feat: 实现用户通知系统，包含通知模型、数据操作、业务逻辑及相关API接口。

internal/handler/notification_handler.go

@@ -0,0 +1,158 @@
+package handler
+
+import (
+	"accounting-app/internal/models"
+	"accounting-app/internal/service"
+	"accounting-app/pkg/api"
+	"net/http"
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+)
+
+type NotificationHandler struct {
+	service *service.NotificationService
+}
+
+func NewNotificationHandler(service *service.NotificationService) *NotificationHandler {
+	return &NotificationHandler{service: service}
+}
+
+// GetNotifications returns a list of notifications for the user
+func (h *NotificationHandler) GetNotifications(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		api.Unauthorized(c, "User not authenticated")
+		return
+	}
+
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "10"))
+
+	var isRead *bool
+	if val, ok := c.GetQuery("is_read"); ok {
+		parsedVal, err := strconv.ParseBool(val)
+		if err == nil {
+			isRead = &parsedVal
+		}
+	}
+
+	notifications, total, err := h.service.GetNotifications(userID.(uint), page, limit, isRead)
+	if err != nil {
+		api.Error(c, http.StatusInternalServerError, "FETCH_ERROR", "Failed to fetch notifications")
+		return
+	}
+
+	api.Success(c, gin.H{
+		"notifications": notifications,
+		"total":         total,
+		"page":          page,
+		"limit":         limit,
+	})
+}
+
+// GetUnreadCount returns the number of unread notifications
+func (h *NotificationHandler) GetUnreadCount(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		api.Unauthorized(c, "User not authenticated")
+		return
+	}
+
+	count, err := h.service.GetUnreadCount(userID.(uint))
+	if err != nil {
+		api.Error(c, http.StatusInternalServerError, "FETCH_ERROR", "Failed to count unread notifications")
+		return
+	}
+
+	api.Success(c, gin.H{
+		"count": count,
+	})
+}
+
+// MarkAsRead marks a specific notification as read
+func (h *NotificationHandler) MarkAsRead(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		api.Unauthorized(c, "User not authenticated")
+		return
+	}
+
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		api.Error(c, http.StatusBadRequest, "INVALID_ID", "Invalid notification ID")
+		return
+	}
+
+	if err := h.service.MarkAsRead(uint(id), userID.(uint)); err != nil {
+		api.Error(c, http.StatusInternalServerError, "UPDATE_ERROR", "Failed to mark as read")
+		return
+	}
+
+	api.Success(c, gin.H{"message": "Marked as read"})
+}
+
+// MarkAllAsRead marks all notifications as read
+func (h *NotificationHandler) MarkAllAsRead(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		api.Unauthorized(c, "User not authenticated")
+		return
+	}
+
+	if err := h.service.MarkAllAsRead(userID.(uint)); err != nil {
+		api.Error(c, http.StatusInternalServerError, "UPDATE_ERROR", "Failed to mark all as read")
+		return
+	}
+
+	api.Success(c, gin.H{"message": "All marked as read"})
+}
+
+// CreateNotificationRequest represents the request body for creating a notification (internal/admin use primarily)
+type CreateNotificationRequest struct {
+	Title   string `json:"title" binding:"required"`
+	Content string `json:"content" binding:"required"`
+	Type    string `json:"type" binding:"required"`
+	Link    string `json:"link"`
+}
+
+// CreateNotification creates a new notification (For testing/admin purposes)
+func (h *NotificationHandler) CreateNotification(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		api.Unauthorized(c, "User not authenticated")
+		return
+	}
+
+	var req CreateNotificationRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		api.Error(c, http.StatusBadRequest, "INVALID_REQUEST", "Invalid request")
+		return
+	}
+
+	err := h.service.CreateNotification(
+		userID.(uint),
+		req.Title,
+		req.Content,
+		models.NotificationType(req.Type),
+		req.Link,
+	)
+	if err != nil {
+		api.Error(c, http.StatusInternalServerError, "CREATE_ERROR", "Failed to create notification")
+		return
+	}
+
+	api.Success(c, gin.H{"message": "Notification created"})
+}
+
+// RegisterRoutes registers the notification routes
+func (h *NotificationHandler) RegisterRoutes(r *gin.RouterGroup) {
+	notifications := r.Group("/notifications")
+	{
+		notifications.GET("", h.GetNotifications)
+		notifications.GET("/unread-count", h.GetUnreadCount)
+		notifications.PUT("/:id/read", h.MarkAsRead)
+		notifications.PUT("/read-all", h.MarkAllAsRead)
+		notifications.POST("", h.CreateNotification) // Admin/Internal use
+	}
+}