			DeviceName: client.DeviceName,
		},
	}
	if len(msg.Attachments) > 0 {
		userMsg.Attachments = msg.Attachments
	}
	h.hub.CacheMessage(client.UserID, client.SessionID, userMsg)

	// 在 goroutine 中进行 AI-Core 调用和流式发送，避免阻塞 ReadPump
	go h.streamResponse(client, mode, reqBody, msg.Content)
}

// streamResponse 调用 AI-Core SSE 流式接口并逐 delta 转发给客户端
func (h *ChatHandler) streamResponse(client *ws.Client, mode string, reqBody []byte, userMsg string) {
	aiCoreURL := h.cfg.AICoreURL + "/api/v1/chat"
	httpReq, err := http.NewRequest("POST", aiCoreURL, bytes.NewReader(reqBody))
	if err != nil {
		logger.Printf("[chat] 创建 AI-Core 请求失败: %v", err)
		h.hub.UpdateSessionState(client.SessionID, "error")
		client.SendMessage(ws.ServerMessage{
			Type:      "error",
			MessageID: "msg_" + generateID(),
			Error:     "服务暂不可用",
			Timestamp: time.Now().UnixMilli(),
		})
		return
	}
	httpReq.Header.Set("Content-Type", "application/json")
	httpReq.Header.Set("Accept", "text/event-stream")

	httpClient := &http.Client{Timeout: 120 * time.Second}
	resp, err := httpClient.Do(httpReq)
	if err != nil {
		logger.Printf("[chat] AI-Core 调用失败: %v", err)
		h.hub.UpdateSessionState(client.SessionID, "error")
		client.SendMessage(ws.ServerMessage{
			Type:      "error",
			MessageID: "msg_" + generateID(),
			Error:     fmt.Sprintf("AI-Core 调用失败: %v", err),
			Timestamp: time.Now().UnixMilli(),
		})
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		logger.Printf("[chat] AI-Core 返回错误 [%d]: %s", resp.StatusCode, string(body))
		h.hub.UpdateSessionState(client.SessionID, "error")
		client.SendMessage(ws.ServerMessage{
			Type:      "error",
			MessageID: "msg_" + generateID(),
			Error:     fmt.Sprintf("AI-Core 错误 (%d)", resp.StatusCode),
			Timestamp: time.Now().UnixMilli(),
		})
		return
	}

	// 使用 bufio.Scanner 逐行读取 SSE 响应
	scanner := bufio.NewScanner(resp.Body)
	// 增大 scanner buffer 以处理大块 SSE 数据
	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)

	// 通知所有客户端 AI 开始生成回复
	h.broadcastToUser(client.UserID, ws.ServerMessage{
		Type:      "stream_start",
		MessageID: "msg_" + generateID(),
		SessionID: client.SessionID,
		Timestamp: time.Now().UnixMilli(),
	})

	var fullText string
	var msgID string
	var hasReview bool             // 是否有审查消息（避免重复持久化）
	var segments []ws.VoiceSegment // 收集断句信息

	for scanner.Scan() {
		line := scanner.Text()

		// 跳过非 data 行
		if !strings.HasPrefix(line, "data: ") {
			continue
		}

		data := strings.TrimPrefix(line, "data: ")

		// SSE 流结束标记
		if data == "[DONE]" {
			break
		}

		// 解析 delta 数据
		var chunk struct {
			Delta     string `json:"delta"`
			Error     string `json:"error,omitempty"`
			MessageID string `json:"message_id,omitempty"`
			Mode      string `json:"mode,omitempty"`
			Done      bool   `json:"done,omitempty"`
			// 断句相关 (来自 AI-Core 新格式)
			Segments []struct {
				Index int    `json:"index"`
				Text  string `json:"text"`
			} `json:"segments,omitempty"`
			// 审查后的结构化消息
			ReviewMessages []ws.ReviewMessage `json:"review_messages,omitempty"`
		}
		if err := json.Unmarshal([]byte(data), &chunk); err != nil {
			logger.Printf("[chat] 解析 SSE delta 失败: %v, raw=%s", err, data)
			continue
		}

		// 错误处理
		if chunk.Error != "" {
			logger.Printf("[chat] AI-Core 流式错误: %s", chunk.Error)
			h.hub.UpdateSessionState(client.SessionID, "error")
			client.SendMessage(ws.ServerMessage{
				Type:      "error",
				MessageID: "msg_" + generateID(),
				Error:     chunk.Error,
				Timestamp: time.Now().UnixMilli(),
			})
			return
		}

		// 记录 message_id
		if chunk.MessageID != "" {
			msgID = chunk.MessageID
		}

		// 如果是结束标记（含 done: true），跳出
		if chunk.Done {
			break
		}

		// 处理审查后的结构化消息 (review)
		if len(chunk.ReviewMessages) > 0 {
			for i, rm := range chunk.ReviewMessages {
				role := "assistant"
				msgType := "chat"
				if rm.Type == "action" {
					role = "action"
					msgType = "action"
				}
				reviewMsgID := fmt.Sprintf("%s_r%d", msgID, i)
				// 持久化每条审查消息
				if h.sessionStore != nil && h.sessionStore.IsAvailable() {
					if err := h.sessionStore.AddMessage(client.SessionID, role, msgType, rm.Content, client.ClientID); err != nil {
						logger.Printf("[chat] 持久化审查消息失败: %v", err)
					}
				}
				clientInfo := &ws.ClientInfo{
					ClientID:   client.ClientID,
					DeviceName: client.DeviceName,
				}
				h.hub.CacheMessage(client.UserID, client.SessionID, ws.Message{
					ID:         reviewMsgID,
					Role:       role,
					Content:    rm.Content,
					Timestamp:  time.Now().UnixMilli(),
					ClientInfo: clientInfo,
				})
				h.broadcastToUser(client.UserID, ws.ServerMessage{
					Type:       "response",
					MessageID:  reviewMsgID,
					Content:    rm.Content,
					Role:       role,
					MsgType:    msgType,
					SessionID:  client.SessionID,
					Timestamp:  time.Now().UnixMilli(),
					ClientInfo: clientInfo,
				})
				// 使用 MessageScheduler 计算的 per-message 延迟
				if rm.DelayMs > 0 {
					time.Sleep(time.Duration(rm.DelayMs) * time.Millisecond)
				}
			}
			hasReview = true
			continue
		}

		// 处理断句事件 (stream_segments)
		if len(chunk.Segments) > 0 {
			for _, seg := range chunk.Segments {
				segments = append(segments, ws.VoiceSegment{
					Index: seg.Index,
					Text:  seg.Text,
				})
			}
			// 发送断句事件给所有客户端
			h.broadcastToUser(client.UserID, ws.ServerMessage{
				Type:      "stream_segments",
				MessageID: msgID,
				Segments:  segments,
				SessionID: client.SessionID,
				Timestamp: time.Now().UnixMilli(),
			})
			continue
		}

		// 逐 delta 积累（不再逐块转发，由审查消息代替）
		if chunk.Delta != "" {
			fullText += chunk.Delta
		}
	}

	if err := scanner.Err(); err != nil {
		logger.Printf("[chat] SSE 读取错误: %v", err)
		h.hub.UpdateSessionState(client.SessionID, "error")
		client.SendMessage(ws.ServerMessage{
			Type:      "error",
			MessageID: "msg_" + generateID(),
			Error:     fmt.Sprintf("流读取错误: %v", err),
			Timestamp: time.Now().UnixMilli(),
		})
		return
	}

	if msgID == "" {
		msgID = "msg_" + generateID()
	}

	// 检测是否为多消息格式（包含空行分隔的多条消息）
	// 如果已有审查消息则跳过，避免与 review_messages 重复
	multiParts := parseMultiMessage(fullText)
	if !hasReview && len(multiParts) > 1 {
		// 发送 multi_message 事件
		var items []ws.MultiMessageItem
		for i, part := range multiParts {
			items = append(items, ws.MultiMessageItem{
				Index:   i,
				Content: part,
			})
		}
		h.broadcastToUser(client.UserID, ws.ServerMessage{
			Type:      "multi_message",
			MessageID: msgID,
			SessionID: client.SessionID,
			MultiMessage: &ws.MultiMessagePayload{
				Messages: items,
			},
			Timestamp: time.Now().UnixMilli(),
		})
	}

	// 发送 stream_end 到所有客户端
	h.broadcastToUser(client.UserID, ws.ServerMessage{
		Type:      "stream_end",
		MessageID: msgID,
		SessionID: client.SessionID,
		Content:   fullText,
		Text:      fullText,
		Timestamp: time.Now().UnixMilli(),
	})

	// 持久化 AI 回复到数据库
	// 如果有审查消息，每条已单独持久化，跳过 fullText 以避免重复
	if !hasReview && fullText != "" {
		if h.sessionStore != nil && h.sessionStore.IsAvailable() {
			if err := h.sessionStore.AddMessage(client.SessionID, "assistant", "chat", fullText, client.ClientID); err != nil {
				logger.Printf("[chat] 持久化 AI 回复失败: %v", err)
			}
		}

		h.hub.CacheMessage(client.UserID, client.SessionID, ws.Message{
			ID:        msgID,
			Role:      "assistant",
			Content:   fullText,
			Timestamp: time.Now().UnixMilli(),
			ClientInfo: &ws.ClientInfo{
				ClientID:   client.ClientID,
				DeviceName: client.DeviceName,
			},
		})
	}
	// RecordMessage 使用不带 [review] 标记的文本
	recordText := fullText
	if hasReview {
		recordText = strings.ReplaceAll(fullText, "[review]", "")
	}
	h.hub.RecordMessage(client.SessionID, "assistant", recordText)

	// 设置会话状态为 idle
	h.hub.UpdateSessionState(client.SessionID, "idle")
}

// handleVoiceInput 处理语音输入
func (h *ChatHandler) handleVoiceInput(client *ws.Client, msg ws.ClientMessage) {
	audioB64 := msg.AudioData
	if audioB64 == "" {
		client.SendMessage(ws.ServerMessage{
			Type:      "error",
			MessageID: "msg_" + generateID(),
			Error:     "语音数据为空",
			Timestamp: time.Now().UnixMilli(),
		})
		return
	}

	format := msg.Mode
	if format == "" {
		format = "webm"
	}

	// 在 goroutine 中处理转录，避免阻塞 ReadPump
	go func() {
		text, err := h.transcribeAudio(audioB64, format)
		if err != nil {
			logger.Printf("[voice] 转录失败: %v", err)
			client.SendMessage(ws.ServerMessage{
				Type:      "voice_transcript",
				MessageID: "msg_" + generateID(),
				Error:     fmt.Sprintf("语音识别失败: %v", err),
				Timestamp: time.Now().UnixMilli(),
			})
			return
		}

		if text == "" {
			client.SendMessage(ws.ServerMessage{
				Type:      "voice_transcript",
				MessageID: "msg_" + generateID(),
				Text:      "",
				Timestamp: time.Now().UnixMilli(),
			})
			return
		}

		// 发送转录结果给前端
		client.SendMessage(ws.ServerMessage{
			Type:      "voice_transcript",
			MessageID: "msg_" + generateID(),
			Text:      text,
			Timestamp: time.Now().UnixMilli(),
		})

		// 将转录文本作为聊天消息处理
		chatMsg := ws.ClientMessage{
			Type:    "message",
			Content: text,
			Mode:    msg.Mode,
		}
		h.handleChatMessage(client, chatMsg)
	}()
}

// transcribeAudio 将 base64 编码的音频发送到 voice-service 进行转录。
func (h *ChatHandler) transcribeAudio(audioB64 string, format string) (string, error) {
	audioData, err := decodeBase64(audioB64)
	if err != nil {
		return "", fmt.Errorf("解码音频数据失败: %w", err)
	}

	// 构建 multipart form
	var buf bytes.Buffer
	mw := multipart.NewWriter(&buf)

	ext := ".webm"
	switch format {
	case "wav", "wave":
		ext = ".wav"
	case "mp3", "mpeg":
		ext = ".mp3"
	case "ogg", "opus":
		ext = ".ogg"
	case "pcm":
		ext = ".pcm"
	}

	fw, err := mw.CreateFormFile("audio", "recording"+ext)
	if err != nil {
		return "", fmt.Errorf("创建表单字段失败: %w", err)
	}
	if _, err := fw.Write(audioData); err != nil {
		return "", fmt.Errorf("写入音频数据失败: %w", err)
	}
	mw.Close()

	voiceURL := h.cfg.VoiceServiceURL
	if voiceURL == "" {
		voiceURL = "http://localhost:8093"
	}

	httpReq, err := http.NewRequest("POST", voiceURL+"/api/v1/transcribe", &buf)
	if err != nil {
		return "", fmt.Errorf("创建请求失败: %w", err)
	}
	httpReq.Header.Set("Content-Type", mw.FormDataContentType())

	httpClient := &http.Client{Timeout: 60 * time.Second}
	resp, err := httpClient.Do(httpReq)
	if err != nil {
		return "", fmt.Errorf("voice-service 调用失败: %w", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("读取响应失败: %w", err)
	}

	var result struct {
		Success bool   `json:"success"`
		Text    string `json:"text"`
		Error   string `json:"error"`
	}
	if err := json.Unmarshal(respBody, &result); err != nil {
		return "", fmt.Errorf("解析响应失败: %w", err)
	}

	if !result.Success {
		if result.Error != "" {
			return "", fmt.Errorf("%s", result.Error)
		}
		return "", fmt.Errorf("转录返回空结果")
	}

	return result.Text, nil
}

// decodeBase64 解码 base64 字符串（支持 Data URL 前缀）。
func decodeBase64(s string) ([]byte, error) {
	// 移除 data:xxx;base64, 前缀
	if idx := strings.Index(s, ","); idx != -1 {
		s = s[idx+1:]
	}
	return base64.StdEncoding.DecodeString(s)
}

// handleHistoryRequest 处理历史消息请求
func (h *ChatHandler) handleHistoryRequest(client *ws.Client, msg ws.ClientMessage) {
	// 优先使用请求中的 session_id，否则使用客户端的 session_id
	sessionID := msg.SessionID
	if sessionID == "" {
		sessionID = client.SessionID
	}

	messages := h.hub.GetConversation(client.UserID, sessionID)

	// 如果内存缓存为空，尝试从数据库恢复（网关重启后缓存丢失的情况）
	if len(messages) == 0 && h.sessionStore != nil && h.sessionStore.IsAvailable() {
		dbMessages, err := h.sessionStore.GetMessages(sessionID, 50, 0)
		if err == nil && len(dbMessages) > 0 {
			logger.Printf("[history] 从数据库恢复会话历史: session=%s, %d 条消息", sessionID, len(dbMessages))
			// 恢复到内存缓存
			for _, dbMsg := range dbMessages {
				var ci *ws.ClientInfo
				if dbMsg.ClientID != "" {
					ci = h.hub.ClientInfo(dbMsg.ClientID)
					if ci == nil {
						ci = &ws.ClientInfo{ClientID: dbMsg.ClientID}
					}
				}
				messages = append(messages, ws.Message{
					ID:         fmt.Sprintf("db_%d", dbMsg.ID),
					Role:       dbMsg.Role,
					MsgType:    dbMsg.MsgType,
					Content:    dbMsg.Content,
					Timestamp:  dbMsg.CreatedAt.UnixMilli(),
					ClientInfo: ci,
				})
				h.hub.CacheMessage(client.UserID, sessionID, ws.Message{
					ID:         fmt.Sprintf("db_%d", dbMsg.ID),
					Role:       dbMsg.Role,
					MsgType:    dbMsg.MsgType,
					Content:    dbMsg.Content,
					Timestamp:  dbMsg.CreatedAt.UnixMilli(),
					ClientInfo: ci,
				})
			}
		}
	}

	if messages == nil {
		messages = []ws.Message{}
	}

	response := ws.ServerMessage{
		Type:      "history_response",
		MessageID: "hist_" + generateID(),
		Messages:  messages,
		Timestamp: time.Now().UnixMilli(),
	}

	if err := client.SendMessage(response); err != nil {
		logger.Printf("[WS] 发送历史消息失败: %v", err)
	}
}

// SendSystemMessage 向用户发送系统消息（用于主动通知）
func (h *ChatHandler) SendSystemMessage(userID, sessionID, text string) error {
	msg := ws.ServerMessage{
		Type:      "response",
		MessageID: "sys_" + generateID(),
		Text:      text,
		Timestamp: time.Now().UnixMilli(),
	}

	data, err := json.Marshal(msg)
	if err != nil {
		return err
	}

	h.hub.SendToSession(userID, sessionID, data)
	return nil
}

// HandleProactiveMessage 处理来自 AI-Core 后台思考的主动消息
// POST /api/v1/internal/proactive-message
func (h *ChatHandler) HandleProactiveMessage(c *gin.Context) {
	var req struct {
		UserID    string `json:"user_id" binding:"required"`
		Content   string `json:"content" binding:"required"`
		SessionID string `json:"session_id"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效: " + err.Error()})
		return
	}

	// Parse content to split (action) from chat text.
	segments := parseProactiveContent(req.Content)

	// Check online status.
	onlineCount := h.hub.UserClientCount(req.UserID)

	sessionID := req.SessionID
	if sessionID == "" {
		sessionID = "session_admin_main"
	}

	timestamp := time.Now().UnixMilli()

	for i, seg := range segments {
		msgID := fmt.Sprintf("proactive_%s_%d", generateID(), i)
		msgType := "chat"
		role := "assistant"
		if seg.msgType == "action" {
			msgType = "action"
			role = "action"
		}

		msg := ws.ServerMessage{
			Type:      "response",
			MessageID: msgID,
			Content:   seg.content,
			Role:      role,
			MsgType:   msgType,
			SessionID: sessionID,
			Timestamp: timestamp + int64(i),
		}

		data, err := json.Marshal(msg)
		if err != nil {
			logger.Printf("[proactive] 序列化消息失败: %v", err)
			continue
		}

		if onlineCount == 0 {
			h.hub.QueueProactiveMessage(req.UserID, data)
		} else {
			h.hub.SendToUser(req.UserID, data)
			if i < len(segments)-1 {
				delay := 200 + int(time.Now().UnixNano()%200)
				time.Sleep(time.Duration(delay) * time.Millisecond)
			}
		}

		// Persist to database so proactive messages survive restarts.
		if h.sessionStore != nil && h.sessionStore.IsAvailable() {
			if err := h.sessionStore.AddMessage(sessionID, role, msgType, seg.content, ""); err != nil {
				logger.Printf("[proactive] 持久化消息失败: %v", err)
			}
		}

		// Cache each segment to conversation history.
		h.hub.CacheMessage(req.UserID, sessionID, ws.Message{
			ID:        msgID,
			Role:      role,
			MsgType:   msgType,
			Content:   seg.content,
			Timestamp: timestamp,
		})
		h.hub.RecordMessage(sessionID, role, seg.content)
	}

	logger.Printf("[proactive] 主动消息已推送: user=%s, online=%d, segments=%d", req.UserID, onlineCount, len(segments))

	reason := "delivered"
	if onlineCount == 0 {
		reason = "queued"
	}
	c.JSON(http.StatusOK, gin.H{
		"success":   true,
		"message":   "消息已推送",
		"segments":  len(segments),
		"delivered": onlineCount,
		"reason":    reason,
	})
}

// proactiveSegment holds a parsed piece of a proactive message.
type proactiveSegment struct {
	msgType string // "chat" or "action"
	content string
}

// parseProactiveContent splits text by (parenthesized actions).
// "(笑) 你好呀 (调暗灯光) 今天过得如何" →
//   [action: "笑", chat: "你好呀", action: "调暗灯光", chat: "今天过得如何"]
func parseProactiveContent(text string) []proactiveSegment {
	if text == "" {
		return nil
	}

	var segments []proactiveSegment
	remaining := []rune(text)

	for len(remaining) > 0 {
		actionStart := -1 // index in remaining
		actionEnd := -1   // index after closing paren
		var actionContent string

		for i, r := range remaining {
			if r == '(' || r == '（' {
				actionStart = i
				closeRune := ')'
				if r == '（' {
					closeRune = '）'
				}
				for j := i + 1; j < len(remaining); j++ {
					if remaining[j] == closeRune {
						actionEnd = j + 1
						actionContent = string(remaining[i+1 : j])
						break
					}
				}
				break
			}
		}

		if actionStart >= 0 {
			if actionStart > 0 {
				prefix := strings.TrimSpace(string(remaining[:actionStart]))
				if prefix != "" {
					segments = append(segments, proactiveSegment{msgType: "chat", content: prefix})
				}
			}
			content := strings.TrimSpace(actionContent)
			if content != "" {
				segments = append(segments, proactiveSegment{msgType: "action", content: content})
			}
			remaining = remaining[actionEnd:]
		} else {
			text := strings.TrimSpace(string(remaining))
			if text != "" {
				segments = append(segments, proactiveSegment{msgType: "chat", content: text})
			}
			break
		}
	}

	if len(segments) == 0 && text != "" {
		segments = append(segments, proactiveSegment{msgType: "chat", content: strings.TrimSpace(text)})
	}

	return segments
}

// ========== 多端客户端管理 API ==========

// HandleListClients returns all known clients for the authenticated user.
// GET /api/v1/admin/clients
func (h *ChatHandler) HandleListClients(c *gin.Context) {
	userID := c.Query("user_id")
	if userID == "" {
		userID = "admin"
	}
	clients := h.hub.GetKnownClients(userID)

	// Merge with persisted notes from DB
	if h.sessionStore != nil && h.sessionStore.IsAvailable() {
		dbClients, err := h.sessionStore.GetClients(userID)
		if err == nil {
			noteByID := make(map[string]string)
			for _, dc := range dbClients {
				noteByID[dc.ClientID] = dc.Note
			}
			for i := range clients {
				if note, ok := noteByID[clients[i].ClientID]; ok && note != "" {
					clients[i].Note = note
				}
			}
		}
	}

	c.JSON(http.StatusOK, gin.H{
		"clients": clients,
		"total":   len(clients),
	})
}

// HandleUpdateClientNote sets a label/note on a client.
// PUT /api/v1/admin/clients/:id/note
func (h *ChatHandler) HandleUpdateClientNote(c *gin.Context) {
	clientID := c.Param("id")
	var req struct {
		Note string `json:"note"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}

	// Update in-memory
	if !h.hub.UpdateClientNote(clientID, req.Note) {
		c.JSON(http.StatusNotFound, gin.H{"error": "客户端未找到"})
		return
	}

	// Persist to DB
	if h.sessionStore != nil && h.sessionStore.IsAvailable() {
		if err := h.sessionStore.UpdateClientNote(clientID, req.Note); err != nil {
			logger.Printf("[clients] 持久化备注失败: %v", err)
		}
	}

	c.JSON(http.StatusOK, gin.H{"status": "ok", "client_id": clientID, "note": req.Note})
}

func generateID() string {
	return time.Now().Format("20060102150405") + randomStr(6)
}

func randomStr(n int) string {
	b := make([]byte, n)
	if _, err := rand.Read(b); err != nil {
		// fallback: deterministic but hard to predict
		for i := range b {
			b[i] = byte(time.Now().UnixNano() % 256)
		}
	}
	return hex.EncodeToString(b)[:n]
}

// broadcastToUser sends a server message to ALL connected clients for a user.
func (h *ChatHandler) broadcastToUser(userID string, msg ws.ServerMessage) {
	data, err := json.Marshal(msg)
	if err != nil {
		logger.Printf("[chat] 序列化广播消息失败: %v", err)
		return
	}
	h.hub.SendToUser(userID, data)
}

// parseMultiMessage 检测并解析多消息格式
// 如果文本包含空行分隔的多条消息，拆分为多条；否则返回单条
func parseMultiMessage(text string) []string {
	if text == "" {
		return nil
	}
	// 按双换行（空行）分割
	parts := strings.Split(text, "\n\n")
	// 过滤空字符串并去除首尾空白
	var result []string
	for _, p := range parts {
		p = strings.TrimSpace(p)
		if p != "" {
			result = append(result, p)
		}
	}
	// 如果只有一条，返回 nil 表示不是多消息格式
	if len(result) <= 1 {
		return nil
	}
	return result
}