drive: implement "rclone backend copyid" command for copying files by ID

This allows files to be copied by ID from google drive. These can be
copied to any rclone remote and if the remote is a google drive then
server side copy will be attempted.

Fixes #3625

backend/drive/drive.go

@@ -35,6 +35,7 @@ import (
 	"github.com/rclone/rclone/fs/config/obscure"
 	"github.com/rclone/rclone/fs/fserrors"
 	"github.com/rclone/rclone/fs/fshttp"
+	"github.com/rclone/rclone/fs/fspath"
 	"github.com/rclone/rclone/fs/hash"
 	"github.com/rclone/rclone/fs/operations"
 	"github.com/rclone/rclone/fs/walk"
@@ -2959,6 +2960,38 @@ func (f *Fs) unTrashDir(ctx context.Context, dir string, recurse bool) (r unTras
 	return f.unTrash(ctx, dir, directoryID, true)
 }
 
+// copy file with id to dest
+func (f *Fs) copyID(ctx context.Context, id, dest string) (err error) {
+	info, err := f.getFile(id, f.fileFields)
+	if err != nil {
+		return errors.Wrap(err, "couldn't find id")
+	}
+	if info.MimeType == driveFolderType {
+		return errors.Errorf("can't copy directory use: rclone copy --drive-root-folder-id %s %s %s", id, fs.ConfigString(f), dest)
+	}
+	info.Name = f.opt.Enc.ToStandardName(info.Name)
+	o, err := f.newObjectWithInfo(info.Name, info)
+	if err != nil {
+		return err
+	}
+	destDir, destLeaf, err := fspath.Split(dest)
+	if err != nil {
+		return err
+	}
+	if destLeaf == "" {
+		destLeaf = info.Name
+	}
+	dstFs, err := cache.Get(destDir)
+	if err != nil {
+		return err
+	}
+	_, err = operations.Copy(ctx, dstFs, nil, destLeaf, o)
+	if err != nil {
+		return errors.Wrap(err, "copy failed")
+	}
+	return nil
+}
+
 var commandHelp = []fs.CommandHelp{{
 	Name:  "get",
 	Short: "Get command for fetching the drive config parameters",
@@ -3059,6 +3092,29 @@ Result:
         "Errors": 0
     }
 `,
+}, {
+	Name:  "copyid",
+	Short: "Copy files by ID",
+	Long: `This command copies files by ID
+
+Usage:
+
+    rclone backend copyid drive: ID path
+    rclone backend copyid drive: ID1 path1 ID2 path2
+
+It copies the drive file with ID given to the path (an rclone path which
+will be passed internally to rclone copyto). The ID and path pairs can be
+repeated.
+
+The path should end with a / to indicate copy the file as named to
+this directory. If it doesn't end with a / then the last path
+component will be used as the file name.
+
+If the destination is a drive backend then server side copying will be
+attempted if possible.
+
+Use the -i flag to see what would be copied before copying.
+`,
 }}
 
 // Command the backend to run a named command
@@ -3130,6 +3186,19 @@ func (f *Fs) Command(ctx context.Context, name string, arg []string, opt map[str
 			dir = arg[0]
 		}
 		return f.unTrashDir(ctx, dir, true)
+	case "copyid":
+		if len(arg)%2 != 0 {
+			return nil, errors.New("need an even number of arguments")
+		}
+		for len(arg) > 0 {
+			id, dest := arg[0], arg[1]
+			arg = arg[2:]
+			err = f.copyID(ctx, id, dest)
+			if err != nil {
+				return nil, errors.Wrapf(err, "failed copying %q to %q", id, dest)
+			}
+		}
+		return nil, nil
 	default:
 		return nil, fs.ErrorCommandNotFound
 	}

backend/drive/drive_internal_test.go

@@ -7,6 +7,8 @@ import (
 	"io"
 	"io/ioutil"
 	"mime"
+	"os"
+	"path"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -272,14 +274,15 @@ func (f *Fs) InternalTestDocumentLink(t *testing.T) {
 	}
 }
 
-// TestIntegration/FsMkdir/FsPutFiles/Internal/Shortcuts
-func (f *Fs) InternalTestShortcuts(t *testing.T) {
 const (
 	// from fstest/fstests/fstests.go
 	existingDir    = "hello? sausage"
 	existingFile   = `hello? sausage/êé/Hello, 世界/ " ' @ < > & ? + ≠/z.txt`
 	existingSubDir = "êé"
 )
+
+// TestIntegration/FsMkdir/FsPutFiles/Internal/Shortcuts
+func (f *Fs) InternalTestShortcuts(t *testing.T) {
 	ctx := context.Background()
 	srcObj, err := f.NewObject(ctx, existingFile)
 	require.NoError(t, err)
@@ -408,6 +411,55 @@ func (f *Fs) InternalTestUnTrash(t *testing.T) {
 	require.NoError(t, f.Purge(ctx, "trashDir"))
 }
 
+// TestIntegration/FsMkdir/FsPutFiles/Internal/CopyID
+func (f *Fs) InternalTestCopyID(t *testing.T) {
+	ctx := context.Background()
+	obj, err := f.NewObject(ctx, existingFile)
+	require.NoError(t, err)
+	o := obj.(*Object)
+
+	dir, err := ioutil.TempDir("", "rclone-drive-copyid-test")
+	require.NoError(t, err)
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+
+	checkFile := func(name string) {
+		filePath := filepath.Join(dir, name)
+		fi, err := os.Stat(filePath)
+		require.NoError(t, err)
+		assert.Equal(t, int64(100), fi.Size())
+		err = os.Remove(filePath)
+		require.NoError(t, err)
+	}
+
+	t.Run("BadID", func(t *testing.T) {
+		err = f.copyID(ctx, "ID-NOT-FOUND", dir+"/")
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "couldn't find id")
+	})
+
+	t.Run("Directory", func(t *testing.T) {
+		rootID, err := f.dirCache.RootID(ctx, false)
+		require.NoError(t, err)
+		err = f.copyID(ctx, rootID, dir+"/")
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "can't copy directory")
+	})
+
+	t.Run("WithoutDestName", func(t *testing.T) {
+		err = f.copyID(ctx, o.id, dir+"/")
+		require.NoError(t, err)
+		checkFile(path.Base(existingFile))
+	})
+
+	t.Run("WithDestName", func(t *testing.T) {
+		err = f.copyID(ctx, o.id, dir+"/potato.txt")
+		require.NoError(t, err)
+		checkFile("potato.txt")
+	})
+}
+
 func (f *Fs) InternalTest(t *testing.T) {
 	// These tests all depend on each other so run them as nested tests
 	t.Run("DocumentImport", func(t *testing.T) {
@@ -424,6 +476,7 @@ func (f *Fs) InternalTest(t *testing.T) {
 	})
 	t.Run("Shortcuts", f.InternalTestShortcuts)
 	t.Run("UnTrash", f.InternalTestUnTrash)
+	t.Run("CopyID", f.InternalTestCopyID)
 }
 
 var _ fstests.InternalTester = (*Fs)(nil)