feat: 新增 AI 记账功能，包括流式聊天、洞察生成、语音转录和交易确认接口。

internal/handler/ai_handler.go

@@ -2,6 +2,7 @@ package handler
 
 import (
 	"encoding/json"
+	"io"
 	"net/http"
 
 	"accounting-app/internal/service"
@@ -14,6 +15,61 @@ type AIHandler struct {
 	aiService *service.AIBookkeepingService
 }
 
+// StreamChat handles streaming chat messages
+// POST /api/v1/ai/chat/stream
+func (h *AIHandler) StreamChat(c *gin.Context) {
+	var req ChatRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{
+			"success": false,
+			"error":   "Invalid request: " + err.Error(),
+		})
+		return
+	}
+
+	// Get user ID from context
+	userID := uint(1)
+	if id, exists := c.Get("user_id"); exists {
+		userID = id.(uint)
+	}
+
+	// Set headers for SSE
+	c.Writer.Header().Set("Content-Type", "text/event-stream")
+	c.Writer.Header().Set("Cache-Control", "no-cache")
+	c.Writer.Header().Set("Connection", "keep-alive")
+	c.Writer.Header().Set("Transfer-Encoding", "chunked")
+
+	c.Stream(func(w io.Writer) bool {
+		// Define the callback for chunks
+		onChunk := func(chunk string) {
+			// Sanitize chunk for SSE format (replace newlines to avoid breaking the stream protocol,
+			// or just send raw if client handles it. Usually data: <content>\n\n)
+			// For robustness, we JSON encode the data payload
+			dataMap := map[string]string{"text": chunk}
+			jsonData, _ := json.Marshal(dataMap)
+			// message event
+			c.SSEvent("message", string(jsonData))
+		}
+
+		// Call service
+		response, err := h.aiService.StreamProcessChat(c.Request.Context(), userID, req.SessionID, req.Message, onChunk)
+
+		if err != nil {
+			// Send error event
+			errMap := map[string]string{"error": err.Error()}
+			jsonErr, _ := json.Marshal(errMap)
+			c.SSEvent("error", string(jsonErr))
+			return false
+		}
+
+		// Send final result event with metadata
+		jsonResult, _ := json.Marshal(response)
+		c.SSEvent("result", string(jsonResult))
+
+		return false // Stop stream
+	})
+}
+
 // NewAIHandler creates a new AIHandler
 func NewAIHandler(aiService *service.AIBookkeepingService) *AIHandler {
 	return &AIHandler{
@@ -47,6 +103,7 @@ func (h *AIHandler) RegisterRoutes(rg *gin.RouterGroup) {
 	ai := rg.Group("/ai")
 	{
 		ai.POST("/chat", h.Chat)
+		ai.POST("/chat/stream", h.StreamChat) // New streaming endpoint
 		ai.POST("/transcribe", h.Transcribe)
 		ai.POST("/confirm", h.Confirm)
 		ai.POST("/insight", h.Insight)