feat: 优化文件上传服务

- 添加文件大小和类型验证
- 支持更多文件格式
- 优化文件存储逻辑

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

server/internal/handler/upload_handler.go

@@ -1,18 +1,23 @@
 package handler
 
 import (
+	"io"
+	"mime"
 	"net/http"
+	"path/filepath"
 
 	"github.com/gin-gonic/gin"
+	"x-agents/server/internal/repository"
 	"x-agents/server/internal/service"
 )
 
 type UploadHandler struct {
-	uploadService *service.UploadService
+	uploadService    *service.UploadService
+	knowledgeRepo    *repository.KnowledgeRepository
 }
 
-func NewUploadHandler(uploadService *service.UploadService) *UploadHandler {
-	return &UploadHandler{uploadService: uploadService}
+func NewUploadHandler(uploadService *service.UploadService, knowledgeRepo *repository.KnowledgeRepository) *UploadHandler {
+	return &UploadHandler{uploadService: uploadService, knowledgeRepo: knowledgeRepo}
 }
 
 // Upload 上传文件
@@ -58,3 +63,71 @@ func (h *UploadHandler) Delete(c *gin.Context) {
 
 	c.JSON(http.StatusOK, gin.H{"success": true, "message": "File deleted"})
 }
+
+// ProxyFile 代理文件访问（解决 MinIO 内网地址和 HTTPS 问题）
+func (h *UploadHandler) ProxyFile(c *gin.Context) {
+	fileKey := c.Query("key")
+	kbID := c.Query("kb_id")
+
+	if fileKey == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"success": false, "message": "File key is required"})
+		return
+	}
+
+	var content io.Reader
+	var contentType string
+
+	// 如果提供了知识库 ID，使用知识库的存储配置
+	if kbID != "" && h.knowledgeRepo != nil {
+		kb, err := h.knowledgeRepo.FindByID(kbID)
+		if err == nil && kb.StorageConfig.Type == "minio" {
+			reader, ct, err := h.uploadService.GetFileContentWithConfig(fileKey, kb.StorageConfig)
+			if err != nil {
+				c.JSON(http.StatusInternalServerError, gin.H{"success": false, "message": err.Error()})
+				return
+			}
+			content = reader
+			contentType = ct
+			defer reader.Close()
+		} else {
+			// 使用全局配置
+			reader, ct, err := h.uploadService.GetFileContent(fileKey)
+			if err != nil {
+				c.JSON(http.StatusInternalServerError, gin.H{"success": false, "message": err.Error()})
+				return
+			}
+			content = reader
+			contentType = ct
+			defer reader.Close()
+		}
+	} else {
+		// 使用全局配置
+		reader, ct, err := h.uploadService.GetFileContent(fileKey)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"success": false, "message": err.Error()})
+			return
+		}
+		content = reader
+		contentType = ct
+		defer reader.Close()
+	}
+
+	// 设置响应头
+	// 如果 Content-Type 是 application/octet-stream，根据文件扩展名推断
+	if contentType == "application/octet-stream" {
+		ext := filepath.Ext(fileKey)
+		if detected := mime.TypeByExtension(ext); detected != "" {
+			contentType = detected
+		}
+	}
+
+	if contentType != "" {
+		c.Header("Content-Type", contentType)
+	} else {
+		c.Header("Content-Type", "application/octet-stream")
+	}
+	c.Header("Content-Disposition", "inline")
+
+	// 直接流式输出文件内容
+	c.DataFromReader(http.StatusOK, -1, contentType, content, nil)
+}