Path completion for sync command (#208)

Follow up to #207.

cmd/sync/completion.go

@@ -0,0 +1,82 @@
+package sync
+
+import (
+	"context"
+	"fmt"
+	"path"
+	"strings"
+
+	"github.com/databricks/databricks-sdk-go"
+	"github.com/databricks/databricks-sdk-go/service/workspace"
+	"github.com/spf13/cobra"
+)
+
+// List directories or repos under the specified path.
+// Returns a channel such that we can list multiple paths in parallel.
+func fetchDirs(ctx context.Context, wsc *databricks.WorkspaceClient, path string) <-chan []string {
+	ch := make(chan []string, 1)
+	go func() {
+		defer close(ch)
+
+		files, err := wsc.Workspace.ListAll(ctx, workspace.List{
+			Path: path,
+		})
+		if err != nil {
+			return
+		}
+
+		// Filter directories and repos.
+		// We're interested only in paths we can sync to.
+		dirs := []string{}
+		for _, file := range files {
+			switch file.ObjectType {
+			case workspace.ObjectTypeDirectory, workspace.ObjectTypeRepo:
+				dirs = append(dirs, file.Path)
+			}
+		}
+
+		ch <- dirs
+	}()
+
+	return ch
+}
+
+func completeRemotePath(
+	ctx context.Context,
+	wsc *databricks.WorkspaceClient,
+	toComplete string,
+) ([]string, cobra.ShellCompDirective) {
+	me, err := wsc.CurrentUser.Me(ctx)
+	if err != nil {
+		return nil, cobra.ShellCompDirectiveError
+	}
+
+	prefixes := []string{
+		path.Clean(fmt.Sprintf("/Users/%s", me.UserName)) + "/",
+		path.Clean(fmt.Sprintf("/Repos/%s", me.UserName)) + "/",
+	}
+
+	validPrefix := false
+	for _, p := range prefixes {
+		if strings.HasPrefix(toComplete, p) {
+			validPrefix = true
+		}
+	}
+
+	if !validPrefix {
+		return prefixes, cobra.ShellCompDirectiveNoSpace
+	}
+
+	// If the user is TAB-ing their way through a path, the path in `toComplete`
+	// is valid and we should list nested directories.
+	// If the path in `toComplete` is incomplete, however,
+	// then we should list adjacent directories.
+	nested := fetchDirs(ctx, wsc, toComplete)
+	adjacent := fetchDirs(ctx, wsc, path.Dir(toComplete))
+	dirs := <-nested
+	if dirs == nil {
+		dirs = <-adjacent
+	}
+
+	return dirs, cobra.ShellCompDirectiveNoSpace
+}

cmd/sync/sync.go

@@ -103,6 +103,33 @@ var syncCmd = &cobra.Command{
 
 		return s.RunOnce(ctx)
 	},
+
+	ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		err := root.TryConfigureBundle(cmd, args)
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+
+		// No completion in the context of a bundle.
+		// Source and destination paths are taken from bundle configuration.
+		b := bundle.GetOrNil(cmd.Context())
+		if b != nil {
+			return nil, cobra.ShellCompDirectiveNoFileComp
+		}
+
+		switch len(args) {
+		case 0:
+			return nil, cobra.ShellCompDirectiveFilterDirs
+		case 1:
+			wsc, err := databricks.NewWorkspaceClient()
+			if err != nil {
+				return nil, cobra.ShellCompDirectiveError
+			}
+			return completeRemotePath(cmd.Context(), wsc, toComplete)
+		default:
+			return nil, cobra.ShellCompDirectiveNoFileComp
+		}
+	},
 }
 
 // project files polling interval