fix(google_drive): support Google Workspace native file exports

drivers/google_drive/driver.go

@@ -52,17 +52,35 @@ func (d *GoogleDrive) List(ctx context.Context, dir model.Obj, args model.ListAr
 }
 
 func (d *GoogleDrive) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (*model.Link, error) {
-	url := fmt.Sprintf("https://www.googleapis.com/drive/v3/files/%s?includeItemsFromAllDrives=true&supportsAllDrives=true", file.GetID())
-	_, err := d.request(url, http.MethodGet, nil, nil)
+	fileID := file.GetID()
+	metaURL := fmt.Sprintf("https://www.googleapis.com/drive/v3/files/%s", fileID)
+
+	var meta FileMeta
+	_, err := d.request(metaURL, http.MethodGet, func(req *resty.Request) {
+		req.SetQueryParam("fields", FileLinkFields)
+	}, &meta)
 	if err != nil {
 		return nil, err
 	}
+
+	if !meta.Capabilities.CanDownload {
+		return nil, fmt.Errorf("file %q cannot be downloaded: download capability is not granted", fileID)
+	}
+
+	strategy, err := resolveDownloadStrategy(meta.MimeType)
+	if err != nil {
+		return nil, err
+	}
+
 	link := model.Link{
-		URL: url + "&alt=media&acknowledgeAbuse=true",
+		URL: buildDownloadURL(fileID, strategy),
 		Header: http.Header{
 			"Authorization": []string{"Bearer " + d.AccessToken},
 		},
 	}
+	if strategy.Kind == kindExport {
+		link.FileName = exportedFileName(file.GetName(), strategy.Extension)
+	}
 	return &link, nil
 }
 

drivers/google_drive/types.go

@@ -9,6 +9,74 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+// Google Workspace source MIME types.
+const (
+	mimeTypeGoogleDoc      = "application/vnd.google-apps.document"
+	mimeTypeGoogleSheet    = "application/vnd.google-apps.spreadsheet"
+	mimeTypeGoogleSlides   = "application/vnd.google-apps.presentation"
+	mimeTypeGoogleDrawing  = "application/vnd.google-apps.drawing"
+	mimeTypeGoogleScript   = "application/vnd.google-apps.script"
+	mimeTypeGoogleFolder   = "application/vnd.google-apps.folder"
+	mimeTypeGoogleShortcut = "application/vnd.google-apps.shortcut"
+	mimeTypeGoogleForm     = "application/vnd.google-apps.form"
+	mimeTypeGoogleSite     = "application/vnd.google-apps.site"
+	mimeTypeGoogleMap      = "application/vnd.google-apps.map"
+	mimeTypeGoogleVid      = "application/vnd.google-apps.vid"
+	mimeTypeGoogleJam      = "application/vnd.google-apps.jam"
+	// Third-party shortcut created by a Drive app; the app must handle the download.
+	mimeTypeGoogleDriveSDK = "application/vnd.google-apps.drive-sdk"
+)
+
+// Export target MIME types.
+const (
+	mimeTypeDocx       = "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
+	mimeTypeXlsx       = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
+	mimeTypePptx       = "application/vnd.openxmlformats-officedocument.presentationml.presentation"
+	mimeTypePDF        = "application/pdf"
+	mimeTypeScriptJSON = "application/vnd.google-apps.script+json"
+)
+
+// exportFormat pairs a files.export target MIME type with the file extension
+// that should be appended to the downloaded filename.
+type exportFormat struct {
+	MIME      string
+	Extension string
+}
+
+// googleWorkspaceExports maps exportable Google Workspace source MIME types to their
+// files.export target format.
+var googleWorkspaceExports = map[string]exportFormat{
+	mimeTypeGoogleDoc:     {MIME: mimeTypeDocx, Extension: ".docx"},
+	mimeTypeGoogleSheet:   {MIME: mimeTypeXlsx, Extension: ".xlsx"},
+	mimeTypeGoogleSlides:  {MIME: mimeTypePptx, Extension: ".pptx"},
+	mimeTypeGoogleDrawing: {MIME: mimeTypePDF, Extension: ".pdf"},
+	mimeTypeGoogleScript:  {MIME: mimeTypeScriptJSON, Extension: ".json"},
+}
+
+var googleWorkspaceUnsupported = map[string]string{
+	mimeTypeGoogleFolder:   "folders cannot be downloaded",
+	mimeTypeGoogleShortcut: "shortcuts must be resolved before downloading",
+	mimeTypeGoogleDriveSDK: "third-party shortcuts cannot be downloaded directly",
+
+	// Forms, Sites, Vids, and Jamboard require the files.download
+	// long-running-operation flow, which this driver does not implement.
+	mimeTypeGoogleForm: "requires the files.download long-running-operation flow, which this driver does not implement",
+	mimeTypeGoogleSite: "requires the files.download long-running-operation flow, which this driver does not implement",
+	mimeTypeGoogleVid:  "requires the files.download long-running-operation flow, which this driver does not implement",
+	mimeTypeGoogleJam:  "requires the files.download long-running-operation flow, which this driver does not implement",
+
+	// Google My Maps has no supported download/export strategy implemented here.
+	mimeTypeGoogleMap: "no supported download/export strategy is implemented for Google My Maps",
+}
+
+// FileMeta holds the fields we need from a files.get metadata response inside Link().
+type FileMeta struct {
+	MimeType     string `json:"mimeType"`
+	Capabilities struct {
+		CanDownload bool `json:"canDownload"`
+	} `json:"capabilities"`
+}
+
 type TokenError struct {
 	Error            string `json:"error"`
 	ErrorDescription string `json:"error_description"`

drivers/google_drive/util.go

@@ -7,9 +7,11 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"os"
 	"regexp"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/OpenListTeam/OpenList/v4/internal/op"
@@ -31,10 +33,81 @@ import (
 const (
 	// File list query fields
 	FilesListFields = "files(id,name,mimeType,size,modifiedTime,createdTime,thumbnailLink,shortcutDetails,md5Checksum,sha1Checksum,sha256Checksum),nextPageToken"
-	// Single file query fields
+	// Single file query fields (used when fetching shortcut target metadata)
 	FileInfoFields = "id,name,mimeType,size,md5Checksum,sha1Checksum,sha256Checksum"
+	// Fields fetched during Link() to decide the download strategy
+	FileLinkFields = "mimeType,capabilities/canDownload"
 )
 
+// downloadKind distinguishes the two Drive download strategies.
+type downloadKind int
+
+const (
+	kindMedia  downloadKind = iota // files.get?alt=media
+	kindExport                     // files.export?mimeType=...
+)
+
+// downloadStrategy describes which endpoint and parameters to use for a given file.
+type downloadStrategy struct {
+	Kind       downloadKind
+	ExportMIME string
+	// Extension is the file extension (e.g. ".pptx") to append to the downloaded filename
+	// for kindExport strategies. Empty for kindMedia.
+	Extension string
+}
+
+// resolveDownloadStrategy returns the correct download strategy for the given Drive source
+// MIME type. It returns an error for Google Workspace types that cannot be downloaded.
+func resolveDownloadStrategy(sourceMIME string) (downloadStrategy, error) {
+	if ef, ok := googleWorkspaceExports[sourceMIME]; ok {
+		return downloadStrategy{Kind: kindExport, ExportMIME: ef.MIME, Extension: ef.Extension}, nil
+	}
+	if reason, ok := googleWorkspaceUnsupported[sourceMIME]; ok {
+		return downloadStrategy{}, fmt.Errorf("unsupported Google Workspace file type %q: %s", sourceMIME, reason)
+	}
+	// All other MIME types — including unrecognised application/vnd.google-apps.* variants
+	// and all binary/uploaded files — fall through to the media download endpoint to preserve
+	// compatibility with Drive MIME types not covered by the maps above.
+	return downloadStrategy{Kind: kindMedia}, nil
+}
+
+// buildDownloadURL constructs the correct Drive download URL for the given file ID and strategy.
+//
+// Binary files use files.get with alt=media:
+//
+//	GET /drive/v3/files/{id}?alt=media&acknowledgeAbuse=true&...
+//
+// Workspace-native files use files.export with only mimeType:
+//
+//	GET /drive/v3/files/{id}/export?mimeType=<encoded-mime>
+//
+// Note: files.export responses are capped by Google Drive at 10 MB. Larger or unsupported
+// Workspace downloads may require the files.download long-running-operation (LRO) flow.
+func buildDownloadURL(fileID string, strategy downloadStrategy) string {
+	base := "https://www.googleapis.com/drive/v3/files/" + fileID
+	switch strategy.Kind {
+	case kindExport:
+		q := url.Values{}
+		q.Set("mimeType", strategy.ExportMIME)
+		return base + "/export?" + q.Encode()
+	default: // kindMedia
+		q := url.Values{}
+		q.Set("alt", "media")
+		q.Set("acknowledgeAbuse", "true")
+		q.Set("supportsAllDrives", "true")
+		return base + "?" + q.Encode()
+	}
+}
+
+// exportedFileName returns name with ext appended, unless name already ends with
+// ext (case-insensitive), which avoids doubling extensions like "file.pptx.pptx".
+func exportedFileName(name, ext string) string {
+	if strings.HasSuffix(strings.ToLower(name), strings.ToLower(ext)) {
+		return name
+	}
+	return name + ext
+}
+
 type googleDriveServiceAccount struct {
 	// Type                    string `json:"type"`
 	// ProjectID               string `json:"project_id"`