Add by-id mount directory

mount.go

@@ -73,6 +73,8 @@ func runMountCommand(args []string, cfg config, password string) error {
 
 func buildMountTree(ctx context.Context, client *DocspellClient, items []SearchItem) *dirNode {
 	root := &dirNode{name: "", children: map[string]fs.Node{}}
+	byID := &dirNode{name: "by-id", children: map[string]fs.Node{}}
+	root.children["by-id"] = byID
 	for _, item := range items {
 		if full, err := client.GetItem(ctx, item.ID); err == nil {
 			item = *full
@@ -112,7 +114,16 @@ func buildMountTree(ctx context.Context, client *DocspellClient, items []SearchI
 				}
 			}
 			name = uniqueName(dir.children, sanitizeName(name))
-			dir.children[name] = &fileNode{name: name, attachmentID: att.ID, size: uint64(size), knownSize: size > 0, modTime: modTime, client: client}
+			node := &fileNode{name: name, attachmentID: att.ID, size: uint64(size), knownSize: size > 0, modTime: modTime, client: client}
+			dir.children[name] = node
+
+			byIDName := item.ID + ext
+			if len(item.Attachments) > 1 {
+				if i > 0 {
+					byIDName = fmt.Sprintf("%s-%d%s", item.ID, i+1, ext)
+				}
+			}
+			byID.children[uniqueName(byID.children, sanitizeName(byIDName))] = node
 		}
 	}
 	return root

mount_test.go

@@ -70,3 +70,26 @@ func TestFileNodeUnknownSizeDoesNotAdvertiseZeroLength(t *testing.T) {
 		t.Fatal("expected unknown size before download")
 	}
 }
+
+func TestBuildMountTreeAddsByIDDirectory(t *testing.T) {
+	items := []SearchItem{{
+		ID:   "item-1",
+		Name: "Invoice",
+		Attachments: []ItemAttachment{
+			{ID: "att-1", Name: "original.pdf"},
+			{ID: "att-2", Name: "extra.txt"},
+			{ID: "att-3", Name: "scan.pdf"},
+		},
+	}}
+
+	root := buildMountTree(context.Background(), &DocspellClient{}, items)
+	byID, ok := root.children["by-id"].(*dirNode)
+	if !ok {
+		t.Fatalf("expected by-id directory, got %#v", root.children)
+	}
+	for _, name := range []string{"item-1.pdf", "item-1-2.txt", "item-1-3.pdf"} {
+		if _, ok := byID.children[name].(*fileNode); !ok {
+			t.Fatalf("expected %s in by-id, got %#v", name, byID.children)
+		}
+	}
+}