聊天增加图片功能

backend/internal/modules/chat/service.go

@@ -2,6 +2,7 @@ package chat
 
 import (
 	"errors"
+	"net/url"
 	"strings"
 )
 
@@ -63,15 +64,54 @@ func (s *Service) SendMessage(principal Principal, conversationID uint64, req Se
 		return nil, ErrDependencyUnavailable
 	}
 	req.Content = strings.TrimSpace(req.Content)
-	if conversationID == 0 || req.Content == "" {
+	attachments, ok := normalizeAttachmentURLS(req.AttachmentURLS)
+	req.AttachmentURLS = attachments
+	if conversationID == 0 || (req.Content == "" && len(req.AttachmentURLS) == 0) {
 		return nil, ErrInvalidMessage
 	}
 	if len([]rune(req.Content)) > 1000 {
 		return nil, ErrInvalidMessage
 	}
+	if !ok {
+		return nil, ErrInvalidMessage
+	}
 	return s.repo.SendMessage(principal, conversationID, req)
 }
 
+func normalizeAttachmentURLS(items []string) ([]string, bool) {
+	if len(items) > 9 {
+		return nil, false
+	}
+	result := make([]string, 0, len(items))
+	for _, item := range items {
+		value := strings.TrimSpace(item)
+		if value == "" {
+			continue
+		}
+		if len(value) > 500 || strings.Contains(value, "..") {
+			return nil, false
+		}
+		parsed, err := url.Parse(value)
+		if err != nil {
+			return nil, false
+		}
+		if parsed.Host != "" {
+			return nil, false
+		}
+		switch parsed.Path {
+		case "/api/files/object", "/api/admin/files/object", "/api/public/files/object":
+		default:
+			return nil, false
+		}
+		key := strings.TrimSpace(parsed.Query().Get("key"))
+		if key == "" || strings.Contains(key, "..") {
+			return nil, false
+		}
+		result = append(result, value)
+	}
+	return result, true
+}
+
 func (s *Service) MarkRead(principal Principal, conversationID uint64) error {
 	if s.repo == nil {
 		return ErrDependencyUnavailable