feat(backend): implement download endpoint for shared files with password protection

backend/internal/controllers/download.go

@@ -0,0 +1,55 @@
+package controllers
+
+import (
+	"backend/internal/models"
+	"backend/internal/services"
+	"backend/internal/utils"
+	"backend/middleware"
+	"errors"
+	"fmt"
+
+	"github.com/labstack/echo/v4"
+)
+
+func DownloadShare(c echo.Context) error {
+	cc := c.(*middleware.CustomContext)
+	shareId := cc.Param("id")
+	password := cc.QueryParam("password")
+
+	if shareId == "" {
+		return utils.HTTPErrorHandler(c, errors.New("缺少分享ID"))
+	}
+
+	shareInfo, err := models.GetRedisShareInfo(shareId)
+	if err != nil {
+		return utils.HTTPErrorHandler(c, err)
+	}
+	if shareInfo == nil {
+		return utils.HTTPErrorHandler(c, errors.New("分享不存在"))
+	}
+	if shareInfo.Password != "" && shareInfo.Password != password {
+		return utils.HTTPErrorHandler(c, errors.New("分享密码错误"))
+	}
+
+	if shareInfo.Type == models.ShareTypeFile {
+		fileInfo, err := models.GetRedisFileInfo(shareInfo.Data)
+		if err != nil {
+			return utils.HTTPErrorHandler(c, err)
+		}
+		if fileInfo == nil {
+			return utils.HTTPErrorHandler(c, errors.New("分享文件不存在"))
+		}
+		if fileInfo.FileType != models.FileTypeUpload {
+			return utils.HTTPErrorHandler(c, errors.New("分享文件状态错误"))
+		}
+		uploadPath, err := services.GetUploadDirPath()
+		if err != nil {
+			return err
+		}
+		return cc.Attachment(fmt.Sprintf("%s/%s", uploadPath, utils.GetFileId(fileInfo.FileHash, fileInfo.FileSize)), shareInfo.FileName)
+	}
+
+	return utils.HTTPSuccessHandler(c, map[string]any{
+		"data": shareInfo.Data,
+	})
+}

backend/main.go

@@ -21,5 +21,7 @@ func main() {
 	e.POST("/share", controllers.CreateShareInfo)
 	e.GET("/config", controllers.GetConfig)
 
+	e.GET("/download/:id", controllers.DownloadShare)
+
 	e.Logger.Fatal(e.Start(":1323"))
 }